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Sinclair D, Canty AJ, Ziebell JM, Woodhouse A, Collins JM, Perry S, Roccati E, Kuruvilla M, Leung J, Atkinson R, Vickers JC, Cook AL, King AE. Experimental laboratory models as tools for understanding modifiable dementia risk. Alzheimers Dement 2024; 20:4260-4289. [PMID: 38687209 PMCID: PMC11180874 DOI: 10.1002/alz.13834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/29/2024] [Accepted: 03/18/2024] [Indexed: 05/02/2024]
Abstract
Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia. This review provides an overview of experimental research into 15 established and putative modifiable dementia risk factors: less early-life education, hearing loss, depression, social isolation, life stress, hypertension, obesity, diabetes, physical inactivity, heavy alcohol use, smoking, air pollution, anesthetic exposure, traumatic brain injury, and disordered sleep. It explores how experimental models have been, and can be, used to address questions about modifiable dementia risk and prevention that cannot readily be addressed in human studies. HIGHLIGHTS: Modifiable dementia risk factors are promising targets for dementia prevention. Interrogation of mechanisms underlying dementia risk is difficult in human populations. Studies using diverse experimental models are revealing modifiable dementia risk mechanisms. We review experimental research into 15 modifiable dementia risk factors. Laboratory science can contribute uniquely to dementia prevention.
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Affiliation(s)
- Duncan Sinclair
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Alison J. Canty
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
- Global Brain Health Institute, Trinity CollegeDublinIreland
| | - Jenna M. Ziebell
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jessica M. Collins
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Sharn Perry
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Eddy Roccati
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Maneesh Kuruvilla
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jacqueline Leung
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Rachel Atkinson
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - James C. Vickers
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anthony L. Cook
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anna E. King
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
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Bellelli F. Cognitive Interventions: Symptomatic or Disease-Modifying Treatments in the Brain? JAR LIFE 2024; 13:60-64. [PMID: 38808149 PMCID: PMC11130643 DOI: 10.14283/jarlife.2024.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 04/15/2024] [Indexed: 05/30/2024]
Abstract
Recent findings suggest that brain-stimulating activities may have beneficial effects on both Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD). However, whether cognitive interventions merely enhance cognitive reserve or truly attenuate, or even reverse, the disease's pathophysiology is still controversial. The aim of the present article is to discuss the potential for brain-stimulating activities, including cognitive stimulation (CS), cognitive rehabilitation (CR), and cognitive training (CT), to be symptomatic or disease-modifying interventions in the context of cognitive decline. While emerging evidence indicates that CT can enhance synaptic plasticity, suggesting a potential role in augmenting cognitive reserve, its impact on AD pathology remains uncertain. Small-scale studies suggest that CT and CS may slow down neurodegeneration in MCI patients and that multidomain interventions combining physical activity with CT may benefit Aβ pathology. However, the considerable heterogeneity across studies limits the comparability of findings. It underscores the necessity for a more standardized approach to cognitive interventions in future guidelines for preventing and managing cognitive decline.
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Affiliation(s)
- F. Bellelli
- Fellowship in Geriatric and Gerontology, University of Milan, Milan, Italy
- Gérontopôle de Toulouse, Institut du Vieillissement, Centre Hospitalo-Universitaire de Toulouse, Toulouse, France
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Harris BN, Yavari M, Ramalingam L, Mounce PL, Alers Maldonado K, Chavira AC, Thomas S, Scoggin S, Biltz C, Moustaid-Moussa N. Impact of Long-Term Dietary High Fat and Eicosapentaenoic Acid on Behavior and Hypothalamic-Pituitary-Adrenal Axis Activity in Amyloidogenic APPswe/PSEN1dE9 Mice. Neuroendocrinology 2024; 114:553-576. [PMID: 38301617 PMCID: PMC11153005 DOI: 10.1159/000536586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 01/30/2024] [Indexed: 02/03/2024]
Abstract
INTRODUCTION Alzheimer's disease (AD) alters neurocognitive and emotional function and causes dysregulation of multiple homeostatic processes. The leading AD framework pins amyloid beta plaques and tau tangles as primary drivers of dysfunction. However, many additional variables, including diet, stress, sex, age, and pain tolerance, interact in ways that are not fully understood to impact the onset and progression of AD pathophysiology. We asked: (1) does high-fat diet, compared to low-fat diet, exacerbate AD pathophysiology and behavioral decline? And, (2) can supplementation with eicosapentaenoic (EPA)-enriched fish oil prevent high-fat-diet-induced changes? METHODS Male and female APPswePSdE9 mice, and their non-transgenic littermates, were randomly assigned to a diet condition (low-fat, high-fat, high-fat with EPA) and followed from 2 to 10 months of age. We assessed baseline corticosterone concentration during aging, pain tolerance, cognitive function, stress coping, and corticosterone response to a stressor. RESULTS Transgenic mice were consistently more active than non-transgenic mice but did not perform worse on either cognitive task, even though we recently reported that these same transgenic mice exhibited metabolic changes and had increased amyloid beta. Mice fed high-fat diet had higher baseline and post-stressor corticosterone, but diet did not impact cognition or pain tolerance. Sex had the biggest influence, as female mice were consistently more active and had higher corticosterone than males. CONCLUSION Overall, diet, genotype, and sex did not have consistent impacts on outcomes. We found little support for predicted interactions and correlations, suggesting diet impacts metabolic function and amyloid beta levels, but these outcomes do not translate to changes in behaviors measured here.
