Medicine and Health Sciences Commons^™

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 …

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 …

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 …

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, …

Water Exchange Rate Across The Blood-Brain Barrier Is Associated With Csf Amyloid-Β 42 In Healthy Older Adults, Brian T. Gold, Xingfeng Shao, Tiffany L. Sudduth, Gregory A. Jicha, Donna M. Wilcock, Elayna R. Seago, Danny J. J. Wang

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: We tested if water exchange across the blood-brain barrier (BBB), estimated with a noninvasive magnetic resonance imaging (MRI) technique, is associated with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and neuropsychological function.

METHODS: Forty cognitively normal older adults (67–86 years old) were scanned with diffusion‐prepared, arterial spin labeling (DP‐ASL), which estimates water exchange rate across the BBB (k_w). Participants also underwent CSF draw and neuropsychological testing. Multiple linear regression models were run with kw as a predictor of CSF concentrations and neuropsychological scores.

RESULTS: In multiple brain regions, BBB kw was positively associated with CSF amyloid …

Infectious Hypothesis Of Alzheimer Disease, Charles E. Seaks, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

No abstract provided.

Ceramide Analog [18F]F-Hpa-12 Detects Sphingolipid Disbalance In The Brain Of Alzheimer’S Disease Transgenic Mice By Functioning As A Metabolic Probe, Simone M. Crivelli, Daan Van Kruining, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Andreas Paulus, Matthias Bauwens, Dusan Berkes, Helga E. De Vries, Monique T. Mulder, Jochen Walter, Etienne Waelkens, Rita Derua, Johannes V. Swinnen, Jonas Dehairs, Felix M. Mottaghy, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez

Physiology Faculty Publications

The metabolism of ceramides is deregulated in the brain of Alzheimer’s disease (AD) patients and is associated with apolipoprotein (APO) APOE4 and amyloid-β pathology. However, how the ceramide metabolism changes over time in AD, in vivo, remains unknown. Distribution and metabolism of [¹⁸F]F-HPA-12, a radio-fluorinated version of the ceramide analog N-(3-hydroxy-1-hydroxymethyl-3-phenylpropyl) dodecanamide, was investigated in the brain of AD transgenic mouse models (FAD) on an APOE4 or APOE3 genetic background, by positron emission tomography and by gamma counter. We found that FAD mice displayed a higher uptake of [¹⁸F]F-HPA-12 in the brain, independently from the APOE4 …

Distribution Of Microglial Phenotypes As A Function Of Age And Alzheimer's Disease Neuropathology In The Brains Of People With Down Syndrome, Alessandra C. Martini, Alex M. Helman, Katie L. Mccarty, Ira T. Lott, Eric Doran, Frederick A. Schmitt, Elizabeth Head

Sanders-Brown Center on Aging Faculty Publications

Introduction: Microglial cells play an important role in the development of Alzheimer's disease (AD). People with Down syndrome (DS) inevitably develop AD neuropathology (DSAD) by 40 years of age. We characterized the distribution of different microglial phenotypes in the brains of people with DS and DSAD.

Methods: Autopsy tissue from the posterior cingulate cortex (PCC) from people with DS, DSAD, and neurotypical controls was immunostained with the microglial marker Iba1 to assess five microglia morphological types.

Results: Individuals with DS have more hypertrophic microglial cells in their white matter. In the gray matter, individuals with DSAD had significantly fewer ramified …

Will "Social Distancing" Lead To Future "Research Distancing": A Reflection On Covid-19 Impacts On Alzheimer's Disease Research, Shoshana H. Bardach, Allison K. Gibson, Elizabeth K. Rhodus, Gregory A. Jicha

Sanders-Brown Center on Aging Faculty Publications

Coronavirus disease 19 (COVID-19) has dramatically altered everyday life, including the field of Alzheimer's disease (AD) research. This perspective article explores some of the ways in which COVID-19 has already impacted the field, anticipates some of the long-lasting effects, and explores strategies for addressing current and future needs. Areas of impact include study integrity, regulatory and industry issues, and participant engagement. Proposed strategies for addressing these challenges include analytic methods to deal with large degrees of missing data and development of patient-centered, user-friendly, remote data collection tools and assessments. We also highlight the importance of maintaining participant well-being as a …

