Neurosciences Commons^™

Sex Differences In The Association Between Episodic Memory Residual Reserve Index And Change In Executive Function, Cheyenne Chooi, Brandon E. Gavett, David Ames, Paul Maruff, Vincent Doré, Victor L. Villemagne, Pierrick Bourgeat, Ying Xia, Colin L. Masters, Ralph N. Martins, Kevin Taddei, Christopher C. Rowe, Michael Weinborn, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

Sex differences in cognitive reserve might contribute to females being disproportionately affected by Alzheimer's disease (AD). We investigated sex differences in the protective effects of cognitive reserve, and whether brain beta-amyloid accounts for differences. Older adults (n = 997 from the Australian Imaging, Biomarkers and Lifestyle Study of Ageing) diagnosed as Cognitively Normal, Mild Cognitive Impairment, or AD at baseline were assessed every 18 months for up to a maximum of seven visits. Cognitive reserve was calculated from the variance in episodic memory not explained by demographic or brain measures. Executive functioning (EF) intercept and slope were regressed onto the …

Association Of Common And Rare Variants With Alzheimer’S Disease In More Than 13,000 Diverse Individuals With Whole-Genome Sequencing From The Alzheimer’S Disease Sequencing Project, Wan-Ping Lee, Seung Hoan Choi, Margaret G Shea, Po-Liang Cheng, Beth A Dombroski, Achilleas N Pitsillides, Nancy L Heard-Costa, Hui Wang, Katia Bulekova, Amanda B Kuzma, Yuk Yee Leung, John J Farrell, Honghuang Lin, Brian W Kunkle, Adam Naj, Elizabeth E Blue, Frederick Nusetor, Dongyu Wang, Eric Boerwinkle, William S Bush, Xiaoling Zhang, Philip L De Jager, Josée Dupuis, Lindsay A Farrer, Myriam Fornage, Eden Martin, Margaret Pericak-Vance, Sudha Seshadri, Ellen M Wijsman, Li-San Wang, Alzheimer's Disease Sequencing Project;, Gerard D Schellenberg, Anita L Destefano, Jonathan L Haines, Gina M Peloso

Faculty, Staff and Student Publications

INTRODUCTION: Alzheimer's disease (AD) is a common disorder of the elderly that is both highly heritable and genetically heterogeneous.

METHODS: We investigated the association of AD with both common variants and aggregates of rare coding and non-coding variants in 13,371 individuals of diverse ancestry with whole genome sequencing (WGS) data.

RESULTS: Pooled-population analyses of all individuals identified genetic variants at apolipoprotein E (APOE) and BIN1 associated with AD (p < 5 × 10

DISCUSSION: We observed that complementary pooled-population and subgroup-specific analyses offered unique insights into the genetic architecture of AD.

HIGHLIGHTS: We determine the association of genetic variants with Alzheimer's disease (AD) using …

Tyk2 Regulates Tau Levels, Phosphorylation And Aggregation In A Tauopathy Mouse Model, Jiyoen Kim, Bakhos Tadros, Yan Hong Liang, Youngdoo Kim, Cristian Lasagna-Reeves, Jun Young Sonn, Dah-Eun Chloe Chung, Bradley Hyman, David M Holtzman, Huda Yahya Zoghbi

Faculty, Staff and Students Publications

Alzheimer's disease is one of at least 26 diseases characterized by tau-positive accumulation in neurons, glia or both. However, it is still unclear what modifications cause soluble tau to transform into insoluble aggregates. We previously performed genetic screens that identified tyrosine kinase 2 (TYK2) as a candidate regulator of tau levels. Here we verified this finding and found that TYK2 phosphorylates tau at tyrosine 29 (Tyr29) leading to its stabilization and promoting its aggregation in human cells. We discovered that TYK2-mediated Tyr29 phosphorylation interferes with autophagic clearance of tau. We also show that TYK2-mediated phosphorylation of Tyr29 facilitates pathological tau …

