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Corre PHC, Mainwaring JM, Peralta KKZ, Lokman PM, Porteous R, Wibowo E. Low dose of propyl-pyrazole-triol, an agonist of estrogen receptor alpha, administration stimulates the Coolidge effect in fadrozole-treated male rats. Horm Behav 2024; 161:105520. [PMID: 38447331 DOI: 10.1016/j.yhbeh.2024.105520] [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: 10/03/2023] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/08/2024]
Abstract
Estrogen receptor (ER) α is involved in male sexual function. Here, we aim to investigate how ERα activation influences sexual satiety and the Coolidge effect (i.e., when a rat, that has reached sexual satiety, experiences an increased arousal after exposure to a novel sexual partner) in estrogen-deprived male rats. Male rats (8 per group) were treated daily for 29 days with either saline (Control group) or fadrozole dissolved in saline (1 mg/kg/day) 1 h before mating. On Days 13 and 29, rats treated with fadrozole received either no additional treatment (fadrozole group) or a single injection of propyl-pyrazole-triol (ERα-agonist group, dissolved in sesame oil, 1 mg/kg). Rats mated until reaching sexual satiety on Days 13 and 29. In these sessions, the Control group displayed higher frequency of intromission and ejaculation than the other groups. The ERα-agonist group mounted more frequently but reached sexual satiety sooner than the Control group. On Day 29, when exposed to a new sexual partner, the fadrozole-treated rats were less likely to display intromission than the other groups, or ejaculation than the Control group, or mounting than the ERα-agonist group. The Control group showed more ejaculatory behavior and shorter ejaculation latency than the other groups. Body weights, testosterone levels, estradiol levels, and ERα-immunoreactive cell counts in brain regions for sexual behavior were comparable between groups after 29 days of treatments. Our data suggest that estrogen helps regulate sexual satiety and the Coolidge effect in male rats.
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Affiliation(s)
- P Hanna C Corre
- Department of Anatomy, University of Otago, Dunedin 9016, New Zealand.
| | | | - K Kenn Z Peralta
- Department of Anatomy, University of Otago, Dunedin 9016, New Zealand.
| | - P Mark Lokman
- Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
| | - Robert Porteous
- Otago Micro and Nanoscale Imaging, University of Otago, Dunedin 9016, New Zealand.
| | - Erik Wibowo
- Department of Anatomy, University of Otago, Dunedin 9016, New Zealand.
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2
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Chen MH, Lin HC, Chao T, Lee VSY, Hou CL, Wang TJ, Chen JR. Hyaluronic Acid Conjugated with 17β-Estradiol Effectively Alleviates Estropause-Induced Cognitive Deficits in Rats. Int J Mol Sci 2023; 24:15569. [PMID: 37958552 PMCID: PMC10649161 DOI: 10.3390/ijms242115569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 11/15/2023] Open
Abstract
Women are at a higher risk of cognitive impairments and Alzheimer's disease (AD), particularly after the menopause, when the estrous cycle becomes irregular and diminishes. Numerous studies have shown that estrogen deficiency, especially estradiol (E2) deficiency, plays a key role in this phenomenon. Recently, a novel polymeric drug, hyaluronic acid-17β-estradiol conjugate (HA-E2), has been introduced for the delivery of E2 to brain tissues. Studies have indicated that HA-E2 crosses the blood-brain barrier (BBB) and facilitates a prolonged E2 release profile while lowering the risk of estrogen-supplement-related side effects. In this study, we used ovariohysterectomy (OHE) rats, a postmenopausal cognitive deficit model, to explore the effect of a 2-week HA-E2 treatment (210 ng/kg body weight, twice a week) on the cholinergic septo-hippocampal innervation system, synaptic transmission in hippocampal pyramidal neurons and cognitive improvements. Our study revealed an 11% rise in choline acetyltransferase (ChAT) expression in both the medial septal nucleus (MS nucleus) and the hippocampus, along with a 14-18% increase in dendritic spine density in hippocampal pyramidal neurons, following HA-E2 treatment in OHE rats. These enhancements prompted the recovery of cognitive functions such as spatial learning and memory. These findings suggest that HA-E2 may prevent and improve estrogen-deficiency-induced cognitive impairment and AD.
