Medicine and Health Sciences Commons^™

The Effect Of Traumatic Brain Injury On Tau Pathology By A Potential Seeding Mechanism, George Edwards Iii

Dissertations & Theses (Open Access)

The misfolding, aggregation and accumulation of specific proteins is the overarching concept in protein misfolding disorders (PMDs). The microtubule associated protein tau is known to form insoluble filaments known as neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau (pTau) found in a subset of PMDs called tauopathies, such as Alzheimer’s disease (AD) and chronic traumatic encephalopathy (CTE), among others. Misfolded tau engenders a structurally alternative intermediate conformation that is prone to aggregate having amyloidogenic properties. Formation of amyloids, such as tau aggregates, is proposed to follow a nucleation-polymerization model where misfolded, soluble oligomeric seeds can trigger native proteins to misfold and …

Mri Investigations Of Metabolic And Structural Brain Changes In Alzheimer’S Disease And Vitamin D Deprivation, Dickson Wong

Electronic Thesis and Dissertation Repository

Alzheimer's disease (AD) is a neurodegenerative disorder of the brain that presents as progressive impairment across several cognitive domains. The biological mechanisms underlying the development of AD remain unclear, with amyloid-beta plaques, neurofibrillary tangles, calcium dysregulation, and oxidative stress all contributing to neurodegeneration in AD. Vitamin D (VitD) deficiency, a common condition in the elderly, may modulate these mechanisms and complicate the AD process. Due to this complicated pathogenesis, the diagnosis of AD requires subjective clinical judgement, staging of AD is challenging, and it remains difficult to predict when and who will progress to AD. The purpose of this thesis …

Diabetes-Related Amylin Dyshomeostasis: A Contributing Factor To Cerebrovascular Pathology And Dementia, Han Ly, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

Type 2 diabetes (T2D) increases the risk for cerebrovascular disease (CVD) and dementia. The underlying molecular mechanisms remain elusive, which hampers the development of treatment or/and effective prevention strategies. Recent studies suggest that dyshomeostasis of amylin, a satiety hormone that forms pancreatic amyloid in patients with T2D, promotes accumulation of amylin in cerebral small blood vessels and interaction with Alzheimer's disease (AD) pathology. Overexpression of human amylin in rodents (rodent amylin does not form amyloid) leads to late-life onset T2D and neurologic deficits. In this Review, we discuss clinical evidence of amylin pathology in CVD and AD and identify critical …

Alzheimer's Disease Drug Development Pipeline: 2019, Jeffrey Cummings, Garam Lee, Aaron Ritter, Marwan Sabbagh, Kate Zhong

School of Medicine Faculty Publications

Introduction Alzheimer's disease (AD) has few available treatments, and there is a high rate of failure in AD drug development programs. Study of the AD drug development pipeline can provide insight into the evolution of drug development and how best to optimize development practices. Methods We reviewed clinicaltrials.gov and identified all pharmacologic AD trials of all agents currently being developed for treatment of AD. Results There are 132 agents in clinical trials for the treatment of AD. Twenty-eight agents are in 42 phase 3 trials; 74 agents are in 83 phase 2 trials; and 30 agents are in 31 phase …

Identifying Neuroimaging And Genetic Correlates Of Delusions And Hallucinations In Alzheimer’S Disease, Juweiriya Ahmed

Electronic Thesis and Dissertation Repository

The co-occurrence of psychotic symptoms and Alzheimer’s disease (AD) is a devastating phenotype that affects around 50% of individuals with AD. We hypothesized that distinct interactions between brain structures and genetic variants in dopaminergic, cholinergic and glutamatergic neurotransmitter systems may be associated with the presence of hallucinations and delusions in AD. Using the Alzheimer’s Disease Neuroimaging Initiative, we identified participants that presented with symptoms of delusions, hallucinations, or both symptoms. PLS-CA was used to identify differences in patterns of interactions between 15 single nucleotide polymorphisms and 82 neuroanatomical regions of interest between AD patients endorsing symptoms of delusions, hallucinations, and …

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …

Using Genetic Diversity To Understand Susceptibility To Cognitive Decline In Aging And Alzheimer’S Disease, Sarah M. Neuner

Theses and Dissertations (ETD)

An individual's genetic makeup plays an important role in determining susceptibility to cognitive aging and transition to dementia such as Alzheimer's disease (AD). Identifying the specific genetic variants that contribute to cognitive aging and AD may aid in early diagnosis of at-risk patients, as well as identify novel therapeutics targets to treat or prevent development of symptoms. Challenges to identifying these specific genes in human studies include complex genetics, difficulty in controlling environmental factors, and limited access to human brain tissue. Here, we turned to genetically diverse mice from the BXD genetic reference panel (GRP) to overcome some of the …

