Medicine and Health Sciences Commons^™

Assessment Of Brain-Derived Extracellular Vesicle Enrichment For Blood Biomarker Analysis In Age-Related Neurodegenerative Diseases: An International Overview, Amanpreet Badhwar, Yael Hirschberg, Natalia Valle-Tamayo, Florencia Iulita, Chinedu Momoh, Anna Matton, Rawan Tarawneh, Robert Rissman, Aurélie Ledreux, Charisse Winston

Brain and Mind Institute

INTRODUCTION Brain-derived extracellular vesicles (BEVs) in blood allows for minimally-invasive investigations of central nervous system (CNS) -specific markers of age-related neurodegenerative diseases (NDDs). Polymer-based EV- and immunoprecipitation (IP)-based BEV-enrichment protocols from blood have gained popularity. We systematically investigated protocol consistency across studies, and determined CNS-specificity of proteins associated with these protocols.

METHODS NDD articles investigating BEVs in blood using polymer-based and/or IP-based BEV enrichment protocols were systematically identified, and protocols compared. Proteins used for BEV-enrichment and/or post-enrichment were assessed for CNS- and brain-cell-type-specificity, extracellular domains (ECD+), and presence in EV-databases.

RESULTS A total of 82.1% of studies used polymer-based (ExoQuick) …

Sorghum Grain Polyphenolic Extracts Demonstrate Neuroprotective Effects Related To Alzheimer’S Disease In Cellular Assays Sorghum Grain Polyphenolic Extracts Demonstrate Neuroprotective Effects Related To Alzheimer’S Disease In Cellular Assays, Nasim Rezaee, Eugene Hone, Hamid R. Sohrabi, Stuart Johnson, Leizhou Zhong, Prakhar Chatur, Stuart Gunzburg, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Sorghum grain contains high levels and a diverse profile of polyphenols (PPs), which are antioxidants known to reduce oxidative stress when consumed in the diet. Oxidative stress leading to amyloid-β (Aβ) aggregation, neurotoxicity, and mitochondrial dysfunction is implicated in the pathogenesis of Alzheimer’s disease (AD). Thus, PPs have gained attention as possible therapeutic agents for combating AD. This study aimed to (a) quantify the phenolic compounds (PP) and antioxidant capacities in extracts from six different varieties of sorghum grain and (b) investigate whether these PP extracts exhibit any protective effects on human neuroblastoma (BE(2)-M17) cells against Aβ- and tau-induced toxicity, …

Alzheimer’S Disease And Microorganisms: The Non-Coding Rnas Crosstalk, Hanieh Mohammadi-Pilehdarboni, Mohammad Shenagari, Farahnaz Joukar, Hamed Naziri, Fariborz Mansour-Ghanaei

Department of Neurology Faculty Papers

Alzheimer’s disease (AD) is a complex, multifactorial disorder, influenced by a multitude of variables ranging from genetic factors, age, and head injuries to vascular diseases, infections, and various other environmental and demographic determinants. Among the environmental factors, the role of the microbiome in the genesis of neurodegenerative disorders (NDs) is gaining increased recognition. This paradigm shift is substantiated by an extensive body of scientific literature, which underscores the significant contributions of microorganisms, encompassing viruses and gut-derived bacteria, to the pathogenesis of AD. The mechanism by which microbial infection exerts its influence on AD hinges primarily on inflammation. Neuroinflammation, activated in …

A Systematic Review Of Dementia Research Priorities, Manonita Ghosh, Pelden Chejor, Melanie Baker, Davina Porock

Research outputs 2022 to 2026

Introduction: Patient involvement is a critical component of dementia research priority-setting exercises to ensure that research benefits are relevant and acceptable to those who need the most. This systematic review synthesises research priorities and preferences identified by people living with dementia and their caregivers. Methods: Guided by Joanna Briggs Institute methodology, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework, we conducted a systematic search in five electronic databases: CINAHL, Medline, PsycINFO, Web of Science and Scopus. The reference lists of the included studies were also manually searched. We combined quantitative and qualitative data for synthesis and descriptive thematic …

Predicting The Risk Of Alzheimer's Disease And Related Dementia In Patients With Mild Cognitive Impairment Using A Semi-Competing Risk Approach, Zhaoyi Chen, Yuchen Yang, Dazheng Zhang, Jingchuan Guo, Yi Guo, Xia Hu, Yong Chen, Jiang Bian