Detection And Staging Of Alzheimer's Disease By Plasma Ptau217 On A High Throughput Immunoassay Platform, Azadeh Feizpour, James David Doecke, Vincent Doré, Natasha Krishnadas, Kun Huang, Pierrick Bourgeat, Simon Matthew Laws, Christopher Fowler, Joanne Robertson, Lucy Mackintosh, Scott Ayton, Ralph Martins, Stephanie Ruth Rainey-Smith, Kevin Taddei, Larry Ward, Eddie Stage, Anthony Wilson Bannon, Colin Louis Masters, Jurgen Fripp, Victor Luis Villemagne, Christopher Cleon Rowe

Research outputs 2022 to 2026

Background: Plasma phospho-tau 217 (pTau217) assays can accurately detect Alzheimer's disease (AD) pathology, but clinical application is limited by the need for specialised equipment. This study tests the performance of a plasma pTau217 assay performed on the Lumipulse-G® platform, that is in widespread clinical use, for selecting patients for therapy based on β-amyloid (Aβ) status and tau staging. Methods: Participants included 388 individuals with 18F-NAV4694 Aβ-PET and 18F-MK6240 tau-PET. Association of pTau217 with PET was examined using Spearman's correlation. Discriminative performance for Aβ and tau PET status as well as tau staging was assessed using Receiver Operating Characteristic analysis. Findings: …

A Genome-Wide Association Meta-Analysis Of All-Cause And Vascular Dementia, Mega Vascular Cognitive Impairment And Dementia (Megavcid) Consortium

Faculty, Staff and Students Publications

INTRODUCTION: Dementia is a multifactorial disease with Alzheimer's disease (AD) and vascular dementia (VaD) pathologies making the largest contributions. Yet, most genome-wide association studies (GWAS) focus on AD.

METHODS: We conducted a GWAS of all-cause dementia (ACD) and examined the genetic overlap with VaD. Our dataset includes 800,597 individuals, with 46,902 and 8702 cases of ACD and VaD, respectively. Known AD loci for ACD and VaD were replicated. Bioinformatic analyses prioritized genes that are likely functionally relevant and shared with closely related traits and risk factors.

RESULTS: For ACD, novel loci identified were associated with energy transport (SEMA4D), neuronal excitability …

Resting State Electrophysiological Profiles And Their Relationship With Cognitive Performance In Cognitively Unimpaired Older Adults: A Systematic Review, Brenda Chino, David López-Sanz, Sandra Doval, Lucía Torres-Simón, Jaisalmer De Frutos Lucas, Lydia Giménez-Llort, Jonathan Zegarra-Valdivia, Fernando Maestú

Research outputs 2022 to 2026

Background: Aging is a complex and natural process. The physiological decline related to aging is accompanied by a slowdown in cognitive processes, which begins shortly after individuals reach maturity. These changes have been sometimes interpreted as a compensatory sign and others as a fingerprint of deterioration. Objective: In this context, our aim is to uncover the mechanisms that underlie and support normal cognitive functioning in the brain during the later stages of life. Methods: With this purpose, a systematic literature search was conducted using PubMed, Scopus, and Web of Science databases, which identified 781 potential articles. After applying inclusion and …

The Relationship Between Diet, Depression, And Alzheimer's Disease: A Narrative Review, Hilal Salim Said Al Shamsi, Stephanie R. Rainey-Smith, Samantha L. Gardener, Hamid R. Sohrabi, Rodrigo Canovas, Ralph N. Martins, Warnakulasuriya Mary Ann Dipika Binosha Fernando

Research outputs 2022 to 2026

Purpose of Review: This narrative review evaluates the role of diet in the relationship between depression and Alzheimer's disease (AD). Recent Findings: AD and depression are often comorbid, and depression appears to independently increase the future risk of AD. Evidence suggests diet influences the risk of both conditions directly and indirectly. Diet impacts neurochemical and biological processes that may affect the development and progression of depression and cognitive dysfunction. The dietary components offering the greatest protection against depression and AD are yet to be determined. Current evidence highlights the importance of polyphenolic compounds, folate, B vitamins, and polyunsaturated fatty acids, …