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 …

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 …

Mitochondrial Metabolism In Major Neurological Diseases, Zhengqiu Zhou, Grant L. Austin, Lyndsay E. A. Young, Lance A. Johnson, Ramon Sun

Molecular and Cellular Biochemistry Faculty Publications

Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell’s ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation–functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly …

Age Drives Distortion Of Brain Metabolic, Vascular And Cognitive Functions, And The Gut Microbiome, Jared D. Hoffman, Ishita Parikh, Stefan J. Green, George Chlipala, Robert P. Mohney, Mignon Keaton, Bjoern Bauer, Anika M. S. Hartz, Ai-Ling Lin

Sanders-Brown Center on Aging Faculty Publications

Advancing age is the top risk factor for the development of neurodegenerative disorders, including Alzheimer’s disease (AD). However, the contribution of aging processes to AD etiology remains unclear. Emerging evidence shows that reduced brain metabolic and vascular functions occur decades before the onset of cognitive impairments, and these reductions are highly associated with low-grade, chronic inflammation developed in the brain over time. Interestingly, recent findings suggest that the gut microbiota may also play a critical role in modulating immune responses in the brain via the brain-gut axis. In this study, our goal was to identify associations between deleterious changes in …

Methods For Diagnosing And Treating Alzheimer's Disease (Ad) Using The Molecules That Stabilize Intracellular Calcium (Ca2+) Release, Philip W. Landfield, John C. Gant, Eric M. Blalock, Kuey-Chu Chen, Olivier Thibault, Nada M. Porter

Pharmacology and Nutritional Sciences Faculty Patents

The subject technology relates, in part, to a method of treating Alzheimer's Disease (AD), early-stage AD, elevated risk of AD, mild cognitive impairment (MCI), or other forms of age-related cognitive decline in a subject in need thereof by administering to the subject a molecule that promotes calcium-release stabilization in ryanodine receptors (RyRs) and/or inosital triphosphate receptors (InsP3Rs) in brain cells. Diagnostic methods using calcium-release stabilizing immunophilins, junctophilins or calmodulin are also disclosed.

Diabetes Is Associated With Cerebrovascular But Not Alzheimer's Disease Neuropathology, Erin L. Abner, Peter T. Nelson, Richard J. Kryscio, Frederick A. Schmitt, David W. Fardo, Randall L. Woltjer, Nigel J. Cairns, Lei Yu, Hiroko H. Dodge, Chengjie Xiong, Kamal Masaki, Suzanne L. Tyas, David A. Bennett, Julie A. Schneider, Zoe Arvanitakis

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: The relationship of diabetes to specific neuropathologic causes of dementia is incompletely understood.

METHODS: We used logistic regression to evaluate the association between diabetes and infarcts, Braak neurofibrillary tangle stage, and neuritic plaque score in 2365 autopsied persons. In a subset of >1300 persons with available cognitive data, we examined the association between diabetes and cognition using Poisson regression.

RESULTS: Diabetes increased odds of brain infarcts (odds ratio [OR] = 1.57, P < .0001), specifically lacunes (OR = 1.71, P < .0001), but not Alzheimer's disease neuropathology. Diabetes plus infarcts was associated with lower cognitive scores at end of life than infarcts or diabetes alone, and diabetes plus high level of Alzheimer's neuropathologic changes was associated with lower mini-mental state examination scores than the pathology alone.

DISCUSSION: This study supports the conclusions that diabetes increases the risk of cerebrovascular but not Alzheimer's disease pathology, and at least some of diabetes' relationship to …

Reversal Of Aging-Related Neuronal Ca2+ Dysregulation And Cognitive Impairment By Delivery Of A Transgene Encoding Fk506-Binding Protein 12.6/1b To The Hippocampus, John C. Gant, Kuey-Chu Chen, Inga Kadish, Eric M. Blalock, Olivier Thibault, Nada M. Porter, Philip W. Landfield

Pharmacology and Nutritional Sciences Faculty Publications

Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca(2+)-dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca(2+) channel activity and ryanodine receptor (RyR)-mediated Ca(2+) release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca(2+) release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer's disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca(2+) responses. …