Student and Faculty Publications

Alzheimer's disease (AD) and AD-related dementias (AD/ADRD) are a group of progressive neurodegenerative diseases. The progression of AD can be conceptualized as a continuum in which patients progress from normal cognition to preclinical AD (i.e., no symptoms but biological changes in the brain) to mild cognitive impairment (MCI) due to AD (i.e., mild symptoms but not interfere with daily activities), followed by increasing severity of dementia due to AD. Early detection and prediction models for the transition of MCI to AD/ADRD are needed, and efforts have been made to build predictions of MCI conversion to AD/ADRD. However, most existing studies …

Alcohol As A Modifiable Risk Factor For Alzheimer’S Disease—Evidence From Experimental Studies, Devaraj V. Chandrashekar, Ross A. Steinberg, Derick Han, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by cognitive impairment and memory loss. Epidemiological evidence suggests that heavy alcohol consumption aggravates AD pathology, whereas low alcohol intake may be protective. However, these observations have been inconsistent, and because of methodological discrepancies, the findings remain controversial. Alcohol-feeding studies in AD mice support the notion that high alcohol intake promotes AD, while also hinting that low alcohol doses may be protective against AD. Chronic alcohol feeding to AD mice that delivers alcohol doses sufficient to cause liver injury largely promotes and accelerates AD pathology. The mechanisms by which alcohol can …

Characterizing Performance Gaps Of A Code-Based Dementia Algorithm In A Population-Based Cohort Of Cognitive Aging, Maria Vassilaki, Sunyang Fu, Luke R Christenson, Muskan Garg, Ronald C Petersen, Jennifer St Sauver, Sunghwan Sohn

Student and Faculty Publications

BACKGROUND: Multiple algorithms with variable performance have been developed to identify dementia using combinations of billing codes and medication data that are widely available from electronic health records (EHR). If the characteristics of misclassified patients are clearly identified, modifying existing algorithms to improve performance may be possible.

OBJECTIVE: To examine the performance of a code-based algorithm to identify dementia cases in the population-based Mayo Clinic Study of Aging (MCSA) where dementia diagnosis (i.e., reference standard) is actively assessed through routine follow-up and describe the characteristics of persons incorrectly categorized.

METHODS: There were 5,316 participants (age at baseline (mean (SD)): 73.3 …

Lipids And Lipoproteins May Play A Role In The Neuropathology Of Alzheimer’S Disease, Omer Akyol, Sumeyya Akyol, Mei-Chuan Chou, Shioulan Chen, Ching-Kuan Liu, Salih Selek, Jair C Soares, Chu-Huang Chen

Student and Faculty Publications

Alzheimer's disease (AD) and other classes of dementia are important public health problems with overwhelming social, physical, and financial effects for patients, society, and their families and caregivers. The pathophysiology of AD is poorly understood despite the extensive number of clinical and experimental studies. The brain's lipid-rich composition is linked to disturbances in lipid homeostasis, often associated with glucose and lipid abnormalities in various neurodegenerative diseases, including AD. Moreover, elevated low-density lipoprotein (LDL) cholesterol levels may be related to a higher probability of AD. Here, we hypothesize that lipids, and electronegative LDL (L5) in particular, may be involved in the …

Tackling Dementia Together Via The Australian Dementia Network (Adnet): A Summary Of Initiatives, Progress And Plans, Sharon L. Naismith, Johannes C. Michaelian, Cherry Santos, Inga Mehrani, Joanne Robertson, Kasey Wallis, Xiaoping Lin, Stephanie A. Ward, Ralph Martins, Colin L. Masters, Michael Breakspear, Susannah Ahern, Jurgen Fripp, Peter R. Schofield, Perminder S. Sachdev, Christopher C. Rowe

Research outputs 2022 to 2026

In 2018, the Australian Dementia Network (ADNeT) was established to bring together Australia's leading dementia researchers, people with living experience and clinicians to transform research and clinical care in the field. To address dementia diagnosis, treatment, and care, ADNeT has established three core initiatives: the Clinical Quality Registry (CQR), Memory Clinics, and Screening for Trials. Collectively, the initiatives have developed an integrated clinical and research community, driving practice excellence in this field, leading to novel innovations in diagnostics, clinical care, professional development, quality and harmonization of healthcare, clinical trials, and translation of research into practice. Australia now has a national …

