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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 Dec 2022

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 …


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 Feb 2022

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 …


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 Oct 2021

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 Sep 2021

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 Sep 2021

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 …


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 Apr 2021

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 (Aβ1-40, Aβ1-42), and glial fibrillary acidic protein (GFAP) were undertaken with …


Protecting P-Glycoprotein At The Blood-Brain Barrier From Degradation In An Alzheimer's Disease Mouse Model, Yujie Ding, Yu Zhong, Andrea Baldeshwiler, Erin L. Abner, Björn Bauer, Anika M. S. Hartz Mar 2021

Protecting P-Glycoprotein At The Blood-Brain Barrier From Degradation In An Alzheimer's Disease Mouse Model, Yujie Ding, Yu Zhong, Andrea Baldeshwiler, Erin L. Abner, Björn Bauer, Anika M. S. Hartz

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Failure to clear Aβ from the brain is partly responsible for Aβ brain accumulation in Alzheimer's disease (AD). A critical protein for clearing Aβ across the blood-brain barrier is the efflux transporter P-glycoprotein (P-gp). In AD, P-gp levels are reduced, which contributes to impaired Aβ brain clearance. However, the mechanism responsible for decreased P-gp levels is poorly understood and there are no strategies available to protect P-gp. We previously demonstrated in isolated brain capillaries ex vivo that human Aβ40 (hAβ40) triggers P-gp degradation by activating the ubiquitin-proteasome pathway. In this pathway, hAβ40 initiates P-gp ubiquitination, leading to internalization and …


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 Jan 2021

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 Jan 2021

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 …


New Evidence For P-Gp-Mediated Export Of Amyloid-Β Peptides In Molecular, Blood-Brain Barrier And Neuronal Models, Amanda B. Chai, Anika M. S. Hartz, Xuexin Gao, Alryel Yang, Richard Callaghan, Ingrid C. Gelissen Jan 2021

New Evidence For P-Gp-Mediated Export Of Amyloid-Β Peptides In Molecular, Blood-Brain Barrier And Neuronal Models, Amanda B. Chai, Anika M. S. Hartz, Xuexin Gao, Alryel Yang, Richard Callaghan, Ingrid C. Gelissen

Sanders-Brown Center on Aging Faculty Publications

Defective clearance mechanisms lead to the accumulation of amyloid-beta (Aβ) peptides in the Alzheimer’s brain. Though predominantly generated in neurons, little is known about how these hydrophobic, aggregation-prone, and tightly membrane-associated peptides exit into the extracellular space where they deposit and propagate neurotoxicity. The ability for P-glycoprotein (P-gp), an ATP-binding cassette (ABC) transporter, to export Aβ across the blood-brain barrier (BBB) has previously been reported. However, controversies surrounding the P-gp–Aβ interaction persist. Here, molecular data affirm that both Aβ40 and Aβ42 peptide isoforms directly interact with and are substrates of P-gp. This was reinforced ex vivo by the …


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 Dec 2020

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 Sep 2020

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 Aug 2020

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 …


Β-Amyloid And Tau Drive Early Alzheimer's Disease Decline While Glucose Hypometabolism Drives Late Decline, Tyler C. Hammond, Xin Xing, Chris Wang, David Ma, Kwangsik Nho, Paul K. Crane, Fanny Elahi, David A. Ziegler, Gongbo Liang, Qiang Cheng, Lucille M. Yanckello, Nathan Jacobs, Ai-Ling Lin Jul 2020

Β-Amyloid And Tau Drive Early Alzheimer's Disease Decline While Glucose Hypometabolism Drives Late Decline, Tyler C. Hammond, Xin Xing, Chris Wang, David Ma, Kwangsik Nho, Paul K. Crane, Fanny Elahi, David A. Ziegler, Gongbo Liang, Qiang Cheng, Lucille M. Yanckello, Nathan Jacobs, Ai-Ling Lin

