Medical Sciences Commons^™

Dementia Risk Reduction: Why Haven't The Pharmacological Risk Reduction Trials Worked? An In-Depth Exploration Of Seven Established Risk Factors, Ruth Peters, John Breitner, Sarah James, Gregory A. Jicha, Pierre-Francois Meyer, Marcus Richards, A. David Smith, Hussein N. Yassine, Erin L. Abner, Atticus H. Hainsworth, Patrick G. Kehoe, Nigel Beckett, Christopher Weber, Craig Anderson, Kaarin J. Anstey, Hiroko H. Dodge

Neurology Faculty Publications

Identifying the leading health and lifestyle factors for the risk of incident dementia and Alzheimer's disease has yet to translate to risk reduction. To understand why, we examined the discrepancies between observational and clinical trial evidence for seven modifiable risk factors: type 2 diabetes, dyslipidemia, hypertension, estrogens, inflammation, omega-3 fatty acids, and hyperhomocysteinemia. Sample heterogeneity and paucity of intervention details (dose, timing, formulation) were common themes. Epidemiological evidence is more mature for some interventions (eg, non-steroidal anti-inflammatory drugs [NSAIDs]) than others. Trial data are promising for anti-hypertensives and B vitamin supplementation. Taken together, these risk factors highlight a future need …

Multi-Vendor And Multisite Evaluation Of Cerebrovascular Reactivity Mapping Using Hypercapnia Challenge, Peiying Liu, Dengrong Jiang, Marilyn Albert, Christopher E. Bauer, Arvind Caprihan, Brian T. Gold, Steven M. Greenberg, Karl G. Helmer, Kay Jann, Gregory A. Jicha, Pavel Rodriguez, Claudia L Satizabal, Sudha Seshadri, Herpreet Singh, Jeffrey F. Thompson, Danny J. J. Wang, Hanzhang Lu

Neuroscience Faculty Publications

Cerebrovascular reactivity (CVR), which measures the ability of cerebral blood vessels to dilate or constrict in response to vasoactive stimuli such as CO2 inhalation, is an important index of the brain's vascular health. Quantification of CVR using BOLD MRI with hypercapnia challenge has shown great promises in research and clinical studies. However, in order for it to be used as a potential imaging biomarker in large-scale and multi-site studies, the reliability of CO2-CVR quantification across different MRI acquisition platforms and researchers/raters must be examined. The goal of this report from the MarkVCID small vessel disease biomarkers consortium is to evaluate …

Cessation And Resumption Of Elective Neurointerventional Procedures During The Coronavirus Disease 2019 Pandemic And Future Pandemics, Tim W. Malisch, Sameer A. Ansari, Gary R. Duckwiler, Kyle M. Fargen, Steven W. Hetts, Franklin A. Marden, Athos Patsalides, Clemens M. Schirmer, Allan Brook, Justin F. Fraser

Neurosurgery Faculty Publications

At the time of this writing, the coronavirus disease 2019 pandemic continues to be a global threat, disrupting usual processes, and protocols for delivering health care around the globe. There have been significant regional and national differences in the scope and timing of these disruptions. Many hospitals were forced to temporarily halt elective neurointerventional procedures with the first wave of the pandemic in the spring of 2020, in order to prioritize allocation of resources for acutely ill patients and also to minimize coronavirus disease 2019 transmission risks to non-acute patients, their families, and health care workers. This temporary moratorium on …

Mitochondrial Phenotypes In Purified Human Immune Cell Subtypes And Cell Mixtures, Shannon Rausser, Caroline Trumpff, Marlon A. Mcgill, Alex Junker, Wei Wang, Siu-Hong Ho, Anika Mitchell, Kalpita R. Karan, Catherine Monk, Suzanne C. Segerstrom, Rebecca G. Reed, Martin Picard