Ketone Bodies Mediate Alterations In Brain Energy Metabolism And Biomarkers Of Alzheimer’S Disease, Matin Ramezani, Malika Fernando, Shaun Eslick, Prita R. Asih, Sina Shadfar, Ekanayaka M. S. Bandara, Heidi Hillebrandt, Silochna Meghwar, Maryam Shahriari, Pratishtha Chatterjee, Rohith Thota, Cintia B. Dias, Manohar L. Garg, Ralph N. Martins

Research outputs 2022 to 2026

Alzheimer’s disease (AD) is the most common form of dementia. AD is a progressive neurodegenerative disorder characterized by cognitive dysfunction, including learning and memory deficits, and behavioral changes. Neuropathology hallmarks of AD such as amyloid beta () plaques and neurofibrillary tangles containing the neuron-specific protein tau is associated with changes in fluid biomarkers including A , phosphorylated tau (p-tau)-181, p-tau 231, p-tau 217, glial fibrillary acidic protein (GFAP), and neurofilament light (NFL). Another pathological feature of AD is neural damage and hyperactivation of astrocytes, that can cause increased pro-inflammatory mediators and oxidative stress. In addition, reduced brain glucose metabolism and …

Sixteen-Year Longitudinal Evaluation Of Blood-Based Dna Methylation Biomarkers For Early Prediction Of Alzheimer's Disease, Fernanda Schäfer Hackenhaar, Maria Josefsson, Annelie Nordin Adolfsson, Mattias Landfors, Karolina Kauppi, Tenielle Porter, Lidija Milicic, Simon M. Laws, Magnus Hultdin, Rolf Adolfsson, Sofie Degerman, Sara Pudas, Australian Imaging Biomarkers And Lifestyle Study

Research outputs 2022 to 2026

BACKGROUND: DNA methylation (DNAm), an epigenetic mark reflecting both inherited and environmental influences, has shown promise for Alzheimer's disease (AD) prediction. OBJECTIVE: Testing long-term predictive ability ( > 15 years) of existing DNAm-based epigenetic age acceleration (EAA) measures and identifying novel early blood-based DNAm AD-prediction biomarkers. METHODS: EAA measures calculated from Illumina EPIC data from blood were tested with linear mixed-effects models (LMMs) in a longitudinal case-control sample (50 late-onset AD cases; 51 matched controls) with prospective data up to 16 years before clinical onset, and post-onset follow-up. Novel DNAm biomarkers were generated with epigenome-wide LMMs, and Sparse Partial Least Squares …

Genetic Expression Changes And Pathologic Findings Associated With Hyperhomocysteinemia In Human Autopsy Brain Tissue, Erica M. Weekman, Zachary Winder, Colin B. Rogers, Erin L. Abner, Tiffany L. Sudduth, Ela Patel, Adam J. Dugan, Shuling X. Fister, Brandi Wasek, Peter T. Nelson, Gregory A. Jicha, Teodoro Bottiglieri, David W. Fardo, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Introduction: Vascular contributions to cognitive impairment and dementia (VCID) are a leading cause of dementia. An underappreciated, modifiable risk factor for VCID is hyperhomocysteinemia (HHcy), defined by elevated levels of plasma homocysteine, most often due to impaired B vitamin absorption in aged persons. Studies aimed at identifying neuropathologic features and gene expression profiles associated with HHcy have been lacking.

Methods: A subset of research volunteers from the University of Kentucky Alzheimer’s Disease Research Center longitudinal cohort came to autopsy and had ante mortem plasma homocysteine levels available. Brain tissue and blood plasma drawn closest to death were used to measure …

Loss Of Lamp5 Interneurons Drives Neuronal Network Dysfunction In Alzheimer’S Disease, Yuanyuan Deng, Mian Bi, Fabien Delerue, Shelley L Forrest, Gabriella Chan, Julia Van Der Hoven, Annika Van Hummel, Astrid F Feiten, Seojin Lee, Ivan Martinez-Valbuena, Tim Karl, Gabor G Kovacs, Grant Morahan, Yazi D Ke, Lars M Ittner

Student and Faculty Publications

In Alzheimer's disease (AD), where amyloid-β (Aβ) and tau deposits in the brain, hyperexcitation of neuronal networks is an underlying disease mechanism, but its cause remains unclear. Here, we used the Collaborative Cross (CC) forward genetics mouse platform to identify modifier genes of neuronal hyperexcitation. We found LAMP5 as a novel regulator of hyperexcitation in mice, critical for the survival of distinct interneuron populations. Interestingly, synaptic LAMP5 was lost in AD brains and LAMP5 interneurons degenerated in different AD mouse models. Genetic reduction of LAMP5 augmented functional deficits and neuronal network hypersynchronicity in both Aβ- and tau-driven AD mouse models. …

