Medicine and Health Sciences Commons^™

Suboptimal Self-Reported Sleep Efficiency And Duration Are Associated With Faster Accumulation Of Brain Amyloid Beta In Cognitively Unimpaired Older Adults, Louise N. Pivac, Belinda M. Brown, Kelsey R. Sewell, James D. Doecke, Victor L. Villemagne, Vincent Doré, Michael Weinborn, Hamid R. Sohrabi, Samantha L. Gardener, Romola S. Bucks, Simon M. Laws, Kevin Taddei, Paul Maruff, Colin L. Masters, Christopher Rowe, Ralph N. Martins, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

INTRODUCTION: This study investigated whether self-reported sleep quality is associated with brain amyloid beta (AB) accumulation. METHODS: Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean ± standard deviation 74.0 ± 6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain AB measured over a minimum of three time points (range 33.3–72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) 4 allele status, and time, adjusting for sex and baseline age. RESULTS: Sleep duration < 6 hours, in APOE 4 carriers, and sleep efficiency < 65%, in the whole sample and APOE 4 non-carriers, is associated with faster accumulation of brain AB. DISCUSSION: These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer's disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. Highlights: In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (AB) accumulation. Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype. Sleep duration < 6 hours is associated with faster brain AB accumulation in APOE 4 carriers. Sleep efficiency < 65% is associated with faster brain AB accumulation in APOE 4 non-carriers. Personalized sleep interventions should be studied for potential to slow AB accumulation.

Htra1 Disaggregates Α-Synuclein Amyloid Fibrils And Converts Them Into Non-Toxic And Seeding Incompetent Species, Sheng Chen, Anuradhika Puri, Braxton Bell, Joseph Fritsche, Hector H Palacios, Maurie Balch, Macy L Sprunger, Matthew K Howard, Jeremy J Ryan, Jessica N Haines, Gary J Patti, Albert A Davis, Meredith E Jackrel

2020-Current year OA Pubs

Parkinson's disease (PD) is closely linked to α-synuclein (α-syn) misfolding and accumulation in Lewy bodies. The PDZ serine protease HTRA1 degrades fibrillar tau, which is associated with Alzheimer's disease, and inactivating mutations to mitochondrial HTRA2 are implicated in PD. Here, we report that HTRA1 inhibits aggregation of α-syn as well as FUS and TDP-43, which are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. The protease domain of HTRA1 is necessary and sufficient for inhibiting aggregation, yet this activity is proteolytically-independent. Further, HTRA1 disaggregates preformed α-syn fibrils, rendering them incapable of seeding aggregation of endogenous α-syn, while reducing HTRA1 …

Advanced Structural Brain Aging In Preclinical Autosomal Dominant Alzheimer Disease, Peter R Millar, Brian A Gordon, Julie K Wisch, Tammie L.S. Benzinger, Carlos Cruchaga, Jason J Hassenstab, Laura Ibanez, Celeste Karch, Jorge J Llibre-Guerra, John C Morris, Richard J Perrin, Charlene Supnet-Bell, Chengjie Xiong, Randall J Bateman, Beau M Ances, Eric M Mcdade, Et Al.

2020-Current year OA Pubs

BACKGROUND: "Brain-predicted age" estimates biological age from complex, nonlinear features in neuroimaging scans. The brain age gap (BAG) between predicted and chronological age is elevated in sporadic Alzheimer disease (AD), but is underexplored in autosomal dominant AD (ADAD), in which AD progression is highly predictable with minimal confounding age-related co-pathology.

METHODS: We modeled BAG in 257 deeply-phenotyped ADAD mutation-carriers and 179 non-carriers from the Dominantly Inherited Alzheimer Network using minimally-processed structural MRI scans. We then tested whether BAG differed as a function of mutation and cognitive status, or estimated years until symptom onset, and whether it was associated with established …

Cognitive Impact Of Multidomain Intervention And Omega 3 According To Blood Aβ42/40 Ratio: A Subgroup Analysis From The Randomized Mapt Trial, Julien Delrieu, Bruno Vellas, Sophie Guyonnet, Christelle Cantet, Vitaliy Ovod, Yan Li, James Bollinger, Randall Bateman, Sandrine Andrieu, Mapt/Dsa Group

2020-Current year OA Pubs

BACKGROUND: In MAPT (Multidomain Alzheimer Preventive Trial), a cognitive effect of multidomain intervention (MI) was showed in non-demented subjects with positive amyloid PET. However, screening eligible patients for multidomain intervention by PET is difficult to generalize in real-world settings.