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Affiliation(s)
- Breanna N. Harris
- Department of Biological Sciences, Texas Tech University, Lubbock, TX
- Obesity Research Institute, Office of Research & Innovation, Texas Tech University
| | - Mahsa Yavari
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
- Obesity Research Institute, Office of Research & Innovation, Texas Tech University
- Current address: Department of Molecular Metabolism, School of Public Health, Harvard University, Boston, MA
| | - Latha Ramalingam
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
- Obesity Research Institute, Office of Research & Innovation, Texas Tech University
- Current address: Department of Nutritional and Food Studies Syracuse University, Syracuse, NY
| | - P. Logan Mounce
- Department of Biological Sciences, Texas Tech University, Lubbock, TX
| | | | - Angela C. Chavira
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
| | - Sarah Thomas
- Department of Biological Sciences, Texas Tech University, Lubbock, TX
| | - Shane Scoggin
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
| | - Caroline Biltz
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
| | - Naima Moustaid-Moussa
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX
- Obesity Research Institute, Office of Research & Innovation, Texas Tech University
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Villemagne VL, Doré V, Chong L, Kassiou M, Mulligan R, Feizpour A, Taylor J, Roesner M, Miller T, Rowe CC. Brain 11β-Hydroxysteroid Dehydrogenase Type 1 Occupancy by Xanamem™ Assessed by PET in Alzheimer's Disease and Cognitively Normal Individuals. J Alzheimers Dis 2024; 97:1463-1475. [PMID: 38250767 PMCID: PMC10836555 DOI: 10.3233/jad-220542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2023] [Indexed: 01/23/2024]
Abstract
BACKGROUND 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) regulates intracellular cortisol and its inhibition by the small molecule inhibitor, Xanamem™, may provide a disease-modifying strategy for Alzheimer's disease (AD). Animal models suggest a range of 30-60% enzyme inhibition may suffice to provide neuroprotection. OBJECTIVE To determine the regional brain occupancy of 11β-HSD1 by Xanamem™ in cognitively normal participants (CN) and mild cognitive impairment (MCI)/mild AD patients to investigate potential dosing ranges for future efficacy studies. METHODS Seventeen MCI/AD and 23 CN were included. Regional brain time-activity curves (TAC), standardized uptake values (SUV40-60) and volume of distribution (VT) from Logan plot with image derived input function from 11C-TARACT positron emission tomography (PET) were used to assess the degree of 11β-HSD1 occupancy by increasing doses of Xanamem™ (5 mg, 10 mg, 20 mg or 30 mg daily for 7 days). RESULTS All measures showed high 11β-HSD1 occupancy with Xanamem to similar degree in CN and MCI/AD. The dose-response relationship was relatively flat above 5 mg. Respective median (interquartile range [Q1-Q3]) 11β-HSD1 occupancy in the MCI/AD and CN groups after treatment with 10 mg Xanamem were 80% [79-81%] and 75% [71-76%] in the neocortex, 69% [64-70%] and 61% [52-63%] in the medial temporal lobe, 80% [79-80%] and 73% [68-73%] in the basal ganglia, and 71% [67-75%] and 66% [62-68%] in the cerebellum. CONCLUSIONS TAC, SUV40-60, and VT measures indicate Xanamem achieves high target occupancy levels with near saturation at 10 mg daily. These data support exploration of doses of≤10 mg daily in future clinical studies.