Mesenchymal Stromal Cells For The Treatment Of Alzheimer’S Disease: Strategies And Limitations, Shobha Regmi, Daniel Dan Liu, Michelle Shen, Bhavesh D Kevadiya, Abantika Ganguly, Rosita Primavera, Shashank Chetty, Reza Yarani, Avnesh S Thakor

Student and Faculty Publications

Alzheimer's disease (AD) is a major cause of age-related dementia and is characterized by progressive brain damage that gradually destroys memory and the ability to learn, which ultimately leads to the decline of a patient's ability to perform daily activities. Although some of the pharmacological treatments of AD are available for symptomatic relief, they are not able to limit the progression of AD and have several side effects. Mesenchymal stem/stromal cells (MSCs) could be a potential therapeutic option for treating AD due to their immunomodulatory, anti-inflammatory, regenerative, antioxidant, anti-apoptotic, and neuroprotective effects. MSCs not only secret neuroprotective and anti-inflammatory factors …

Prostacyclin Promotes Degenerative Pathology In A Model Of Alzheimer’S Disease, Tasha R. Womack, Craig T. Vollert, Odochi Ohia-Nwoko, Monika Schmitt, Saghi Montazari, Tina L. Beckett, David Mayerich, Michael Paul Murphy, Jason L. Eriksen

Sanders-Brown Center on Aging Faculty Publications

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that is the most common form of dementia in aged populations. A substantial amount of data demonstrates that chronic neuroinflammation can accelerate neurodegenerative pathologies. In AD, chronic neuroinflammation results in the upregulation of cyclooxygenase and increased production of prostaglandin H2, a precursor for many vasoactive prostanoids. While it is well-established that many prostaglandins can modulate the progression of neurodegenerative disorders, the role of prostacyclin (PGI2) in the brain is poorly understood. We have conducted studies to assess the effect of elevated prostacyclin biosynthesis in a mouse model of AD. Upregulated prostacyclin expression …

Higher Coffee Consumption Is Associated With Slower Cognitive Decline And Less Cerebral Aβ-Amyloid Accumulation Over 126 Months: Data From The Australian Imaging, Biomarkers, And Lifestyle Study, Samantha L. Gardener, Stephanie R. Rainey-Smith, Victor L. Villemagne, Jurgen Fripp, Vincent Doré, Pierrick Bourgeat, Kevin Taddei, Christopher Fowler, Colin L. Masters, Paul Maruff, Christopher C. Rowe, David Ames, Ralph N. Martins, Aibl Investigators

Research outputs 2014 to 2021

Background:

Worldwide, coffee is one of the most popular beverages consumed. Several studies have suggested a protective role of coffee, including reduced risk of Alzheimer’s disease (AD). However, there is limited longitudinal data from cohorts of older adults reporting associations of coffee intake with cognitive decline, in distinct domains, and investigating the neuropathological mechanisms underpinning any such associations.

Methods: The aim of the current study was to investigate the relationship between self-reported habitual coffee intake, and cognitive decline assessed using a comprehensive neuropsychological battery in 227 cognitively normal older adults from the Australian Imaging, Biomarkers, and Lifestyle (AIBL) study, over …

Pairwise Correlation Analysis Of The Alzheimer’S Disease Neuroimaging Initiative (Adni) Dataset Reveals Significant Feature Correlation, Erik D. Huckvale, Matthew W. Hodgman, Brianna B. Greenwood, Devorah O. Stucki, Katrisa M. Ward, Mark T. W. Ebbert, John S. K. Kauwe, The Alzheimer’S Disease Neuroimaging Initiative, The Alzheimer’S Disease Metabolomics Consortium, Justin B. Miller

Sanders-Brown Center on Aging Faculty Publications

The Alzheimer’s Disease Neuroimaging Initiative (ADNI) contains extensive patient measurements (e.g., magnetic resonance imaging [MRI], biometrics, RNA expression, etc.) from Alzheimer’s disease (AD) cases and controls that have recently been used by machine learning algorithms to evaluate AD onset and progression. While using a variety of biomarkers is essential to AD research, highly correlated input features can significantly decrease machine learning model generalizability and performance. Additionally, redundant features unnecessarily increase computational time and resources necessary to train predictive models. Therefore, we used 49,288 biomarkers and 793,600 extracted MRI features to assess feature correlation within the ADNI dataset to determine the …