METHODS: MAPT study was a 3-year, randomized, placebo-controlled trial followed by a 2-year observational and optional extension. All participants were non-demented and randomly assigned (1:1:1:1) to the MI plus omega 3, MI plus placebo, omega 3 alone, or placebo alone group. The objectives were to assess the cognitive effect of MAPT interventions (omega 3 supplementation, MI, combined intervention) in non-demented subjects …

A Blood Biomarker Test For Brain Amyloid Impacts The Clinical Evaluation Of Cognitive Impairment, Mark Monane, B Joy Snider, Et Al.

2020-Current year OA Pubs

OBJECTIVE: The objective of this study was to examine clinicians' patient selection and result interpretation of a clinically validated mass spectrometry test measuring amyloid beta and ApoE blood biomarkers combined with patient age (PrecivityAD® blood test) in symptomatic patients evaluated for Alzheimer's disease (AD) or other causes of cognitive decline.

METHODS: The Quality Improvement and Clinical Utility PrecivityAD Clinician Survey (QUIP I, ClinicalTrials.gov Identifier: NCT05477056) was a prospective, single-arm cohort study among 366 patients evaluated by neurologists and other cognitive specialists. Participants underwent blood biomarker testing and received an amyloid probability score (APS), indicating the likelihood of a positive result …

Independent Study Demonstrates Amyloid Probability Score Accurately Indicates Amyloid Pathology, Ilana Fogelman, Randall J Bateman, David M Holtzman, Et Al.

2020-Current year OA Pubs

BACKGROUND: The amyloid probability score (APS) is the model read-out of the analytically validated mass spectrometry-based PrecivityAD

PURPOSE: This study aimed to provide additional independent evidence that the pre-established APS algorithm, along with its cutoff values, discriminates between amyloid positive and negative individuals.

METHODS: The diagnostic performance of the PrecivityAD test was analyzed in a cohort of 200 nonrandomly selected Australian Imaging, Biomarker & Lifestyle Flagship Study of Aging (AIBL) study participants, who were either cognitively impaired or healthy controls, and for whom a blood sample and amyloid PET imaging were available.

RESULTS: In a subset of the dataset aligned …

Large Multi-Ethnic Genetic Analyses Of Amyloid Imaging Identify New Genes For Alzheimer Disease, Muhammad Ali, Priyanka Gorijala, Daniel Western, Jigyasha Timsina, Maria V Fernández, Gengsheng Chen, Brian Gordon, Tammie L S Benzinger, Chengjie Xiong, John C Morris, Randall J Bateman, Celeste M Karch, Eric Mcdade, Yun Ju Sung, Carlos Cruchaga, Et Al.

2020-Current year OA Pubs

Amyloid PET imaging has been crucial for detecting the accumulation of amyloid beta (Aβ) deposits in the brain and to study Alzheimer's disease (AD). We performed a genome-wide association study on the largest collection of amyloid imaging data (N = 13,409) to date, across multiple ethnicities from multicenter cohorts to identify variants associated with brain amyloidosis and AD risk. We found a strong APOE signal on chr19q.13.32 (top SNP: APOE ɛ4; rs429358; β = 0.35, SE = 0.01, P = 6.2 × 10

Brain Aerobic Glycolysis And Resilience In Alzheimer Disease, Manu S Goyal, Tyler Blazey, Nicholas V Metcalf, Mark P Mcavoy, Jeremy F Strain, Maryam Rahmani, Tony J Durbin, Chengjie Xiong, Tammie L-S Benzinger, John C Morris, Marcus E Raichle, Andrei G Vlassenko

2020-Current year OA Pubs

The distribution of brain aerobic glycolysis (AG) in normal young adults correlates spatially with amyloid-beta (Aβ) deposition in individuals with symptomatic and preclinical Alzheimer disease (AD). Brain AG decreases with age, but the functional significance of this decrease with regard to the development of AD symptomatology is poorly understood. Using PET measurements of regional blood flow, oxygen consumption, and glucose utilization-from which we derive AG-we find that cognitive impairment is strongly associated with loss of the typical youthful pattern of AG. In contrast, amyloid positivity without cognitive impairment was associated with preservation of youthful brain AG, which was even higher …