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Affiliation(s)
- Victor L. Villemagne
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
- Department of Psychiatry, The University of Pittsburgh, Pittsburgh, PA, USA
| | - Vincent Doré
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
- CSIRO e-Health Research Centre, Brisbane, QLD, Australia
| | - Lee Chong
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
| | - Michael Kassiou
- The University of Sydney, School of Chemistry, Sydney, Australia
| | - Rachel Mulligan
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VA, Australia
| | - Azadeh Feizpour
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VA, Australia
| | | | | | | | - Christopher C. Rowe
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VA, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VA, Australia
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Taylor J, Jaros M, Chen C, Harrison J, Hilt D. Plasma pTau181 Predicts Clinical Progression in a Phase 2 Randomized Controlled Trial of the 11β-HSD1 Inhibitor Xanamem® for Mild Alzheimer's Disease. J Alzheimers Dis 2024; 100:139-150. [PMID: 38848180 PMCID: PMC11307031 DOI: 10.3233/jad-231456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2024] [Indexed: 06/09/2024]
Abstract
Background Blood biomarkers are proposed as a diagnostic alternative to amyloid PET or cerebrospinal fluid (CSF) analyses for the diagnosis of Alzheimer's disease (AD). Relatively little is known of the natural history of patients identified by different blood biomarkers. Objective To identify patients with elevated plasma phosphorylated tau (pTau)181 from a prior Phase 2a trial, and explore the natural histories of their clinical progression, and potential efficacy of Xanamem, a selective inhibitor of 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in these patients. Methods A prespecified, double-blind analysis was conducted in 72 participants with clinically diagnosed AD and available plasma samples from baseline and Week 12 of the "XanADu" Phase 2a trial of Xanamem versus placebo. The analysis prespecified plasma pTau181 > median to identify patients more likely to have AD ("H", > 6.74 pg/mL, n = 34). Cohen's d (d) of≥0.2 defined potential clinical significance. Results In the placebo group, H patients showed greater clinical progression compared to L patients (pTau181≤median) on ADCOMS (d = 0.55, p < 0.001), CDR-SB (d = 0.63, p < 0.001), MMSE (d = 0.52, p = 0.12), and ADAS-Cog14 (d = 0.53, p = 0.19). In H patients, a potentially clinically meaningful Xanamem treatment effect compared to placebo was seen in the CDR-SB (LS mean difference 0.6 units, d = 0.41, p = 0.09) and Neuropsychological Test Battery (NTB; LS mean difference 1.8 units, d = 0.26, p = 0.48) but not ADCOMS or ADAS-Cog14. Conclusions This trial demonstrates that elevated plasma pTau181 identifies participants more likely to have progressive AD and is a suitable method for enrichment in AD clinical trials. Xanamem treatment showed evidence of potential clinically meaningful benefits.