Committee On High-Quality Alzheimer’S Disease Studies (Chads) Consensus Report, Gregory A. Jicha, Erin L. Abner, Steven E. Arnold, Maria C. Carrillo, Hiroko H. Dodge, Steven D. Edland, Keith N. Fargo, Howard H. Feldman, Larry B. Goldstein, James A. Hendrix, Ruth Peters, Julie M. Robillard, Lon S. Schneider, Jodi R. Titiner, Christopher J. Weber

Sanders-Brown Center on Aging Faculty Publications

Background: Consensus guidance for the development and identification of high-quality Alzheimer's disease clinical trials is needed for protocol development and conduct of clinical trials.

Methods: An ad hoc consensus committee was convened in conjunction with the Alzheimer's Association to develop consensus recommendations.

Results: Consensus was readily reached for the need to provide scientific justification, registration of trials, institutional review board oversight, conflict of interest disclosure, funding source disclosure, defined trial population, recruitment resources, definition of the intervention, specification of trial duration, appropriate payment for participant engagement, risk-benefit disclosure as part of the consent process, and the requirement …

Longitudinal Cognitive Performance Of Alzheimer's Disease Neuropathological Subtypes, Madeline Uretsky, Laura E. Gibbons, Shubhabrata Mukherjee, Emily H. Trittschuh, David W. Fardo, Patricia A. Boyle, C. Dirk Keene, Andrew J. Saykin, Paul K. Crane, Julie A. Schneider, Jesse Mez

Sanders-Brown Center on Aging Faculty Publications

Introduction: Alzheimer's disease (AD) neuropathological subtypes (limbic predominant [lpAD], hippocampal sparing [HpSpAD], and typical [tAD]), defined by relative neurofibrillary tangle (NFT) burden in limbic and cortical regions, have not been studied in prospectively characterized epidemiological cohorts with robust cognitive assessments.

Methods: Two hundred ninety-two participants with neuropathologically confirmed AD from the Religious Orders Study and Memory and Aging Project were categorized by neuropathological subtype based on previously specified diagnostic criteria using quantitative regional NFT counts. Rates of cognitive decline were compared across subtypes using linear mixed-effects models that included subtype, time, and a subtype-time interaction as predictors and four cognitive …

Apoε4 Lowers Energy Expenditure In Females And Impairs Glucose Oxidation By Increasing Flux Through Aerobic Glycolysis, Brandon C. Farmer, Holden C. Williams, Nicholas A. Devanney, Margaret A. Piron, Grant K. Nation, David J. Carter, Adeline E. Walsh, Rebika Khanal, Lyndsay E. A. Young, Jude C. Kluemper, Gabriela Hernandez, Elizabeth J. Allenger, Rachel Mooney, Lesley R. Golden, Cathryn T. Smith, J. Anthony Brandon, Vedant A. Gupta, Philip A. Kern, Matthew S. Gentry, Josh M. Morganti, Ramon C. Sun, Lance A. Johnson

Physiology Faculty Publications

BACKGROUND: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer's disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field.

METHODS: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4.

RESULTS: Single-cell …

Cross-Sectional Exploration Of Plasma Biomarkers Of Alzheimer's Disease In Down Syndrome: Early Data From The Longitudinal Investigation For Enhancing Down Syndrome Research (Life-Dsr) Study, James A. Hendrix, David C. Airey, Angela Britton, Anna D. Burke, George T. Capone, Ronelyn Chavez, Jacqueline Chen, Brian Chicoine, Alberto C. S. Costa, Jeffrey L. Dage, Eric Doran, Anna Esbensen, Casey L. Evans, Kelley M. Faber, Tatiana M. Foroud, Sarah Hart, Kelsey Haugen, Elizabeth Head, Suzanne Hendrix, Hampus Hillerstrom, Frederick A. Schmitt

Sanders-Brown Center on Aging Faculty Publications

With improved healthcare, the Down syndrome (DS) population is both growing and aging rapidly. However, with longevity comes a very high risk of Alzheimer’s disease (AD). The LIFE-DSR study (NCT04149197) is a longitudinal natural history study recruiting 270 adults with DS over the age of 25. The study is designed to characterize trajectories of change in DS-associated AD (DS-AD). The current study reports its cross-sectional analysis of the first 90 subjects enrolled. Plasma biomarkers phosphorylated tau protein (p-tau), neurofilament light chain (NfL), amyloid β peptides (Aβ_1-40, Aβ_1-42), and glial fibrillary acidic protein (GFAP) were undertaken with …