Brainwave: A Flexible Method For Noninvasive Stimulation Of Brain Rhythms Across Species, Matthew K. Attokaren, Nuri Jeong, Lou Blanpain, Abigail L. Paulson, Kristie M. Garza, Ben Borron, Michael Walelign, Jon Willie, Annabelle C. Singer

2020-Current year OA Pubs

Rhythmic neural activity, which coordinates brain regions and neurons to achieve multiple brain functions, is impaired in many diseases. Despite the therapeutic potential of driving brain rhythms, methods to noninvasively target deep brain regions are limited. Accordingly, we recently introduced a noninvasive stimulation approach using flickering lights and sounds ("flicker"). Flicker drives rhythmic activity in deep and superficial brain regions. Gamma flicker spurs immune function, clears pathogens, and rescues memory performance in mice with amyloid pathology. Here, we present substantial improvements to this approach that is flexible, user-friendly, and generalizable across multiple experimental settings and species. We present novel open-source …

Chronic Trem2 Activation Exacerbates Aβ-Associated Tau Seeding And Spreading, Nimansha Jain, Caroline A Lewis, Jason D Ulrich, David M Holtzman

2020-Current year OA Pubs

Variants in the triggering receptor expressed on myeloid cells 2 (TREM2) gene are associated with increased risk for late-onset AD. Genetic loss of or decreased TREM2 function impairs the microglial response to amyloid-β (Aβ) plaques, resulting in more diffuse Aβ plaques and increased peri-plaque neuritic dystrophy and AD-tau seeding. Thus, microglia and TREM2 are at a critical intersection of Aβ and tau pathologies in AD. Since genetically decreasing TREM2 function increases Aβ-induced tau seeding, we hypothesized that chronically increasing TREM2 signaling would decrease amyloid-induced tau-seeding and spreading. Using a mouse model of amyloidosis in which AD-tau is injected into the …

An Overview Of Blood-Based Biomarkers In Ad, Steve Pedrini

Theses: Doctorates and Masters

Alzheimer’s disease (AD) is the most common form of dementia in the elderly whose main neuropathological features are the presence of extracellular senile plaques in the brain and the intracellular accumulation of hyperphosphorylated tau filaments. However, a relatively cheap and non-invasive method for the diagnosis of AD remains elusive. Recent studies have indicated that cerebral biochemical changes take place decades before the clinical onset of the disease, but current methodologies, brain scan (PET amyloid imaging) and cerebrospinal fluid (CSF) analysis, are unsuited for community-wide screening. Brain scanning methods non-invasively assess amyloid load but are extremely expensive and cannot be used …

The Performance Of Plasma Amyloid Beta Measurements In Identifying Amyloid Plaques In Alzheimer's Disease: A Literature Review, Abby L Brand, Paige E Lawler, James G Bollinger, Yan Li, Suzanne E Schindler, Melody Li, Samir Lopez, Vitaliy Ovod, Akinori Nakamura, Leslie M Shaw, Henrik Zetterberg, Oskar Hansson, Randall J Bateman

2020-Current year OA Pubs

The extracellular buildup of amyloid beta (Aβ) plaques in the brain is a hallmark of Alzheimer's disease (AD). Detection of Aβ pathology is essential for AD diagnosis and for identifying and recruiting research participants for clinical trials evaluating disease-modifying therapies. Currently, AD diagnoses are usually made by clinical assessments, although detection of AD pathology with positron emission tomography (PET) scans or cerebrospinal fluid (CSF) analysis can be used by specialty clinics. These measures of Aβ aggregation, e.g. plaques, protofibrils, and oligomers, are medically invasive and often only available at specialized medical centers or not covered by medical insurance, and PET …

Alzheimer's Disease, Dylan L. Weber

Student Publications

An overview of the background, etiology, pathophysiology, clinical features, diagnosis, treatment and prevention of Alzheimer's disease.

