Medical Neurobiology Commons^™

A Novel Spatiotemporal Graph Convolutional Network Framework For Functional Connectivity Biomarkers Identification Of Alzheimer’S Disease, Ying Zhang, Le Xue, Shuoyan Zhang, Jiacheng Yang, Qi Zhang, Min Wang, Luyao Wang, Mingkai Zhang, Jiehui Jiang, Yunxia Li

Faculty, Staff and Student Publications

BACKGROUND: Functional connectivity (FC) biomarkers play a crucial role in the early diagnosis and mechanistic study of Alzheimer's disease (AD). However, the identification of effective FC biomarkers remains challenging. In this study, we introduce a novel approach, the spatiotemporal graph convolutional network (ST-GCN) combined with the gradient-based class activation mapping (Grad-CAM) model (STGC-GCAM), to effectively identify FC biomarkers for AD.

METHODS: This multi-center cross-racial retrospective study involved 2,272 participants, including 1,105 cognitively normal (CN) subjects, 790 mild cognitive impairment (MCI) individuals, and 377 AD patients. All participants underwent functional magnetic resonance imaging (fMRI) and T1-weighted MRI scans. In this study, …

Precision Medicine Approach To Alzheimer’S Disease: Rationale And Implications, Dale E. Bredesen, Kat Toups, Ann Hathaway, Deborha Gordon, Henrianna Chung, Cyrus Raji, Alan Boyd, Benjamin D. Hill, Sharon Hausman-Cohen, Mouna Attarha, Won Jong Chwa, Alexei Kurakin, Michael Jarrett

University Faculty and Staff Publications

The neurodegenerative disease field has enjoyed extremely limited success in the development of effective therapeutics. One potential reason is the lack of disease models that yield accurate predictions and optimal therapeutic targets. Standard clinical trials have pre-determined a single treatment modality, which may be unrelated to the primary drivers of neurodegeneration. Recent proof-of-concept clinical trials using a precision medicine approach suggest a new model of Alzheimer’s disease (AD) as a chronic innate encephalitis that creates a network insufficiency. Identifying and addressing the multiple potential contributors to cognitive decline for each patient may represent a more effective strategy. Here we review …

Traumatic Brain Injury-Associated Epigenetic Changes And The Risk For Neurodegenerative Diseases, Paul Smolen, Pramod K Dash, John B Redell

Faculty, Staff and Student Publications

Epidemiological studies have shown that traumatic brain injury (TBI) increases the risk for developing neurodegenerative diseases (NDs). However, molecular mechanisms that underlie this risk are largely unidentified. TBI triggers widespread epigenetic modifications. Similarly, NDs such as Alzheimer's or Parkinson's are associated with numerous epigenetic changes. Although epigenetic changes can persist after TBI, it is unresolved if these modifications increase the risk of later ND development and/or dementia. We briefly review TBI-related epigenetic changes, and point out putative feedback loops that might contribute to long-term persistence of some modifications. We then focus on evidence suggesting persistent TBI-associated epigenetic changes may contribute …

Characterization Of A Bioactive Peptide T14 In The Human And Rodent Substantia Nigra: Implications For Neurodegenerative Disease, Susan Adele Greenfield, Giovanni Ferrati, Clive W Coen, Auguste Vadisiute, Zoltan Molnár, Sara Garcia-Rates, Sally Frautschy, Gregory M Cole

Faculty, Staff and Student Publications

The substantia nigra is generally considered to show significant cell loss not only in Parkinson's but also in Alzheimer's disease, conditions that share several neuropathological traits. An interesting feature of this nucleus is that the pars compacta dopaminergic neurons contain acetylcholinesterase (AChE). Independent of its enzymatic role, this protein is released from pars reticulata dendrites, with effects that have been observed in vitro, ex vivo and in vivo. The part of the molecule responsible for these actions has been identified as a 14-mer peptide, T14, cleaved from the AChE C-terminus and acting at an allosteric site on alpha-7 nicotinic receptors, …

Uncovering The Role Of Apoe4 On Alzheimer’S Disease-Related Neuroinflammation, Courtney Marie Kloske

