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Terstege DJ, Epp JR. Parvalbumin as a sex-specific target in Alzheimer's disease research - A mini-review. Neurosci Biobehav Rev 2023; 153:105370. [PMID: 37619647 DOI: 10.1016/j.neubiorev.2023.105370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/14/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, and both the incidence of this disease and its associated cognitive decline disproportionally effect women. While the etiology of AD is unknown, recent work has demonstrated that the balance of excitatory and inhibitory activity across the brain may serve as a strong predictor of cognitive impairments in AD. Across the cortex, the most prominent source of inhibitory signalling is from a class of parvalbumin-expressing interneurons (PV+). In this mini-review, the impacts of sex- and age-related factors on the function of PV+ neurons are examined within the context of vulnerability to AD pathology. These primary factors of influence include changes in brain metabolism, circulating sex hormone levels, and inflammatory response. In addition to positing the increased vulnerability of PV+ neurons to dysfunction in AD, this mini-review highlights the critical importance of presenting sex stratified data in the study of AD.
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Affiliation(s)
- Dylan J Terstege
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Jonathan R Epp
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada.
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2
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Huang J, Xu B, Chen X, Yang L, Liu D, Lin J, Liu Y, Lei X, Huang C, Dou W, Guo D, Wei X, Zhang P, Huang Y, Gu X, Zhang H. Sex Hormone-Binding Globulin and Risk of Incident Dementia in Middle-Aged to Older Women: Results from the UK Biobank Cohort Study. Neuroendocrinology 2023; 114:170-178. [PMID: 37725912 DOI: 10.1159/000533929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 08/28/2023] [Indexed: 09/21/2023]
Abstract
INTRODUCTION The association of serum sex hormone-binding globulin (SHBG) concentrations with dementia risk remains uncertain in middle-aged to older women. We examined associations of serum SHBG levels with incidence of all-cause dementia and its subtypes in middle-aged to older women from the large population-based UK Biobank cohort study. METHODS Serum total SHBG levels were measured by immunoassay. The incidence of all-cause dementia and its subtypes was recorded. Cox proportional hazards models were used to calculate hazard ratios (HR) for main outcomes. RESULTS Among 171,482 community-dwelling women (mean [SD] age was 59.9 [5.4] years, median follow-up of 11.8 years), 2,368 developed dementia, including 1,088 from Alzheimer's disease (AD), 451 from vascular dementia (VAD), and 1,609 from other dementia. After multivariable adjustments, higher serum SHBG levels were significantly associated with higher risks of all-cause dementia, AD, and other dementia (all p < 0.05). Compared to those in the lowest quartile of SHBG levels, participants in the highest quartile of SHBG levels had a higher risk of all-cause dementia (HR: 1.34; 95% confidence interval [CI]: 1.16-1.53), AD (HR: 1.32; 95% CI: 1.07-1.62), and other dementia (HR: 1.44; 95% CI: 1.21-1.70). However, this relationship was not significant for VAD (HR: 1.16; 95% CI: 0.86-1.56). CONCLUSION These findings indicated that higher serum SHBG concentrations were independently associated with higher risks of incident all-cause dementia, as well as AD and other dementia among middle-aged to older women. No association was found for VAD.
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Affiliation(s)
- Junlin Huang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Bingyan Xu
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaomin Chen
- Department of Endocrinology, Zhongshan Hospital Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Linjie Yang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Deying Liu
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiayang Lin
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yating Liu
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuzhen Lei
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chensihan Huang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Weijuan Dou
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Dan Guo
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xueyun Wei
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Peizhen Zhang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yan Huang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuejiang Gu
- Dpartment of Endocrine and Metabolic Diseases, 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Huijie Zhang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Guangzhou, China
- State Key Laboratory of Organ Failure Research, Guangzhou, China
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Song L, Chen H, Qiao D, Zhang B, Guo F, Zhang Y, Wang C, Li S, Cui H. ZIP9 mediates the effects of DHT on learning, memory and hippocampal synaptic plasticity of male Tfm and APP/PS1 mice. Front Endocrinol (Lausanne) 2023; 14:1139874. [PMID: 37305050 PMCID: PMC10248430 DOI: 10.3389/fendo.2023.1139874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 05/15/2023] [Indexed: 06/13/2023] Open
Abstract
Androgens are closely associated with functions of hippocampal learning, memory, and synaptic plasticity. The zinc transporter ZIP9 (SLC39A9) regulates androgen effects as a binding site distinct from the androgen receptor (AR). However, it is still unclear whether androgens regulate their functions in hippocampus of mice through ZIP9. Compared with wild-type (WT) male mice, we found that AR-deficient male testicular feminization mutation (Tfm) mice with low androgen levels had learning and memory impairment, decreased expression of hippocampal synaptic proteins PSD95, drebrin, SYP, and dendritic spine density. Dihydrotestosterone (DHT) supplementation significantly improved these conditions in Tfm male mice, although the beneficial effects disappeared after hippocampal ZIP9 knockdown. To explore the underlying mechanism, we first detected the phosphorylation of ERK1/2 and eIF4E in the hippocampus and found that it was lower in Tfm male mice than in WT male mice, it upregulated with DHT supplementation, and it downregulated after hippocampal ZIP9 knockdown. Next, we found that the expression of PSD95, p-ERK1/2, and p-eIF4E increased in DHT-treated mouse hippocampal neuron HT22 cells, and ZIP9 knockdown or overexpression inhibited or further enhanced these effects. Using the ERK1/2 specific inhibitor SCH772984 and eIF4E specific inhibitor eFT508, we found that DHT activated ERK1/2 through ZIP9, resulting in eIF4E phosphorylation, thus promoting PSD95 protein expression in HT22 cells. Finally, we found that ZIP9 mediated the effects of DHT on the expression of synaptic proteins PSD95, drebrin, SYP, and dendritic spine density in the hippocampus of APP/PS1 mice through the ERK1/2-eIF4E pathway and affected learning and memory. This study demonstrated that androgen affected learning and memory in mice through ZIP9, providing new experimental evidence for improvement in learning and memory in Alzheimer's disease with androgen supplementation.
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Affiliation(s)
- Leigang Song
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Department of Sports Human Science, Hebei Sport University, Shijiazhuang, Hebei, China
| | - Huan Chen
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Dan Qiao
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Bohan Zhang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Fangzhen Guo
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yizhou Zhang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Chang Wang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Sha Li
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Huixian Cui
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
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Vaňková M, Velíková M, Vejražková D, Včelák J, Lukášová P, Rusina R, Vaňková H, Jarolímová E, Kancheva R, Bulant J, Horáčková L, Bendlová B, Hill M. The Role of Steroidomics in the Diagnosis of Alzheimer's Disease and Type 2 Diabetes Mellitus. Int J Mol Sci 2023; 24:ijms24108575. [PMID: 37239922 DOI: 10.3390/ijms24108575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Epidemiological studies suggest an association between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). This study aimed to investigate the pathophysiological markers of AD vs. T2DM for each sex separately and propose models that would distinguish control, AD, T2DM, and AD-T2DM comorbidity groups. AD and T2DM differed in levels of some circulating steroids (measured mostly by GC-MS) and in other observed characteristics, such as markers of obesity, glucose metabolism, and liver function tests. Regarding steroid metabolism, AD patients (both sexes) had significantly higher sex hormone binding globulin (SHBG), cortisol, and 17-hydroxy progesterone, and lower estradiol and 5α-androstane-3α,17β-diol, compared to T2DM patients. However, compared to healthy controls, changes in the steroid spectrum (especially increases in levels of steroids from the C21 group, including their 5α/β-reduced forms, androstenedione, etc.) were similar in patients with AD and patients with T2DM, though more expressed in diabetics. It can be assumed that many of these steroids are involved in counter-regulatory protective mechanisms that mitigate the development and progression of AD and T2DM. In conclusion, our results demonstrated the ability to effectively differentiate AD, T2DM, and controls in both men and women, distinguish the two pathologies from each other, and differentiate patients with AD and T2DM comorbidities.
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Affiliation(s)
- Markéta Vaňková
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Marta Velíková
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | | | - Josef Včelák
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Petra Lukášová
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Robert Rusina
- Department of Neurology, Third Faculty of Medicine, Charles University and Thomayer University Hospital, Ruská 2411, 100 00 Prague, Czech Republic
| | - Hana Vaňková
- Third Faculty of Medicine, Charles University, Ruská 2411, 100 00 Prague, Czech Republic
| | - Eva Jarolímová
- Third Faculty of Medicine, Charles University, Ruská 2411, 100 00 Prague, Czech Republic
| | - Radmila Kancheva
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Josef Bulant
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Lenka Horáčková
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Běla Bendlová
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
| | - Martin Hill
- Institute of Endocrinology, Národní 8, 110 00 Prague, Czech Republic
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Wrigglesworth J, Harding IH, Ward P, Woods RL, Storey E, Fitzgibbon B, Egan G, Murray A, Shah RC, Trevaks RE, Ward S, McNeil JJ, Ryan J. Factors Influencing Change in Brain-Predicted Age Difference in a Cohort of Healthy Older Individuals. J Alzheimers Dis Rep 2022; 6:163-176. [PMID: 35591948 PMCID: PMC9108625 DOI: 10.3233/adr-220011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 03/09/2022] [Indexed: 12/11/2022] Open
Abstract
Background: There is considerable variability in the rate at which we age biologically, and the brain is particularly susceptible to the effects of aging. Objective: We examined the test-retest reliability of brain age at one- and three-year intervals and identified characteristics that predict the longitudinal change in brain-predicted age difference (brain-PAD, defined by deviations of brain age from chronological age). Methods: T1-weighted magnetic resonance images were acquired at three timepoints from 497 community-dwelling adults (73.8±3.5 years at baseline, 48% were female). Brain age was estimated from whole brain volume, using a publicly available algorithm trained on an independent dataset. Linear mixed models were used, adjusting for sex, age, and age2. Results: Excellent retest reliability of brain age was observed over one and three years. We identified a significant sex difference in brain-PAD, where a faster rate of brain aging (worsening in brain age relative to chronological age) was observed in men, and this finding replicated in secondary analyses. The effect size, however, was relatively weak, equivalent to 0.16 years difference per year. A higher score in physical health related quality of life and verbal fluency were associated with a faster rate of brain aging, while depression was linked to a slower rate of brain aging, but these findings were not robust. Conclusion: Our study provides consistent evidence that older men have slightly faster brain atrophy than women. Given the sparsity of longitudinal research on brain age in older populations, future prospective studies are needed to confirm our findings.