The Crosstalk Between Amyloid-Β, Retina, And Sleep For The Early Diagnosis Of Alzheimer's Disease: A Narrative Review, Isaiah Lorenzo De Guia, Shaun Eslick, Sharon L. Naismith, Swathi Kanduri, Tejal M. Shah, Ralph N. Martins

Research outputs 2022 to 2026

Alzheimer's disease (AD) is the most common type of dementia, which is characterised by progressive memory loss and accumulation of hallmark markers amyloid-β (Aβ) and neurofibrillary tangles in the diseased brain. The current gold standard diagnostic methods have limitations of being invasive, costly, and not easily accessible. Thus, there is a need for new avenues, such as imaging the retina for early AD diagnosis. Sleep disruption is symptomatically frequent across preclinical and AD subjects. As circadian activity, such as the sleep-wake cycle, is linked to the retina, analysis of their association may be useful additions for achieving predictive AD diagnosis. …

The Australian Multidomain Approach To Reduce Dementia Risk By Protecting Brain Health With Lifestyle Intervention Study (Au-Arrow): A Study Protocol For A Single-Blind, Multi-Site, Randomized Controlled Trial, Samantha L. Gardener, Stephanie J. Fuller, Sharon L. Naismith, Laura Baker, Miia Kivipelto, Victor L. Villemagne, Stuart M. Grieve, Paul Yates, Stephanie R. Rainey-Smith, Juliana Chen, Belinda Thompson, Nicola J. Armstrong, Malika G. Fernando, Carolina B. Castro, Silochna Meghwar, Rema Raman, Andrew Gleason, Catriona Ireland, Roger Clarnette, Kaarin J. Anstey, Kevin Taddei, Manohar Garg, Hamid R. Sohrabi, Ralph N. Martins

Research outputs 2022 to 2026

Introduction: The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER.

Method: AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55–79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a …

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.

Longitudinal Associations Between Exercise And Biomarkers In Autosomal Dominant Alzheimer's Disease, Kelsey R. Sewell, James D. Doecke, Chengjie Xiong, Tammie Benzinger, Colin L. Masters, Christoph Laske, Mathias Jucker, Francisco Lopera, Brian A. Gordon, Jorge Llibre-Guerra, Johannes Levin, Edward D. Huey, Jason Hassenstab, Peter R. Schofield, Gregory S. Day, Nick C. Fox, Jasmeer Chhatwal, Laura Ibanez, Jee Hoon Roh, Richard Perrin, Jae Hong Lee, Ralph N. Martins, Stephanie Rainey-Smith, Samantha L. Gardener, Hamid R. Sohrabi, Belinda Brown

Research outputs 2022 to 2026

INTRODUCTION: We investigated longitudinal associations between self-reported exercise and Alzheimer's disease (AD)-related biomarkers in individuals with autosomal dominant AD (ADAD) mutations. METHODS: Participants were 308 ADAD mutation carriers aged 39.7 ± 10.8 years from the Dominantly Inherited Alzheimer's Network. Weekly exercise volume was measured via questionnaire and associations with brain volume (magnetic resonance imaging), cerebrospinal fluid biomarkers, and brain amyloid beta (Aβ) measured by positron emission tomography were investigated. RESULTS: Greater volume of weekly exercise at baseline was associated with slower accumulation of brain Aβ at preclinical disease stages β = –0.16 [–0.23 to –0.08], and a slower decline in …

Sleep Discrepancy And Brain Glucose Metabolism In Community-Dwelling Older Adults, Nadia Soh, Michael Weinborn, James D. Doecke, Rodrigo Canovas, Vincent Doré, Ying Xia, Jurgen Fripp, Kevin Taddei, Romola S. Bucks, Hamid R. Sohrabi, Ralph N. Martins, Melissa Ree, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