Psychology Faculty Publications

Using a high-throughput mitochondrial phenotyping platform to quantify multiple mitochondrial features among molecularly defined immune cell subtypes, we quantify the natural variation in mitochondrial DNA copy number (mtDNAcn), citrate synthase, and respiratory chain enzymatic activities in human neutrophils, monocytes, B cells, and naïve and memory T lymphocyte subtypes. In mixed peripheral blood mononuclear cells (PBMCs) from the same individuals, we show to what extent mitochondrial measures are confounded by both cell type distributions and contaminating platelets. Cell subtype-specific measures among women and men spanning four decades of life indicate potential age- and sex-related differences, including an age-related elevation in mtDNAcn, …

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 …

Intra-Arterial Combination Therapy For Experimental Acute Ischemic Stroke, Michael E. Maniskas, Jill M. Roberts, Amanda A. Gorman, Gregory J. Bix, Justin F. Fraser

Neurosurgery Faculty Publications

Acute ischemic stroke continues to devastate millions of individuals worldwide. Current treatments work to restore blood flow but not rescue affected tissue. Our goal was to develop a combination of neuroprotective agents administered intra-arterially following recanalization to target ischemic tissue. Using C57Bl/6J male mice, we performed tandem transient ipsilateral middle cerebral/common carotid artery occlusion, followed by immediate intra-arterial pharmacotherapy administration through a standardized protocol. Two pharmacotherapy agents, verapamil and lubeluzole, were selected based on their potential to modulate different aspects of the ischemic cascade; verapamil, a calcium channel blocker, works in an acute fashion blocking L-type calcium channels, whereas lubeluzole, …

Smoking-Induced Sex Differences In Clinical Outcomes In Patients Undergoing Mechanical Thrombectomy For Stroke, Jacqueline A. Frank, Kara Jo Swafford, Jill M. Roberts, Amanda L. Trout, Ann M. Stowe, Douglas E. Lukins, Stephen Grupke, Keith R. Pennypacker, Justin F. Fraser

Neurology Faculty Publications

OBJECTIVE: Ischemic stroke is the fifth leading cause of death in the United States. Smoking accelerates the onset of stroke by 10 years. The effects of smoking status on percent change in National Institutes of Health Stroke Scale (NIHSS) score, infarct volume, and edema volume were examined following mechanical thrombectomy for large vessel occlusion in patients with acute ischemic stroke.

METHODS: Subjects (N = 90; >18 years old) were divided into 3 groups based on smoking status: current smokers, previous smokers (defined as having quit >6 months before the ischemic event), and nonsmokers. Percent change in NIHSS score was …

Reduced Mitochondrial Dna And Oxphos Protein Content In Skeletal Muscle Of Children With Cerebral Palsy, Ferdinand Von Walden, Ivan J. Vechetti Jr., Davis A. Englund, Vandré C. Figueiredo, Rodrigo Fernandez-Gonzalo, Kevin A. Murach, Jessica Pingel, John J. Mccarthy, Per Stål, Eva Pontén

Physiology Faculty Publications

AIM: To provide a detailed gene and protein expression analysis related to mitochondrial biogenesis and assess mitochondrial content in skeletal muscle of children with cerebral palsy (CP).

METHOD: Biceps brachii muscle samples were collected from 19 children with CP (mean [SD] age 15y 4mo [2y 6mo], range 9-18y, 16 males, three females) and 10 typically developing comparison children (mean [SD] age 15y [4y], range 7-21y, eight males, two females). Gene expression (quantitative reverse transcription polymerase chain reaction [PCR]), mitochondrial DNA (mtDNA) to genomic DNA ratio (quantitative PCR), and protein abundance (western blotting) were analyzed. Microarray data sets (CP/aging/bed rest) were …

Intracranial Vcam1 At Time Of Mechanical Thrombectomy Predicts Ischemic Stroke Severity, Benton Maglinger, Madison Sands, Jacqueline A. Frank, Christopher J. Mclouth, Amanda L. Trout, Jill M. Roberts, Stephen Grupke, Jadwiga Turchan-Cholewo, Ann M. Stowe, Justin F. Fraser, Keith R. Pennypacker

Behavioral Science Faculty Publications

BACKGROUND: Emergent large vessel occlusion (ELVO) strokes are devastating ischemic vascular events for which novel treatment options are needed. Using vascular cell adhesion molecule 1 (VCAM1) as a prototype, the objective of this study was to identify proteomic biomarkers and network signaling functions that are potential therapeutic targets for adjuvant treatment for mechanical thrombectomy.