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Affiliation(s)
- Jo Wrigglesworth
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Ian H. Harding
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Phillip Ward
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
- Turner Institute for Brain and Mental Health, Monash University, Clayton, VIC, Australia
- Australian Research Council Centre of Excellence for Integrative Brain Function, Clayton, VIC, Australia
| | - Robyn L. Woods
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Elsdon Storey
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Bernadette Fitzgibbon
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Gary Egan
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
- Australian Research Council Centre of Excellence for Integrative Brain Function, Clayton, VIC, Australia
| | - Anne Murray
- Berman Center for Outcomes & Clinical Research, Hennepin Healthcare Research Institute, Minneapolis, MN, USA
- Department of Medicine, Division of Geriatrics, Hennepin Healthcare, University of Minnesota, Minneapolis, MN, USA
| | - Raj C. Shah
- Department of Family Medicine and the Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Ruth E. Trevaks
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Stephanie Ward
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
- Centre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, NSW, Australia
- Department of Geriatric Medicine, Prince of Wales Hospital, Randwick, NSW, Australia
| | - John J. McNeil
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Joanne Ryan
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
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Yao Z, Liu B, Wang Y, Dong X. High cortisol and the risk of Alzheimer disease: A protocol for systematic review and meta-analysis. Medicine (Baltimore) 2021; 100:e27319. [PMID: 34596132 PMCID: PMC8483835 DOI: 10.1097/md.0000000000027319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Morning cortisol levels have been reported to be elevated among patients with Alzheimer disease (AD). We perform a protocol for systematic review and meta-analysis to assess morning central or peripheral cortisol levels in AD patients as compared with cognitively normal individuals. METHODS Studies were identified through systematic searches in August 2021 with no restrictions on date and time, language, and publication status using the following bibliographic databases: Embase, Medline, PubMed, Web of Science, Science Direct, and the Cochrane Library. Studies were identified using search terms related to cortisol, Alzheimer disease, and cognitive impairment. The study quality of included papers was evaluated using the "National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies." Statistical analyses were performed using Stata (version 14, StataCorp, College Station, TX). RESULTS The findings of this study will be submitted to peer-reviewed journals for publication. CONCLUSION Morning cortisol was elevated in AD patients and may have diagnostic and prognostic values for AD.
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Affiliation(s)
- Zhuang Yao
- Department of Nursing, Jiamusi College of Heilongjiang University of Chinese Medicine, Heilongjiang, China
| | - Bin Liu
- Department of Basic Western Medicine, Jiamusi College of Heilongjiang University of Chinese Medicine, Heilongjiang, China
| | - Yueyang Wang
- Institute of Acupuncture, Heilongjiang University of Chinese Medicine, Heilongjiang, China
| | - Xiaohong Dong
- Department of Nursing, Jiamusi College of Heilongjiang University of Chinese Medicine, Heilongjiang, China
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7
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Saelzler UG, Verhaeghen P, Panizzon MS, Moffat SD. Intact circadian rhythm despite cortisol hypersecretion in Alzheimer's disease: A meta-analysis. Psychoneuroendocrinology 2021; 132:105367. [PMID: 34340133 DOI: 10.1016/j.psyneuen.2021.105367] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/15/2021] [Accepted: 07/22/2021] [Indexed: 12/26/2022]
Abstract
Hypersecretion of the glucocorticoid steroid hormone cortisol by individuals with Alzheimer's disease (AD) has been suspected for several decades, during which time dozens of examinations of this phenomenon have been conducted and published. The goals of this investigation were to summarize this sizeable body of literature, test whether participant and methodological characteristics modify the magnitude of the AD-associated basal cortisol hypersecretion, and examine whether cortisol circadian rhythmicity is maintained among individuals with AD. To this end, the present meta-analysis and systematic review examined over 300 comparisons of indices of basal HPA-axis functioning between individuals with AD and cognitively normal older adults. AD was associated with basal cortisol elevations (g = 0.45) but the magnitude of the effect was not systematically impacted by any of the participant characteristics considered or the time-of-day of the cortisol sampling. Further, there was no evidence of group differences among direct indices of circadian rhythmicity such as the cortisol awakening response or the diurnal cortisol slope. These results suggest that basal hypersecretion of cortisol, but not circadian dysrhythmia, is characteristic of individuals with AD. Mechanistically, the observed hypersecretion is consistent with the theorized AD-driven deterioration of the hippocampus and subsequent reduction in hypothalamic-pituitary-adrenal axis inhibition. Further investigation is warranted to elucidate the role and timing of cortisol elevations in the progression of AD.
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Affiliation(s)
- Ursula G Saelzler
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr. La Jolla, San Diego, CA 92093, USA.
| | - Paul Verhaeghen
- Department of Psychology, Georgia Institute of Technology, 648 Cherry St. NW, Atlanta GA 30313, USA.
| | - Matthew S Panizzon
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr. La Jolla, San Diego, CA 92093, USA.
| | - Scott D Moffat
- Department of Psychology, Georgia Institute of Technology, 648 Cherry St. NW, Atlanta GA 30313, USA.
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Zhu D, Montagne A, Zhao Z. Alzheimer's pathogenic mechanisms and underlying sex difference. Cell Mol Life Sci 2021; 78:4907-4920. [PMID: 33844047 PMCID: PMC8720296 DOI: 10.1007/s00018-021-03830-w] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/09/2021] [Accepted: 03/29/2021] [Indexed: 01/01/2023]
Abstract
AD is a neurodegenerative disease, and its frequency is often reported to be higher for women than men: almost two-thirds of patients with AD are women. One prevailing view is that women live longer than men on average of 4.5 years, plus there are more women aged 85 years or older than men in most global subpopulations; and older age is the greatest risk factor for AD. However, the differences in the actual risk of developing AD for men and women of the same age is difficult to assess, and the findings have been mixed. An increasing body of evidence from preclinical and clinical studies as well as the complications in estimating incidence support the sex-specific biological mechanisms in diverging AD risk as an important adjunct explanation to the epidemiologic perspective. Although some of the sex differences in AD prevalence are due to differences in longevity, other distinct biological mechanisms increase the risk and progression of AD in women. These risk factors include (1) deviations in brain structure and biomarkers, (2) psychosocial stress responses, (3) pregnancy, menopause, and sex hormones, (4) genetic background (i.e., APOE), (5) inflammation, gliosis, and immune module (i.e., TREM2), and (6) vascular disorders. More studies focusing on the underlying biological mechanisms for this phenomenon are needed to better understand AD. This review presents the most recent data in sex differences in AD-the gateway to precision medicine, therefore, shaping expert perspectives, inspiring researchers to go in new directions, and driving development of future diagnostic tools and treatments for AD in a more customized way.
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Affiliation(s)
- Donghui Zhu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.
- Neuroscience Graduate Program, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA.
| | - Axel Montagne
- UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Zhen Zhao
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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9
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Wang X, Lv Z, Wu Q, Liu H, Gu Y, Ye T. Lower Plasma Total Testosterone Levels Were Associated With Steeper Decline in Brain Glucose Metabolism in Non-demented Older Men. Front Aging Neurosci 2021; 13:592845. [PMID: 33935680 PMCID: PMC8082135 DOI: 10.3389/fnagi.2021.592845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 03/17/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE There is growing evidence that testosterone may be implicated in the pathogenesis of Alzheimer's disease (AD). We aimed to examine the relationship between plasma total testosterone levels and change in brain glucose metabolism over time among non-demented older people. METHODS The association of plasma total testosterone levels with change in brain glucose metabolism among non-demented older people was investigated cross-sectionally and longitudinally. Given a significant difference in levels of plasma total testosterone between gender, we performed our analysis in a sex-stratified way. At baseline, 228 non-demented older people were included: 152 males and 76 females. RESULTS In the cross-sectional analysis, no significant relationship between plasma total testosterone levels and brain glucose metabolism was found in males or females. In the longitudinal analysis, we found a significant association of plasma total testosterone levels with change in brain glucose metabolism over time in males, but not in females. More specifically, in males, higher levels of total testosterone in plasma at baseline were associated with slower decline in brain glucose metabolism. CONCLUSION We found that higher levels of total testosterone in plasma at baseline were associated with slower decline in brain glucose metabolism in males without dementia, indicating that testosterone may have beneficial effects on brain function.
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Affiliation(s)
- Xiwu Wang
- Department of Psychiatry, Wenzhou Seventh People’s Hospital, Wenzhou, China
| | - Zhaoting Lv
- Department of Psychiatry, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Qian Wu
- School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Huitao Liu
- Department of Orthopedics, Taizhou Hospital of Zhejiang Province, Taizhou, China
| | - Yanrou Gu
- School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Teng Ye
- Department of Ultrasound, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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10
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Cortisol hypersecretion and the risk of Alzheimer's disease: A systematic review and meta-analysis. Ageing Res Rev 2020; 64:101171. [PMID: 32971258 DOI: 10.1016/j.arr.2020.101171] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/21/2020] [Accepted: 08/30/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Morning cortisol levels have been reported to be elevated among patients with Alzheimer's disease (AD); yet no meta-analysis has been conducted to confirm the existence and magnitude of this association. It also remains unclear whether hypercortisolism is a risk factor for AD. METHODS PubMed, EMBASE, and PsycINFO were systematically searched for eligible studies. Cross-sectional data were pooled using random-effects meta-analyses; the differences in morning cortisol levels between patients and cognitively normal controls were quantified. Longitudinal studies were qualitatively synthesised due to methodological heterogeneity. RESULTS 17,245 participants from 57 cross-sectional studies and 19 prospective cohort studies were included. Compared with cognitively normal controls, AD patients had moderately increased morning cortisol in blood (g = 0.422, P < 0.001; I2 = 48.5 %), saliva (g = 0.540, P < 0.001; I2 = 13.6 %), and cerebrospinal fluids (g = 0.565, P = 0.003; I2 = 75.3 %). A moderate elevation of morning cortisol was also detected in cerebrospinal fluids from patients with mild cognitive impairment (MCI) versus controls (g = 0.309, P = 0.001; I2 = 0.0 %). Cohort studies suggested that higher morning cortisol may accelerate cognitive decline in MCI or mild AD patients, but the results in cognitively healthy adults were inconsistent. CONCLUSIONS Morning cortisol was confirmed to be moderately elevated in AD patients and may have diagnostic and prognostic values for AD.
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Blood-brain barrier integrity in the pathogenesis of Alzheimer's disease. Front Neuroendocrinol 2020; 59:100857. [PMID: 32781194 DOI: 10.1016/j.yfrne.2020.100857] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/27/2020] [Accepted: 07/29/2020] [Indexed: 02/06/2023]
Abstract
The blood-brain barrier (BBB) tightly controls the molecular exchange between the brain parenchyma and blood. Accumulated evidence from transgenic animal Alzheimer's disease (AD) models and human AD patients have demonstrated that BBB dysfunction is a major player in AD pathology. In this review, we discuss the role of the BBB in maintaining brain integrity and how this is mediated by crosstalk between BBB-associated cells within the neurovascular unit (NVU). We then discuss the role of the NVU, in particular its endothelial cell, pericyte, and glial cell constituents, in AD pathogenesis. The effect of substances released by the neuroendocrine system in modulating BBB function and AD pathogenesis is also discussed. We perform a systematic review of currently available AD treatments specifically targeting pericytes and BBB glial cells. In summary, this review provides a comprehensive overview of BBB dysfunction in AD and a new perspective on the development of therapeutics for AD.
