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Browsing by Author "Howell, Gareth R."
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Item Assessment of Neurovascular Uncoupling: APOE Status is a Key Driver of Early Metabolic and Vascular Dysfunction(bioRxiv, 2024-03-13) Onos, Kristen; Lin, Peter B.; Pandey, Ravi S.; Persohn, Scott A.; Burton, Charles P.; Miner, Ethan W.; Eldridge, Kierra; Nyandu Kanyinda, Jonathan; Foley, Kate E.; Carter, Gregory W.; Howell, Gareth R.; Territo, Paul R.; Neurology, School of MedicineBackground: Alzheimer's disease (AD) is the most common cause of dementia worldwide, with apolipoprotein ε4 (APOEε4) being the strongest genetic risk factor. Current clinical diagnostic imaging focuses on amyloid and tau; however, new methods are needed for earlier detection. Methods: PET imaging was used to assess metabolism-perfusion in both sexes of aging C57BL/6J, and hAPOE mice, and were verified by transcriptomics, and immunopathology. Results: All hAPOE strains showed AD phenotype progression by 8 mo, with females exhibiting the regional changes, which correlated with GO-term enrichments for glucose metabolism, perfusion, and immunity. Uncoupling analysis revealed APOEε4/ε4 exhibited significant Type-1 uncoupling (↓ glucose uptake, ↑ perfusion) at 8 and 12 mo, while APOEε3/ε4 demonstrated Type-2 uncoupling (↑ glucose uptake, ↓ perfusion), while immunopathology confirmed cell specific contributions. Discussion: This work highlights APOEε4 status in AD progression manifest as neurovascular uncoupling driven by immunological activation, and may serve as an early diagnostic biomarker.Item Assessment of neurovascular uncoupling: APOE status is a key driver of early metabolic and vascular dysfunction(Wiley, 2024) Onos, Kristen D.; Lin, Peter B.; Pandey, Ravi S.; Persohn, Scott A.; Burton, Charles P.; Miner, Ethan W.; Eldridge, Kierra; Nyandu Kanyind, Jonathan; Foley, Kate E.; Carter, Gregory W.; Howell, Gareth R.; Territo, Paul R.; Neurology, School of MedicineBackground: Alzheimer's disease (AD) is the most common cause of dementia worldwide, with apolipoprotein Eε4 (APOEε4) being the strongest genetic risk factor. Current clinical diagnostic imaging focuses on amyloid and tau; however, new methods are needed for earlier detection. Methods: PET imaging was used to assess metabolism-perfusion in both sexes of aging C57BL/6J, and hAPOE mice, and were verified by transcriptomics, and immunopathology. Results: All hAPOE strains showed AD phenotype progression by 8 months, with females exhibiting the regional changes, which correlated with GO-term enrichments for glucose metabolism, perfusion, and immunity. Uncoupling analysis revealed APOEε4/ε4 exhibited significant Type-1 uncoupling (↓ glucose uptake, ↑ perfusion) at 8 and 12 months, while APOEε3/ε4 demonstrated Type-2 uncoupling (↑ glucose uptake, ↓ perfusion), while immunopathology confirmed cell specific contributions. Discussion: This work highlights APOEε4 status in AD progression manifests as neurovascular uncoupling driven by immunological activation, and may serve as an early diagnostic biomarker. Highlights: We developed a novel analytical method to analyze PET imaging of 18F-FDG and 64Cu-PTSM data in both sexes of aging C57BL/6J, and hAPOEε3/ε3, hAPOEε4/ε4, and hAPOEε3/ε4 mice to assess metabolism-perfusion profiles termed neurovascular uncoupling. This analysis revealed APOEε4/ε4 exhibited significant Type-1 uncoupling (decreased glucose uptake, increased perfusion) at 8 and 12 months, while APOEε3/ε4 demonstrated significant Type-2 uncoupling (increased glucose uptake, decreased perfusion) by 8 months which aligns with immunopathology and transcriptomic signatures. This work highlights that there may be different mechanisms underlying age related changes in APOEε4/ε4 compared with APOEε3/ε4. We predict that these changes may be driven by immunological activation and response, and may serve as an early diagnostic biomarker.Item Characterizing Molecular and Synaptic Signatures in mouse models of Late-Onset Alzheimer’s Disease Independent of Amyloid and Tau Pathology(bioRxiv, 2023-12-20) Kotredes, Kevin P.; Pandey, Ravi S.; Persohn, Scott; Elderidge, Kierra; Burton, Charles P.; Miner, Ethan W.; Haynes, Kathryn A.; Santos, Diogo Francisco S.; Williams, Sean-Paul; Heaton, Nicholas; Ingraham, Cynthia