Sleep discrepancy (negative discrepancy reflects worse self-reported sleep than objective measures, such as actigraphy, and positive discrepancy the opposite) has been linked to adverse health outcomes. This study is first to investigate the relationship between sleep discrepancy and brain glucose metabolism (assessed globally and regionally via positron emission tomography), and to evaluate the contribution of insomnia severity and depressive symptoms to any associations. Using data from cognitively unimpaired community-dwelling older adults (N = 68), cluster analysis was used to characterise sleep discrepancy (for total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE)), and logistic regression was …

Editorial: Neurotoxins In Alzheimer's Disease And Other Dementias, Alexandre Henriques, Philippe L. L. Poindron, Binosha Fernando, Kevin N. Hascup

Research outputs 2022 to 2026

Alzheimer's disease (AD) and other dementias are neurodegenerative disorders characterized by a progressive decline in cognition and independence from activities of daily living. Dementia is multifactorial with numerous risk factors including age, genes, molecules, lifestyle, and environmental contributions to disease onset and progression. In recent years, an emerging focus on neurotoxins has added a new layer of complexity to our understanding of dementia. This editorial aims to discuss recent updates regarding the role of neurotoxins in the pathogenesis of dementia.

Integrative Bayesian Tensor Regression For Imaging Genetics Applications, Yajie Liu, Nilanjana Chakraborty, Zhaohui S Qin, Suprateek Kundu

Faculty, Staff and Student Publications

Identifying biomarkers for Alzheimer's disease with a goal of early detection is a fundamental problem in clinical research. Both medical imaging and genetics have contributed informative biomarkers in literature. To further improve the performance, recently, there is an increasing interest in developing analytic approaches that combine data across modalities such as imaging and genetics. However, there are limited methods in literature that are able to systematically combine high-dimensional voxel-level imaging and genetic data for accurate prediction of clinical outcomes of interest. Existing prediction models that integrate imaging and genetic features often use region level imaging summaries, and they typically do …

Plasma Glial Fibrillary Acidic Protein In Autosomal Dominant Alzheimer's Disease: Associations With Aβ-Pet, Neurodegeneration, And Cognition, Pratishtha Chatterjee, Lisa Vermunt, Brian A. Gordon, Steve Pedrini, Lynn Boonkamp, Nicola J. Armstrong, Chengjie Xiong, Abhay K. Singh, Yan Li, Hamid R. Sohrabi, Kevin Taddei, Mark Molloy, Tammie L. S. Benzinger, John C. Morris, Celeste Karch, Sarah Berman, Jasmeer Chhatwal, Carlos Cruchaga, Neill R. Graff-Radford, Gregory S. Day, Martin Farlow, Nick Fox, Alison Goate, Jason Hassenstab, Jae-Hong Lee, Johannes Levin, Eric Mcdade, Hiroshi Mori, Richard Perrin, Raquel Sanchez-Valle, Peter R. Schofield, Allan Levey, Mathias Jucker, Colin L. Masters, Anne M. Fagan, Randall J. Bateman, Ralph N. Martins, Charlotte Teunissen, Dominantly Inherited Alzheimer Network

Research outputs 2022 to 2026

Background: Glial fibrillary acidic protein (GFAP) is a promising candidate blood-based biomarker for Alzheimer's disease (AD) diagnosis and prognostication. The timing of its disease-associated changes, its clinical correlates, and biofluid-type dependency will influence its clinical utility. Methods: We evaluated plasma, serum, and cerebrospinal fluid (CSF) GFAP in families with autosomal dominant AD (ADAD), leveraging the predictable age at symptom onset to determine changes by stage of disease. Results: Plasma GFAP elevations appear a decade before expected symptom onset, after amyloid beta (A ) accumulation and prior to neurodegeneration and cognitive decline. Plasma GFAP distinguished A -positive from A -negative ADAD …