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12
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Tooze A, Sheehan JP. Neurocognitive changes in pituitary adenoma patients after Gamma Knife radiosurgery. J Neurosurg 2019; 129:55-62. [PMID: 30544290 DOI: 10.3171/2018.7.gks181595] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/26/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVEPituitary adenomas and the treatment required for the underlying neuropathology have frequently been associated with cognitive dysfunction. However, the mechanisms for these impairments remain the subject of much debate. The authors evaluated cognitive outcomes in patients treated with or without Gamma Knife radiosurgery (GKRS) for an underlying pituitary adenoma.METHODSThis was a retrospective, institutional review board-approved, single-institution study. A total of 51 patients (23 male, 28 female) treated for pituitary adenoma were included in this neurocognitive study. Twenty-one patients underwent GKRS following transsphenoidal surgery, 22 patients were treated with transsphenoidal surgery alone, and eight patients were conservatively managed or were treated with medical management alone. Comparisons using psychometric tests of general intellectual abilities, memory, and executive functions were made between the treatment groups, between male and female patients, and between patients with Cushing's disease and those with nonfunctioning adenoma (NFA).RESULTSThe entire patient sample, the NFA group, and the GKRS group scored significantly below expected on measures of both immediate and delayed memory, particularly for visually presented information (p ≤ 0.05); however, there were no significant differences between the patients with Cushing's disease and those with NFA (t ≤ 0.56, p ≥ 0.52). In those who underwent GKRS, memory scores were not significantly different from those in the patients who did not undergo GKRS (t ≤ 1.32, p ≥ 0.19). Male patients across the sample were more likely to demonstrate impairments in both immediate memory (t = -3.41, p = 0.003) and delayed memory (t = -3.80, p = 0.001) than were female patients (t ≤ 1.09, p ≥ 0.29). There were no impairments on measures of general intellectual functioning or executive functions in any patient group. The potential contributions of tumor size and hormone levels are discussed.CONCLUSIONSOverall, pituitary adenoma patients demonstrated relative impairment in anterograde memory. However, GKRS did not lead to adverse effects for immediate or delayed memory in pituitary adenoma patients. Cognitive assessment of pituitary adenoma patients is important in their longitudinal care.
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Affiliation(s)
- Alana Tooze
- 1Sussex Rehabilitation Centre, Princess Royal Hospital, Haywards Heath, Sussex, United Kingdom; and
| | - Jason P Sheehan
- 2Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia
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Honarpisheh P, McCullough LD. Sex as a biological variable in the pathology and pharmacology of neurodegenerative and neurovascular diseases. Br J Pharmacol 2019; 176:4173-4192. [PMID: 30950038 DOI: 10.1111/bph.14675] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/19/2019] [Accepted: 02/24/2019] [Indexed: 12/14/2022] Open
Abstract
The incidence of dementia, most commonly caused by cerebrovascular and neurodegenerative diseases, continues to grow as our population ages. Alzheimer disease (AD) and vascular cognitive impairment (VCI) are responsible for more than 80% of all cases of dementia. There are few effective, long-term treatments for AD and VCI-related conditions (e.g., stroke and cerebral amyloid angiopathy (CAA)). This review focuses on AD (as the most common "neurodegenerative" cause of dementia), CAA (as an "emerging" cause of dementia), and stroke (as the most common cause of "vascular" dementia). We will discuss the available literature on the pharmacological therapies that demonstrate sex differences, which refer to any combination of structural, chromosomal, gonadal, or hormonal differences between males and females. We will emphasize the importance of considering sex as a biological variable in the design of preclinical and clinical studies that investigate underlying pathologies or response to pharmacological interventions in dementia. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.
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Affiliation(s)
- Pedram Honarpisheh
- Department of Neurology, University of Texas McGovern Medical School, Houston, Texas
| | - Louise D McCullough
- Department of Neurology, University of Texas McGovern Medical School, Houston, Texas
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14
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Tenkorang MAA, Duong P, Cunningham RL. NADPH Oxidase Mediates Membrane Androgen Receptor-Induced Neurodegeneration. Endocrinology 2019; 160:947-963. [PMID: 30811529 PMCID: PMC6435014 DOI: 10.1210/en.2018-01079] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/22/2019] [Indexed: 12/21/2022]
Abstract
Oxidative stress (OS) is a common characteristic of several neurodegenerative disorders, including Parkinson disease (PD). PD is more prevalent in men than in women, indicating the possible involvement of androgens. Androgens can have either neuroprotective or neurodamaging effects, depending on the presence of OS. Specifically, in an OS environment, androgens via a membrane-associated androgen receptor (mAR) exacerbate OS-induced damage. To investigate the role of androgens on OS signaling and neurodegeneration, the effects of testosterone and androgen receptor activation on the major OS signaling cascades, the reduced form of NAD phosphate (NADPH) oxidase (NOX)1 and NOX2 and the Gαq/inositol trisphosphate receptor (InsP3R), were examined. To create an OS environment, an immortalized neuronal cell line was exposed to H2O2 prior to cell-permeable/cell-impermeable androgens. Different inhibitors were used to examine the role of G proteins, mAR, InsP3R, and NOX1/2 on OS generation and cell viability. Both testosterone and DHT/3-O-carboxymethyloxime (DHT)-BSA increased H2O2-induced OS and cell death, indicating the involvement of an mAR. Furthermore, classical AR antagonists did not block testosterone's negative effects in an OS environment. Because there are no known antagonists specific for mARs, an AR protein degrader, ASC-J9, was used to block mAR action. ASC-J9 blocked testosterone's negative effects. To determine OS-related signaling mediated by mAR, this study examined NOX1, NOX2, Gαq. NOX1, NOX2, and the Gαq complex with mAR. Only NOX inhibition blocked testosterone-induced cell loss and OS. No effects of blocking either Gαq or G protein activation were observed on testosterone's negative effects. These results indicate that androgen-induced OS is via the mAR-NOX complex and not the mAR-Gαq complex.
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Affiliation(s)
- Mavis A A Tenkorang
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
| | - Phong Duong
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rebecca L Cunningham
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
- Correspondence: Rebecca L. Cunningham, PhD, Department of Physiology and Anatomy, University of North Texas Health Science Center, 3400 Camp Bowie Boulevard, Fort Worth, Texas 76107. E-mail:
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Carr JS, Bonham LW, Morgans AK, Ryan CJ, Yokoyama JS, Geier EG. Genetic Variation in the Androgen Receptor and Measures of Plasma Testosterone Levels Suggest Androgen Dysfunction in Alzheimer's Disease. Front Neurosci 2018; 12:529. [PMID: 30131669 PMCID: PMC6090298 DOI: 10.3389/fnins.2018.00529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/13/2018] [Indexed: 01/08/2023] Open
Abstract
Alzheimer’s disease (AD) prevalence varies by sex, suggesting that sex chromosomes, sex hormones and/or their signaling could potentially modulate AD risk and progression. Low testosterone levels are reported in men with AD. Further, variation in the androgen receptor (AR) gene has been associated with AD risk and cognitive impairment. We assessed measures of plasma testosterone levels as a biomarker of AD in male participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort. Baseline testosterone levels were significantly different between clinical diagnosis groups [cognitively normal controls, mild cognitive impairment (MCI), or AD], with the lowest testosterone levels in men with AD. Lower baseline testosterone levels were associated with higher baseline clinical severity. Change in testosterone levels between baseline and 1-year follow-up varied by diagnosis; MCI had the greatest decreases in testosterone levels between baseline and 1-year follow-up. Despite differences by clinical diagnosis, there was no association between plasma testosterone and CSF biomarkers of AD pathology. We also tested single nucleotide polymorphisms (SNPs) in AR for association with AD risk in a separate cohort from ADNI and found 26 SNPs associated with risk for AD. The top associated SNP is predicted to be an expression quantitative trait locus for AR in multiple tissues, including brain, with the AD-associated risk allele predicted to confer lower AR expression. Our findings suggest a link between the androgen pathway and AD through Aβ/tau independent pathways. These effects may be most pronounced during conversion from MCI to dementia.
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Affiliation(s)
- Jessie S Carr
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States
| | - Luke W Bonham
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States.,Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States.,School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Alicia K Morgans
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, United States
| | - Charles J Ryan
- Helen Diller Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, United States
| | - Jennifer S Yokoyama
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States
| | - Ethan G Geier
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States
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Pike CJ. Sex and the development of Alzheimer's disease. J Neurosci Res 2017; 95:671-680. [PMID: 27870425 DOI: 10.1002/jnr.23827] [Citation(s) in RCA: 244] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022]
Abstract
Men and women exhibit differences in the development and progression of Alzheimer's disease (AD). The factors underlying the sex differences in AD are not well understood. This Review emphasizes the contributions of sex steroid hormones to the relationship between sex and AD. In women, events that decrease lifetime exposure to estrogens are generally associated with increased AD risk, whereas estrogen-based hormone therapy administered near the time of menopause may reduce AD risk. In men, estrogens do not exhibit age-related reduction and are not significantly associated with AD risk. Rather, normal age-related depletions of testosterone in plasma and brain predict enhanced vulnerability to AD. Both estrogens and androgens exert numerous protective actions in the adult brain that increase neural functioning and resilience as well as specifically attenuating multiple aspects of AD-related neuropathology. Aging diminishes the activational effects of sex hormones in sex-specific manners, which is hypothesized to contribute to the relationship between aging and AD. Sex steroid hormones may also drive sex differences in AD through their organizational effects during developmental sexual differentiation of the brain. Specifically, sex hormone actions during early development may confer inherent vulnerability of the female brain to development of AD in advanced age. The combined effects of organizational and activational effects of sex steroids yield distinct sex differences in AD pathogenesis, a significant variable that must be more rigorously considered in future research. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Christian J Pike
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
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17
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Lee JH, Byun MS, Yi D, Choe YM, Choi HJ, Baek H, Sohn BK, Lee JY, Kim HJ, Kim JW, Lee Y, Kim YK, Sohn CH, Woo JI, Lee DY. Sex-specific association of sex hormones and gonadotropins, with brain amyloid and hippocampal neurodegeneration. Neurobiol Aging 2017; 58:34-40. [DOI: 10.1016/j.neurobiolaging.2017.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/20/2017] [Accepted: 06/09/2017] [Indexed: 02/08/2023]
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18
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Ruan Q, D'onofrio G, Wu T, Greco A, Sancarlo D, Yu Z. Sexual dimorphism of frailty and cognitive impairment: Potential underlying mechanisms (Review). Mol Med Rep 2017; 16:3023-3033. [PMID: 28713963 DOI: 10.3892/mmr.2017.6988] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 01/01/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to assess systematically gender differences in susceptibility to frailty and cognitive performance decline, and the underlying mechanisms. A systematic assessment was performed of the identified reviews of cohort, mechanistic and epidemiological studies. The selection criteria of the present study included: i) Sexual dimorphism of frailty, ii) sexual dimorphism of subjective memory decline (impairment) and atrophy of hippocampus during early life, iii) sexual dimorphism of late‑onset Alzheimer's disease and iv) sexual dimorphism mechanisms underlying frailty and cognitive impairment. Males exhibit a susceptibility to poor memory performance and a severe atrophy of the hippocampus during early life and females demonstrate a higher prevalence for frailty and late‑life dementia. The different alterations within the hypothalamic‑pituitary‑gonadal/adrenal axis, particularly with regard to gonadal hormones, cortisol and dehydroepiandrosterone/sulfate‑bound dehydroepiandrosterone prior to and following andropause in males and menopause in females, serve important roles in sexual dimorphism of frailty and cognitive impairment. These endocrine changes may accelerate immunosenescence, weaken neuroprotective and neurotrophic effects, and promote muscle catabolism. The present study suggested that these age‑associated endocrine alterations interact with gender‑specific genetic and epigenetic factors, together with immunosenescence and iron accumulation. Environment factors, including psychological factors, are additional potential causes of the sexual dimorphism of frailty and cognitive impairment.