METHODS: The blood and clot thrombectomy and collaboration (BACTRAC) study is a continually enrolling tissue bank and registry from stroke patients undergoing mechanical thrombectomy. Plasma proteins from intracranial (distal to clot) and systemic arterial blood (carotid) were analyzed by Olink Proteomics for N=42 subjects. Statistical …

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 …

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 (Aβ_1-40, Aβ_1-42), and glial fibrillary acidic protein (GFAP) were undertaken with …

Gait And Balance Changes With Investigational Peripheral Nerve Cell Therapy During Deep Brain Stimulation In People With Parkinson’S Disease, Geetanjali Gera, Zain Guduru, Tritia R. Yamasaki, Julie A. Gurwell, Monica Chau, Anna Krotinger, Frederick A. Schmitt, John T. Slevin, Greg A. Gerhardt, Craig G. Van Horne, Jorge E. Quintero

Physical Therapy Faculty Publications

Background: The efficacy of deep brain stimulation (DBS) and dopaminergic therapy is known to decrease over time. Hence, a new investigational approach combines implanting autologous injury-activated peripheral nerve grafts (APNG) at the time of bilateral DBS surgery to the globus pallidus interna. Objectives: In a study where APNG was unilaterally implanted into the substantia nigra, we explored the effects on clinical gait and balance assessments over two years in 14 individuals with Parkinson’s disease. Methods: Computerized gait and balance evaluations were performed without medication, and stimulation was in the off state for at least 12 h to best assess the …

Method Of Intra-Arterial Drug Administration In A Rat: Sex Based Optimization Of Infusion Rate, Sarah J. Messmer, Justin F. Fraser, Keith R. Pennypacker, Jill M. Roberts

Center for Advanced Translational Stroke Science Faculty Publications

BACKGROUND: Endovascular thrombectomy is the process of removing a blood clot and re-establishing blood flow in patients with emergent large vessel occlusion. The technique provides an opportunity to deliver therapeutics directly to the site of injury. The intra-arterial (IA) route of drug administration in the mouse was developed to bridge the gap between animal stroke treatments and clinical stroke therapy. Here, we adapted the IA method for use in rats, by investigating various flow rates to optimize the IA injection through the internal carotid artery (ICA).

METHODS: Male and female Sprague-Dawley rats (∼4 months of age) were subjected to placement …

Space-Occupying Brain Lesions, Trauma-Related Tau Astrogliopathy, And Artag: A Report Of Two Cases And A Literature Review, Adam D. Bachstetter, Filip G. Garrett, Gregory A. Jicha, Peter T. Nelson

Spinal Cord and Brain Injury Research Center Faculty Publications

Astrocytes with intracellular accumulations of misfolded phosphorylated tau protein have been observed in advanced-stage chronic traumatic encephalopathy (CTE) and in other neurodegenerative conditions. There is a growing awareness that astrocytic tau inclusions are also relatively common in the brains of persons over 70 years of age-affecting approximately one-third of autopsied individuals. The pathologic hallmarks of aging-related tau astrogliopathy (ARTAG) include phosphorylated tau protein within thorn-shaped astrocytes (TSA) in subpial, subependymal, perivascular, and white matter regions, whereas granular-fuzzy astrocytes are often seen in gray matter. CTE and ARTAG share molecular and histopathologic characteristics, suggesting that trauma-related mechanism(s) may predispose to the …

Differential Leukocyte And Platelet Profiles In Distinct Models Of Traumatic Brain Injury, William Brad Hubbard, Meenakshi Banerjee, Hemendra J. Vekaria, Kanakanagavalli Shravani Prakhya, Smita Joshi, Qingjun Wang, Kathryn E. Saatman, Sidney W. Whiteheart, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Traumatic brain injury (TBI) affects over 3 million individuals every year in the U.S. There is growing appreciation that TBI can produce systemic modifications, which are in part propagated through blood–brain barrier (BBB) dysfunction and blood–brain cell interactions. As such, platelets and leukocytes contribute to mechanisms of thromboinflammation after TBI. While these mechanisms have been investigated in experimental models of contusion brain injury, less is known regarding acute alterations following mild closed head injury. To investigate the role of platelet dynamics and bioenergetics after TBI, we employed two distinct, well-established models of TBI in mice: the controlled cortical impact (CCI) …