Sanders-Brown Center on Aging Faculty Publications

Clinical trials focusing on therapeutic candidates that modify β-amyloid (Aβ) have repeatedly failed to treat Alzheimer’s disease (AD), suggesting that Aβ may not be the optimal target for treating AD. The evaluation of Aβ, tau, and neurodegenerative (A/T/N) biomarkers has been proposed for classifying AD. However, it remains unclear whether disturbances in each arm of the A/T/N framework contribute equally throughout the progression of AD. Here, using the random forest machine learning method to analyze participants in the Alzheimer’s Disease Neuroimaging Initiative dataset, we show that A/T/N biomarkers show varying importance in predicting AD development, with elevated biomarkers of Aβ …


Ccl2 Overexpression In The Brain Promotes Glial Activation And Accelerates Tau Pathology In A Mouse Model Of Tauopathy, Aurelie Joly-Amado, Jordan Hunter, Zainuddin Quadri, Frank Zamudio, Patricia V. Rocha-Rangel, Deanna Chan, Anisha Kesarwani, Kevin Nash, Daniel C. Lee, Dave Morgan, Marcia N. Gordon, Maj-Linda B. Selenica May 2020

Ccl2 Overexpression In The Brain Promotes Glial Activation And Accelerates Tau Pathology In A Mouse Model Of Tauopathy, Aurelie Joly-Amado, Jordan Hunter, Zainuddin Quadri, Frank Zamudio, Patricia V. Rocha-Rangel, Deanna Chan, Anisha Kesarwani, Kevin Nash, Daniel C. Lee, Dave Morgan, Marcia N. Gordon, Maj-Linda B. Selenica

Sanders-Brown Center on Aging Faculty Publications

Innate immune activation is a major contributor to Alzheimer’s Disease (AD) pathophysiology, although the mechanisms involved are poorly understood. Chemokine C-C motif ligand (CCL) 2 is produced by neurons and glial cells and is upregulated in the AD brain. Transgene expression of CCL2 in mouse models of amyloidosis produces microglia-induced amyloid β oligomerization, a strong indication of the role of these activation pathways in the amyloidogenic processes of AD. We have previously shown that CCL2 polarizes microglia in wild type mice. However, how CCL2 signaling contributes to tau pathogenesis remains unknown. To address this question, CCL2 was delivered via recombinant …


Rivastigmine Modifies The Α-Secretase Pathway And Potentially Early Alzheimer's Disease, Balmiki Ray, Bryan Maloney, Kumar Sambamurti, Hanuma K. Karnati, Peter T. Nelson, Nigel H. Greig, Debomoy K. Lahiri Feb 2020

Rivastigmine Modifies The Α-Secretase Pathway And Potentially Early Alzheimer's Disease, Balmiki Ray, Bryan Maloney, Kumar Sambamurti, Hanuma K. Karnati, Peter T. Nelson, Nigel H. Greig, Debomoy K. Lahiri

Sanders-Brown Center on Aging Faculty Publications

Rivastigmine (or Exelon) is a cholinesterase inhibitor, currently used as a symptomatic treatment for mild-to-moderate Alzheimer’s disease (AD). Amyloid-β peptide (Aβ) generated from its precursor protein (APP) by β-secretase (or BACE1) and γ-secretase endoproteolysis. Alternative APP cleavage by α-secretase (a family of membrane-bound metalloproteases– Adamalysins) precludes the generation of toxic Aβ and yields a neuroprotective and neurotrophic secreted sAPPα fragment. Several signal transduction pathways, including protein kinase C and MAP kinase, stimulate α-secretase. We present data to suggest that rivastigmine, in addition to anticholinesterase activity, directs APP processing away from BACE1 and towards α-secretases. We treated rat neuronal PC12 cells …


Astrocyte Activation And The Calcineurin/Nfat Pathway In Cerebrovascular Disease, Susan D. Kraner, Christopher M. Norris Sep 2018

Astrocyte Activation And The Calcineurin/Nfat Pathway In Cerebrovascular Disease, Susan D. Kraner, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

Calcineurin (CN) is a Ca2+/calmodulin-dependent protein phosphatase with high abundance in nervous tissue. Though enriched in neurons, CN can become strongly induced in subsets of activated astrocytes under different pathological conditions where it interacts extensively with the nuclear factor of activated T cells (NFATs). Recent work has shown that regions of small vessel damage are associated with the upregulation of a proteolized, highly active form of CN in nearby astrocytes, suggesting a link between the CN/NFAT pathway and chronic cerebrovascular disease. In this Mini Review article, we discuss CN/NFAT signaling properties in the context of vascular disease and …