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Affiliation(s)
- Qingwei Ruan
- Department of Geriatrics, Shanghai Key Laboratory of Clinical Geriatrics, Shanghai Institute of Geriatrics and Gerontology, Huadong Hospital and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai 200040, P.R. China
| | - Grazia D'onofrio
- Department of Medical Sciences, Geriatric Unit and Laboratory of Gerontology and Geriatrics, The Scientific Institute for Research and Health Care, Home for Relief of the Suffering Hospital, San Giovanni Rotondo, Foggia I‑71013, Italy
| | - Tao Wu
- Department of Geriatrics, Shanghai Key Laboratory of Clinical Geriatrics, Shanghai Institute of Geriatrics and Gerontology, Huadong Hospital and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai 200040, P.R. China
| | - Antonio Greco
- Department of Medical Sciences, Geriatric Unit and Laboratory of Gerontology and Geriatrics, The Scientific Institute for Research and Health Care, Home for Relief of the Suffering Hospital, San Giovanni Rotondo, Foggia I‑71013, Italy
| | - Daniele Sancarlo
- Department of Medical Sciences, Geriatric Unit and Laboratory of Gerontology and Geriatrics, The Scientific Institute for Research and Health Care, Home for Relief of the Suffering Hospital, San Giovanni Rotondo, Foggia I‑71013, Italy
| | - Zhuowei Yu
- Department of Geriatrics, Shanghai Key Laboratory of Clinical Geriatrics, Shanghai Institute of Geriatrics and Gerontology, Huadong Hospital and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai 200040, P.R. China
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Swerdloff RS, Dudley RE, Page ST, Wang C, Salameh WA. Dihydrotestosterone: Biochemistry, Physiology, and Clinical Implications of Elevated Blood Levels. Endocr Rev 2017; 38:220-254. [PMID: 28472278 PMCID: PMC6459338 DOI: 10.1210/er.2016-1067] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 04/20/2017] [Indexed: 02/07/2023]
Abstract
Benefits associated with lowered serum DHT levels after 5α-reductase inhibitor (5AR-I) therapy in men have contributed to a misconception that circulating DHT levels are an important stimulus for androgenic action in target tissues (e.g., prostate). Yet evidence from clinical studies indicates that intracellular concentrations of androgens (particularly in androgen-sensitive tissues) are essentially independent of circulating levels. To assess the clinical significance of modest elevations in serum DHT and the DHT/testosterone (T) ratio observed in response to common T replacement therapy, a comprehensive review of the published literature was performed to identify relevant data. Although the primary focus of this review is about DHT in men, we also provide a brief overview of DHT in women. The available published data are limited by the lack of large, well-controlled studies of long duration that are sufficiently powered to expose subtle safety signals. Nonetheless, the preponderance of available clinical data indicates that modest elevations in circulating levels of DHT in response to androgen therapy should not be of concern in clinical practice. Elevated DHT has not been associated with increased risk of prostate disease (e.g., cancer or benign hyperplasia) nor does it appear to have any systemic effects on cardiovascular disease safety parameters (including increased risk of polycythemia) beyond those commonly observed with available T preparations. Well-controlled, long-term studies of transdermal DHT preparations have failed to identify safety signals unique to markedly elevated circulating DHT concentrations or signals materially different from T.
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Affiliation(s)
- Ronald S Swerdloff
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine at UCLA, Torrance, California 90502
| | | | - Stephanie T Page
- Division of Metabolism, Endocrinology, and Nutrition, University of Washington School of Medicine, Seattle, Washington 98195
| | - Christina Wang
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine at UCLA, Torrance, California 90502.,UCLA Clinical and Translational Science Institute, Harbor-UCLA Medical Center, and Los Angeles Biomedical Research Institute, David Geffen School of Medicine at UCLA, Torrance, California 90509
| | - Wael A Salameh
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine at UCLA, Torrance, California 90502
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Zhang C, Zhang Y, Shen Y, Zhao G, Xie Z, Dong Y. Anesthesia/Surgery Induces Cognitive Impairment in Female Alzheimer's Disease Transgenic Mice. J Alzheimers Dis 2017; 57:505-518. [PMID: 28269788 DOI: 10.3233/jad-161268] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Anesthesia and/or surgery may promote Alzheimer's disease (AD) by accelerating its neuropathogenesis. Other studies showed different findings. However, the potential sex difference among these studies has not been well considered, and it is unknown whether male or female AD patients are more vulnerable to develop postoperative cognitive dysfunction. We therefore set out to perform a proof of concept study to determine whether anesthesia and surgery can have different effects in male and female AD transgenic (Tg) mice, and in female AD Tg plus Cyclophilin D knockout (CypD KO) mice. The mice received an abdominal surgery under sevoflurane anesthesia (anesthesia/surgery). Fear Conditioning System (FCS) was used to assess the cognitive function. Hippocampal levels of synaptic marker postsynaptic density 95 (PSD-95) and synaptophysin (SVP) were measured using western blot analysis. Here we showed that the anesthesia/surgery decreased the freezing time in context test of FCS at 7 days after the anesthesia/surgery in female, but not male, mice. The anesthesia/surgery reduced hippocampus levels of synaptic marker PSD-95 and SVP in female, but not male, mice. The anesthesia/surgery induced neither reduction in freezing time in FCS nor decreased hippocampus levels of PSD-95 and SVP in the AD Tg plus CypD KO mice. These data suggest that the anesthesia/surgery induced a sex-dependent cognitive impairment and reduction in hippocampus levels of synaptic markers in AD Tg mice, potentially via a mitochondria-associated mechanism. These findings could promote clinical investigations to determine whether female AD patients are more vulnerable to the development of postoperative cognitive dysfunction.
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Affiliation(s)
- Ce Zhang
- Department of Anesthesia, China-Japan Union Hospital of Jilin University, Changchun, Jilin, P.R. China
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yiying Zhang
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yuan Shen
- Department of Psychiatry, Tenth People's Hospital of Tongji University, Shanghai, P.R. China
| | - Guoqing Zhao
- Department of Anesthesia, China-Japan Union Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Zhongcong Xie
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yuanlin Dong
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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Uchoa MF, Moser VA, Pike CJ. Interactions between inflammation, sex steroids, and Alzheimer's disease risk factors. Front Neuroendocrinol 2016; 43:60-82. [PMID: 27651175 PMCID: PMC5123957 DOI: 10.1016/j.yfrne.2016.09.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/10/2016] [Accepted: 09/14/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder for which there are no effective strategies to prevent or slow its progression. Because AD is multifactorial, recent research has focused on understanding interactions among the numerous risk factors and mechanisms underlying the disease. One mechanism through which several risk factors may be acting is inflammation. AD is characterized by chronic inflammation that is observed before clinical onset of dementia. Several genetic and environmental risk factors for AD increase inflammation, including apolipoprotein E4, obesity, and air pollution. Additionally, sex steroid hormones appear to contribute to AD risk, with age-related losses of estrogens in women and androgens in men associated with increased risk. Importantly, sex steroid hormones have anti-inflammatory actions and can interact with several other AD risk factors. This review examines the individual and interactive roles of inflammation and sex steroid hormones in AD, as well as their relationships with the AD risk factors apolipoprotein E4, obesity, and air pollution.
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Affiliation(s)
- Mariana F Uchoa
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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Pan W, Han S, Kang L, Li S, Du J, Cui H. Effects of dihydrotestosterone on synaptic plasticity of the hippocampus in mild cognitive impairment male SAMP8 mice. Exp Ther Med 2016; 12:1455-1463. [PMID: 27588067 PMCID: PMC4997989 DOI: 10.3892/etm.2016.3470] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/21/2016] [Indexed: 01/03/2023] Open
Abstract
The current study focused on how dihydrotestosterone (DHT) regulates synaptic plasticity in the hippocampus of mild cognitive impairment male senescence-accelerated mouse prone 8 (SAMP8) mice. Five-month-old SAMP8 mice were divided into the control, castrated and castrated-DHT groups, in which the mice were castrated and treated with physiological doses of DHT for a period of 2 months. To determine the regulatory mechanisms of DHT in the cognitive capacity, the effects of DHT on the morphology of the synapse and the expression of synaptic marker proteins in the hippocampus were investigated using immunohistochemistry, qPCR and western blot analysis. The results showed that the expression of cAMP-response element binding protein (CREB), postsynaptic density protein 95 (PSD95), synaptophysin (SYN) and developmentally regulated brain protein (Drebrin) was reduced in the castrated group compared to the control group. However, DHT promoted the expression of CREB, PSD95, SYN and Drebrin in the hippocampus of the castrated-DHT group. Thus, androgen depletion impaired the synaptic plasticity in the hippocampus of SAMP8 and accelerated the development of Alzheimer's disease (AD)-like neuropathology, suggesting that a similar mechanism may underlie the increased risk for AD in men with low testosterone. In addition, DHT regulated synaptic plasticity in the hippocampus of mild cognitive impairment (MCI) SAMP8 mice and delayed the progression of disease to Alzheimer's dementia. In conclusion, androgen-based hormone therapy is a potentially useful strategy for preventing the progression of MCI in aging men. Androgens enhance synaptic markers (SYN, PSD95, and Drebrin), activate CREB, modulate the fundamental biology of synaptic structure, and lead to the structural changes of plasticity in the hippocampus, all of which result in improved cognitive function.
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Affiliation(s)
- Wensen Pan
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China; Department of Respiration Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
| | - Shuo Han
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Lin Kang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Sha Li
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Juan Du
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Huixian Cui
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China; Hebei Key Laboratory for Brain Aging and Cognitive Neuroscience, Shijiazhuang, Hebei 050031, P.R. China
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23
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Moser VA, Pike CJ. Obesity and sex interact in the regulation of Alzheimer's disease. Neurosci Biobehav Rev 2015; 67:102-18. [PMID: 26708713 DOI: 10.1016/j.neubiorev.2015.08.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/01/2015] [Accepted: 08/03/2015] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which a number of genetic, environmental, and lifestyle risk factors have been identified. A significant modifiable risk factor is obesity in mid-life. Interestingly, both obesity and AD exhibit sex differences and are regulated by sex steroid hormones. Accumulating evidence suggests interactions between obesity and sex in regulation of AD risk, although the pathways underlying this relationship are unclear. Inflammation and the E4 allele of apolipoprotein E have been identified as independent risk factors for AD and both interact with obesity and sex steroid hormones. We review the individual and cooperative effects of obesity and sex on development of AD and examine the potential contributions of apolipoprotein E, inflammation, and their interactions to this relationship.