CertL Reduces C16 Ceramide, Amyloid-Β Levels, And Inflammation In A Model Of Alzheimer’S Disease, Simone M. Crivelli, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Daan Van Kruining, Gerard Bode, Sandra Den Hoedt, Barbara Hobo, Anna-Lena Scheithauer, Jochen Walter, Monique T. Mulder, Christopher Exley, Matthew Mold, Michelle M. Mielke, Helga E. De Vries, Kristiaan Wouters, Daniel L. A. Van Den Hove, Dusan Berkes, María Dolores Ledesma, Joost Verhaagen, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez

Physiology Faculty Publications

BACKGROUND: Dysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-β (Aβ) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain.

METHODS: A plasmid expressing CERT_L, the long isoform of CERTs, was used to study the interaction of CERT_L with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERT_L protein …

Machine Intelligence Identifies Soluble Tnfa As A Therapeutic Target For Spinal Cord Injury, J. R. Huie, A. R. Ferguson, N. Kyritsis, J. Z. Pan, K.-A. Irvine, J. L. Nielson, P. G. Schupp, M. C. Oldham, John C. Gensel, A. Lin, M. R. Segal, R. R. Ratan, J. C. Bresnahan, M. S. Beattie

Spinal Cord and Brain Injury Research Center Faculty Publications

Traumatic spinal cord injury (SCI) produces a complex syndrome that is expressed across multiple endpoints ranging from molecular and cellular changes to functional behavioral deficits. Effective therapeutic strategies for CNS injury are therefore likely to manifest multi-factorial effects across a broad range of biological and functional outcome measures. Thus, multivariate analytic approaches are needed to capture the linkage between biological and neurobehavioral outcomes. Injury-induced neuroinflammation (NI) presents a particularly challenging therapeutic target, since NI is involved in both degeneration and repair. Here, we used big-data integration and large-scale analytics to examine a large dataset of preclinical efficacy tests combining five …

Macrophage-Engineered Vesicles For Therapeutic Delivery And Bidirectional Reprogramming Of Immune Cell Polarization, Khaga R. Neupane, J. Robert Mccorkle, Timothy J. Kopper, Jourdan E. Lakes, Surya P. Aryal, Masud Abdullah, Aaron A. Snell, John C. Gensel, Jill M. Kolesar, Christopher I. Richards

Spinal Cord and Brain Injury Research Center Faculty Publications

Macrophages, one of the most important phagocytic cells of the immune system, are highly plastic and are known to exhibit diverse roles under different pathological conditions. The ability to repolarize macrophages from pro-inflammatory (M1) to anti-inflammatory (M2) or vice versa offers a promising therapeutic approach for treating various diseases such as traumatic injury and cancer. Herein, it is demonstrated that macrophage-engineered vesicles (MEVs) generated by disruption of macrophage cellular membranes can be used as nanocarriers capable of reprogramming macrophages and microglia toward either pro- or anti-inflammatory phenotypes. MEVs can be produced at high yields and easily loaded with diagnostic molecules …

Genetic Approach To Elucidate The Role Of Cyclophilin D In Traumatic Brain Injury Pathology, Ryan D. Readnower, W. Brad Hubbard, Olivia J. Kalimon, James W. Geddes, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the …

The Association Of Circulating Amylin With Β-Amyloid In Familial Alzheimer's Disease, Han Gia Ly, Nirmal Verma, Savita Sharma, Deepak Kotiya, Sanda Despa, Erin L. Abner, Peter T. Nelson, Gregory A. Jicha, Donna M. Wilcock, Larry B. Goldstein, Rita Guerreiro, José Brás, Angela J. Hanson, Suzanne Craft, Andrew J. Murray, Geert Jan Biessels, Claire Troakes, Henrik Zetterberg, John Hardy, Tammaryn Lashley, Alzheimer’S Disease Exome Sequencing Group, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

Introduction

This study assessed the hypothesis that circulating human amylin (amyloid‐forming) cross‐seeds with amyloid beta (Aβ) in early Alzheimer's disease (AD).