Ca2+, Astrocyte Activation And Calcineurin/Nfat Signaling In Age-Related Neurodegenerative Diseases, Pradoldej Sompol, Christopher M. Norris Jul 2018

Ca2+, Astrocyte Activation And Calcineurin/Nfat Signaling In Age-Related Neurodegenerative Diseases, Pradoldej Sompol, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

Mounting evidence supports a fundamental role for Ca2+ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca2+/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca2+ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and …


Preventing P-Gp Ubiquitination Lowers Aβ Brain Levels In An Alzheimer's Disease Mouse Model, Anika M. S. Hartz, Yu Zhong, Andrew N. Shen, Erin L. Abner, Björn Bauer Jun 2018

Preventing P-Gp Ubiquitination Lowers Aβ Brain Levels In An Alzheimer's Disease Mouse Model, Anika M. S. Hartz, Yu Zhong, Andrew N. Shen, Erin L. Abner, Björn Bauer

Sanders-Brown Center on Aging Faculty Publications

One characteristic of Alzheimer’s disease (AD) is excessive accumulation of amyloid-β (Aβ) in the brain. Aβ brain accumulation is, in part, due to a reduction in Aβ clearance from the brain across the blood-brain barrier. One key element that contributes to Ab brain clearance is P-glycoprotein (P-gp) that transports Aβ from brain to blood. In AD, P-gp protein expression and transport activity levels are significantly reduced, which impairs Aβ brain clearance. The mechanism responsible for reduced P-gp expression and activity levels is poorly understood. We recently demonstrated that Aβ40 triggers P-gp degradation through the ubiquitin-proteasome pathway. Consistent with these …


Retention Of Normal Glia Function By An Isoform-Selective Protein Kinase Inhibitor Drug Candidate That Modulates Cytokine Production And Cognitive Outcomes, Zhengqiu Zhou, Adam D. Bachstetter, Claudia B. Späni, Saktimayee M. Roy, D. Martin Watterson, Linda J. Van Eldik Apr 2017

Retention Of Normal Glia Function By An Isoform-Selective Protein Kinase Inhibitor Drug Candidate That Modulates Cytokine Production And Cognitive Outcomes, Zhengqiu Zhou, Adam D. Bachstetter, Claudia B. Späni, Saktimayee M. Roy, D. Martin Watterson, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

Background: Brain p38α mitogen-activated protein kinase (MAPK), a potential therapeutic target for cognitive dysfunction based on the neuroinflammation-synaptic dysfunction cycle of pathophysiology progression, offers an innovative pharmacological strategy via inhibiting the same activated target in both glia and neurons, thereby enhancing the possibility for efficacy. The highly selective, brain-penetrant p38αMAPK inhibitor MW150 attenuates cognitive dysfunction in two distinct Alzheimer's disease (AD)-relevant models and avoids the problems encountered with previous mixed-kinase inhibitor drug candidates. Therefore, it is essential that the glial effects of this CNS-active kinase inhibitor be addressed in order to anticipate future use in clinical investigations.

Methods: …


Mtor: Alzheimer's Disease Prevention For Apoe4 Carriers, Ai-Ling Lin, D. Allan Butterfield, Arlan Richardson Jun 2016

Mtor: Alzheimer's Disease Prevention For Apoe4 Carriers, Ai-Ling Lin, D. Allan Butterfield, Arlan Richardson

Sanders-Brown Center on Aging Faculty Publications

No abstract provided.