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Affiliation(s)
- Jack Taylor
- Actinogen Medical, Sydney, New South Wales, Australia
| | | | - Christopher Chen
- Department of Pharmacology, Memory Aging and Cognition Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - John Harrison
- Scottish Brain Sciences, Edinburgh, UK
- King’s College, London, UK
- Alzheimercentrum, AUmc, Amsterdam, The Netherlands
| | - Dana Hilt
- Actinogen Medical, Sydney, New South Wales, Australia
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Harris BN, Roberts BR, DiMarco GM, Maldonado KA, Okwunwanne Z, Savonenko AV, Soto PL. Hypothalamic-pituitary-adrenal (HPA) axis activity and anxiety-like behavior during aging: A test of the glucocorticoid cascade hypothesis in amyloidogenic APPswe/PS1dE9 mice. Gen Comp Endocrinol 2023; 330:114126. [PMID: 36122793 PMCID: PMC10250074 DOI: 10.1016/j.ygcen.2022.114126] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/06/2022] [Accepted: 09/13/2022] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a progressive, dementing, whole-body disorder that presents with decline in cognitive, behavioral, and emotional functions, as well as endocrine dysregulation. The etiology of AD is not fully understood but stress- and anxiety-related hormones may play a role in its development and trajectory. The glucocorticoid cascade hypothesis posits that levels of glucocorticoids increase with age, leading to dysregulated negative feedback, further elevated glucocorticoids, and resulting neuropathology. We examined the impact of age (from 2 to 10 months) and stressor exposure (predator odor) on hormone levels (corticosterone and ghrelin), anxiety-like behavior (open field and light dark tests), and memory-related behavior (novel object recognition; NOR), and whether these various measures correlated with neuropathology (hippocampus and cortex amyloid beta, Aβ) in male and female APPswe/PS1dE9 transgenic and non-transgenic mice. Additionally, we performed exploratory analyses to probe if the open field and light dark test as commonly used tasks to assess anxiety levels were correlated. Consistent with the glucocorticoid cascade hypothesis, baseline corticosterone increased with age. Predator odor exposure elevated corticosterone at each age, but in contrast to the glucocorticoid cascade hypothesis, the magnitude of stressor-induced elevations in corticosterone levels did not increase with age. Overall, transgenic mice had higher post-stressor, but not baseline, corticosterone than non-transgenic mice, and across both genotypes, females consistently had higher (baseline and post-stressor) corticosterone than males. Behavior in the open field test primarily showed decreased locomotion with age, and this was pronounced in transgenic females. Anxiety-like behaviors in the light dark test were exacerbated following predator odor, and female transgenic mice were the most impacted. Compared to transgenic males, transgenic females had higher Aβ concentrations and showed more anxiety-like behavior. Performance on the NOR did not differ significantly between genotypes. Lastly, we did not find robust, statistically significant correlations among corticosterone, ghrelin, recognition memory, anxiety-like behaviors, or Aβ, suggesting outcomes are not strongly related on the individual level. Our data suggest that despite Aβ accumulation in the hippocampus and cortex, male and female APPswePS1dE9 transgenic mice do not differ robustly from their non-transgenic littermates in physiological, endocrine, and behavioral measures at the range of ages studied here.
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Affiliation(s)
- Breanna N Harris
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States.
| | - Breanna R Roberts
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| | - Giuliana M DiMarco
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States; Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | | | - Zenobia Okwunwanne
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| | - Alena V Savonenko
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Paul L Soto
- Department of Psychology, Louisiana State University, Baton Rouge, LA, United States
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Xiao R, Ali S, Caligiuri MA, Cao L. Enhancing Effects of Environmental Enrichment on the Functions of Natural Killer Cells in Mice. Front Immunol 2021; 12:695859. [PMID: 34394087 PMCID: PMC8355812 DOI: 10.3389/fimmu.2021.695859] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/14/2021] [Indexed: 01/02/2023] Open
Abstract
The environment of an organism can convey a powerful influence over its biology. Environmental enrichment (EE), as a eustress model, has been used extensively in neuroscience to study neurogenesis and brain plasticity. EE has also been used as an intervention for the treatment and prevention of neurological and psychiatric disorders with limited clinical application. By contrast, the effects of EE on the immune system are relatively less investigated. Recently, accumulating evidence has demonstrated that EE can robustly impact immune function. In this review, we summarize the major components of EE, the impact of EE on natural killer (NK) cells, EE's immunoprotective roles in cancer, and the underlying mechanisms of EE-induced NK cell regulation. Moreover, we discuss opportunities for translational application based on insights from animal research of EE-induced NK cell regulation.
