Medicine and Health Sciences Commons^™

Clinically Relevant Intronic Splicing Enhancer Mutation In Myelin Proteolipid Protein Leads To Progressive Microglia And Astrocyte Activation In White And Gray Matter Regions Of The Brain, Adam D. Bachstetter, Scott J. Webster, Linda J. Van Eldik, Franca Cambi

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: Mutations in proteolipid protein (PLP), the most abundant myelin protein in the CNS, cause the X-linked dysmyelinating leukodystrophies, Pelizaeus-Merzbacher disease (PMD) and spastic paraplegia type 2 (SPG2). Point mutations, deletion, and duplication of the PLP1 gene cause PMD/SPG2 with varying clinical presentation. Deletion of an intronic splicing enhancer (ISEdel) within intron 3 of the PLP1 gene is associated with a mild form of PMD. Clinical and preclinical studies have indicated that mutations in myelin proteins, including PLP, can induce neuroinflammation, but the temporal and spatial onset of the reactive glia response in a clinically relevant mild form of PMD …

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 …

Dose- And Time-Dependent Neuroprotective Effects Of Pycnogenol® Following Traumatic Brain Injury, Mubeen A. Ansari, Kelly N. Roberts, Stephen W. Scheff

Sanders-Brown Center on Aging Faculty Publications

After traumatic brain injury (TBI), both primary and secondary injury cascades are initiated, leading to neuronal death and cognitive dysfunction. We have previously shown that the combinational bioflavonoid, Pycnogenol® (PYC), alters some secondary injury cascades and protects synaptic proteins when administered immediately following trauma. The purpose of the present study was to explore further the beneficial effects of PYC and to test whether it can be used in a more clinically relevant fashion. Young adult male Sprague-Dawley rats were subjected to a unilateral moderate/severe cortical contusion. Subjects received a single intravenous (i.v.) injection of PYC (1, 5, or 10 mg/kg) …

Hippocampal Sclerosis Of Aging, A Prevalent And High-Morbidity Brain Disease, Peter T. Nelson, Charles D. Smith, Erin L. Abner, Bernard J. Wilfred, Wang-Xia Wang, Janna H. Neltner, Michael Baker, David W. Fardo, Richard J. Kryscio, Stephen W. Scheff, Gregory A. Jicha, Kurt A. Jellinger, Linda J. Van Eldik, Frederick A. Schmitt

Sanders-Brown Center on Aging Faculty Publications

Hippocampal sclerosis of aging (HS-Aging) is a causative factor in a large proportion of elderly dementia cases. The current definition of HS-Aging rests on pathologic criteria: neuronal loss and gliosis in the hippocampal formation that is out of proportion to AD-type pathology. HS-Aging is also strongly associated with TDP-43 pathology. HS-Aging pathology appears to be most prevalent in the oldest-old: autopsy series indicate that 5-30 % of nonagenarians have HS-Aging pathology. Among prior studies, differences in study design have contributed to the study-to-study variability in reported disease prevalence. The presence of HS-Aging pathology correlates with significant cognitive impairment which is …

Development Of Novel In Vivo Chemical Probes To Address Cns Protein Kinase Involvement In Synaptic Dysfunction, D Martin Watterson, Valerie L. Grum-Tokars, Saktimayee M. Roy, James P. Schavocky, Brinda Desai Bradaric, Adam D. Bachstetter, Bin Xing, Edgardo Dimayuga, Faisal Saeed, Hong Zhang, Agnieszka Staniszewski, Jeffrey C. Pelletier, George Minasov, Wayne F. Anderson, Ottavio Arancio, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

Serine-threonine protein kinases are critical to CNS function, yet there is a dearth of highly selective, CNS-active kinase inhibitors for in vivo investigations. Further, prevailing assumptions raise concerns about whether single kinase inhibitors can show in vivo efficacy for CNS pathologies, and debates over viable approaches to the development of safe and efficacious kinase inhibitors are unsettled. It is critical, therefore, that these scientific challenges be addressed in order to test hypotheses about protein kinases in neuropathology progression and the potential for in vivo modulation of their catalytic activity. Identification of molecular targets whose in vivo modulation can attenuate synaptic …

Relationship Between Serum And Brain Carotenoids, Α-Tocopherol, And Retinol Concentrations And Cognitive Performance In The Oldest Old From The Georgia Centenarian Study, Elizabeth J. Johnson, Rohini Vishwanathan, Mary Ann Johnson, Dorothy B. Hausman, Adam Davey, Tammy M. Scott, Robert C. Green, L. Stephen Miller, Marla Gearing, John Woodard, Peter T. Nelson, Hae-Yun Chung, Wolfgang Schalch, Jonas Wittwer, Leonard W. Poon

Sanders-Brown Center on Aging Faculty Publications

Oxidative stress is involved in age-related cognitive decline. The dietary antioxidants, carotenoids, tocopherols, and vitamin A may play a role in the prevention or delay in cognitive decline. In this study, sera were obtained from 78 octogenarians and 220 centenarians from the Georgia Centenarian Study. Brain tissues were obtained from 47 centenarian decedents. Samples were analyzed for carotenoids, α-tocopherol, and retinol using HPLC. Analyte concentrations were compared with cognitive tests designed to evaluate global cognition, dementia, depression and cognitive domains (memory, processing speed, attention, and executive functioning). Serum lutein, zeaxanthin, and β-carotene concentrations were most consistently related to better cognition …