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Affiliation(s)
- V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA.
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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Association between Plasma Leptin and Estrogen in Female Patients of Amnestic Mild Cognitive Impairment. DISEASE MARKERS 2015; 2015:450237. [PMID: 26693203 PMCID: PMC4677007 DOI: 10.1155/2015/450237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 10/28/2015] [Accepted: 11/01/2015] [Indexed: 11/18/2022]
Abstract
Increasing evidences suggested the association between leptin and cognitive functions. Estrogen is an important factor that regulates the production and metabolism of leptin. However, little is known about the relationship between leptin and estrogen in mild cognitive impairment (MCI). Plasma levels of leptin, total estradiol, and β-amyloid protein (Aβ) were measured in a total of 23 female amnestic MCI (aMCI) patients and 19 female cognitively normal controls. This study showed that female aMCI patients had lower plasma levels of leptin and higher levels of estradiol compared to female normal controls. Leptin and estradiol levels were not correlated with cognitive performances or plasma Aβ levels in either aMCI patients or normal controls. There was a significant negative correlation between leptin and estrogen in female aMCI patients (r = -0.633, p = 0.002) but not in female normal controls. The potential mechanisms of this disease-stage-specific association between leptin and estrogen need further investigations.
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Seidl JNT, Massman PJ. Relationships between testosterone levels and cognition in patients with Alzheimer disease and nondemented elderly men. J Geriatr Psychiatry Neurol 2015; 28:27-39. [PMID: 25009157 DOI: 10.1177/0891988714541872] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND/AIMS Previous research suggests that low levels of testosterone may be associated with the development of Alzheimer disease (AD), as well as poorer performance on certain neuropsychological tests and increased risk of depression. METHODS This study utilized data from 61 nondemented older men and 68 men with probable AD. RESULTS Testosterone levels did not differ between the groups. Regression analyses in men with AD revealed that testosterone levels did not significantly predict performance on neuropsychological tests or a measure of depression. Among controls, testosterone levels predicted estimated premorbid verbal IQ and performance on a verbal fluency test. CONCLUSION Findings suggest that testosterone is not associated with most neuropsychological test performances in patients with AD.
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Affiliation(s)
| | - Paul J Massman
- Department of Psychology, University of Houston, Houston, TX, USA Department of Neurology, Alzheimer's Disease and Memory Disorders Center, Baylor College of Medicine, Houston, TX, USA
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Blair JA, McGee H, Bhatta S, Palm R, Casadesus G. Hypothalamic-pituitary-gonadal axis involvement in learning and memory and Alzheimer's disease: more than "just" estrogen. Front Endocrinol (Lausanne) 2015; 6:45. [PMID: 25859241 PMCID: PMC4373369 DOI: 10.3389/fendo.2015.00045] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/12/2015] [Indexed: 11/25/2022] Open
Abstract
Accumulating studies affirm the effects of age-related endocrine dysfunction on cognitive decline and increasing risk of neurodegenerative diseases. It is well known that estrogens can be protective for cognitive function, and more recently androgens and luteinizing hormone have also been shown to modulate learning and memory. Understanding the mechanisms underlying hypothalamic-pituitary-gonadal axis-associated cognitive dysfunction is crucial for therapeutic advancement. Here, we emphasize that reproductive hormones are influential in maintaining neuronal health and enhancing signaling cascades that lead to cognitive impairment. We summarize and critically evaluate age-related changes in the endocrine system, their implications in the development of Alzheimer's disease, and the therapeutic potential of endocrine modulation in the prevention of age-related cognitive decline.
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Affiliation(s)
- Jeffrey A. Blair
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Henry McGee
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Sabina Bhatta
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Russell Palm
- University of Toledo School of Medicine, Toledo, OH, USA
| | - Gemma Casadesus
- Department of Biological Sciences, Kent State University, Kent, OH, USA
- *Correspondence: Gemma Casadesus, Department of Biological Sciences, Kent State University, 256 Cunningham Hall, Kent, OH 44242, USA e-mail:
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Jayaraman A, Lent-Schochet D, Pike CJ. Diet-induced obesity and low testosterone increase neuroinflammation and impair neural function. J Neuroinflammation 2014; 11:162. [PMID: 25224590 PMCID: PMC4190446 DOI: 10.1186/s12974-014-0162-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 08/28/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Low testosterone and obesity are independent risk factors for dysfunction of the nervous system including neurodegenerative disorders such as Alzheimer's disease (AD). In this study, we investigate the independent and cooperative interactions of testosterone and diet-induced obesity on metabolic, inflammatory, and neural health indices in the central and peripheral nervous systems. METHODS Male C57B6/J mice were maintained on normal or high-fat diet under varying testosterone conditions for a four-month treatment period, after which metabolic indices were measured and RNA isolated from cerebral cortex and sciatic nerve. Cortices were used to generate mixed glial cultures, upon which embryonic cerebrocortical neurons were co-cultured for assessment of neuron survival and neurite outgrowth. Peripheral nerve damage was determined using paw-withdrawal assay, myelin sheath protein expression levels, and Na+,K+-ATPase activity levels. RESULTS Our results demonstrate that detrimental effects on both metabolic (blood glucose, insulin sensitivity) and proinflammatory (cytokine expression) responses caused by diet-induced obesity are exacerbated by testosterone depletion. Mixed glial cultures generated from obese mice retain elevated cytokine expression, although low testosterone effects do not persist ex vivo. Primary neurons co-cultured with glial cultures generated from high-fat fed animals exhibit reduced survival and poorer neurite outgrowth. In addition, low testosterone and diet-induced obesity combine to increase inflammation and evidence of nerve damage in the peripheral nervous system. CONCLUSIONS Testosterone and diet-induced obesity independently and cooperatively regulate neuroinflammation in central and peripheral nervous systems, which may contribute to observed impairments in neural health. Together, our findings suggest that low testosterone and obesity are interactive regulators of neuroinflammation that, in combination with adipose-derived inflammatory pathways and other factors, increase the risk of downstream disorders including type 2 diabetes and Alzheimer's disease.
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Affiliation(s)
| | | | - Christian J Pike
- Davis School of Gerontology, University of Southern California, 3715 McClintock Avenue, Los Angeles 90089, CA, USA.
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Kang L, Li S, Xing Z, Li J, Su Y, Fan P, Wang L, Cui H. Dihydrotestosterone treatment delays the conversion from mild cognitive impairment to Alzheimer's disease in SAMP8 mice. Horm Behav 2014; 65:505-15. [PMID: 24717850 DOI: 10.1016/j.yhbeh.2014.03.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/07/2014] [Accepted: 03/31/2014] [Indexed: 01/25/2023]
Abstract
The senescence-accelerated-prone mouse 8 (SAMP8) has been proposed as a suitable, naturally derived animal model for Alzheimer's disease (AD). In the current study, we focus on the problem whether SAMP8 mice show abnormal behavioral and neuropathological signs before they present the characteristic of AD. Our results demonstrated that given the presence of the senescent, behavioral and neuropathological characteristics, the "middle-aged" SAMP8 mice appear to be a suitable and naturally derived animal model for MCI basic research. There is relatively less evidence that androgen may be involved in the pathogenesis of AD. We determined testosterone (T) levels of SAMR1 and SAMP8 mice and found that the marked age-related decrease in serum androgen levels may be one of the risk factors for Alzheimer's dementia. We also evaluated the interventional effect on MCI phase by dihydrotestosterone (DHT) in male SAMP8 mice and found that timely and appropriate androgen intervention can postpone the onset and improve the symptoms of dementia.
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Affiliation(s)
- Lin Kang
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Sha Li
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Zhaoguo Xing
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Jianzhong Li
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Yuhong Su
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Ping Fan
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Lei Wang
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China
| | - Huixian Cui
- Department of Human Anatomy, Hebei Medical University, Hebei, PR China; Hebei Key Laboratory for Brain Aging and Cognitive Neuroscience, Hebei, PR China.
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Verdile G, Laws SM, Henley D, Ames D, Bush AI, Ellis KA, Faux NG, Gupta VB, Li QX, Masters CL, Pike KE, Rowe CC, Szoeke C, Taddei K, Villemagne VL, Martins RN. Associations between gonadotropins, testosterone and β amyloid in men at risk of Alzheimer's disease. Mol Psychiatry 2014; 19:69-75. [PMID: 23089633 DOI: 10.1038/mp.2012.147] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 08/07/2012] [Accepted: 09/04/2012] [Indexed: 11/09/2022]
Abstract
Testosterone and gonadotropins have been associated with cognitive decline in men and the modulation of β amyloid (Aβ) metabolism. The relatively few studies that have investigated whether changes in one or a combination of these hormones influence Aβ levels have focused primarily on plasma Aβ(1-40) and not on the more pathogenic Aβ(1-42). Currently, no study has investigated whether these hormones are associated with an increase in brain amyloid deposition, ante mortem. Through the highly characterised Australian imaging, biomarkers and lifestyle study, we have determined the impact of these hormones on plasma Aβ levels and brain amyloid burden (Pittsburgh compound B (PiB) retention). Spearman's rank correlation and linear regression analysis was carried out across the cohort and within subclassifications. Luteinizing hormone (LH) was the only variable shown, in the total cohort, to have a significant impact on plasma Aβ(1-40) and Aβ(1-42) levels (beta=0.163, P<0.001; beta=0.446, P<0.001). This held in subjective memory complainers (SMC) (Aβ(1-40); beta=0.208, P=0.017; Aβ(1-42); beta=0.215, P=0.017) but was absent in mild cognitive impairment (MCI) and Alzheimer's disease (AD) groups. In SMC, increased frequency of the APOE-ɛ4 allele (beta=0.536, P<0.001) and increasing serum LH levels (beta=0.421, P=0.004) had a significant impact on PiB retention. Whereas in MCI, PiB retention was associated with increased APOE-ɛ4 allele copy number (beta=0.674, P<0.001) and decreasing calculated free testosterone (beta=-0.303, P=0.043). These findings suggest a potential progressive involvement of LH and testosterone in the early preclinical stages of AD. Furthermore, these hormones should be considered while attempting to predict AD at these earliest stages of the disease.