Hippocampal Δfosb Expression Is Associated With Cognitive Impairment In A Subgroup Of Patients With Childhood Epilepsies, Chia-Hsuan Fu, Jason C You, Carrie Mohila, Robert A Rissman, Daniel Yoshor, Angela N Viaene, Jeannie Chin

Faculty, Staff and Students Publications

Epilepsy is a chronic neurological disorder characterized by recurrent seizures, and is often comorbid with other neurological and neurodegenerative diseases, such as Alzheimer's disease (AD). Patients with recurrent seizures often present with cognitive impairment. However, it is unclear how seizures, even when infrequent, produce long-lasting deficits in cognition. One mechanism may be seizure-induced expression of ΔFosB, a long-lived transcription factor that persistently regulates expression of plasticity-related genes and drives cognitive dysfunction. We previously found that, compared with cognitively-intact subjects, the activity-dependent expression of ΔFosB in the hippocampal dentate gyrus (DG) was increased in individuals with mild cognitive impairment (MCI) and …

Physical Activity And Brain Amyloid Beta: A Longitudinal Analysis Of Cognitively Unimpaired Older Adults, Michael G. Slee, Stephanie R. Rainey-Smith, Victor L. Villemagne, James D. Doecke, Hamid R. Sohrabi, Kevin Taddei, David Ames, Vincent Dore, Paul Maruff, Simon M. Laws, Colin L. Masters, Christopher C. Rowe, Ralph N. Martins, Kirk I. Erickson, Belinda M. Brown

Research outputs 2022 to 2026

Introduction: The current study evaluated the relationship between habitual physical activity (PA) levels and brain amyloid beta (A ) over 15 years in a cohort of cognitively unimpaired older adults. Methods: PA and A measures were collected over multiple timepoints from 731 cognitively unimpaired older adults participating in the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Aging. Regression modeling examined cross-sectional and longitudinal relationships between PA and brain A . Moderation analyses examined apolipoprotein E (APOE) 4 carriage impact on the PA-A relationship. Results: PA was not associated with brain A at baseline ( = –0.001, p = 0.72) …

Longitudinal Trajectories Of Basal Forebrain Volume In Normal Aging And Alzheimer's Disease, Ying Xia, Paul Maruff, Vincent Doré, Pierrick Bourgeat, Simon M. Laws, Christopher Fowler, Stephanie R. Rainey-Smith, Ralph N. Martins, Victor L. Villemagne, Christopher C. Rowe, Colin L. Masters, Elizabeth J. Coulson, Jurgen Fripp

Research outputs 2022 to 2026

Dysfunction of the cholinergic basal forebrain (BF) system and amyloid- (A ) deposition are early pathological features in Alzheimer's disease (AD). However, their association in early AD is not well-established. This study investigated the nature and magnitude of volume loss in the BF, over an extended period, in 516 older adults who completed A -PET and serial magnetic resonance imaging scans. Individuals were grouped at baseline according to the presence of cognitive impairment (CU, CI) and A status (A −, A +). Longitudinal volumetric changes in the BF and hippocampus were assessed across groups. The results indicated that high A …

Rna Editing Of Microtubule-Associated Protein Tau Circular Rnas Promotes Their Translation And Tau Tangle Formation, Justin Ralph Welden, Giorgi Margvelani, Karol Andrea Arizaca Maquera, Bhavani Gudlavalleti, Sandra C. Miranda Sardón, Alexandre Rosa Campos, Noémie Robil, Daniel C. Lee, Alvaro G. Hernandez, Wang-Xia Wang, Jing Di, Pierre De La Grange, Peter T. Nelson, Stefan Stamm

Sanders-Brown Center on Aging Faculty Publications

Aggregation of the microtubule-associated protein tau characterizes tauopathies, including Alzheimer’s disease and frontotemporal lobar degeneration (FTLD-Tau). Gene expression regulation of tau is complex and incompletely understood. Here we report that the human tau gene (MAPT) generates two circular RNAs (circRNAs) through backsplicing of exon 12 to either exon 7 (12→7 circRNA) or exon 10 (12→10 circRNA). Both circRNAs lack stop codons. The 12→7 circRNA contains one start codon and is translated in a rolling circle, generating a protein consisting of multimers of the microtubule-binding repeats R1–R4. For the 12→10 circRNA, a start codon can be introduced by two …