Effect Of Race On Prediction Of Brain Amyloidosis By Plasma Aβ42/Aβ40, Phosphorylated Tau, And Neurofilament Light, Suzanne E Schindler, Rachel L Henson, Yan Li, Benjamin Saef, Krista L Moulder, David Bradford, Anne M Fagan, Brian A Gordon, Tammie L S Benzinger, Joyce Balls-Berry, Randall J Bateman, Chengjie Xiong, John C Morris, Et Al

2020-Current year OA Pubs

BACKGROUND AND OBJECTIVES: To evaluate whether plasma biomarkers of amyloid (Aβ42/Aβ40), tau (p-tau181 and p-tau231), and neuroaxonal injury (neurofilament light chain [NfL]) detect brain amyloidosis consistently across racial groups.

METHODS: Individuals enrolled in studies of memory and aging who self-identified as African American (AA) were matched 1:1 to self-identified non-Hispanic White (NHW) individuals by age,

RESULTS: There were 76 matched pairs of AA and NHW participants (n = 152 total). For both AA and NHW groups, the median age was 68.4 years, 42% were

DISCUSSION: Models predicting brain amyloidosis using a high-performance plasma Aβ42/Aβ40 assay may provide an accurate and …

Exogenous Short Chain Fatty Acid Effects In App/Ps1 Mice, Diana J. Zajac, Benjamin C. Shaw, David J. Braun, Stefan J. Green, Joshua M. Morganti, Steven Estus

Sanders-Brown Center on Aging Faculty Publications

Elucidating the impact of the gut microbiome on Alzheimer’s Disease (AD) is an area of intense interest. Short chain fatty acids (SCFAs) are major microbiota metabolites that have been implicated as a mediator of gut microbiome effects in the brain. Here, we tested the effects of SCFA-treated water vs. saline-treated water on APPswe/PSEN1dE9 mice maintained under standard laboratory conditions. Mice were treated with SCFAs from five months of age until ten months of age, when they were evaluated for microbiome profile, impaired spatial memory as evaluated with the radial arm water maze, astrocyte activation as measured by Gfap expression and …

Novel App Knock-In Mouse Model Shows Key Features Of Amyloid Pathology And Reveals Profound Metabolic Dysregulation Of Microglia., Dan Xia, Steve Lianoglou, Thomas Sandmann, Meredith Calvert, Jung H Suh, Elliot Thomsen, Jason Dugas, Michelle E Pizzo, Sarah L Devos, Timothy K Earr, Chia-Ching Lin, Sonnet Davis, Connie Ha, Amy Wing-Sze Leung, Hoang Nguyen, Roni Chau, Ernie Yulyaningsih, Isabel Lopez, Hilda Solanoy, Shababa T Masoud, Chun-Chi Liang, Karin Lin, Giuseppe Astarita, Nathalie Khoury, Joy Yu Zuchero, Robert G Thorne, Kevin Shen, Stephanie Miller, Jorge J Palop, Dylan Garceau, Michael Sasner, Jennifer D Whitesell, Julie A Harris, Selina Hummel, Johannes Gnörich, Karin Wind, Lea Kunze, Artem Zatcepin, Matthias Brendel, Michael Willem, Christian Haass, Daniel Barnett, Till S Zimmer, Anna G Orr, Kimberly Scearce-Levie, Joseph W Lewcock, Gilbert Di Paolo, Pascal E Sanchez

Faculty Research 2022

BACKGROUND: Genetic mutations underlying familial Alzheimer's disease (AD) were identified decades ago, but the field is still in search of transformative therapies for patients. While mouse models based on overexpression of mutated transgenes have yielded key insights in mechanisms of disease, those models are subject to artifacts, including random genetic integration of the transgene, ectopic expression and non-physiological protein levels. The genetic engineering of novel mouse models using knock-in approaches addresses some of those limitations. With mounting evidence of the role played by microglia in AD, high-dimensional approaches to phenotype microglia in those models are critical to refine our understanding …

Complement In Autoimmune Inflammatory Myopathies, The Role Of Myositis-Associated Antibodies, Covid-19 Associations, And Muscle Amyloid Deposits., Marinos Dalakas

Department of Neurology Faculty Papers

Introduction

The inflammatory myopathies (IM) have now evolved into distinct subsets requiring clarification about their immunopathogenesis to guide applications of targeted therapies

Areas Covered

Immunohistopathologic criteria of IM with a focus on complement, anti-complement therapeutics, and other biologic immunotherapies. The COVID19-triggered muscle autoimmunity along with the correct interpretation of muscle amyloid deposits is discussed.