Methods

Evidence of amylin‐AD pathology interaction was tested in brains of 31 familial AD mutation carriers and 20 cognitively unaffected individuals, in cerebrospinal fluid (CSF) (98 diseased and 117 control samples) and in genetic databases. For functional testing, we genetically manipulated amylin secretion in APP/PS1 and non‐APP/PS1 rats.

Results

Amylin‐Aβ cross‐seeding was identified in AD brains. High CSF amylin levels were associated with decreased CSF Aβ42 concentrations. AD risk and amylin gene are not correlated. Suppressed amylin secretion protected …

Encephalopathy And Complex Hyperkinesia In A Patient With Severe Acute Respiratory Syndrome Coronavirus-2 Infection, Wenyang Li, Elif Pinar Coskun, Rolando Berger, John T. Slevin, L. Creed Pettigrew

Neurology Faculty Publications

No abstract provided.

Mitochondria Exert Age-Divergent Effects On Recovery From Spinal Cord Injury, Andrew N. Stewart, Katelyn E. Mcfarlane, Hemendra J. Vekaria, William M. Bailey, Stacey A. Slone, Lauren A. Tranthem, Bei Zhang, Samir P. Patel, Patrick G. Sullivan, John C. Gensel

Physiology Faculty Publications

The extent that age-dependent mitochondrial dysfunction drives neurodegeneration is not well understood. This study tested the hypothesis that mitochondria contribute to spinal cord injury (SCI)-induced neurodegeneration in an age-dependent manner by using 2,4-dinitrophenol (DNP) to uncouple electron transport, thereby increasing cellular respiration and reducing reactive oxygen species (ROS) production. We directly compared the effects of graded DNP doses in 4- and 14-month-old (MO) SCI-mice and found DNP to have increased efficacy in mitochondria isolated from 14-MO animals. In vivo, all DNP doses significantly exacerbated 4-MO SCI neurodegeneration coincident with worsened recovery. In contrast, low DNP doses (1.0-mg/kg/day) improved tissue …

Dystrophic Microglia Are Associated With Neurodegenerative Disease And Not Healthy Aging In The Human Brain, Ryan K. Shahidehpour, Rebecca E. Higdon, Nicole G. Crawford, Janna H. Neltner, Eseosa T. Ighodaro, Ela Patel, Douglas Price, Peter T. Nelson, Adam D. Bachstetter

Spinal Cord and Brain Injury Research Center Faculty Publications

Loss of physiological microglial function may increase the propagation of neurodegenerative diseases. Cellular senescence is a hallmark of aging; thus, we hypothesized age could be a cause of dystrophic microglia. Stereological counts were performed for total microglia, 2 microglia morphologies (hypertrophic and dystrophic) across the human lifespan. An age-associated increase in the number of dystrophic microglia was found in the hippocampus and frontal cortex. However, the increase in dystrophic microglia was proportional to the age-related increase in the total number of microglia. Thus, aging alone does not explain the presence of dystrophic microglia. We next tested if dystrophic microglia could …

Commentary: Use Of Bactrac Proteomic Database-Uromodulin Protein Expression During Ischemic Stroke, Gabriella-Salome K. Armstrong, Jacqueline A. Frank, Christopher J. Mclouth, Ann M. Stowe, Jill M. Roberts, Amanda L. Trout, Justin F. Fraser, Keith R. Pennypacker

Neurology Faculty Publications

Introduction: Uromodulin (UMOD) is a glycoprotein expressed by the epithelial cells of the thick ascending limb of Henle's loop in the kidney. Research has shown that increased uromodulin expression may be associated with lower risk of cardiovascular disease in adults. Utilizing the Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC) (clinicaltrials.gov NCT03153683), a continuously enrolling tissue bank, we aimed to examine the associations between serum uromodulin, age, and high BMI (BMI> 25) and its relationship to stroke in patients.

Methods: Arterial blood distal and proximal to the thrombus was collected during a thrombectomy procedure using the BACTRAC protocol and sent …