M.; Lloyd, Christopher; Garceau, Dylan; O’Rourke, Rita; Herrick, Sarah; Rangel-Barajas, Claudia; Maharjan, Surendra; Wang, Nian; Sasner, Michael; Lamb, Bruce T.; Territo, Paul R.; Sukoff Rizzo, Stacey J.; Carter, Gregory W.; Howell, Gareth R.; Oblak, Adrian L.; Medical and Molecular Genetics, School of MedicineIntroduction: MODEL-AD is creating and distributing novel mouse models with humanized, clinically relevant genetic risk factors to more accurately mimic LOAD than commonly used transgenic models. Methods: We created the LOAD2 model by combining APOE4, Trem2*R47H, and humanized amyloid-beta. Mice aged up to 24 months were subjected to either a control diet or a high-fat/high-sugar diet (LOAD2+HFD) from two months of age. We assessed disease-relevant outcomes, including in vivo imaging, biomarkers, multi-omics, neuropathology, and behavior. Results: By 18 months, LOAD2+HFD mice exhibited cortical neuron loss, elevated insoluble brain Aβ42, increased plasma NfL, and altered gene/protein expression related to lipid metabolism and synaptic function. In vivo imaging showed age-dependent reductions in brain region volume and neurovascular uncoupling. LOAD2+HFD mice also displayed deficits in acquiring touchscreen-based cognitive tasks. Discussion: Collectively the comprehensive characterization of LOAD2+HFD mice reveal this model as important for preclinical studies that target features of LOAD independent of amyloid and tau.Item Comprehensive Evaluation of the 5XFAD Mouse Model for Preclinical Testing Applications: A MODEL-AD Study(Frontiers Media, 2021-07-23) Oblak, Adrian L.; Lin, Peter B.; Kotredes, Kevin P.; Pandey, Ravi S.; Garceau, Dylan; Williams, Harriet M.; Uyar, Asli; O’Rourke, Rita; O’Rourke, Sarah; Ingraham, Cynthia; Bednarczyk, Daria; Belanger, Melisa; Cope, Zackary A.; Little, Gabriela J.; Williams, Sean-Paul G.; Ash, Carl; Bleckert, Adam; Ragan, Tim; Logsdon, Benjamin A.; Mangravite, Lara M.; Sukoff Rizzo, Stacey J.; Territo, Paul R.; Carter, Gregory W.; Howell, Gareth R.; Sasner, Michael; Lamb, Bruce T.; Radiology and Imaging Sciences, School of MedicineThe ability to investigate therapeutic interventions in animal models of neurodegenerative diseases depends on extensive characterization of the model(s) being used. There are numerous models that have been generated to study Alzheimer’s disease (AD) and the underlying pathogenesis of the disease. While transgenic models have been instrumental in understanding AD mechanisms and risk factors, they are limited in the degree of characteristics displayed in comparison with AD in humans, and the full spectrum of AD effects has yet to be recapitulated in a single mouse model. The Model Organism Development and Evaluation for Late-Onset Alzheimer’s Disease (MODEL-AD) consortium was assembled by the National Institute on Aging (NIA) to develop more robust animal models of AD with increased relevance to human disease, standardize the characterization of AD mouse models, improve preclinical testing in animals, and establish clinically relevant AD biomarkers, among other aims toward enhancing the translational value of AD models in clinical drug design and treatment development. Here we have conducted a detailed characterization of the 5XFAD mouse, including transcriptomics, electroencephalogram, in vivo imaging, biochemical characterization, and behavioral assessments. The data from this study is publicly available through the AD Knowledge Portal.Item Corrigendum: Uncovering Disease Mechanisms in a Novel Mouse Model Expressing Humanized APOEε4 and Trem2*R47H(Frontiers Media, 2022-02-07) Kotredes, Kevin P.; Oblak, Adrian; Pandey, Ravi S.; Lin, Peter Bor-Chian; Garceau, Dylan; Williams, Harriet; Uyar, Asli; O’Rourke, Rita; O’Rourke, Sarah; Ingraham, Cynthia; Bednarczyk, Daria; Belanger, Melisa; Cope, Zackary; Foley, Kate E.; Logsdon, Benjamin A.; Mangravite, Lara M.; Sukoff Rizzo, Stacey J.; Territo, Paul R.; Carter, Gregory W.; Sasner, Michael; Lamb, Bruce T.; Howell, Gareth R.; Pharmacology and Toxicology, School of MedicineAn author name was incorrectly spelled as “Daria Bednarycek”. The correct spelling is “Daria Bednarczyk”. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.Item Exercise prevents obesity-induced cognitive decline and white matter damage in mice(Elsevier, 2019-08) Graham, Leah C.; Grabowska, Weronika A.; Chun, Yoona; Risacher, Shannon L.; Philip, Vivek M.; Saykin, Andrew J.; Sukoff Rizzo, Stacey J.; Howell, Gareth R.; Radiology and Imaging Sciences, School of MedicineObesity in the western world has reached epidemic proportions, and yet the long-term effects on brain health are not well understood. To address this, we performed transcriptional profiling of brain regions from a mouse model of western diet (WD)-induced obesity. Both the cortex and hippocampus from C57BL/6J (B6) mice fed either a WD or a control diet from 2 months of age to 12 months of age (equivalent to midlife in a human population) were profiled. Gene set enrichment analyses predicted that genes involved in myelin generation, inflammation, and cerebrovascular health were differentially expressed in brains from WD-fed compared to control diet-fed mice. White matter damage and cerebrovascular decline were evident in brains from WD-fed mice using immunofluorescence and electron microscopy. At the cellular level, the WD caused an increase in the numbers of oligodendrocytes and myeloid cells suggesting that a WD is perturbing myelin turnover. Encouragingly, cerebrovascular damage and white matter damage were prevented by exercising WD-fed mice despite mice still gaining a significant amount of weight. Collectively, these data show that chronic consumption of a WD in B6 mice causes obesity, neuroinflammation, and cerebrovascular and white matter damage, but these potentially damaging effects can be prevented by modifiable risk factors such as exercise.Item In vivo validation of late-onset Alzheimer's disease genetic risk factors(bioRxiv, 2023-12-24) Sasner, Michael; Preuss, Christoph; Pandey, Ravi S.; Uyar, Asli; Garceau, Dylan; Kotredes, Kevin P.; Williams, Harriet; Oblak, Adrian L.; Lin, Peter Bor-Chian; Perkins, Bridget; Soni, Disha; Ingraham, Cindy; Lee-Gosselin, Audrey; Lamb, Bruce T.; Howell, Gareth R.; Carter, Gregory W.; Radiology and Imaging Sciences, School of MedicineIntroduction: Genome-wide association studies have identified over 70 genetic loci associated with late-onset Alzheimer's disease (LOAD), but few candidate polymorphisms have been functionally assessed for disease relevance and mechanism of action. Methods: Candidate genetic risk variants were informatically prioritized and individually engineered into a LOAD-sensitized mouse model that carries the AD risk variants APOE4 and Trem2*R47H. Potential disease relevance of each model was assessed by comparing brain transcriptomes measured with the Nanostring Mouse AD Panel at 4 and 12 months of age with human study cohorts. Results: We created new models for 11 coding and loss-of-function risk variants. Transcriptomic effects from multiple genetic variants recapitulated a variety of human gene expression patterns observed in LOAD study cohorts. Specific models matched to emerging molecular LOAD subtypes. Discussion: These results provide an initial functionalization of 11 candidate risk variants and identify potential preclinical models for testing targeted therapeutics.Item Model organism development and evaluation for late‐onset Alzheimer's disease: MODEL‐AD(Wiley, 2020-11-23) Oblak, Adrian L.; Forner, Stefania; Territo, Paul R.; Sasner, Michael; Carter, Gregory W.; Howell, Gareth R.; Sukoff-Rizzo, Stacey J.; Logsdon, Benjamin A.; Mangravite, Lara M.; Mortazavi, Ali; Baglietto-Vargas, David; Green, Kim N.; MacGregor, Grant R.; Wood, Marcelo A.; Tenner, Andrea J.; LaFerla, Frank M.; Lamb, Bruce T.; Radiology and Imaging Sciences, School of MedicineAlzheimer's disease (AD) is a major cause of dementia, disability, and death in the elderly. Despite recent advances in our understanding of the basic biological mechanisms underlying AD, we do not know how to prevent it, nor do we have an approved disease‐modifying intervention. Both are essential to slow or stop the growth in dementia prevalence. While our current animal models of AD have provided novel insights into AD disease mechanisms, thus far, they have not been successfully used to predict the effectiveness of therapies that have moved into AD clinical trials. The Model Organism Development and Evaluation for Late‐onset Alzheimer's Disease (MODEL‐AD; www.model-ad.org) Consortium was established to maximize human datasets to identify putative