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Affiliation(s)
- G Verdile
- 1] Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia [2] Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia, Australia
| | - S M Laws
- 1] Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia [2] Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia, Australia [3] Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com
| | - D Henley
- 1] Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia [2] School of Medicine and Pharmacology, University of Western Australia, Crawley, Western Australia, Australia
| | - D Ames
- 1] Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, St Vincent's Aged Psychiatry Service, St George's Hospital, Melbourne, Victoria, Australia [2] National Ageing Research Institute, Parkville, Victoria, Australia
| | - A I Bush
- 1] Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com [2] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [3] Centre for Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - K A Ellis
- 1] Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, St Vincent's Aged Psychiatry Service, St George's Hospital, Melbourne, Victoria, Australia [2] National Ageing Research Institute, Parkville, Victoria, Australia [3] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - N G Faux
- 1] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [2] Centre for Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - V B Gupta
- 1] Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia [2] Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia, Australia
| | - Q-X Li
- 1] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [2] Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | - C L Masters
- 1] Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com [2] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [3] Centre for Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - K E Pike
- 1] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [2] Centre for Neuroscience, The University of Melbourne, Parkville, Victoria, Australia [3] Department of Nuclear Medicine & Centre for PET, Austin Health, Heidelberg, Victoria, Australia [4] School of Psychological Science, La Trobe University, Bundoora, Victoria Australia
| | - C C Rowe
- Department of Nuclear Medicine & Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - C Szoeke
- 1] National Ageing Research Institute, Parkville, Victoria, Australia [2] CSIRO, Parkville, Victoria, Australia
| | - K Taddei
- 1] Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia [2] Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia, Australia [3] Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com
| | - V L Villemagne
- 1] Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia [2] Department of Nuclear Medicine & Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - R N Martins
- 1] Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia [2] Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia, Australia [3] Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com
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Abstract
As America’s baby boomer population matures, there is an increasing interest in supplements that can delay or oppose the aging process. This antiaging movement has exploded over the past decade. While most supplements are not supported by scientific literature or government controls, a number of products have been the subject of significant scientific inquiry. Hormone replacement therapy, including testosterone and growth hormone, has mixed results, and antioxidative strategies are supported by basic science but lack clinical evidence-based outcomes. While the process of aging has become better understood leading to more rational approaches to combat its effects on health, the clinician is reminded to carefully discern between the science and marketing that is available in this area.
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Rettberg JR, Yao J, Brinton RD. Estrogen: a master regulator of bioenergetic systems in the brain and body. Front Neuroendocrinol 2014; 35:8-30. [PMID: 23994581 PMCID: PMC4024050 DOI: 10.1016/j.yfrne.2013.08.001] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/09/2013] [Accepted: 08/10/2013] [Indexed: 01/12/2023]
Abstract
Estrogen is a fundamental regulator of the metabolic system of the female brain and body. Within the brain, estrogen regulates glucose transport, aerobic glycolysis, and mitochondrial function to generate ATP. In the body, estrogen protects against adiposity, insulin resistance, and type II diabetes, and regulates energy intake and expenditure. During menopause, decline in circulating estrogen is coincident with decline in brain bioenergetics and shift towards a metabolically compromised phenotype. Compensatory bioenergetic adaptations, or lack thereof, to estrogen loss could determine risk of late-onset Alzheimer's disease. Estrogen coordinates brain and body metabolism, such that peripheral metabolic state can indicate bioenergetic status of the brain. By generating biomarker profiles that encompass peripheral metabolic changes occurring with menopause, individual risk profiles for decreased brain bioenergetics and cognitive decline can be created. Biomarker profiles could identify women at risk while also serving as indicators of efficacy of hormone therapy or other preventative interventions.
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Affiliation(s)
- Jamaica R Rettberg
- Neuroscience Department, University of Southern California, Los Angeles, CA 90033, United States
| | - Jia Yao
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, United States
| | - Roberta Diaz Brinton
- Neuroscience Department, University of Southern California, Los Angeles, CA 90033, United States; Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, United States; Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
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32
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Panizzon MS, Hauger R, Xian H, Vuoksimaa E, Spoon KM, Mendoza SP, Jacobson KC, Vasilopoulos T, Rana BK, McKenzie R, McCaffery JM, Lyons MJ, Kremen WS, Franz CE. Interaction of APOE genotype and testosterone on episodic memory in middle-aged men. Neurobiol Aging 2013; 35:1778.e1-8. [PMID: 24444806 DOI: 10.1016/j.neurobiolaging.2013.12.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/19/2013] [Accepted: 12/21/2013] [Indexed: 01/12/2023]
Abstract
Age-related changes in testosterone are believed to be a key component of the processes that contribute to cognitive aging in men. The APOE-ε4 allele may interact with testosterone and moderate the hormone's association with cognition. The goals of the present study were to examine the degree to which free testosterone is associated with episodic memory in a community-based sample of middle-aged men, and examine the potential interaction between free testosterone and the APOE-ε4 allele. Data were used from 717 participants in the Vietnam Era Twin Study of Aging. Average age was 55.4 years (standard deviation = 2.5). Significant positive associations were observed between free testosterone level and verbal episodic memory, as well as a significant interaction between free testosterone and APOE-ε4 status. In ε4 carriers free testosterone was positively associated with verbal episodic memory performance (story recall), whereas no association was observed in ε4 noncarriers. Results support the hypothesis that APOE-ε4 status increases susceptibility to other risk factors, such as low testosterone, which may ultimately contribute to cognitive decline or dementia.
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Affiliation(s)
- Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA.
| | - Richard Hauger
- Department of Psychiatry, University of California, San Diego, CA, USA; VA San Diego Healthcare System, CA, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, USA
| | - Hong Xian
- Department of Biostatistics, St. Louis University, College for Public Health & Social Justice, St. Louis, MO, USA; Research Service, St. Louis Veterans Affairs Medical Center, St. Louis, MO
| | - Eero Vuoksimaa
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA; Department of Public Health, University of Helsinki, Helsinki, Finland
| | - Kelly M Spoon
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
| | - Sally P Mendoza
- Department of Psychology, University of California, Davis, CA, USA
| | | | | | - Brinda K Rana
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA
| | - Ruth McKenzie
- Department of Psychology, Boston University, Boston, MA, USA
| | - Jeanne M McCaffery
- Department of Psychiatry and Human Behavior, The Miriam Hospital and Warren Alpert School of Medicine at Brown University, Providence, RI, USA
| | - Michael J Lyons
- Department of Psychology, Boston University, Boston, MA, USA
| | - William S Kremen
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA; VA San Diego Healthcare System, CA, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, USA
| | - Carol E Franz
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA
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Xing Y, Jia J, Ji X, Tian T. Estrogen associated gene polymorphisms and their interactions in the progress of Alzheimer's disease. Prog Neurobiol 2013; 111:53-74. [DOI: 10.1016/j.pneurobio.2013.09.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 08/21/2013] [Accepted: 09/24/2013] [Indexed: 10/26/2022]
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Hogervorst E. Effects of gonadal hormones on cognitive behaviour in elderly men and women. J Neuroendocrinol 2013; 25:1182-95. [PMID: 23895362 DOI: 10.1111/jne.12080] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/02/2013] [Accepted: 07/24/2013] [Indexed: 01/04/2023]
Abstract
Over the last four decades, animal and cell culture studies have shown that sex steroids can have protective effects on the ageing brain. Limited short-term positive effects (2-4 months) of oestrogen treatment were found in women without (as well as with) dementia. By contrast to these initial promising findings, several large treatment studies showed that longer-term oestrogen treatment, particularly when given in combination with progesterone, could exert negative effects on cognitive function in women aged over 65 years. Several observational studies of older women and men also suggest that longer exposure to higher endogenous oestrogen levels at an older age might confer risk for accelerated cognitive decline and dementia. However, health of participants may modify this association and, in women closer to the age at the onset of menopause, positive associations of oestrogens with cognition were also found. The 'healthy cell bias' theory suggests that oestrogens have protective effects in healthy neurones, although cells undergoing pathological change show acceleration in their demise when exposed to oestrogens. In older men, most studies reported higher bioavailable testosterone levels to be associated with better cognitive function. Other studies have reported optimal testosterone levels for better global cognitive function and a reduced risk of cognitive decline. Variation in health status over time and the use of (in)sensitive cognitive tests and hormone assays may explain why this was not always found. In older women, this association (of testosterone with cognition) is less clear. Small studies reported some benefits of testosterone treatment in combination with oestrogen on cognition, although these were of short duration. Several observational studies, on the other hand, found negative associations between high testosterone levels and worse cognitive function in older women. Age, health status, duration of treatment and sex may thus modify effects of longer-term elevated sex steroid levels on brain function.
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Affiliation(s)
- E Hogervorst
- Applied Cognitive Research Group, SSEHS, Loughborough University, Loughborough, Leicestershire, UK
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35
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A novel selective androgen receptor modulator, NEP28, is efficacious in muscle and brain without serious side effects on prostate. Eur J Pharmacol 2013; 720:107-14. [DOI: 10.1016/j.ejphar.2013.10.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 10/18/2013] [Accepted: 10/23/2013] [Indexed: 01/10/2023]
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36
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Associations between sex hormones and cognitive and neuropsychiatric manifestations in vascular dementia (VaD). Arch Gerontol Geriatr 2013; 56:85-90. [DOI: 10.1016/j.archger.2012.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 09/27/2012] [Accepted: 10/02/2012] [Indexed: 11/18/2022]
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Dubal DB, Broestl L, Worden K. Sex and gonadal hormones in mouse models of Alzheimer's disease: what is relevant to the human condition? Biol Sex Differ 2012; 3:24. [PMID: 23126652 PMCID: PMC3524653 DOI: 10.1186/2042-6410-3-24] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/27/2012] [Indexed: 11/10/2022] Open
Abstract
Biologic sex and gonadal hormones matter in human aging and diseases of aging such as Alzheimer's - and the importance of studying their influences relates directly to human health. The goal of this article is to review the literature to date on sex and hormones in mouse models of Alzheimer's disease (AD) with an exclusive focus on interpreting the relevance of findings to the human condition. To this end, we highlight advances in AD and in sex and hormone biology, discuss what these advances mean for merging the two fields, review the current mouse model literature, raise major unresolved questions, and offer a research framework that incorporates human reproductive aging for future studies aimed at translational discoveries in this important area. Unraveling human relevant pathways in sex and hormone-based biology may ultimately pave the way to novel and urgently needed treatments for AD and other neurodegenerative diseases.
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Affiliation(s)
- Dena B Dubal
- Laboratory of Neuroscience and Aging Research, Department of Neurology, Sandler Neurosciences Center, Room 212B, University of California, San Francisco, San Francisco, CA 94158, USA.
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Chace C, Pang D, Weng C, Temkin A, Lax S, Silverman W, Zigman W, Ferin M, Lee JH, Tycko B, Schupf N. Variants in CYP17 and CYP19 cytochrome P450 genes are associated with onset of Alzheimer's disease in women with down syndrome. J Alzheimers Dis 2012; 28:601-12. [PMID: 22057025 DOI: 10.3233/jad-2011-110860] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
CYP17 and CYP19 are involved in the peripheral synthesis of estrogens, and polymorphisms in CYP17 and CYP19 have been associated with increased risk of estrogen-related disorders. Women with Down syndrome (DS) have early onset and high risk for Alzheimer's disease (AD). We conducted a prospective community-based cohort study to examine the relationship between SNPs in CYP17 and CYP19 and cumulative incidence of AD, hormone levels and sex hormone binding globulin in women with DS. Two hundred and thirty-five women with DS, 31 to 67 years of age and nondemented at initial examination, were assessed for cognitive and functional abilities, behavioral/psychiatric conditions, and health status at 14-20 month intervals over five assessment cycles. We genotyped these individuals for single-nucleotide polymorphisms (SNPs) in CYP17 and CYP19. Four SNPs in CYP17 were associated with a two and one half-fold increased risk of AD, independent of APOE genotype. Four SNPs in CYP19 were associated with a two-fold increased risk of AD, although three were significant only in those without an APOE ε4 allele. Further, carrying high risk alleles in both CYP17 and CYP19 was associated with an almost four-fold increased risk of AD (OR = 3.8, 95% CI, 1.6-9.5) and elevated sex hormone binding globulin in postmenopausal women. The main effect of the CYP17 and CYP19 variants was to decrease the age at onset. These findings suggest that genes contributing to estrogen bioavailability influence risk of AD in women with DS.