CertL Reduces C16 Ceramide, Amyloid-Β Levels, And Inflammation In A Model Of Alzheimer’S Disease, Simone M. Crivelli, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Daan Van Kruining, Gerard Bode, Sandra Den Hoedt, Barbara Hobo, Anna-Lena Scheithauer, Jochen Walter, Monique T. Mulder, Christopher Exley, Matthew Mold, Michelle M. Mielke, Helga E. De Vries, Kristiaan Wouters, Daniel L. A. Van Den Hove, Dusan Berkes, María Dolores Ledesma, Joost Verhaagen, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez

Physiology Faculty Publications

BACKGROUND: Dysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-β (Aβ) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain.

METHODS: A plasmid expressing CERT_L, the long isoform of CERTs, was used to study the interaction of CERT_L with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERT_L protein …

Broad Kinase Inhibition Mitigates Early Neuronal Dysfunction In Tauopathy, Shon A. Koren, Matthew J. Hamm, Ryan Cloyd, Sarah N. Fontaine, Emad Chishti, Chiara Lanzillotta, Jennifer Rodriguez-Rivera, Alexandria Ingram, Michelle Bell, Sara M. Galvis-Escobar, Nicholas Zulia, Fabio Di Domenico, Duc Duong, Nicholas T. Seyfried, David K. Powell, Moriel Vandsburger, Tal Frolinger, Anika M. S. Hartz, John Koren Iii, Jeffrey M. Axten, Nicholas J. Laping, Jose F. Abisambra

Sanders-Brown Center on Aging Faculty Publications

Tauopathies are a group of more than twenty known disorders that involve progressive neurodegeneration, cognitive decline and pathological tau accumulation. Current therapeutic strategies provide only limited, late-stage symptomatic treatment. This is partly due to lack of understanding of the molecular mechanisms linking tau and cellular dysfunction, especially during the early stages of disease progression. In this study, we treated early stage tau transgenic mice with a multi-target kinase inhibitor to identify novel substrates that contribute to cognitive impairment and exhibit therapeutic potential. Drug treatment significantly ameliorated brain atrophy and cognitive function as determined by behavioral testing and a sensitive imaging …

Arginase 1 Insufficiency Precipitates Amyloid-Β Deposition And Hastens Behavioral Impairment In A Mouse Model Of Amyloidosis, Chao Ma, Jerry B. Hunt, Maj-Linda B. Selenica, Awa Sanneh, Leslie A. Sandusky-Beltran, Mallory Watler, Rana Daas, Andrii Kovalenko, Huimin Liang, Devon Placides, Chuanhai Cao, Xiaoyang Lin, 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

Alzheimer’s disease (AD) includes several hallmarks comprised of amyloid-β (Aβ) deposition, tau neuropathology, inflammation, and memory impairment. Brain metabolism becomes uncoupled due to aging and other AD risk factors, which ultimately lead to impaired protein clearance and aggregation. Increasing evidence indicates a role of arginine metabolism in AD, where arginases are key enzymes in neurons and glia capable of depleting arginine and producing ornithine and polyamines. However, currently, it remains unknown if the reduction of arginase 1 (Arg1) in myeloid cell impacts amyloidosis. Herein, we produced haploinsufficiency of Arg1 by the hemizygous deletion in myeloid cells using Arg1 …

Therapeutic Potential Of Mitophagy-Inducing Microflora Metabolite, Urolithin A For Alzheimer’S Disease, Dona Pamoda W. Jayatunga, Eugene Hone, Harjot Khaira, Taciana Lunelli, Harjinder Singh, Gilles J. Guillemin, Binosha Fernando, Manohar L. Garg, Giuseppe Verdile, Ralph N. Martins

Research outputs 2014 to 2021

Mitochondrial dysfunction including deficits of mitophagy is seen in aging and neuro-degenerative disorders including Alzheimer’s disease (AD). Apart from traditionally targeting amyloid beta (Aβ), the main culprit in AD brains, other approaches include investigating impaired mitochondrial pathways for potential therapeutic benefits against AD. Thus, a future therapy for AD may focus on novel candidates that enhance optimal mitochondrial integrity and turnover. Bi-oactive food components, known as nutraceuticals, may serve as such agents to combat AD. Uro-lithin A is an intestinal microbe-derived metabolite of a class of polyphenols, ellagitannins (ETs). Urolithin A is known to exert many health benefits. Its antioxidant, …

