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Weiss AR, Urbanski HF. Effect of short-term androgen supplementation on cognitive performance in older male rhesus macaques. Neurobiol Aging 2023; 132:246-249. [PMID: 37866084 PMCID: PMC10842314 DOI: 10.1016/j.neurobiolaging.2023.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023]
Abstract
Old male rhesus macaques often show cognitive impairment, and also have attenuated circulating levels of testosterone and dehydroepiandrosterone sulfate (DHEAS). However, it is unclear if these age-associated decreases in circulating androgen levels are casually related to mechanisms that support cognition. To test this possibility, old male rhesus macaques were given daily supplements of testosterone and DHEA for ∼7 months, using a paradigm designed to mimic the 24-hour circulating hormone patterns of young adults. Animals completed the Delayed Match-to-Sample (DMS) task to assess recognition, and the Delayed Response (DR) task to assess working memory. The animals all showed significant delay-dependent performance, with longer delays resulting in lower accuracy; and timepoint-dependent performance, showing improvement with the repeated opportunities for practice. However, there were no differences between the androgen supplemented animals and age-matched controls. These data indicate that the specific short-term supplementation paradigm employed here offers no obvious benefits for DMS or DR task performance.
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Affiliation(s)
- Alison Ruth Weiss
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA.
| | - Henryk Francis Urbanski
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA; Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
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Stonebarger GA, Bimonte-Nelson HA, Urbanski HF. The Rhesus Macaque as a Translational Model for Neurodegeneration and Alzheimer's Disease. Front Aging Neurosci 2021; 13:734173. [PMID: 34539388 PMCID: PMC8446616 DOI: 10.3389/fnagi.2021.734173] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/12/2021] [Indexed: 12/01/2022] Open
Abstract
A major obstacle to progress in understanding the etiology of normative and pathological human brain aging is the availability of suitable animal models for experimentation. The present article will highlight our current knowledge regarding human brain aging and neurodegeneration, specifically in the context of Alzheimer's disease (AD). Additionally, it will examine the use of the rhesus macaque monkey as a pragmatic translational animal model in which to study underlying causal mechanisms. Specifically, the discussion will focus on behavioral and protein-level brain changes that occur within the central nervous system (CNS) of aged monkeys, and compare them to the changes observed in humans during clinically normative aging and in AD.
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Affiliation(s)
- Gail A. Stonebarger
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, United States
| | - Heather A. Bimonte-Nelson
- Department of Psychology, Arizona State University, Tempe, AZ, United States
- Arizona Alzheimer’s Consortium, Phoenix, AZ, United States
| | - Henryk F. Urbanski
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, United States
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Bojar I, Pinkas J, Gujski M, Owoc A, Raczkiewicz D, Gustaw-Rothenberg K. Postmenopausal cognitive changes and androgen levels in the context of apolipoprotein E polymorphism. Arch Med Sci 2017; 13:1148-1159. [PMID: 28883857 PMCID: PMC5575214 DOI: 10.5114/aoms.2016.62869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/25/2016] [Indexed: 01/08/2023] Open
Abstract
INTRODUCTION The focus of this study was to assess cognitive functions in relation to androgens and specifically testosterone and dehydroepiandrosterone in postmenopausal women as well as the correlation between cognitive functions and these two androgens according to polymorphism of the apolipoprotein E gene (APOE). MATERIAL AND METHODS A group of 402 women was recruited to the study (minimum 2 years after the last menstruation, follicle-stimulating hormone (FSH) more than 30 U/ml and no dementia signs on Montreal Cognitive Assessment). The computerized battery of the Central Nervous System Vital Signs test was used to diagnose cognitive functions. APOE genotyping was performed by multiplex polymerase chain reaction (PCR). Testosterone (TTE) and dehydroepiandrosterone (DHEA) in the blood serum were assessed for further statistical correlations analysis. RESULTS In the group of postmenopausal women, higher testosterone concentration was associated with lower scores for Neurocognition Index (NCI) (p = 0.028), memory (p = 0.008) and psychomotor speed (p < 0.001). Presence of at least one APOE ε4 allele potentiated testosterone's negative influence on cognitive functions (p < 0.05). Woman with a high normal level of DHEA scored significantly better in verbal (p = 0.027) and visual memory (p < 0.001) than other participants. APOE polymorphism did not modify the relationship between DHEA concentration and scores for cognitive functions. CONCLUSIONS Hormonal balance variations after menopause may influence brain processes concerned with cognition, especially memory and psychomotor speed. The observed effects may be related to androgens' influence on higher cortical functions in the changed hormonal dynamics of the postmenopausal period.