Expert Opinion

The IM, unjustifiably referred as idiopathic, comprise Dermatomyositis (DM), Necrotizing Autoimmune Myositis (NAM), Anti-synthetase syndrome-overlap myositis (Anti-SS-OM), and Inclusion-Body-Myositis (IBM). In DM, complement activation with MAC-mediated endomysial microvascular destruction and perifascicular atrophy is the fundamental process, while innate immunity activation factors, INF1 and …

The Association Between Alzheimer's Disease-Related Markers And Physical Activity In Cognitively Normal Older Adults, Steve Pedrini, Pratishtha Chatterjee, Akinori Nakamura, Michelle Tegg, Eugene Hone, Stephanie R. Rainey-Smith, Christopher C. Rowe, Vincent Dore, Victor L. Villemagne, David Ames, Naoki Kaneko, Samantha L. Gardener, Kevin Taddei, Binosha Fernando, Ian Martins, Prashant Bharadwaj, Hamid R. Sohrabi, Colin L. Masters, Belinda Brown, Ralph N. Martins, Aibl Research Group

Research outputs 2022 to 2026

Previous studies have indicated that physical activity may be beneficial in reducing the risk for Alzheimer's disease (AD), although the underlying mechanisms are not fully understood. The goal of this study was to evaluate the relationship between habitual physical activity levels and brain amyloid deposition and AD-related blood biomarkers (i.e., measured using a novel high-performance mass spectrometry-based assay), in apolipoprotein E (APOE) ε4 carriers and noncarriers. We evaluated 143 cognitively normal older adults, all of whom had brain amyloid deposition assessed using positron emission tomography and had their physical activity levels measured using the International Physical Activity Questionnaire (IPAQ). We …

Α-Synuclein Fibrils As Penrose Machines: A Chameleon In The Gear, Francesca De Giorgi, Vladimir N. Uversky, François Ichas

Molecular Medicine Faculty Publications

In 1957, Lionel Penrose built the first man-made self-replicating mechanical device and illustrated its function in a series of machine prototypes, prefiguring our current view of the genesis and the proliferation of amyloid fibrils. He invented and demonstrated, with the help of his son Roger, the concepts that decades later, would become the fundamentals of prion and prion-like neurobiology: nucleation, seeding and conformational templating of monomers, linear polymer elongation, fragmentation, and spread. He published his premonitory discovery in a movie he publicly presented at only two conferences in 1958, a movie we thus reproduce here. By making a 30-year-jump in …

The Future Of Ad Clinical Trials With The Advent Of Anti-Amyloid Therapies: An Ctad Task Force Report, J Delrieu, R J Bateman, J Touchon, M Sabbagh, J Cummings

2020-Current year OA Pubs

BACKGROUND: Aducanumab (ADUHELMTM) was approved for the treatment of Alzheimer's disease (AD) in the US. This approval was supported by an effect on the cerebral amyloid plaque load and evidence of cognitive efficacy to be confirmed in post-marketing trials. Other anti-amyloid antibodies are under investigation in phase III (donanemab, lecanemab, gantenerumab) and have shown preliminary evidence of a cognitive benefit in phase II trials. Although these agents target a small segment of patients with mild cognitive impairment due to AD or mild AD dementia, their advent will change the design of future clinical trials both for anti-amyloid and non-amyloid drugs. …

Cerebrospinal Fluid Levels Of Fatty Acid–Binding Protein 3 Are Associated With Likelihood Of Amyloidopathy In Cognitively Healthy Individuals, Kunal Dhiman, Victor L. Villemagne, Christopher Fowler, Pierrick Bourgeat, Qiao-Xin Li, Steven Collins, Christopher C. Rowe, Colin L. Masters, David Ames, Kaj Blennow, Henrik Zetterberg, Ralph N. Martins, Veer Gupta