variants, genes, and biomarkers for AD; to generate, characterize, and validate the next generation of mouse models of AD; and to develop a preclinical testing pipeline. MODEL‐AD is a collaboration among Indiana University (IU); The Jackson Laboratory (JAX); University of Pittsburgh School of Medicine (Pitt); Sage BioNetworks (Sage); and the University of California, Irvine (UCI) that will generate new AD modeling processes and pipelines, data resources, research results, standardized protocols, and models that will be shared through JAX's and Sage's proven dissemination pipelines with the National Institute on Aging–supported AD Centers, academic and medical research centers, research institutions, and the pharmaceutical industry worldwide.Item New directions for Alzheimer's disease research from the Jackson Laboratory Center for Alzheimer's and Dementia Research 2022 workshop(Wiley, 2024-03-10) Telpoukhovskaia, Maria A.; Murdy, Thomas J.; Marola, Olivia J.; Charland, Kevin; MacLean, Michael; Luquez, Tain; Lish, Alexandra M.; Neuner, Sarah; Dunn, Amy; Onos, Kristen D.; Wiley, Jesse; Archer, Derek; Huentelman, Matthew J.; Arnold, Matthias; Menon, Vilas; Goate, Alison; Van Eldik, Linda J.; Territo, Paul R.; Howell, Gareth R.; Carter, Gregory W.; O’Connell, Kristen M. S.; Kaczorowski, Catherine C.; 2022 JAX CADR Workshop; Medicine, School of MedicineIntroduction: In September 2022, The Jackson Laboratory Center for Alzheimer's and Dementia Research (JAX CADR) hosted a workshop with leading researchers in the Alzheimer's disease and related dementias (ADRD) field. Methods: During the workshop, the participants brainstormed new directions to overcome current barriers to providing patients with effective ADRD therapeutics. The participants outlined specific areas of focus. Following the workshop, each group used standard literature search methods to provide background for each topic. Results: The team of invited experts identified four key areas that can be collectively addressed to make a significant impact in the field: (1) Prioritize the diversification of disease targets, (2) enhance factors promoting resilience, (3) de-risk clinical pipeline, and (4) centralize data management. Discussion: In this report, we review these four objectives and propose innovations to expedite ADRD therapeutic pipelines.Item A novel systems biology approach to evaluate mouse models of late-onset Alzheimer’s disease(BMC, 2020-11-10) Preuss, Christoph; Pandey, Ravi; Piazza, Erin; Fine, Alexander; Uyar, Asli; Perumal, Thanneer; Garceau, Dylan; Kotredes, Kevin P.; Williams, Harriet; Mangravite, Lara M.; Lamb, Bruce T.; Oblak, Adrian L.; Howell, Gareth R.; Sasner, Michael; Logsdon, Benjamin A.; Carter, Gregory W.; Psychiatry, School of MedicineBackground Late-onset Alzheimer’s disease (LOAD) is the most common form of dementia worldwide. To date, animal models of Alzheimer’s have focused on rare familial mutations, due to a lack of frank neuropathology from models based on common disease genes. Recent multi-cohort studies of postmortem human brain transcriptomes have identified a set of 30 gene co-expression modules associated with LOAD, providing a molecular catalog of relevant endophenotypes. Results This resource enables precise gene-based alignment between new animal models and human molecular signatures of disease. Here, we describe a new resource to efficiently screen mouse models for LOAD relevance. A new NanoString nCounter® Mouse AD panel was designed to correlate key human disease processes and pathways with mRNA from mouse brains. Analysis of the 5xFAD mouse, a widely used amyloid pathology model, and three mouse models based on LOAD genetics carrying APOE4 and TREM2*R47H alleles demonstrated overlaps with distinct human AD modules that, in turn, were functionally enriched in key disease-associated pathways. Comprehensive comparison with full transcriptome data from same-sample RNA-Seq showed strong correlation between gene expression changes independent of experimental platform. Conclusions Taken together, we show that the nCounter Mouse AD panel offers a rapid, cost-effective and highly reproducible approach to assess disease relevance of potential LOAD mouse models. Supplementary information Supplementary information accompanies this paper at 10.1186/s13024-020-00412-5.