Theses and Dissertations--Physiology

Alzheimer’s disease (AD) is the most common neurodegenerative disease and is characterized by two hallmark pathologies: amyloid-beta plaques (Ab plaques) and hyperphosphorylated, aggregated tau tangles. These pathologies are typically accompanied by the presence of neuroinflammation which is primarily mediated by microglia. Interestingly, several genetic risk factors that increase the risk of AD also have direct impacts on neuroinflammation. Of interest, Apolipoprotein E (ApoE) is the largest genetic risk factor for AD. ApoE has three isoforms- E4 confers an increased risk for AD, E3 is considered the “control” phenotype, and E2 is protective against AD. E4 plays a role in virtually …

Microrna-146a-5p, Neurotropic Viral Infection And Prion Disease (Prd), Aileen I. Pogue, Walter J. Lukiw

School of Graduate Studies Faculty Publications

The human brain and central nervous system (CNS) harbor a select sub-group of potentially pathogenic microRNAs (miRNAs), including a well-characterized NF-kB-sensitive Homo sapiens microRNA hsa-miRNA-146a-5p (miRNA-146a). miRNA-146a is significantly over-expressed in progressive and often lethal viral- and prion-mediated and related neurological syndromes associated with progressive inflammatory neurodegeneration. These include ~18 different viral-induced encephalopathies for which data are available, at least ~10 known prion diseases (PrD) of animals and humans, Alzheimer’s disease (AD) and other sporadic and progressive age-related neurological disorders. Despite the apparent lack of nucleic acids in prions, both DNA- and RNA-containing viruses along with prions significantly induce miRNA-146a …

The Effect Of The Interaction Of Exercise Training And Isolation On The Serotonergic System Of App/Ps1 Mice, Bailey J. Dansby

Graduate Theses/Dissertations

Alzheimer’s disease (AD) is a complex neurodegenerative disease that is characterized by the deposition of amyloid beta (Ab) peptides and, consecutively, by a loss of memory and cognitive functions. The amyloid cascade hypothesis suggests that Ab deposition is the main pathogenic of AD. There is evidence that both changes in production and clearance of Ab may be involved in AD pathology. Past studies have shown that exercise training leads to an upregulation in proteins directly involved with Ab clearance. Chronic stress is thought to exacerbate AD pathology by increasing production of Ab. Studies have also demonstrated a link between serotonin …

Evidence That Brain-Reactive Autoantibodies Contribute To Chronic Neuronal Internalization Of Exogenous Amyloid-Β1-42 And Key Cell Surface Proteins During Alzheimer's Disease Pathogenesis, Eric L Goldwaser, Nimish K Acharya, Hao Wu, George A Godsey, Abhirup Sarkar, Cassandra A Demarshall, Mary C Kosciuk, Robert G Nagele

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Blood-brain barrier (BBB) permeability is a recognized early feature of Alzheimer's disease (AD). In the present study, we examined consequences of increased BBB permeability on the development of AD-related pathology by tracking selected leaked plasma components and their interactions with neurons in vivo and in vitro. Histological sections of cortical regions of postmortem AD brains were immunostained to determine the distribution of amyloid-β1-42 (Aβ42), cathepsin D, IgG, GluR2/3, and alpha7 nicotinic acetylcholine receptor (α7nAChR). Results revealed that chronic IgG binding to pyramidal neurons coincided with internalization of Aβ42, IgG, GluR2/3, and α7nAChR as well as lysosomal compartment expansion in these …

The Promises And Challenges Of Erythropoietin For Treatment Of Alzheimer's Disease, Jiahong Sun, Jan Michelle Martin, Victoria Vanderpoel, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder in the world, and intracellular neurofibrillary tangles and extracellular amyloid-beta protein deposits represent the major pathological hallmarks of the disease. Currently available treatments provide some symptomatic relief but fail to modify primary pathological processes that underlie the disease. Erythropoietin (EPO), a hematopoietic growth factor, acts primarily to stimulate erythroid cell production, and is clinically used to treat anemia. EPO has evolved as a therapeutic agent for neurodegeneration and has improved neurological outcomes and AD pathology in rodents. However, penetration of the blood–brain barrier (BBB) and negative hematopoietic effects are the two …