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Affiliation(s)
- Run Xiao
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
- The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital and Solove Research Institute, Columbus, OH, United States
| | - Seemaab Ali
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
- The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital and Solove Research Institute, Columbus, OH, United States
- Medical Scientist Training Program, The Ohio State University, Columbus, OH, United States
| | - Michael A. Caligiuri
- Department of Hematology & Hematopoietic Cell Transplantation, City of Hope National Medical Center and the Beckman Research Institute, Los Angeles, CA, United States
| | - Lei Cao
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
- The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital and Solove Research Institute, Columbus, OH, United States
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van Heusden FC, Palacín I Bonsón S, Stiedl O, Smit AB, van Kesteren RE. Longitudinal Assessment of Working Memory Performance in the APPswe/PSEN1dE9 Mouse Model of Alzheimer's Disease Using an Automated Figure-8-Maze. Front Behav Neurosci 2021; 15:655449. [PMID: 34054444 PMCID: PMC8155296 DOI: 10.3389/fnbeh.2021.655449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/29/2021] [Indexed: 01/09/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, with a long preclinical and prodromal phase. To enable the study of disease mechanisms, AD has been modeled in many transgenic animal lines and cognitive functioning has been tested using several widely used behavioral tasks. These tasks, however, are not always suited for repeated longitudinal testing and are often associated with acute stress such as animal transfer, handling, novelty, or stress related to the task itself. This makes it challenging to relate cognitive dysfunction in animal models to cognitive decline observed in AD patients. Here, we designed an automated figure-8-maze (F8M) to test mice in a delayed alternation task (DAT) in a longitudinal manner. Mice were rewarded when they entered alternate sides of the maze on subsequent trials. Automation as well as connection of the F8M set-up with a home cage reduces experimenter interference and minimizes acute stress, thus making it suitable for longitudinal testing and facilitating clinical translation. In the present study, we monitored cognitive functioning of 2-month-old APPswe/PSEN1dE9 (APP/PS1) mice over a period of 4 months. The percentage of correct responses in the DAT did not differ between wild-type and transgenic mice from 2 to 6 months of age. However, 6-month-old mice displayed an increase in the number of consecutive incorrect responses. These results demonstrate the feasibility of longitudinal testing using an automated F8M and suggest that APP/PS1 mice are not impaired at delayed spatial alternation until 6 months of age under the current experimental conditions.
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Affiliation(s)
- Fran C van Heusden
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Sara Palacín I Bonsón
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Oliver Stiedl
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Ronald E van Kesteren
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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Stuart KE, Padgett C. A Systematic Review of the Association Between Psychological Stress and Dementia Risk in Humans. J Alzheimers Dis 2020; 78:335-352. [DOI: 10.3233/jad-191096] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Background: It has been estimated that one third of dementia cases may be preventable through modifiable lifestyle interventions. Epidemiological evidence suggests a link between stressful life events and aging-related cognitive decline and dementia; however, inherent methodological limitations in examining subjective and biological measures of stress separately leads to interpretive constraints. Objective: The aim of the current study was to conduct a systematic review of the research literature investigating the effect of perceived and biological measures of stress on dementia risk. Methods: A systematic review was conducted of cohort, case-control, longitudinal prospective or retrospective studies examining the association between stress and risk of developing dementia. Studies were identified from a systematic search across major electronic databases from inception to February 2020. Results: Overall, 22 studies were identified including a total of 496,556 participants, approximately 50% were females, with sample sizes ranging from 62–270,977. There was considerable heterogeneity in the definition and measurement of stress. Most of the identified studies reported a significant positive association between stress and dementia risk. Conclusion: Evidenced from the current review is that personality traits linked to increased perceived stress and elevated reported perceived stress, are associated with greater statistical risk for dementia. However, this review highlights that caution must be exhibited in interpreting these findings, as methodological issues with confounding adjustment may mediate these results. Future research should focus on the investigation of stress on dementia risk with a full range of confounding adjustment, and on biological measures of stress.
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Affiliation(s)
- Kimberley E. Stuart
- Division of Psychology, School of Medicine, University of Tasmania, Australia
- Wicking Dementia Research and Education Centre, Tasmania, Australia
| | - Christine Padgett
- Division of Psychology, School of Medicine, University of Tasmania, Australia
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The BDNF Val66Met Polymorphism Modulates Resilience of Neurological Functioning to Brain Ageing and Dementia: A Narrative Review. Brain Sci 2020; 10:brainsci10040195. [PMID: 32218234 PMCID: PMC7226504 DOI: 10.3390/brainsci10040195] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 02/06/2023] Open
Abstract
Brain-derived neurotropic factor (BDNF) is an abundant and multi-function neurotrophin in the brain. It is released following neuronal activity and is believed to be particularly important in strengthening neural networks. A common variation in the BDNF gene, a valine to methionine substitution at codon 66 (Val66Met), has been linked to differential expression of BDNF associated with experience-dependent plasticity. The Met allele has been associated with reduced production of BDNF following neuronal stimulation, which suggests a potential role of this variation with respect to how the nervous system may respond to challenges, such as brain ageing and related neurodegenerative conditions (e.g., dementia and Alzheimer’s disease). The current review examines the potential of the BDNF Val66Met variation to modulate an individual’s susceptibility and trajectory through cognitive changes associated with ageing and dementia. On balance, research to date indicates that the BDNF Met allele at this codon is potentially associated with a detrimental influence on the level of cognitive functioning in older adults and may also impart increased risk of progression to dementia. Furthermore, recent studies also show that this genetic variation may modulate an individual’s response to interventions targeted at building cognitive resilience to conditions that cause dementia.