Research outputs 2022 to 2026

Introduction: Fatty acid–binding protein 3 (FABP3) is a biomarker of neuronal membrane disruption, associated with lipid dyshomeostasis—a notable Alzheimer's disease (AD) pathophysiological change. We assessed the association of cerebrospinal fluid (CSF) FABP3 levels with brain amyloidosis and the likelihood/risk of developing amyloidopathy in cognitively healthy individuals. Methods: FABP3 levels were measured in CSF samples of cognitively healthy participants, > 60 years of age (n = 142), from the Australian Imaging, Biomarkers & Lifestyle Flagship Study of Ageing (AIBL). Results: FABP3 levels were positively associated with baseline brain amyloid beta (Aβ) load as measured by standardized uptake value ratio (SUVR, standardized β …

A Blood-Based Diagnostic Test Incorporating Plasma Aβ42/40 Ratio, Apoe Proteotype, And Age Accurately Identifies Brain Amyloid Status: Findings From A Multi Cohort Validity Analysis, Tim West, Kristopher M Kirmess, Matthew R Meyer, Mary S Holubasch, Stephanie S Knapik, Yan Hu, John H Contois, Erin N Jackson, Scott E Harpstrite, Randall J Bateman, David M Holtzman, Philip B Verghese, Ilana Fogelman, Joel B Braunstein, Kevin E Yarasheski

2020-Current year OA Pubs

BACKGROUND: The development of blood-based biomarker tests that are accurate and robust for Alzheimer's disease (AD) pathology have the potential to aid clinical diagnosis and facilitate enrollment in AD drug trials. We developed a high-resolution mass spectrometry (MS)-based test that quantifies plasma Aβ42 and Aβ40 concentrations and identifies the ApoE proteotype. We evaluated robustness, clinical performance, and commercial viability of this MS biomarker assay for distinguishing brain amyloid status.

METHODS: We used the novel MS assay to analyze 414 plasma samples that were collected, processed, and stored using site-specific protocols, from six independent US cohorts. We used receiver operating characteristic …

The Association Of Circulating Amylin With Β-Amyloid In Familial Alzheimer's Disease, Han Gia Ly, Nirmal Verma, Savita Sharma, Deepak Kotiya, Sanda Despa, Erin L. Abner, Peter T. Nelson, Gregory A. Jicha, Donna M. Wilcock, Larry B. Goldstein, Rita Guerreiro, José Brás, Angela J. Hanson, Suzanne Craft, Andrew J. Murray, Geert Jan Biessels, Claire Troakes, Henrik Zetterberg, John Hardy, Tammaryn Lashley, Alzheimer’S Disease Exome Sequencing Group, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

Introduction

This study assessed the hypothesis that circulating human amylin (amyloid‐forming) cross‐seeds with amyloid beta (Aβ) in early Alzheimer's disease (AD).

Methods

Evidence of amylin‐AD pathology interaction was tested in brains of 31 familial AD mutation carriers and 20 cognitively unaffected individuals, in cerebrospinal fluid (CSF) (98 diseased and 117 control samples) and in genetic databases. For functional testing, we genetically manipulated amylin secretion in APP/PS1 and non‐APP/PS1 rats.

Results

Amylin‐Aβ cross‐seeding was identified in AD brains. High CSF amylin levels were associated with decreased CSF Aβ42 concentrations. AD risk and amylin gene are not correlated. Suppressed amylin secretion protected …

Learning Deficit In Cognitively Normal Apoe Ε4 Carriers With Low Β-Amyloid, Yen Ying Lim, Jenalle E. Baker, Andrea Mills, Loren Bruns, Christopher Fowler, Jurgen Fripp, Stephanie R. Rainey-Smith, David Ames, Colin L. Masters, Paul Maruff

Research outputs 2014 to 2021

Introduction: In cognitively normal (CN) adults, increased rates of amyloid beta (Aβ) accumulation can be detected in low Aβ (Aβ–) apolipoprotein E (APOE) ε4 carriers. We aimed to determine the effect of ε4 on the ability to benefit from experience (ie, learn) in Aβ–CNs. Methods: Aβ– CNs(n= 333) underwent episodic memory assessments every 18 months for 108 months. A subset (n = 48) completed the Online Repeatable Cognitive Assessment-Language Learning Test (ORCA-LLT) over 6 days. Results: Aβ– ε4 carriers showed significantly lower rates of improvement on episodic memory over 108 months compared to non-carriers (d = 0.3). Rates of learning …

A Hyperpigmented Plaque In A Female Patient, Harel G. Schwartzberg, Alexandra Bourgeois, Amber Souers, Jeremy Atkinson, Pamela Martin

School of Medicine Faculty Publications

No abstract provided.