Hematologic Safety Of Chronic Brain-Penetrating Erythropoietin Dosing In App/Ps1 Mice, Jiahong Sun, Joshua Yang, Kathrine Whitman, Charlene Zhu, David H. Cribbs, Ruben J. Boado, William M. Pardridge, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Introduction: Low blood-brain barrier (BBB) penetration and hematopoietic side effects limit the therapeutic development of erythropoietin (EPO) for Alzheimer's disease (AD). A fusion protein of EPO and a chimeric monoclonal antibody targeting the mouse transferrin receptor (cTfRMAb) has been engineered. The latter drives EPO into the brain via receptor-mediated transcytosis across the BBB and increases its peripheral clearance to reduce hematopoietic side effects of EPO. Our previous work shows the protective effects of this BBB-penetrating EPO in AD mice but hematologic effects have not been studied. Herein, we investigate the hematologic safety and therapeutic effects of chronic cTfRMAb-EPO dosing, …

Dna Methylation Of The Clusterin Promoter: Associations With Alzheimer’S Disease Risk And Related Phenotypes, Madeline Peretti

Theses: Doctorates and Masters

Background

In 2017 approximately 50 million people worldwide were living with dementia. With Alzheimer’s disease (AD), accounting for 50-70% of dementia cases making this debilitating disease, with no current effective prevention, treatment or cure, a critical healthcare concern. Genome wide association studies (GWAS) have identified a number of risk genes for late onset AD (LOAD); Apolipoprotein E (APOE), a gene involved in the cholesterol/lipid pathway is considered the gene with the greatest risk. The third most associated AD risk gene is Clusterin (CLU), is also involved in the cholesterol/lipid pathway. CLU has been implicated in both …

In Vivo Brainstem Imaging In Alzheimer’S Disease: Potential For Biomarker Development, David J. Braun, Linda J. Van Eldik

Neuroscience Faculty Publications

The dearth of effective treatments for Alzheimer’s disease (AD) is one of the largest public health issues worldwide, costing hundreds of billions of dollars per year. From a therapeutic standpoint, research efforts to date have met with strikingly little clinical success. One major issue is that trials begin after substantial pathological change has occurred, and it is increasingly clear that the most effective treatment regimens will need to be administered earlier in the disease process. In order to identify individuals within the long preclinical phase of AD who are likely to progress to dementia, improvements are required in biomarker development. …

Role Of Microglial Amylin Receptors In Mediating Beta Amyloid (Aβ)-Induced Inflammation, Wen Fu, Vlatka Vukojevic, Aarti Patel, Rania Soudy, David Mactavish, David Westaway, Kamaljit Kaur, Valeri Goncharuk, Jack Jhamandas

Pharmacy Faculty Articles and Research

Background: Neuroinflammation in the brain consequent to activation of microglia is viewed as an important component of Alzheimer’s disease (AD) pathology. Amyloid beta (Aβ) protein is known to activate microglia and unleash an inflammatory cascade that eventually results in neuronal dysfunction and death. In this study, we sought to identify the presence of amylin receptors on human fetal and murine microglia and determine whether Aβ activation of the inflammasome complex and subsequent release of cytokines is mediated through these receptors.

Methods: The presence of dimeric components of the amylin receptor (calcitonin receptor and receptor activity modifying protein 3) …

Milder Alzheimer's Disease Pathology In Heart Failure And Atrial Fibrillation, Luciano A. Sposato, Estefania Ruiz Vargas, Patricia M. Riccio, Jon B. Toledo, John Q. Trojanowski, Walter A. Kukull, Lauren E. Cipriano, Antonia Nucera, Shawn N. Whitehead, Vladimir Hachinski

Anatomy and Cell Biology Publications

Introduction:Heart failure (HF) and atrial fibrillation (AF) have been associated with a higher risk of Alzheimer’s disease (AD). Whether HF and AF are related to AD by enhancing AD neuropathological changes is unknown.