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Affiliation(s)
- Iwona Bojar
- Department for Women Health, Institute of Rural Health, Lublin, Poland
| | - Jarosław Pinkas
- School of Public Health, Center of Postgraduate Medical Education, Warsaw, Poland
| | - Mariusz Gujski
- Department of Prevention of Environmental Hazards and Allergology, Medical University of Warsaw, Warsaw, Poland
| | - Alfred Owoc
- Center for Public Health and Health Promotion, Institute of Rural Health, Lublin, Poland
| | - Dorota Raczkiewicz
- Institute of Statistics and Demography, Warsaw School of Economics, Warsaw, Poland
| | - Kasia Gustaw-Rothenberg
- Lou Ruvo Brain Wellness Center, Neurological Institute, The Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Neurodegenerative Diseases, Institute of Rural Health, Lublin, Poland
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Urbanski HF, Sorwell KG, Garyfallou VT, Garten J, Weiss A, Renner L, Neuringer M, Kohama SG. Androgen supplementation during aging: development of a physiologically appropriate protocol. Rejuvenation Res 2014; 17:150-3. [PMID: 24134213 DOI: 10.1089/rej.2013.1518] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Men show an age-related decline in the circulating levels of testosterone (T) and dehydroepiandrosterone sulfate (DHEAS). Consequently, there is interest in developing androgen supplementation paradigms for old men that replicate the hormone profiles of young adults. In the present study, we used old (21-26 years old) male rhesus monkeys as a model to examine the efficacy of an androgen supplementation paradigm that comprised oral T administration (12 mg/kg body weight, dissolved in sesame oil/chocolate) in the evening, and two oral DHEA administrations, 3 hr apart (0.04 mg/kg body weight, dissolved in sesame oil/chocolate) in the morning. After 5 days of repeated hormone supplementation, serial blood samples were remotely collected from each animal hourly across the 24-hr day, and assayed for cortisol, DHEAS, T, 5α-dihydrotestosterone (DHT), estrone (E1), and 17β-estradiol (E2). Following androgen supplementation, T levels were significantly elevated and this was associated with a more sustained nocturnal elevation of T's primary bioactive metabolites, DHT and E1 and E2. Plasma DHEAS levels were also significantly elevated after androgen supplementation; DHEAS levels rose in the early morning and gradually declined during the course of the day, closely mimicking the profiles observed in young adults (7-12 years old); in contrast, cortisol levels were unaltered by the supplementation. Together the data demonstrate a non-invasive androgen supplementation paradigm that restores youthful circulating androgen levels in old male primates. Because this paradigm preserves the natural circulating circadian hormone patterns, we predict that it will produce fewer adverse side effects, such as perturbed sleep or cognitive impairment.
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Affiliation(s)
- Henryk F Urbanski
- 1 Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University , Beaverton, Oregon
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Sorwell KG, Kohama SG, Urbanski HF. Testosterone increases circulating dehydroepiandrosterone sulfate levels in the male rhesus macaque. Front Endocrinol (Lausanne) 2014; 5:101. [PMID: 25009533 PMCID: PMC4070064 DOI: 10.3389/fendo.2014.00101] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/12/2014] [Indexed: 11/13/2022] Open
Abstract
The adrenal steroid dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are two of the most abundant hormones in the human circulation. Furthermore, they are released in a circadian pattern and show a marked age-associated decline. Adult levels of DHEA and DHEAS are significantly higher in males than in females, but the reason for this sexual dimorphism is unclear. In the present study, we administered supplementary androgens [DHEA, testosterone and 5α-dihydrotestosterone (DHT)] to aged male rhesus macaques (Macaca mulatta). While this paradigm increased circulating DHEAS immediately after DHEA administration, an increase was also observed following either testosterone or DHT administration, resulting in hormonal profiles resembling levels observed in young males in terms of both amplitude and circadian pattern. This stimulatory effect was limited to DHEAS, as an increase in circulating cortisol was not observed. Taken together, these data demonstrate an influence of the hypothalamo-pituitary-testicular axis on adrenal function in males, possibly by sensitizing the zona reticularis to the stimulating action of adrenocorticopic hormone. This represents a plausible mechanism to explain sex differences in circulating DHEA and DHEAS levels, and may have important implications in the development of hormone therapies designed for elderly men and women.
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Affiliation(s)
- Krystina G. Sorwell
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
- Department of Behavioral Neuroscience, Oregon Health & Sciences University, Portland, OR, USA
| | - Steven G. Kohama
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - Henryk F. Urbanski
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
- Department of Behavioral Neuroscience, Oregon Health & Sciences University, Portland, OR, USA
- Department of Physiology and Pharmacology, Oregon Health & Sciences University, Portland, OR, USA
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Beaverton, OR, USA
- *Correspondence: Henryk F. Urbanski, Division of Neuroscience, Oregon National Primate Research Center, 505 NW 185th Avenue, Beaverton, OR 97006, USA e-mail:
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Sorwell KG, Urbanski HF. Causes and consequences of age-related steroid hormone changes: insights gained from nonhuman primates. J Neuroendocrinol 2013; 25:1062-9. [PMID: 23796387 PMCID: PMC3883982 DOI: 10.1111/jne.12064] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 06/14/2013] [Accepted: 06/18/2013] [Indexed: 01/23/2023]
Abstract
Similar to humans, rhesus macaques (Macaca mulatta) are large, long-lived diurnal primates, and show similar age-related changes in the secretion of many steroid hormones, including oestradiol, testosterone, cortisol and dehydroepiandrosterone (DHEA). Consequently, they represent a pragmatic animal model in which to examine the mechanisms by which these steroidal changes contribute to perturbed sleep-wake cycles and cognitive decline in the elderly. Using remote serial blood sampling, we have found the circulating levels of DHEA sulphate, as well as oestradiol and testosterone, decline markedly in old monkeys. Furthermore, using the real-time polymerase chain reaction, we have shown that the genes for the enzymes associated with the conversion of DHEA to oestradiol and testosterone (3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and aromatase) are highly expressed in brain areas associated with cognition and behaviour, including the hippocampus, prefrontal cortex and amygdala. Taken together, these findings suggest that the administration of supplementary DHEA in the elderly may have therapeutic potential for cognitive and behavioural disorders, although with fewer negative side effects outside of the central nervous system. To test this, we have developed a novel steroid supplementation paradigm for use in old animals; this involves the oral administration of DHEA and testosterone at physiologically relevant times of the day to mimic the circadian hormone patterns observed in young adults. We are currently evaluating the efficacy of this steroid supplementation paradigm with respect to reversing age-associated disorders, including perturbed sleep-wake cycles and cognitive decline, as well as an impaired immune response.
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Affiliation(s)
- K G Sorwell
- Departments of Neuroscience and Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA; Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
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