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Affiliation(s)
- Constance Chace
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
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Palm R, Ayala-Fontanez N, Garcia Y, Lee HG, Smith MA, Casadesus G. Neuroendocrinology-based therapy for Alzheimer's disease. Biofactors 2012; 38:123-32. [PMID: 22438197 DOI: 10.1002/biof.1011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 02/03/2012] [Indexed: 01/11/2023]
Abstract
The nervous system interacts directly with the endocrine system to control a plethora of central nervous system (CNS) functions. Metabolic and reproductive hormones are known to be important in the maintenance of neuronal health and their fluctuations are important for CNS aspects ranging from sleep and appetite regulation to cognitive function. This review will summarize and critically evaluate how age-related changes in sex and metabolic hormones modulate affect cognitive function and the implications of targeting the neuroendocrinological system as a therapeutic strategy in Alzheimer's disease.
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Affiliation(s)
- Russell Palm
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
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Barron AM, Pike CJ. Sex hormones, aging, and Alzheimer's disease. Front Biosci (Elite Ed) 2012. [PMID: 22201929 DOI: 10.2741/434] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A promising strategy to delay and perhaps prevent Alzheimer's disease (AD) is to identify the age-related changes that put the brain at risk for the disease. A significant normal age change known to result in tissue-specific dysfunction is the depletion of sex hormones. In women, menopause results in a relatively rapid loss of estradiol and progesterone. In men, aging is associated with a comparatively gradual yet significant decrease in testosterone. We review a broad literature that indicates age-related losses of estrogens in women and testosterone in men are risk factors for AD. Both estrogens and androgens exert a wide range of protective actions that improve multiple aspects of neural health, suggesting that hormone therapies have the potential to combat AD pathogenesis. However, translation of experimental findings into effective therapies has proven challenging. One emerging treatment option is the development of novel hormone mimetics termed selective estrogen and androgen receptor modulators. Continued research of sex hormones and their roles in the aging brain is expected to yield valuable approaches to reducing the risk of AD.
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Affiliation(s)
- Anna M Barron
- USC Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089 USA
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Testosterone levels and cognition in elderly men: a review. Maturitas 2011; 69:322-37. [PMID: 21696899 DOI: 10.1016/j.maturitas.2011.05.012] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 11/24/2022]
Abstract
Average testosterone levels and many cognitive functions show a decline with age. There is evidence to suggest that this association is not just age related. Results from cell culture and animal studies provide convincing evidence that testosterone could have protective effects on brain function. Alzheimer's disease (AD) is characterised by brain pathology affecting cognitive function and AD prevalence increases with age. Testosterone levels are lower in AD cases compared to controls, and some studies have suggested that low free testosterone (FT) may precede AD onset. Men with AD may show accelerated endocrinological ageing, characterised by an earlier lowering of thyroid stimulating hormone, an earlier increase in sex hormone binding globulin (SHBG), a subsequent earlier decrease in FT and an earlier increase in gonadotropin levels in response to this. Positive associations have been found between testosterone levels and global cognition, memory, executive functions and spatial performance in observational studies. However, non-significant associations were also reported. It may be that an optimal level of testosterone exists at which some cognitive functions are improved. This may be modified with an older age, with a shifting of the optimal testosterone curve to maintain cognition to the left and a lower optimal level thus needed to be beneficial for the brain. Genetic factors, such as APOE and CAG polymorphisms may further interact with testosterone levels in their effects on cognition. The roles of SHBG, gonadotropins, thyroid hormones and estrogens in maintaining cognitive function and preventing dementia in men are also not completely understood and should be investigated further. Hypogonadal men do not seem to benefit from testosterone supplementation but small scale, short term intervention studies in eugonadal men with and without cognitive impairments have shown promising results. Larger randomised, controlled trials are needed to further investigate testosterone treatment in protecting against cognitive decline and/or dementia.
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Rosario ER, Chang L, Head EH, Stanczyk FZ, Pike CJ. Brain levels of sex steroid hormones in men and women during normal aging and in Alzheimer's disease. Neurobiol Aging 2011; 32:604-13. [PMID: 19428144 PMCID: PMC2930132 DOI: 10.1016/j.neurobiolaging.2009.04.008] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Revised: 03/21/2009] [Accepted: 04/10/2009] [Indexed: 01/12/2023]
Abstract
We examined the relationships between normal aging, Alzheimer's disease (AD), and brain levels of sex steroid hormones in men and women. In postmortem brain tissue from neuropathologically normal, postmenopausal women, we found no age-related changes in brain levels of either androgens or estrogens. In comparing women with and without AD at different ages, brain levels of estrogens and androgens were lower in AD cases aged 80 years and older but not significantly different in the 60-79 year age range. In male brains, we observed that normal aging was associated with significant decreases in androgens but not estrogens. Further, in men aged 60-79 years, brain levels of testosterone but not estrogens were lower in cases with mild neuropathological changes as well as those with advanced AD neuropathology. In male cases over age 80, brain levels hormones did not significantly vary by neuropathological status. To begin investigating the relationships between hormone levels and indices of AD neuropathology, we measured brain levels of soluble β-amyloid (Aβ). In male cases with mild neuropathological changes, we found an inverse relationship between brain levels of testosterone and soluble Aβ. Collectively, these findings demonstrate sex-specific relationships between normal, age-related depletion of androgens and estrogens in men and women, which may be relevant to development of AD.
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Affiliation(s)
- Emily R. Rosario
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Lilly Chang
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089
| | - Elizabeth H. Head
- Department of Neurology, University of California Irvine, Irvine, CA 92697
| | - Frank Z. Stanczyk
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089
| | - Christian J. Pike
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
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Barron AM, Hojo Y, Mukai H, Higo S, Ooishi Y, Hatanaka Y, Ogiue-Ikeda M, Murakami G, Kimoto T, Kawato S. Regulation of synaptic plasticity by hippocampus synthesized estradiol. Horm Mol Biol Clin Investig 2011; 7:361-75. [PMID: 25961274 DOI: 10.1515/hmbci.2011.118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/21/2011] [Indexed: 01/29/2023]
Abstract
Estradiol is synthesized from cholesterol in hippocampal neurons of adult rats by cytochrome P450 and hydroxysteroid dehydrogenase enzymes. These enzymes are expressed in the glutamatergic neurons of the hippocampus. Surprisingly, the concentration of estradiol and androgen in the hippocampus is significantly higher than that in circulation. Locally synthesized estradiol rapidly and potently modulates synaptic plasticity within the hippocampus. E2 rapidly potentiates long-term depression and induces spinogenesis through synaptic estrogen receptors and kinases. The rapid effects of estradiol are followed by slow genomic effects mediated by both estrogen receptors located at the synapse and nucleus, modulating long-term potentiation and promoting the formation of new functional synaptic contacts. Age-related changes in hippocampally derived estradiol synthesis and distribution of estrogen receptors may alter synaptic plasticity, and could potentially contribute to age-related cognitive decline. Understanding factors which regulate hippocampal estradiol synthesis could lead to the identification of alternatives to conventional hormone therapy to protect against age-related cognitive decline.
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Thornton V, Warden D, Talbot C, Mastana SS, Bandelow S, Hogervorst E. Modification of estrogen's association with Alzheimer's disease risk by genetic polymorphisms. Brain Res 2011; 1379:213-23. [PMID: 21211518 DOI: 10.1016/j.brainres.2010.12.074] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 12/23/2010] [Accepted: 12/23/2010] [Indexed: 11/17/2022]
Abstract
Contrasting effects of estrogen treatment on cognitive function and Alzheimer's disease (AD) risk have been reported. It may be that genetic factors modify these relations. In the present study, 696 participants from the Oxford Project to Investigate Memory and Ageing were included (355 AD cases, 341 controls). Those individuals with other types of dementia and those using hormone treatment had been excluded. Analyses controlled for body mass index, age at blood sampling, and education. Analyses of variance revealed main effects, but not an interaction, for apolipoprotein E (APOE) and Catechol-O-methyl transferase (COMT) genotypes on estradiol (E2) levels in men (p=0.003 and p=0.10, respectively), but not in women (p=0.82 and p=0.49, respectively). Men carrying the APOE ε4 allele had lower E2 levels, while those carrying the COMT Val/Val alleles had higher E2 levels compared to Met/Val (p<0.05) allele carriers. Higher estrone (E1) levels and carrying the APOE ε4 allele (but not COMT alone, or in combination with the APOE genotype) were independent risk factors for AD. Similar to earlier studies, the heterozygous COMT genotype (Met/Val) showed a synergistic effect with the APOE ε4 allele being non-significantly associated with lower cognitive function. In conclusion, the present study suggests that elevated E1 levels significantly increase AD risk in both men and women. However, interactions between APOE ε4 and genetic polymorphisms related to sex steroid metabolism and AD risk need to be further investigated.
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Affiliation(s)
- V Thornton
- Loughborough University, Loughborough, UK
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Safarinejad MR, Shafiei N, Safarinejad S. Association of the (TAAAA)n repeat and Asp327Asn polymorphisms in the sex hormone-binding globulin (SHBG) gene with idiopathic male infertility and relation to serum SHBG concentrations. J Steroid Biochem Mol Biol 2011; 123:37-45. [PMID: 20974254 DOI: 10.1016/j.jsbmb.2010.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 10/16/2010] [Accepted: 10/18/2010] [Indexed: 02/03/2023]
Abstract
Sex hormone binding globulin (SHBG) is involved in delivering sex hormones to target tissues. We investigated the association between the (TAAAA)n repeat polymorphism, and Asp327Asn polymorphism in the SHBG gene with semen quality and idiopathic male infertility. We studied 168 men with idiopathic infertility [oligoasthenoteratozoospermia (OAT)] and equal number of age-matched normal controls. The serum levels of SHBG, reproductive and thyroid hormones, and Inhibin B were measured. Semen parameters were also assessed. The genotype assays for the SHBG polymorphism were done using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Baseline SHBG levels tended to be lower in infertile men (21.1±7.2nmol/l) compared to normal fertile men (24.7±7.9nmol/l). SHBG levels tended to be higher among the subjects with the Asn/Asn (25.84±3.6nmol/l) and S/S (24.50±5.4nmol/l) genotypes compared to subjects with the Asp/Asn (24.38±3.2nmol/l) and L/L (18.44±4.2nmol/l) genotypes of the SHBG gene. The genotype frequencies of Asp/Asp were 80.9% in cases and 71.4% in controls (P=0.001). The variant Asp/Asn genotype was associated with a more than 50% reduced risk of infertility (OR: 0.46, 95% CI: 0.25-0.80, P=0.001). Genotype analysis demonstrated six SHBG (TAAAA)n alleles with 6-11 repeats. Long SHBG (TAAAA)n alleles (>8 repeats) were at greater frequency in infertile men than fertile subjects (P=0.001), whereas short SHBG (TAAAA)n alleles (≤8 repeats) tended to be more frequent in fertile men than cases (P=0.001). Men with the 9/X TAAAA repeat genotype displayed a 2.82-fold increased risk of infertility (95% CI: 1.27-4.79, P=0.01). There were strong and significant positive correlations between plasma SHBG and sperm count (r=0.672, P=0.01), sperm motility (r=0.721, P=0.01) and sperm morphology (r=0.574, P=0.02). We concluded that the SHBG Asp237Asn and (TAAAA)n polymorphisms may influence SHBG levels and as a result, male infertility. Multicenter large scale studies are warranted to better elucidate the role of SHBG gene polymorphism in male infertility.