Periodontitis And The Elderly: An Overview Of The Disease And Its Impact On An Aging Population, Nicole Grace Weissenfluh

Senior Honors Theses

Periodontitis affects millions of Americans each year, and is especially prevalent among the elderly. Since periodontitis is a chronic, progressive condition, uninterrupted disease progression leads to irreversible oral damage; therefore, periodontitis often reduces the oral health-related quality of life. Furthermore, research strongly suggests a correlation between periodontitis and other systemic diseases (e.g., cardiovascular disease and diabetes mellitus), highlighting the importance of understanding, treating, and preventing periodontitis. This thesis explores the pathology and etiology of periodontitis, with special focus given to the prevalence and impact of the disease in the elderly population. Additionally, the connection between periodontitis and other systemic diseases …

Blood-Based Molecular Biomarkers For Alzheimer's Disease, Henrik Zetterberg, Samantha C. Burnham

Research outputs 2014 to 2021

A major barrier to the effective conduct of clinical trials of new drug candidates against Alzheimer's disease (AD) and to identifying patients for receiving future disease-modifying treatments is the limited capacity of the current health system to find and diagnose patients with early AD pathology. This may be related in part to the limited capacity of the current health systems to select those people likely to have AD pathology in order to confirm the diagnosis with available cerebrospinal fluid and imaging biomarkers at memory clinics. In the current narrative review, we summarize the literature on candidate blood tests for AD …

Nmd-12: A New Machine-Learning Derived Screening Instrument To Detect Mild Cognitive Impairment And Dementia, Pai-Yi Chiu, Haipeng Tang, Cheng-Yu Wei, Chaoyang Zhang, Guang-Uei Hung, Weihua Zhou

Faculty Publications

Introduction

Using machine learning techniques, we developed a brief questionnaire to aid neurologists and neuropsychologists in the screening of mild cognitive impairment (MCI) and dementia.

Methods

With the reduction of the survey size as a goal of this research, feature selection based on information gain was performed to rank the contribution of the 45 items corresponding to patient responses to the specified questions. The most important items were used to build the optimal screening model based on the accuracy, practicality, and interpretability. The diagnostic accuracy for discriminating normal cognition (NC), MCI, very mild dementia (VMD) and dementia was validated in …

Evaluating Trajectories Of Episodic Memory In Normal Cognition And Mild Cognitive Impairment: Results From Adni, Xiuhua Ding, Richard J. Charnigo, Frederick A. Schmitt, Richard J. Kryscio, Erin L. Abner, Alzheimer’S Disease Neuroimaging Initiative

Statistics Faculty Publications

BACKGROUND: Memory assessment is a key factor for the diagnosis of cognitive impairment. However, memory performance over time may be quite heterogeneous within diagnostic groups.

METHOD: To identify latent trajectories in memory performance and their associated risk factors, we analyzed data from Alzheimer's Disease Neuroimaging Initiative (ADNI) participants who were classified either as cognitively normal or as Mild Cognitive Impairment (MCI) at baseline and were administered the Rey Auditory Verbal Learning test (RAVLT) for up to 9 years. Group-based trajectory modeling on the 30-minute RAVLT delayed recall score was applied separately to the two baseline diagnostic groups.

RESULTS: There were …

Can Self-Efficacy Training Improve Memory And Functional Activation In Older Adults With Mild Cognitive Impairment? A Proof-Of-Concept Intervention Study, Brainscan, Western University, Lindsay Nagamatsu, Derek Mitchell, Paul Minda, Amer Burhan, Becky Horst

Project Summaries

The goal of this study is to examine the changes in brain activity after a memory self-efficacy training program to better understand the mechanisms of memory self-efficacy. We will conduct a proof-of-concept six-week memory self-efficacy intervention in older adults with MCI, in order to demonstrate that self-efficacy impacts brain function. This will allow us to determine whether self-efficacy interventions may be a potential strategy for combating AD in the future.

Attachment Security And Psychological Health In Adult Child Caregivers And Their Parents With Alzheimer’S Disease And Related Dementias, Wei Aiko Chang

Public Health Theses

Objective: Attachment theory is a helpful framework for examining one of the most fundamental needs in parent-child dyads across the lifespan and how attachment security might protect both dyad members’ psychological health, especially in times of crisis. In this study of adult child caregivers and their parents with early stage Alzheimer’s disease and related dementias (ADRD), we examined the associations between both dyad members’ attachment security, the adult child’s depressive symptoms, and quality of life of the parent with ADRD.