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 Dec 2015

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 …


Transition From An M1 To A Mixed Neuroinflammatory Phenotype Increases Amyloid Deposition In App/Ps1 Transgenic Mice, Erica M. Weekman, Tiffany L. Sudduth, Erin L. Abner, Gabriel J. Popa, Michael D. Mendenhall, Holly M. Brothers, Kaitlyn Braun, Abigail Greenstein, Donna M. Wilcock Jul 2014

Transition From An M1 To A Mixed Neuroinflammatory Phenotype Increases Amyloid Deposition In App/Ps1 Transgenic Mice, Erica M. Weekman, Tiffany L. Sudduth, Erin L. Abner, Gabriel J. Popa, Michael D. Mendenhall, Holly M. Brothers, Kaitlyn Braun, Abigail Greenstein, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: The polarization to different neuroinflammatory phenotypes has been described in early Alzheimer's disease, yet the impact of these phenotypes on amyloid-beta (Aβ) pathology remains unknown. Short-term studies show that induction of an M1 neuroinflammatory phenotype reduces Aβ, but long-term studies have not been performed that track the neuroinflammatory phenotype.

METHODS: Wild-type and APP/PS1 transgenic mice aged 3 to 4 months received a bilateral intracranial injection of adeno-associated viral (AAV) vectors expressing IFNγ or green fluorescent protein in the frontal cortex and hippocampus. Mice were sacrificed 4 or 6 months post-injection. ELISA measurements were used for IFNγ protein levels and …


Soluble Apoe/Aβ Complex: Mechanism And Therapeutic Target For Apoe4-Induced Ad Risk, Leon M. Tai, Shipra Mehra, Varsha Shete, Steven Estus, G. William Rebeck, Guojun Bu, Mary Jo Ladu Jan 2014

Soluble Apoe/Aβ Complex: Mechanism And Therapeutic Target For Apoe4-Induced Ad Risk, Leon M. Tai, Shipra Mehra, Varsha Shete, Steven Estus, G. William Rebeck, Guojun Bu, Mary Jo Ladu

Sanders-Brown Center on Aging Faculty Publications

The APOE4 allele of apolipoprotein E (apoE) is the greatest genetic risk factor for Alzheimer's disease (AD) compared to APOE2 and APOE3. Amyloid-β (Aβ), particularly in a soluble oligomeric form (oAβ), is considered a proximal cause of neurodegeneration in AD. Emerging data indicate that levels of soluble oAβ are increased with APOE4, providing a potential mechanism of APOE4-induced AD risk. However, the pathway(s) by which apoE4 may increase oAβ levels are unclear and the subject of continued inquiry. In this editorial review, we present the hypothesis that apoE isoform-specific interactions with Aβ, namely apoE/Aβ complex, modulate Aβ levels. Specifically, we …


Circulating Micrornas In Alzheimer's Disease: The Search For Novel Biomarkers, Véronique Dorval, Peter T. Nelson, Sébastien S. Hébert Aug 2013

Circulating Micrornas In Alzheimer's Disease: The Search For Novel Biomarkers, Véronique Dorval, Peter T. Nelson, Sébastien S. Hébert

Sanders-Brown Center on Aging Faculty Publications

Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly. While advancements have been made in understanding the genetic and molecular basis of AD, the clinical diagnosis of AD remains difficult, and post-mortem confirmation is often required. Furthermore, the onset of neurodegeneration precedes clinical symptoms by approximately a decade. Consequently, there is a crucial need for an early and accurate diagnosis of AD, which can potentially lead to strategies that can slow down or stop the progression of neurodegeneration and dementia. Recent advances in the non-coding RNA field have shown that microRNAs (miRNAs) can function as powerful biomarkers …


Comparing Clinical Profiles In Alzheimer's Disease And Parkinson's Disease Dementia, Martin R. Farlow, Frederick A. Schmitt, Dag Aarsland, George T. Grossberg, Monique Somogyi, Xiangyi Meng Jan 2013

Comparing Clinical Profiles In Alzheimer's Disease And Parkinson's Disease Dementia, Martin R. Farlow, Frederick A. Schmitt, Dag Aarsland, George T. Grossberg, Monique Somogyi, Xiangyi Meng

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Greater understanding of differences in baseline impairment and disease progression in patients with Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) may improve the interpretation of drug effects and the design of future studies.

METHODS: This was a retrospective analysis of three randomized, double-blind rivastigmine databases (one in PDD, two in AD). Impairment on the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, 10-item Neuropsychiatric Inventory (NPI-10) and the ADCS-Clinical Global Impression of Change (CGIC) was compared [standardized difference (Cohen's d), similar if <0.1].

RESULTS: Patients with AD or PDD had similar levels …