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11
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Insights into the Therapeutic Potential of Glucocorticoid Receptor Modulators for Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21062137. [PMID: 32244957 PMCID: PMC7139912 DOI: 10.3390/ijms21062137] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022] Open
Abstract
Glucocorticoids are crucial for stress-coping, resilience, and adaptation. However, if the stress hormones become dysregulated, the vulnerability to stress-related diseases is enhanced. In this brief review, we discuss the role of glucocorticoids in the pathogenesis of neurodegenerative disorders in both human and animal models, and focus in particular on amyotrophic lateral sclerosis (ALS). For this purpose, we used the Wobbler animal model, which mimics much of the pathology of ALS including a dysfunctional hypothalamic–pituitary–adrenal axis. We discuss recent studies that demonstrated that the pathological cascade characteristic for motoneuron degeneration of ALS is mimicked in the genetically selected Wobbler mouse and can be attenuated by treatment with the selective glucocorticoid receptor antagonist (GRA) CORT113176. In long-term treatment (3 weeks) GRA attenuated progression of the behavioral, inflammatory, excitatory, and cell-death-signaling pathways while increasing the survival signal of serine–threonine kinase (pAkt). The action mechanism of the GRA may be either by interfering with GR deactivation or by restoring the balance between pro- and anti-inflammatory signaling pathways driven by the complementary mineralocorticoid receptor (MR)- and GR-mediated actions of corticosterone. Accordingly, GR antagonism may have clinical relevance for the treatment of neurodegenerative diseases.
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Peña-Bautista C, Casas-Fernández E, Vento M, Baquero M, Cháfer-Pericás C. Stress and neurodegeneration. Clin Chim Acta 2020; 503:163-168. [PMID: 31987795 DOI: 10.1016/j.cca.2020.01.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/13/2022]
Abstract
Neurodegenerative diseases are a great concern because of aging worldwide population. Despite substantial effort to advance our understanding of the etiology and potential treatment of neurodegeneration, there remains a paucity of information with respect to this complex disease process. Interestingly, stress has been implicated among the potential mechanisms implicated in neurodegenerative pathology. Given the increase in chronic stress in modern society, this premise warrants further investigation. The aim of this review is to evaluate the influence of stress on neurodegeneration, the effect of neurodegenerative diseases diagnosis on stress, and therapeutic strategies for neurodegenerative diseases with a special focus on stress reduction. Neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's Disease showed an acceleration in disease progression and a worsening of symptoms under stress. Some therapies (e.g., yoga, meditation) focused on reducing stress showed beneficial effects against neurodegeneration. Nevertheless, more studies are necessary in order to completely understand the implications of stress in neurodegeneration and the usefulness of stress reduction in the treatment thereof.