Method: Thirty-four individuals (parents) with ADRD and their 34 adult-child caregivers each completed the 12-item Experiences in Close Relationship Scale …

Neurogenesis In Neurodegenerative Diseases: Role Of Mfg-E8, C. Cheyuo, M. Aziz, P. Wang

Journal Articles

No abstract provided.

Plasma Neurofilament Light Chain And Amyloid-Β Are Associated With The Kynurenine Pathway Metabolites In Preclinical Alzheimer's Disease, Pratishtha Chatterjee, Henrik Zetterberg, Kathryn Goozee, Chai K. Lim, Kelly R. Jacobs, Nicholas J. Ashton, Abdul Hye, Steve Pedrini, Hamid R. Sohrabi, Tejal Shah, Prita R. Asih, Preeti Dave, Kaikai Shen, Kevin Taddei, David B. Lovejoy, Gilles J. Guillemin, Kaj Blennow, Ralph N. Martins

Research outputs 2014 to 2021

BACKGROUND: Blood markers indicative of neurodegeneration (neurofilament light chain; NFL), Alzheimer's disease amyloid pathology (amyloid-β; Aβ), and neuroinflammation (kynurenine pathway; KP metabolites) have been investigated independently in neurodegenerative diseases. However, the association of these markers of neurodegeneration and AD pathology with neuroinflammation has not been investigated previously. Therefore, the current study examined whether NFL and Aβ correlate with KP metabolites in elderly individuals to provide insight on the association between blood indicators of neurodegeneration and neuroinflammation.

METHODS: Correlations between KP metabolites, measured using liquid chromatography and gas chromatography coupled with mass spectrometry, and plasma NFL and Aβ concentrations, measured using …

Perspectives On Ethnic And Racial Disparities In Alzheimer's Disease And Related Dementias: Update And Areas Of Immediate Need, Ganesh M. Babulal, Yakeel T. Quiroz, Benedict C. Albensi, Eider Arenaza-Urquijo, Arlene J. Astell, Claudio Babiloni, Alex Bahar-Fuchs, Joanne Bell, Gene L. Bowman, Adam M. Brickman, Gael Chetelat, Carrie Ciro, Ann D. Cohen, Peggye Dilworth-Anderson, Hiroko H. Dodge, Simone Dreux, Steven Edland, Anna Esbensen, Lisbeth Evered, Michael Ewers, Keith N. Fargo, Juan Fortea, Hector Gonzalez, Deborah R. Gustafson, Elizabeth Head, James A. Hendrix, Scott M. Hofer, Leigh A. Johnson, Roos Jutten, Kerry Kilborn, Krista L. Lanctot, Jennifer J. Manly, Ralph N. Martins, Michelle M. Mielke, Martha Clare Morris, Melissa E. Murray, Esther S. Oh, Mario A. Parra, Robert A. Rissman, Catherine M. Roe, Octavio A. Santos, Nikolaos Scarmeas, Lon S. Schneider, Nicole Schupf, Sietske Sikkes, Heather M. Snyder, Hamid R. Sohrabi, Yaakov Stern, Andre Strydom, Yi Tang, Graciela Muniz Terrera Muniz Terrera, Yaakov Stern, Andre Strydom, Yi Tang, Graciela Muniz Terrera, Charlotte Teunissen, Debora Melo Van Lent, Michael Weinborn, Linda Wesselman, Donna M. Wilcock, Henrik Zetterberg, Sid E. O’Bryant, International Society To Advance Alzheimer’S Research And Treatment, Alzheimer’S Association

Research outputs 2014 to 2021

Alzheimer's disease and related dementias (ADRDs) are a global crisis facing the aging population and society as a whole. With the numbers of people with ADRDs predicted to rise dramatically across the world, the scientific community can no longer neglect the need for research focusing on ADRDs among underrepresented ethnoracial diverse groups. The Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART; alz.org/ISTAART) comprises a number of professional interest areas (PIAs), each focusing on a major scientific area associated with ADRDs. We leverage the expertise of the existing international cadre of ISTAART scientists and experts to synthesize a …

Decrease In P3-Alcb37 And P3-Alcb40, Products Of Alcadein B Generated By G-Secretase Cleavages, In Aged Monkeys And Patients With Alzheimer’S Disease, Saori Hata, Chiori Omori, Ayano Kimura, Haruka Saito, Nobuyuki Kimura, Veer Gupta, Steve Pedrini, Eugene Hone, Pratishtha Chatterjee, Kevin Taddei, Kensaku Kasuga, Takeshi Ikeuchi, Masaaki Waragai, Masaki Nishimura, Anqi Hu, Tadashi Nakaya, Laurent Meijer, Masahiro Maeda, Tohru Yamamoto, Colin L. Masters, Chris C. Rowe, David Ames, Kazuo Yamamoto, Ralph N. Martins, Sam Gandy, Toshiharu Suzuki