Transcriptional Profiles In Olfactory Pathway-Associated Brain Regions Of African Green Monkeys: Associations With Age And Alzheimer’S Disease Neuropathology, Jacob D Negrey, Dorothy L Dobbins, Timothy D Howard, Karin E Borgmann-Winter, C G Hahn, Sergey Kalinin, Douglas L Feinstein, Suzanne Craft, Carol A Shively, Thomas C Register

Department of Neuroscience Faculty Papers

Introduction: Olfactory impairment in older individuals is associated with an increased risk of Alzheimer's disease (AD). Characterization of age versus neuropathology-associated changes in the brain olfactory pathway may elucidate processes underlying early AD pathogenesis. Here, we report age versus AD neuropathology-associated differential transcription in four brain regions in the olfactory pathway of 10 female African green monkeys (vervet, Chlorocebus aethiops sabaeus), a well-described model of early AD-like neuropathology.

Methods: Transcriptional profiles were determined by microarray in the olfactory bulb (OB), piriform cortex (PC), temporal lobe white matter (WM), and inferior temporal cortex (ITC). Amyloid beta (Aβ) plaque load in …

The Trend Of Disruption In The Functional Brain Network Topology Of Alzheimer’S Disease, Alireza Fathian, Yousef Jamali, Mohammad Reza Raoufy, The Alzheimer's Disease Neuroimaging Initiative, Michael W. Weiner, Norbert Schuf, Howard J. Rosen, Bruce L. Miller, Thomas Neylan, Jacqueline Hayess, Shannon Finley, Paul Aisen, Zaven Khachaturian, Ronald G. Thomas, Charles D. Smith, Gregory A. Jicha, Peter A. Hardy, Partha Sinha, Elizabeth Oates, Gary Conrad

Sanders-Brown Center on Aging Faculty Publications

Alzheimer’s disease (AD) is a progressive disorder associated with cognitive dysfunction that alters the brain’s functional connectivity. Assessing these alterations has become a topic of increasing interest. However, a few studies have examined different stages of AD from a complex network perspective that cover different topological scales. This study used resting state fMRI data to analyze the trend of functional connectivity alterations from a cognitively normal (CN) state through early and late mild cognitive impairment (EMCI and LMCI) and to Alzheimer’s disease. The analyses had been done at the local (hubs and activated links and areas), meso (clustering, assortativity, and …

Sex Differences In The Genetic Architecture Of Cognitive Resilience To Alzheimer’S Disease, Jaclyn M. Eissman, Logan Dumitrescu, Emily R. Mahoney, Alexandra N. Smith, Shubhabrata Mukherjee, Michael L. Lee, Phoebe Scollard, Seo Eun Choi, William S. Bush, Corinne D. Engelman, Qiongshi Lu, David W. Fardo, Emily H. Trittschuh, Jesse Mez, Catherine C. Kaczorowski, Hector Hernandez Saucedo, Keith F. Widaman, Rachel F. Buckley, Michael J. Properzi, Elizabeth C. Mormino, Hyun Sik Yang, Theresa M. Harrison, Trey Hedden, Kwangsik Nho, Shea J. Andrews, Douglas Tommet, Niran Hadad, R. Elizabeth Sanders, Douglas M. Ruderfer, Katherine A. Gifford, Xiaoyuan Zhong, Neha S. Raghavan, Badri Vardarajan, Margaret A. Pericak-Vance, Lindsay A. Farrer, Li San Wang, Carlos Cruchaga, Gerard D. Schellenberg, Nancy J. Cox, Jonathan L. Haines, C. Dirk Keene, Andrew J. Saykin, Eric B. Larson, Reisa A. Sperling, Richard Mayeux, Michael L. Cuccaro, David A. Bennett, Julie A. Schneider, Paul K. Crane, Angela L. Jefferson, Timothy J. Hohman