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Affiliation(s)
| | | | - Máximo Vento
- Health Research Institute La Fe, Valencia, Spain
| | - Miguel Baquero
- Division of Neurology, University and Polytechnic Hospital La Fe, Valencia, Spain
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Stuart KE, King AE, King NE, Collins JM, Vickers JC, Ziebell JM. Late-life environmental enrichment preserves short-term memory and may attenuate microglia in male APP/PS1 mice. Neuroscience 2019; 408:282-292. [PMID: 30999032 DOI: 10.1016/j.neuroscience.2019.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 02/08/2023]
Abstract
Environmental enrichment (EE) has been consistently reported to enhance cognitive function in mouse models of neuropathology. Microglia, implicated in Alzheimer's disease pathology, may mediate this effect. The aim of the present study was to investigate the effect of EE on cognitive function and microglia in mouse models of aging and amyloidosis. Male wild-type (Wt) and APP/PS1 mice were randomly assigned to standard housing (SH) or EE from 12 to 18 months of age. Spatial memory testing was performed using the Y and Barnes maze. Immunohistochemical analysis of Aβ load, Iba1 and CD-68-labeled (phagocytic-type) microglia was examined between conditions. EE from 12 months of age was associated with improved short-term memory performance in APP/PS1 mice, despite no reductions to Aβ load. APP/PS1 mice in SH had significantly increased microglia occupying the neocortex and hippocampus (p = 0.02; p = 0.004, respectively) relative to Wt animals. Microglia labeling was not statistically different between EE-exposed APP/PS1 compared to Wt mice, indicating that EE may attenuate the increased microglial load in aging APP/PS1 mice. APP/PS1 mice from EE had significantly (p = 0.01) higher colocalization of Iba1 and CD-68 labeling, indicative of increased phagocytic microglia compared to mice from SH. The findings of the present study suggest that EE after substantial brain amyloidosis, has the potential to preserve domains of cognitive function, while having no effect on Aβ deposition. The current study demonstrates that EE may attenuate microglia in aging APP/PS1 mice, and may promote alterations in cellular phenotype.
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Affiliation(s)
- Kimberley E Stuart
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia.
| | - Anna E King
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Natalie E King
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Jessica M Collins
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - James C Vickers
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Jenna M Ziebell
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
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Shepherd A, Zhang TD, Zeleznikow-Johnston AM, Hannan AJ, Burrows EL. Transgenic Mouse Models as Tools for Understanding How Increased Cognitive and Physical Stimulation Can Improve Cognition in Alzheimer's Disease. Brain Plast 2018; 4:127-150. [PMID: 30564551 PMCID: PMC6296266 DOI: 10.3233/bpl-180076] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cognitive decline appears as a core feature of dementia, of which the most prevalent form, Alzheimer's disease (AD) affects more than 45 million people worldwide. There is no cure, and therapeutic options remain limited. A number of modifiable lifestyle factors have been identified that contribute to cognitive decline in dementia. Sedentary lifestyle has emerged as a major modifier and accordingly, boosting mental and physical activity may represent a method to prevent decline in dementia. Beneficial effects of increased physical activity on cognition have been reported in healthy adults, showing potential to harness exercise and cognitive stimulation as a therapy in dementia. 'Brain training' (cognitive stimulation) has also been investigated as an intervention protecting against cognitive decline with normal aging. Consequently, the utility of exercise regimes and/or cognitive stimulation to improve cognition in dementia in clinical populations has been a major area of study. However, these therapies are in their infancy and efficacy is unclear. Investigations utilising animal models, where dose and timing of treatment can be tightly controlled, have provided many mechanistic insights. Genetically engineered mouse models are powerful tools to investigate mechanisms underlying cognitive decline, and also how environmental manipulations can alter both cognitive outcomes and pathology. A myriad of effects following physical activity and housing in enriched environments have been reported in transgenic mice expressing Alzheimer's disease-associated mutations. In this review, we comprehensively evaluate all studies applying environmental enrichment and/or increased physical exercise to transgenic mouse models of Alzheimer's disease. It is unclear whether interventions must be applied before first onset of cognitive deficits to be effective. In order to determine the importance of timing of interventions, we specifically scrutinised studies exposing transgenic mice to exercise and environmental enrichment before and after first report of cognitive impairment. We discuss the strengths and weaknesses of these preclinical studies and suggest approaches for enhancing rigor and using mechanistic insights to inform future therapeutic interventions.