Intracranial Injection Of Gammagard, A Human Ivig, Modulates The Inflammatory Response Of The Brain And Lowers AΒ In App/Ps1 Mice Along A Different Time Course Than Anti-AΒ Antibodies, Tiffany L. Sudduth, Abigail Greenstein, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Gammagard IVIg is a therapeutic approach to treat Alzheimer's disease currently in phase 3 clinical trials. Despite the reported efficacy of the approach the mechanism of action is poorly understood. We have previously shown that intracranial injection of anti-Aβ antibodies into the frontal cortex and hippocampus reveals important information regarding the time course of events once the agent is in the brain. In the current study we compared IVIg, mouse-pooled IgG, and the anti-Aβ antibody 6E10 injected intracranially into the frontal cortex and hippocampus of 7-month-old APP/PS1 mice. We established a time course of events ranging from 1 …

A Study Of Small Rnas From Cerebral Neocortex Of Pathology-Verified Alzheimer's Disease, Dementia With Lewy Bodies, Hippocampal Sclerosis, Frontotemporal Lobar Dementia, And Non-Demented Human Controls, Sébastien S. Hébert, Wang-Xia Wang, Qi Zhu, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are small (20-22 nucleotides) regulatory non-coding RNAs that strongly influence gene expression. Most prior studies addressing the role of miRNAs in neurodegenerative diseases (NDs) have focused on individual diseases such as Alzheimer's disease (AD), making disease-to-disease comparisons impossible. Using RNA deep sequencing, we sought to analyze in detail the small RNAs (including miRNAs) in the temporal neocortex gray matter from non-demented controls (n = 2), AD (n = 5), dementia with Lewy bodies (n = 4), hippocampal sclerosis of aging (n = 4), and frontotemporal lobar dementia (FTLD) (n = 5) cases, together accounting for the most prevalent …

White Matter Diffusion Alterations In Normal Women At Risk Of Alzheimer's Disease, Charles D. Smith, Himachandra Chebrolu, Anders H. Andersen, David A. Powell, Mark A. Lovell, Shuling Xiong, Brian T. Gold

Neurology Faculty Publications

Increased white matter mean diffusivity and decreased fractional anisotropy (FA) has been observed in subjects diagnosed with mild cognitive impairment (MCI) and Alzheimer's disease (AD). We sought to determine whether similar alterations of white matter occur in normal individuals at risk of AD. Diffusion tensor images were acquired in 42 cognitively normal right-handed women with both a family history of dementia and at least one apolipoprotein E4 allele. These were compared with images from 23 normal women without either AD risk factor. Group analyses were performed using tract-based spatial statistics. Reduced FA was observed in the fronto-occipital and inferior temporal …

Focus On Rna Isolation: Obtaining Rna For Microrna (Mirna) Expression Profiling Analyses Of Neural Tissue, Wang-Xia Wang, Bernard R. Wilfred, Donald A. Baldwin, R. Benjamin Isett, Na Ren, Arnold J. Stromberg, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are present in all known plant and animal tissues and appear to be somewhat concentrated in the mammalian nervous system. Many different miRNA expression profiling platforms have been described. However, relatively little research has been published to establish the importance of 'upstream' variables in RNA isolation for neural miRNA expression profiling. We tested whether apparent changes in miRNA expression profiles may be associated with tissue processing, RNA isolation techniques, or different cell types in the sample. RNA isolation was performed on a single brain sample using eight different RNA isolation methods, and results were correlated using a conventional …

Nitration And Inactivation Of Manganese Superoxide Dismutase Plays A Critical Role In Metabolic Switch, Muthuswamy Anantharaman

University of Kentucky Doctoral Dissertations

Alzheimer’s disease (AD) is a multifactorial, progressive, age-related neurodegenerative disease. Oxidative stress hypothesis is most prevalent and is gaining significant support. Inspite of the progress achieved on oxidative stress related damages in AD brain; the modification occurring on the various cellular antioxidant enzymes antioxidant has not been identified. Tyrosine nitration, a marker for peroxynitrite induced oxidative damage to protein is widespread in AD brain and Manganese superoxide dismutase (MnSOD), primary mitochondrial antioxidant enzyme is prone to peroxynitrite induced nitration and inactivation. Nitration of proteins involved in energy metabolism has been demonstrated in AD brain, which may explain the altered glucose …