Sanders-Brown Center on Aging Faculty Publications

Approximately 30% of elderly adults are cognitively unimpaired at time of death despite the presence of Alzheimer's disease neuropathology at autopsy. Studying individuals who are resilient to the cognitive consequences of Alzheimer's disease neuropathology may uncover novel therapeutic targets to treat Alzheimer's disease. It is well established that there are sex differences in response to Alzheimer's disease pathology, and growing evidence suggests that genetic factors may contribute to these differences. Taken together, we sought to elucidate sex-specific genetic drivers of resilience.

We extended our recent large scale genomic analysis of resilience in which we harmonized cognitive data across four cohorts …

Making The Case For The Accelerated Withdrawal Of Aducanumab, Peter J. Whitehouse

Faculty Scholarship

U.S. Food and Drug Administration-s (FDA) approval of aducanumab (Aduhelm® in the US) as a treatment for mild cognitive impairment of the Alzheimer type and Alzheimer-s disease has raised such major concerns about efficacy, safety, FDA processes, and regulatory capture that Biogen-s license to market this biologic should be immediately withdrawn. Aducanumab has not demonstrated benefit to patients, failed to meet regulatory guidelines, and is likely to cause both individual and societal harm.

New Insights Into The Genetic Etiology Of Alzheimer’S Disease And Related Dementias, Céline Bellenguez, Fahri Küçükali, Iris Jansen, Luca Kleineidam, Sonia Moreno-Grau, Najaf Amin, Adam C. Naj, Rafael Campos-Martin, David W. Fardo, Yuriko Kastumata, Erin L. Abner, Radb, Gr@Ace, Degesco, Eadi, Gerad, Demgene, Finngen, Adgc, Charge

Sanders-Brown Center on Aging Faculty Publications

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly …

Regulatory Aspects Of Mild Cognitive Impairment: Toward A Harmonized Perspective, Peter J. Whitehouse

Faculty Scholarship

The development of the concept of mild cognitive impairment (MCI) and its practical application have been intimately tied to attempts to produce therapeutic agents. Understanding the regulatory environment and determining the way in which it can be influenced are critical to the development of drugs and their eventual approval. In this article, we review some of the current challenges surrounding the concept of MCI relevant to drug development, summarize activities in various regions of the world, and conclude with some suggested next steps and an alternative framing for approving drugs for MCI and related conditions.

Investigating The Mitochondrial Protein Mitoneet In C. Elegans Models Of Aging And Alzheimer's Disease, Jacob Ryan Boos

Graduate Theses, Dissertations, and Problem Reports (ETD)

Oxidative stress is an imbalance between reactive oxygen species production and elimination, favoring the former. Reactive oxygen species serve as important signaling molecules for physiological homeostasis. However, when produced in excess, these once important signaling molecules become detrimental, disrupting cellular functions, and ultimately leading to cell death. In aging, reactive oxygen species production is increased, accompanied with reductions in oxidative stress resistance, increasing the risk for developing age-related diseases including cardiovascular disease, cancer, stroke, and neurodegenerative diseases. The outer mitochondrial membrane iron-sulfur cluster containing protein mitoNEET (CISD1; gene CISD1) has shown to be a mediator of mitochondrial function and …

Using Imputation To Provide Harmonized Longitudinal Measures Of Cognition Across Aibl And Adni, Rosita Shishegar, Timothy Cox, David Rolls, Pierrick Bourgeat, Vincent Doré, Fiona Lamb, Joanne Robertson, Simon M. Laws, Tenielle Porter, Jurgen Fripp, Duygu Tosun, Paul Maruff, Greg Savage, Christopher C. Rowe, Colin L. Masters, Michael W. Weiner, Victor L. Villemagne, Samantha C. Burnham