Microglial-Associated Responses To Comorbid Amyloid Pathology And Hyperhomocysteinemia In An Aged Knock-In Mouse Model Of Alzheimer's Disease, David J. Braun, Edgardo R. Dimayuga, Josh M. Morganti, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Elevated blood homocysteine levels, termed hyperhomocysteinemia (HHcy), is a prevalent risk factor for Alzheimer's disease (AD) in elderly populations. While dietary supplementation of B-vitamins is a generally effective method to lower homocysteine levels, there is little if any benefit to cognition. In the context of amyloid pathology, dietary-induced HHcy is known to enhance amyloid deposition and certain inflammatory responses. Little is known, however, about whether there is a more specific effect on microglia resulting from combined amyloid and HHcy pathologies.

METHODS: The present study used a knock-in mouse model of amyloidosis, aged to 12 months, given 8 weeks of …

Two C-Terminal Sequence Variations Determine Differential Neurotoxicity Between Human And Mouse Α-Synuclein, Natalie Landeck, Katherine E. Strathearn, Daniel Ysselstein, Kerstin Buck, Sayan Dutta, Siddhartha Banerjee, Zhengjian Lv, John D. Hulleman, Jagadish Hindupur, Li-Kai Lin, Sonal Padalkar, Lia A. Stanciu, Yuri L. Lyubchenko, Deniz Kirik, Jean-Christophe Rochet

Journal Articles: Pharmaceutical Sciences

BACKGROUND: α-Synuclein (aSyn) aggregation is thought to play a central role in neurodegenerative disorders termed synucleinopathies, including Parkinson's disease (PD). Mouse aSyn contains a threonine residue at position 53 that mimics the human familial PD substitution A53T, yet in contrast to A53T patients, mice show no evidence of aSyn neuropathology even after aging. Here, we studied the neurotoxicity of human A53T, mouse aSyn, and various human-mouse chimeras in cellular and in vivo models, as well as their biochemical properties relevant to aSyn pathobiology.

METHODS: Primary midbrain cultures transduced with aSyn-encoding adenoviruses were analyzed immunocytochemically to determine relative dopaminergic neuron viability. …

In Vivo Evidence Of Exosome-Mediated Aβ Neurotoxicity, Ahmed Elsherbini, Haiyan Qin, Zhihui Zhu, Priyanka Tripathi, Simone M. Crivelli, Erhard Bieberich

Physiology Faculty Publications

No abstract provided.

Alzheimer’S Disease, Brandi Herman

Nursing Student Class Projects (Formerly MSN)

Alzheimer’s disease is a cause of dementia that affects older adults worldwide. There is a greater understanding of the disease but the cause remains unknown. Alzheimer’s disease affects the brain ultimately leading to cognitive decline. Although there are modifiable risk factors that could potentially decrease the risk of Alzheimer’s there is no definitive treatment. As numbers increase of Alzheimer’s patients in the United States, updated research and clinical trials are needed to find a cure. Education on managing Alzheimer’s patients along with treating their symptoms is essential.

A Study Of The Antioxidant Versus Pro-Oxidant Nature Of The Amyloid Beta Peptide And An Analysis Of The Natural Products, Isorhamnetin And Narignenin, As Antioxidants, Kaylee Holmes

Honors Theses

Alzheimer’s disease is a neurodegenerative disorder with no cure. Due to the widespread effects of this disease, abundant research efforts have gone towards finding a cure. The amyloid beta (Ab) peptide has been shown to be a potential cause of the disease due to destructive effects on tissues that it can have both by itself and through reactive oxygen species (ROS) generation. This study was performed in order to assess the structural properties of Ab₄₂monomers, fibrils and oligomers, to assess the antioxidant versus pro-oxidant behavior of the Ab peptide, and to assess the antioxidant nature of the natural …