Core Alzheimer’S Disease Cerebrospinal Fluid Biomarker Assays Are Not Affected By Aspiration Or Gravity Drip Extraction Methods, James D. Doecke, Cindy Francois, Christopher J. Fowler, Erik Stoops, Pierrick Bourgeat, Stephanie R. Rainey-Smith, Qiao-Xin Li, Colin L. Masters, Ralph N. Martins, Victor L. Villemagne, Steven J. Collins, Hugo Marcel Vanderstichele

Research outputs 2014 to 2021

Background: CSF biomarkers are well-established for routine clinical use, yet a paucity of comparative assessment exists regarding CSF extraction methods during lumbar puncture. Here, we compare in detail biomarker profiles in CSF extracted using either gravity drip or aspiration. Methods: Biomarkers for β-amyloidopathy (Aβ1–42, Aβ1–40), tauopathy (total tau), or synapse pathology (BACE1, Neurogranin Trunc-p75, α-synuclein) were assessed between gravity or aspiration extraction methods in a sub-population of the Australian Imaging, Biomarkers and Lifestyle (AIBL) study (cognitively normal, N = 36; mild cognitive impairment, N = 8; Alzheimer’s disease, N = 6). Results: High biomarker concordance between extraction methods was seen …

Electrophysiological And Imaging Calcium Biomarkers Of Aging In Male And Female 5×Fad Mice, Adam O. Ghoweri, Lara Ouillette, Hilaree N. Frazier, Katie L. Anderson, Ruei-Lung Lin, John C. Gant, Rachel Parent, Shannon Moore, Geoffrey G. Murphy, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: In animal models and tissue preparations, calcium dyshomeostasis is a biomarker of aging and Alzheimer's disease that is associated with synaptic dysfunction, neuritic pruning, and dysregulated cellular processes. It is unclear, however, whether the onset of calcium dysregulation precedes, is concurrent with, or is the product of pathological cellular events (e.g., oxidation, amyloid-β production, and neuroinflammation). Further, neuronal calcium dysregulation is not always present in animal models of amyloidogenesis, questioning its reliability as a disease biomarker.

OBJECTIVE: Here, we directly tested for the presence of calcium dysregulation in dorsal hippocampal neurons in male and female 5×FAD mice on …

Oral Gavage Delivery Of Stable Isotope Tracer For In Vivo Metabolomics, Holden C. Williams, Margaret A. Piron, Grant K. Nation, Adeline E. Walsh, Lyndsay E. A. Young, Ramon C. Sun, Lance A. Johnson

Sanders-Brown Center on Aging Faculty Publications

Stable isotope-resolved metabolomics (SIRM) is a powerful tool for understanding disease. Advances in SIRM techniques have improved isotopic delivery and expanded the workflow from exclusively in vitro applications to in vivo methodologies to study systemic metabolism. Here, we report a simple, minimally-invasive and cost-effective method of tracer delivery to study SIRM in vivo in laboratory mice. Following a brief fasting period, we orally administered a solution of [U-¹³C] glucose through a blunt gavage needle without anesthesia, at a physiological dose commonly used for glucose tolerance tests (2 g/kg bodyweight). We defined isotopic enrichment in plasma and tissue at …

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 …

Therapeutic Trem2 Activation Ameliorates Amyloid-Beta Deposition And Improves Cognition In The 5xfad Model Of Amyloid Deposition, Brittani R. Price, Tiffany L. Sudduth, Erica M. Weekman, Sherika Johnson, Danielle Hawthorne, Abigail E. Woolums, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Triggering receptor expressed on myeloid cell-2 (TREM2) is a lipid and lipoprotein binding receptor expressed by cells of myeloid origin. Homozygous TREM2 mutations cause early onset progressive presenile dementia while heterozygous, point mutations triple the risk of Alzheimer's disease (AD). Although human genetic findings support the notion that loss of TREM2 function exacerbates neurodegeneration, it is not clear whether activation of TREM2 in a disease state would result in therapeutic benefits. To determine the viability of TREM2 activation as a therapeutic strategy, we sought to characterize an agonistic Trem2 antibody (AL002a) and test its efficacy and mechanism of action …