Research outputs 2014 to 2021

To improve understanding of Alzheimer’s disease, large observational studies are needed to increase power for more nuanced analyses. Combining data across existing observational studies represents one solution. However, the disparity of such datasets makes this a non-trivial task. Here, a machine learning approach was applied to impute longitudinal neuropsychological test scores across two observational studies, namely the Australian Imaging, Biomarkers and Lifestyle Study (AIBL) and the Alzheimer's Disease Neuroimaging Initiative (ADNI) providing an overall harmonised dataset. MissForest, a machine learning algorithm, capitalises on the underlying structure and relationships of data to impute test scores not measured in one study aligning …

Random Forest-Integrated Analysis In Ad And Late Brain Transcriptome-Wide Data To Identify Disease-Specific Gene Expression, Xinxing Wu, Chong Peng, Peter T. Nelson, Qiang Cheng

Sanders-Brown Center on Aging Faculty Publications

Alzheimer's disease (AD) is a complex neurodegenerative disorder that affects thinking, memory, and behavior. Limbic-predominant age-related TDP-43 encephalopathy (LATE) is a recently identified common neurodegenerative disease that mimics the clinical symptoms of AD. The development of drugs to prevent or treat these neurodegenerative diseases has been slow, partly because the genes associated with these diseases are incompletely understood. A notable hindrance from data analysis perspective is that, usually, the clinical samples for patients and controls are highly imbalanced, thus rendering it challenging to apply most existing machine learning algorithms to directly analyze such datasets. Meeting this data analysis challenge is …

Q134r: Small Chemical Compound With Nfat Inhibitory Properties Improves Behavioral Performance And Synapse Function In Mouse Models Of Amyloid Pathology, Pradoldej Sompol, Jenna L. Gollihue, Susan D. Kraner, Irina A. Artiushin, Ryan A. Cloyd, Emad Chishti, Shon A. Koren, Grant K. Nation, Jose F. Abisambra, Orsolya Huzian, Lajos I. Nagy, Miklos Santha, Laszlo Hackler Jr., Laszlo G. Puskas, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

Inhibition of the protein phosphatase calcineurin (CN) ameliorates pathophysiologic and cognitive changes in aging rodents and mice with aging-related Alzheimer's disease (AD)-like pathology. However, concerns over adverse effects have slowed the transition of common CN-inhibiting drugs to the clinic for the treatment of AD and AD-related disorders. Targeting substrates of CN, like the nuclear factor of activated T cells (NFATs), has been suggested as an alternative, safer approach to CN inhibitors. However, small chemical inhibitors of NFATs have only rarely been described. Here, we investigate a newly developed neuroprotective hydroxyquinoline derivative (Q134R) that suppresses NFAT signaling, without inhibiting CN activity. …

Myeloid Arginase 1 Insufficiency Exacerbates Amyloid-Β Associated Neurodegenerative Pathways And Glial Signatures In A Mouse Model Of Alzheimer’S Disease: A Targeted Transcriptome Analysis, Chao Ma, Jerry B. Hunt, Andrii Kovalenko, Huimin Liang, Maj-Linda B. Selenica, Michael B. Orr, Bei Zhang, John C. Gensel, David J. Feola, Marcia N. Gordon, Dave Morgan, Paula C. Bickford, Daniel C. Lee

Sanders-Brown Center on Aging Faculty Publications

Brain myeloid cells, include infiltrating macrophages and resident microglia, play an essential role in responding to and inducing neurodegenerative diseases, such as Alzheimer’s disease (AD). Genome-wide association studies (GWAS) implicate many AD casual and risk genes enriched in brain myeloid cells. Coordinated arginine metabolism through arginase 1 (Arg1) is critical for brain myeloid cells to perform biological functions, whereas dysregulated arginine metabolism disrupts them. Altered arginine metabolism is proposed as a new biomarker pathway for AD. We previously reported Arg1 deficiency in myeloid biased cells using lysozyme M (LysM) promoter-driven deletion worsened amyloidosis-related neuropathology and behavioral impairment. However, …