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Quinlan P, Nordlund A, Lind K, Gustafson D, Edman Å, Wallin A. Thyroid hormones are associated with poorer cognition in mild cognitive impairment. Dement Geriatr Cogn Disord 2010; 30:205-11. [PMID: 20798541 PMCID: PMC2948659 DOI: 10.1159/000319746] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/24/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Alterations in interrelated endocrine axes may be related to the pathogenesis of mild cognitive impairment (MCI) and dementia. METHODS Salivary cortisol before and after a 0.5-mg dexamethasone test, and serum levels of thyroid-stimulating hormone, total thyroxine (T(4)), free T(4), total triiodothyronine (TT(3)), estradiol, testosterone and insulin-like growth factor 1 were measured in 43 MCI cases and 26 healthy controls. All participants underwent a comprehensive neuropsychological test battery covering the cognitive domains of speed/attention, memory, visuospatial functions, language and executive functions. RESULTS The MCI group did not differ in basal levels of endocrine markers compared to controls. Among those with MCI, TT(3) levels were inversely associated with cognitive performance across all domains. After stratifying MCI cases according to TT(3) levels, those with relatively high TT(3) levels showed impairment in memory as well as in visuospatial and executive functions. Those with TT(3) levels at or below the lower boundary of the normal range performed comparably to healthy controls. Other endocrine markers were not related to cognitive performance. CONCLUSIONS Among those with MCI, TT(3) was associated with a neuropsychological profile typical of prodromal Alzheimer's disease. While the mechanisms remain unclear, optimal levels of thyroid hormone under a compromising condition such as MCI and related neuropathology need reconsideration.
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Affiliation(s)
- Patrick Quinlan
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.
| | - Arto Nordlund
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden, USA
| | - Karin Lind
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden, USA
| | - Deborah Gustafson
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden, USA,Departments of Neurology and Medicine, State University of New York, Downstate Medical Center, Brooklyn, N.Y., USA
| | - Åke Edman
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden, USA
| | - Anders Wallin
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden, USA
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Hogervorst E, Mursjid F, Priandini D, Setyawan H, Ismael RI, Bandelow S, Rahardjo TB. Borobudur revisited: soy consumption may be associated with better recall in younger, but not in older, rural Indonesian elderly. Brain Res 2010; 1379:206-12. [PMID: 21035431 DOI: 10.1016/j.brainres.2010.10.083] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/19/2010] [Accepted: 10/20/2010] [Indexed: 10/18/2022]
Abstract
Previous reports have suggested that high frequent tofu consumption is associated with worse cognitive function in East Asian elderly. Some studies also found an increased risk of dementia with high tofu consumption in those older than 65years of age. Tofu and other soy products, such as tempeh, contain high levels of plant estrogens or isoflavones. This study revisited a rural Central Javanese population (56-97 years of age) who were covered by the Borobudur District Health Centers. Data on cognitive performance were available for n=142 participants. Results showed positive linear associations of weekly tofu (beta=.22, p<0.05) and tempeh (beta=.23, p<0.01) consumption with immediate recall, which were significant in those with an average age of 67 years. In those with an average age of 80 years, the earlier reported negative association of tofu with immediate recall was no longer significant. Lifestyle changes (reduction of tofu consumption after dissemination of results) or "healthy survivor effects" may have been responsible for this finding. These findings may be reminiscent of the "Window of Opportunity" theory, which suggests that estrogenic compounds can exert positive effects on verbal memory, but not in older men and women, when no or negative effects of these compounds on brain cells and cognition have been found. Long-term, placebo-controlled treatment studies should investigate whether tempeh, a fermented soybean product that also contains folate, can maintain cognitive function in middle-aged and elderly participants.
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Yao M, Nguyen TVV, Rosario ER, Ramsden M, Pike CJ. Androgens regulate neprilysin expression: role in reducing beta-amyloid levels. J Neurochem 2010; 105:2477-88. [PMID: 18346198 DOI: 10.1111/j.1471-4159.2008.05341.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Age-related testosterone depletion in men is a risk factor for Alzheimer's disease. Prior studies suggest that androgens affect Alzheimer's disease risk by regulating accumulation of beta-amyloid protein (Abeta) by an undefined mechanism. In this study, we investigated the role of the Abeta-catabolizing enzyme neprilysin (NEP) in this process. First, we observed that androgens positively regulate neural expression of NEP in adult male rats. Next, we investigated androgen regulatory effects on both NEP expression and Abeta levels using cultured hippocampal neurons and neuronally differentiated rat pheochromocytoma cell 12 with or without androgen receptor (AR). Dihydrotestosterone (DHT) induced a time-dependent increase in NEP expression. DHT also significantly decreased levels of Abeta in AR-expressing cells transfected with amyloid precursor protein, but did not affect levels of either full-length or non-amyloidogenic, soluble amyloid precursor protein. Importantly, the DHT induced decrease of Abeta was blocked by pharmacological inhibition of NEP. The DHT-mediated increase in NEP expression and decrease in Abeta levels were (i) not observed in rat pheochromocytoma cell 12 lacking AR and (ii) blocked in AR-expressing cells by the antagonists, cyproterone acetate and flutamide. Together, these findings suggest that androgen regulation of Abeta involves an AR-dependent mechanism requiring up-regulation of the Abeta catabolizing enzyme NEP.
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Affiliation(s)
- Mingzhong Yao
- Davis School of Gerontology, University of Southern California, Los Angeles, California 90089-0191, USA
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Napoli N, Varadharajan A, Rini GB, Del Fiacco R, Yarramaneni J, Mumm S, Villareal DT, Armamento-Villareal RC. Effects of polymorphisms of the sex hormone-binding globulin (SHBG) gene on free estradiol and bone mineral density. Bone 2009; 45:1169-74. [PMID: 19679209 PMCID: PMC3689651 DOI: 10.1016/j.bone.2009.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 08/01/2009] [Accepted: 08/04/2009] [Indexed: 11/24/2022]
Abstract
BACKGROUND Polymorphisms of the sex hormone-binding globulin (SHBG) gene are associated with differences in SHBG levels, influencing the risk for breast cancer and polycystic ovarian syndrome, but no association has been reported for osteoporosis in postmenopausal women. OBJECTIVE To determine the effect of G to A substitution in the 5'UTR (rs1799941) and the Asp356Asn (rs6259) polymorphisms of the SHBG gene on bone mineral density (BMD). METHODS This is a cross-sectional study in a university-based research center from May, 2002 to December, 2007. A total of two hundred and thirteen healthy postmenopausal Caucasian women > or = 1 year from last menstrual period participated to this study. Serum estradiol by ultrasensitive radioimmnunoassay, serum sex hormone-binding globulin by immunoradiometric assay, and urinary NTx by enzyme-linked immunoassay were measured. BMD measurements were performed by dual energy X-ray absorptiometry and genotyping by Pyrosequencing. RESULTS There were no significant differences in SHBG levels associated with either rs1799941 or rs6259. Using a p value of <0.00625 for significance, we found that subjects with the A allele (GA+AA) for the rs1799941, had a trend for lower free estradiol index (FEI) compared to the GG genotype (p=0.04). They also had significantly lower BMD at the intertrochanter (p=0.003) and trend for lower BMD at the total hip (p=0.02). There was no significant difference in FEI levels between the genotypes for the rs6259 polymorphism, but women with the Asn allele (Asp/Asn+Asn/Asn), had significantly lower BMD in the total femur (p=0.004) and intertrochanter (0.002) compared to those with the Asp/Asp genotype. CONCLUSIONS Our data suggest that polymorphisms of the SHBG gene are associated with significant differences in BMD at the proximal femur sites. Thus, genetic variations in the SHBG gene may influence BMD at the hip in postmenopausal women.
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Affiliation(s)
- Nicola Napoli
- Division of Bone and Mineral Diseases at Washington University School of Medicine, St. Louis, MO
- Division of Endocrinology, University Campus Bio-Medico, Rome, Italy
| | - Ana Varadharajan
- Internal Medicine, St. Luke’s Hospital, St. Louis, MO, USA; Department of Internal Medicine, University ‘’La Sapienza”, Rome, Italy
| | | | | | - Jayasree Yarramaneni
- Division of Bone and Mineral Diseases at Washington University School of Medicine, St. Louis, MO
| | - Steven Mumm
- Division of Bone and Mineral Diseases at Washington University School of Medicine, St. Louis, MO
| | - Dennis T. Villareal
- Division of Geriatrics and Nutritional Science at Washington University School of Medicine, St. Louis, MO
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Bryan KJ, Mudd JC, Richardson SL, Chang J, Lee HG, Zhu X, Smith MA, Casadesus G. Down-regulation of serum gonadotropins is as effective as estrogen replacement at improving menopause-associated cognitive deficits. J Neurochem 2009; 112:870-81. [PMID: 19943850 DOI: 10.1111/j.1471-4159.2009.06502.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Declining levels of estrogen in women result in increases in gonadotropins such as luteinizing hormone (LH) through loss of feedback inhibition. LH, like estrogen, is modulated by hormone replacement therapy. However, the role of post-menopausal gonadotropin increases on cognition has not been evaluated. Here, we demonstrate that the down-regulation of ovariectomy-driven LH elevations using the gonadotropin releasing hormone super-analogue, leuprolide acetate, improves cognitive function in the Morris water maze and Y-maze tests in the absence of E2. Furthermore, our data suggest that these effects are independent of the modulation of estrogen receptors alpha and beta, or activation of CYP19 and StAR, associated with the production of endogenous E2. Importantly, pathways associated with improved cognition such as CaMKII and GluR1-Ser831 are up-regulated by leuprolide treatment but not by chronic long-term E2 replacement suggesting independent cognition-modulating properties. Our findings suggest that down-regulation of gonadotropins is as effective as E2 in modulating cognition but likely acts through different molecular mechanisms. These findings provide a potential novel protective strategy to treat menopause/age-related cognitive decline and/or prevent the development of AD.
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Affiliation(s)
- Kathryn J Bryan
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
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