Research outputs 2014 to 2021

Introduction Neuronal p3-Alcβ peptides are generated from the precursor protein Alcadein β (Alcβ) through cleavage by α- and γ-secretases of the amyloid β (Aβ) protein precursor (APP). To reveal whether p3-Alcβ is involved in Alzheimer's disease (AD) contributes for the development of novel therapy and/or drug targets. Methods We developed new sandwich enzyme-linked immunosorbent assay (sELISA) systems to quantitate levels of p3-Alcβ in the cerebrospinal fluid (CSF). Results In monkeys, CSF p3-Alcβ decreases with age, and the aging is also accompanied by decreased brain expression of Alcβ. In humans, CSF p3-Alcβ levels decrease to a greater extent in those with …

Investigating Neurogenesis As A Veritable Epigenetic Endophenotype For Alzheimer's Disease, Layne Wells

Scripps Senior Theses

Alzheimer's disease (AD) is the most common neurodegenerative disease, characterized by progressive amyloid plaque aggregation, neurofibrillary tangles, and cortical tissue death. As the prevalence of AD is projected to climb in coming years, there is a vested interest in identifying endophenotypes by which to improve diagnostics and direct clinical interventions. The risk for complex disorders, such as AD, is influenced by multiple genetic, environmental, and lifestyle factors. Significant strides have been made in identifying genetic variants linked to AD through the genome-wide association study (GWAS). It has been estimated in more recent years, however, that GWAS-identified variants account for limited …

Effects Of The Dual Orexin Receptor Antagonist Dora-22 On Sleep In 5xfad Mice, Marilyn J. Duncan, Hannah Farlow, Chairtra Tirumalaraju, Do-Hyun Yun, Chanung Wang, James A. Howard, Madison N. Sanden, Bruce F. O'Hara, Kristen J. Mcquerry, Adam D. Bachstetter

Neuroscience Faculty Publications

Introduction: Sleep disruption is a characteristic of Alzheimer's disease (AD) that may exacerbate disease progression. This study tested whether a dual orexin receptor antagonist (DORA) would enhance sleep and attenuate neuropathology, neuroinflammation, and cognitive deficits in an AD-relevant mouse model, 5XFAD.

Methods: Wild-type (C57Bl6/SJL) and 5XFAD mice received chronic treatment with vehicle or DORA-22. Piezoelectric recordings monitored sleep and spatial memory was assessed via spontaneous Y-maze alternations. Aβ plaques, Aβ levels, and neuroinflammatory markers were measured by immunohistochemistry, enzyme-linked immunosorbent assay, and real-time polymerase chain reaction, respectively.

Results: In 5XFAD mice, DORA-22 significantly increased light-phase sleep without reducing Aβ levels, …

Pathological Tau As A Cause, And Consequence, Of Cellular Dysfunction, Shelby Meier

Theses and Dissertations--Physiology

Tauopathies are a group of neurodegenerative diseases characterized by the abnormal deposition of the protein tau, a microtubule stabilizing protein. Under normal physiological conditions tau is a highly soluble protein that is not prone to aggregation. In disease states alterations to tau lead to enhanced fibril formation and aggregation, eventually forming neurofibrillary tangles (NFTs). The exact cause for NFT deposition is unknown, but increased post-translational modifications and mutations to the tau gene can increase tangle formation.

Tauopathic brains are stuck in a detrimental cycle, with cellular dysfunction contributing to the development of tau pathology and the development of tau pathology …

Toxic Environmental Risk Factors For Alzheimer's Disease: A Systematic Review, Oluwaseyi Olayinka, Olaniyi O. Olayinka, Brook T. Alemu, Muge Akpinar-Elci, George T. Grossberg

Community & Environmental Health Faculty Publications

There is growing evidence of a possible association between toxic environmental factors and Alzheimer’s disease (AD), a disabling neurodegenerative condition with no known cause. Previous reviews of toxic environmental factors for AD either focused on occupational exposures or used a non-systematic methodology. The objective of this systematic review is to assess the evidence on the link between AD and exposure to a variety of toxic environmental risk factors beyond the work environment. Structured database search was used to identify relevant studies. Twenty-nine eligible studies examining the effect of various toxic environmental agents including electromagnetic fields, solvents, pesticides, toxic metals, and …