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 …

Comprehensive Behavioral Characterization Of An App/Ps-1 Double Knock-In Mouse Model Of Alzheimer's Disease, Scott J. Webster, Adam D. Bachstetter, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: Despite the extensive mechanistic and pathological characterization of the amyloid precursor protein (APP)/presenilin-1 (PS-1) knock-in mouse model of Alzheimer's disease (AD), very little is known about the AD-relevant behavioral deficits in this model. Characterization of the baseline behavioral performance in a variety of functional tasks and identification of the temporal onset of behavioral impairments are important to provide a foundation for future preclinical testing of AD therapeutics. Here we perform a comprehensive behavioral characterization of this model, discuss how the observed behavior correlates with the mechanistic and pathological observations of others, and compare this model with other commonly used …

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 …

The P38Α Mapk Regulates Microglial Responsiveness To Diffuse Traumatic Brain Injury, Adam D. Bachstetter, Rachel K. Rowe, Machi Kaneko, Danielle Goulding, Jonathan Lifshitz, Linda J Van Eldik

Sanders-Brown Center on Aging Faculty Publications

Neuropathology after traumatic brain injury (TBI) is the result of both the immediate impact injury and secondary injury mechanisms. Unresolved post-traumatic glial activation is a secondary injury mechanism that contributes to a chronic state of neuroinflammation in both animal models of TBI and human head injury patients. We recently demonstrated, using in vitro models, that p38α MAPK signaling in microglia is a key event in promoting cytokine production in response to diverse disease-relevant stressors and subsequent inflammatory neuronal dysfunction. From these findings, we hypothesized that the p38α signaling pathway in microglia could be contributing to the secondary neuropathologic sequelae after …

Intracranial Injection Of Aav Expressing Nep But Not Ide Reduces Amyloid Pathology In App+Ps1 Transgenic Mice, Nikisha Carty, Kevin R. Nash, Milene Brownlow, Dana Cruite, Donna M. Wilcock, Maj-Linda B. Selenica, Daniel C. Lee, Marcia N. Gordon, Dave Morgan

Sanders-Brown Center on Aging Faculty Publications

The accumulation of β-amyloid peptides in the brain has been recognized as an essential factor in Alzheimer's disease pathology. Several proteases, including Neprilysin (NEP), endothelin converting enzyme (ECE), and insulin degrading enzyme (IDE), have been shown to cleave β-amyloid peptides (Aβ). We have previously reported reductions in amyloid in APP+PS1 mice with increased expression of ECE. In this study we compared the vector-induced increased expression of NEP and IDE. We used recombinant adeno-associated viral vectors expressing either native forms of NEP (NEP-n) or IDE (IDE-n), or engineered secreted forms of NEP (NEP-s) or IDE (IDE-s). In a six-week study, immunohistochemistry …

Bapineuzumab Alters Aβ Composition: Implications For The Amyloid Cascade Hypothesis And Anti-Amyloid Immunotherapy, Alex E. Roher, David H. Cribbs, Ronald C. Kim, Chera L. Maarouf, Charisse M. Whiteside, Tyler A. Kokjohn, Ian D. Daugs, Elizabeth Head, Carolyn Liebsack, Geidy Serrano, Christine Belden, Marwan N. Sabbagh, Thomas G. Beach

Sanders-Brown Center on Aging Faculty Publications

The characteristic neuropathological changes associated with Alzheimer's disease (AD) and other lines of evidence support the amyloid cascade hypothesis. Viewing amyloid deposits as the prime instigator of dementia has now led to clinical trials of multiple strategies to remove or prevent their formation. We performed neuropathological and biochemical assessments of 3 subjects treated with bapineuzumab infusions. Histological analyses were conducted to quantify amyloid plaque densities, Braak stages and the extent of cerebral amyloid angiopathy (CAA). Amyloid-β (Aβ) species in frontal and temporal lobe samples were quantified by ELISA. Western blots of amyloid-β precursor protein (AβPP) and its C-terminal (CT) fragments …

Deficiency In P38Β Mapk Fails To Inhibit Cytokine Production Or Protect Neurons Against Inflammatory Insult In In Vitro And In Vivo Mouse Models, Bin Xing, Adam D. Bachstetter, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

The p38 MAPK pathway plays a key role in regulating the production of proinflammatory cytokines, such as TNFα and IL-1β, in peripheral inflammatory disorders. There are four major isoforms of p38 MAPK (p38α, β, δ, γ), with p38α and p38β the targets of most p38 MAPK inhibitor drugs. Our previous studies demonstrated that the p38α MAPK isoform is an important contributor to stressor-induced proinflammatory cytokine up-regulation and neurotoxicity in the brain. However, the potential role of the p38β MAPK isoform in CNS proinflammatory cytokine overproduction and neurotoxicity is poorly understood. In the current studies, we used primary microglia from wild …

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 …