Methods:We applied network analyses and multiple logistic regression models to assess the association between HF and AF with severity of AD neuropathology in patients from the National Alzheimer’s Coordinating Center database with primary neuropathological diagnosis of AD.

Results:We included 1593 patients, of whom 129 had HF and 250 had AF. HF and AF patients were older and had milder AD pathology. In the network …

Tumor Necrosis Factor Α Inhibition For Alzheimer's Disease, Rudy Chang, Kei-Lwun Yee, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Tumor necrosis factor α (TNF-α) plays a central role in the pathophysiology of Alzheimer’s disease (AD). Food and Drug Administration–approved biologic TNF-α inhibitors are thus a potential treatment for AD, but they do not cross the blood-brain barrier. In this short review, we discuss the involvement of TNF-α in AD, challenges associated with the development of existing biologic TNF-α inhibitors for AD, and potential therapeutic strategies for targeting TNF-α for AD therapy.

Cyclic Ac253, A Novel Amylin Receptor Antagonist, Improves Cognitive Deficits In A Mouse Model Of Alzheimer’S Disease, Rania Soudy, Aarti Patel, Wen Fu, Kamaljit Kaur, David Mactavish, David Westaway, Rachel Davey, Jeffrey Zajac, Jack Jhamandas

Pharmacy Faculty Articles and Research

Introduction: Amylin receptor serves as a portal for the expression of deleterious effects of amyloid b-protein (Ab), a key pathologic hallmark of Alzheimer’s disease. Previously, we showed that AC253, an amylin receptor antagonist, is neuroprotective against Ab toxicity in vitro and abrogates Ab-induced impairment of hippocampal long-term potentiation.

Methods: Amyloid precursor protein–overexpressing TgCRND8 mice received intracerebroventricularly AC253 for 5 months. New cyclized peptide cAC253 was synthesized and administered intraperitoneally three times a week for 10 weeks in the same mouse model. Cognitive functions were monitored, and pathologic changes were quantified biochemically and immunohistochemically.

Results: AC253, when administered …

Rapamycin Rescues Vascular, Metabolic And Learning Deficits In Apolipoprotein E4 Transgenic Mice With Pre-Symptomatic Alzheimer’S Disease, Ai-Ling Lin, Jordan B. Jahrling, Wei Zhang, Nicholas Derosa, Vikas Bakshi, Peter Romero, Veronica Galvan, Arlan Richardson

Sanders-Brown Center on Aging Faculty Publications

Apolipoprotein E ɛ4 allele is a common susceptibility gene for late-onset Alzheimer's disease. Brain vascular and metabolic deficits can occur in cognitively normal apolipoprotein E ɛ4 carriers decades before the onset of Alzheimer's disease. The goal of this study was to determine whether early intervention using rapamycin could restore neurovascular and neurometabolic functions, and thus impede pathological progression of Alzheimer's disease-like symptoms in pre-symptomatic Apolipoprotein E ɛ4 transgenic mice. Using in vivo, multimodal neuroimaging, we found that apolipoprotein E ɛ4 mice treated with rapamycin had restored cerebral blood flow, blood–brain barrier integrity and glucose metabolism, compared …

Aβ Alters The Dna Methylation Status Of Cell-Fate Genes In An Alzheimer’S Disease Model, Gary D. Isaacs, Noor Taher, Courtney Mckenzie, Rebecca Garrett, Matthew Baker, Nena Fox

Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by neurofibrillary tangles and extracellular amyloid-β plaques (Aβ). Despite ongoing research, some ambiguity remains surrounding the role of Aβ in the pathogenesis of this neurodegenerative disease. While several studies have focused on the mutations associated with AD, our understanding of the epigenetic contributions to the disease remains less clear. To that end, we determined the changes in DNA methylation in differentiated human neurons with and without Aβ treatment. We isolated the DNA from neurons treated with Aβ or vehicle, and digested the two samples with either a methylation-sensitive (HpaII) or a methylation-insensitive (MspI) restriction endonuclease. …