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Affiliation(s)
- Amy Shepherd
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Tracy D Zhang
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Ariel M Zeleznikow-Johnston
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, Australia
| | - Emma L Burrows
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
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Krishna KV, Saha RN, Singhvi G, Dubey SK. Pre-clinical pharmacokinetic-pharmacodynamic modelling and biodistribution studies of donepezil hydrochloride by a validated HPLC method. RSC Adv 2018; 8:24740-24749. [PMID: 35542150 PMCID: PMC9082346 DOI: 10.1039/c8ra03379j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/24/2018] [Indexed: 12/25/2022] Open
Abstract
A simple, sensitive and robust HPLC-PDA assay was developed and validated for rapid determination of donepezil hydrochloride (DNP), a potent acetylcholinesterase inhibitor in rat plasma and tissues. All biological samples were prepared by the solid-phase extraction method using loratadine as an internal standard. Separation of the analytes was achieved on a Waters Nova-Pak C18 column (3.9 × 150 mm, 4 μm) using an isocratic mobile phase of acetonitrile and ammonium formate (pH 6.4; 0.01 M) (62 : 38% v/v) at a flow rate of 1 mL min-1. All validation parameter results were within the acceptable range described in the guidelines for bioanalytical method validation. The method showed linearity in the concentration range of 50-5000 ng mL-1 with LOD of 20 ng mL-1 and LLOQ of 50 ng mL-1. Moreover, the advantage of this method over previously published methods is the short analysis run time of 6 min in HPLC itself, alongside its application not only for plasma samples but also in tissues, with low LLOQ. The method was successfully applied for studying the compartmental pharmacokinetics, tissue distribution and pharmacodynamics. A two-compartmental micro model was statistically fitted for the assessment of pharmacokinetic parameters. The tissue distribution studies suggest that the kidneys, lungs and liver are the primarily responsible organs for metabolism and elimination of DNP. Pharmacodynamic studies were performed by measuring acetylcholinesterase inhibitory activity of DNP, which indicated that the pharmacokinetic and pharmacodynamic data are in correlation with each other.
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Affiliation(s)
- Kowthavarapu Venkata Krishna
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani (BITS-PILANI), Pilani Campus Rajasthan India 333031 +91 8239703734
| | - Ranendra Narayana Saha
- Department of Biotechnology, Birla Institute of Technology and Science, Pilani (BITS-PILANI), Dubai Campus Dubai UAE
| | - Gautam Singhvi
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani (BITS-PILANI), Pilani Campus Rajasthan India 333031 +91 8239703734
| | - Sunil Kumar Dubey
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani (BITS-PILANI), Pilani Campus Rajasthan India 333031 +91 8239703734
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Woodhouse A, Fernandez-Martos CM, Atkinson RAK, Hanson KA, Collins JM, O'Mara AR, Terblanche N, Skinner MW, Vickers JC, King AE. Repeat propofol anesthesia does not exacerbate plaque deposition or synapse loss in APP/PS1 Alzheimer's disease mice. BMC Anesthesiol 2018; 18:47. [PMID: 29699479 PMCID: PMC5921792 DOI: 10.1186/s12871-018-0509-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/13/2018] [Indexed: 12/14/2022] Open
Abstract
Background There is increasing interest in whether anesthetic agents affect the risk or progression of Alzheimer’s disease (AD). To mitigate many of the methodological issues encountered in human retrospective cohort studies we have used a transgenic model of AD to investigate the effect of propofol on AD pathology. Methods Six month-old amyloid precursor protein/presenilin 1 (APP/PS1) transgenic AD mice and control mice were exposed to 3 doses of propofol (200 mg/kg) or vehicle, delivered at monthly intervals. Results There was no difference in the extent of β-amyloid (Aβ) immunolabeled plaque deposition in APP/PS1 mice in vehicle versus propofol treatment groups. We also detected no difference in plaque-associated synapse loss in APP/PS1 mice following repeat propofol exposure relative to vehicle. Western blotting indicated that there was no difference in post-synaptic density protein 95, synaptophysin or glutamic acid decarboxylase 65/67 expression in control or APP/PS1 mice subjected to repeat propofol treatment relative to vehicle. Conclusions These data suggest that repeat propofol anesthesia may not exacerbate plaque deposition or associated synapse loss in AD. Interestingly, this data also provides some of the first evidence suggesting that repeat propofol exposure in adult wild-type mice does not result in robust long-term alterations in the levels of key excitatory and inhibitory synaptic markers. Electronic supplementary material The online version of this article (10.1186/s12871-018-0509-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Adele Woodhouse
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia.
| | | | | | - Kelsey Anne Hanson
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia
| | - Jessica Marie Collins
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia
| | - Aidan Ryan O'Mara
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia
| | - Nico Terblanche
- Tasmanian Health Service, Royal Hobart Hospital, Hobart, Australia.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Marcus Welby Skinner
- Department of Health and Human Services Tasmania, Royal Hobart Hospital, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - James Clement Vickers
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia
| | - Anna Elizabeth King
- Wicking Dementia Research and Education Centre , University of Tasmania, Hobart, Australia
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