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Affiliation(s)
- Mu-Hsuan Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, No. 145, Xingda Rd., Taichung 402202, Taiwan; (M.-H.C.); (H.-C.L.); (T.C.)
| | - Hsiao-Chun Lin
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, No. 145, Xingda Rd., Taichung 402202, Taiwan; (M.-H.C.); (H.-C.L.); (T.C.)
| | - Tzu Chao
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, No. 145, Xingda Rd., Taichung 402202, Taiwan; (M.-H.C.); (H.-C.L.); (T.C.)
| | - Viola Szu-Yuan Lee
- Basic Research Division, Holy Stone Healthcare Co., Ltd., Taipei 11493, Taiwan; (V.S.-Y.L.); (C.-L.H.)
| | - Chia-Lung Hou
- Basic Research Division, Holy Stone Healthcare Co., Ltd., Taipei 11493, Taiwan; (V.S.-Y.L.); (C.-L.H.)
| | - Tsyr-Jiuan Wang
- Department of Nursing, National Taichung University of Science and Technology, No. 193, Section 1, Sanmin Rd., Taichung 403027, Taiwan
| | - Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, No. 145, Xingda Rd., Taichung 402202, Taiwan; (M.-H.C.); (H.-C.L.); (T.C.)
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3
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Daniel JM, Lindsey SH, Mostany R, Schrader LA, Zsombok A. Cardiometabolic health, menopausal estrogen therapy and the brain: How effects of estrogens diverge in healthy and unhealthy preclinical models of aging. Front Neuroendocrinol 2023; 70:101068. [PMID: 37061205 PMCID: PMC10725785 DOI: 10.1016/j.yfrne.2023.101068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/23/2023] [Accepted: 04/10/2023] [Indexed: 04/17/2023]
Abstract
Research in preclinical models indicates that estrogens are neuroprotective and positively impact cognitive aging. However, clinical data are equivocal as to the benefits of menopausal estrogen therapy to the brain and cognition. Pre-existing cardiometabolic disease may modulate mechanisms by which estrogens act, potentially reducing or reversing protections they provide against cognitive decline. In the current review we propose mechanisms by which cardiometabolic disease may alter estrogen effects, including both alterations in actions directly on brain memory systems and actions on cardiometabolic systems, which in turn impact brain memory systems. Consideration of mechanisms by which estrogen administration can exert differential effects dependent upon health phenotype is consistent with the move towards precision or personalized medicine, which aims to determine which treatment interventions will work for which individuals. Understanding effects of estrogens in both healthy and unhealthy models of aging is critical to optimizing the translational link between preclinical and clinical research.
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Affiliation(s)
- Jill M Daniel
- Department of Psychology and Brain Institute, Tulane University, New Orleans, LA, United States.
| | - Sarah H Lindsey
- Department of Pharmacology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Ricardo Mostany
- Department of Pharmacology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Laura A Schrader
- Department of Cell & Molecular Biology and Brain Institute, Tulane University, New Orleans, LA, United States
| | - Andrea Zsombok
- Department of Physiology and Brain Institute, Tulane University, New Orleans, LA, United States
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4
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Hodges TE, Puri TA, Blankers SA, Qiu W, Galea LAM. Steroid hormones and hippocampal neurogenesis in the adult mammalian brain. VITAMINS AND HORMONES 2021; 118:129-170. [PMID: 35180925 DOI: 10.1016/bs.vh.2021.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hippocampal neurogenesis persists across the lifespan in many species, including rodents and humans, and is associated with cognitive performance and the pathogenesis of neurodegenerative disease and psychiatric disorders. Neurogenesis is modulated by steroid hormones that change across development and differ between the sexes in rodents and humans. Here, we discuss the effects of stress and glucocorticoid exposure from gestation to adulthood as well as the effects of androgens and estrogens in adulthood on neurogenesis in the hippocampus. Throughout the review we highlight sex differences in the effects of steroid hormones on neurogenesis and how they may relate to hippocampal function and disease. These data highlight the importance of examining age and sex when evaluating the effects of steroid hormones on hippocampal neurogenesis.
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Affiliation(s)
- Travis E Hodges
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Tanvi A Puri
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Samantha A Blankers
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Wansu Qiu
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Liisa A M Galea
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
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5
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Cardinali CAEF, Martins YA, Torrão AS. Use of Hormone Therapy in Postmenopausal Women with Alzheimer's Disease: A Systematic Review. Drugs Aging 2021; 38:769-791. [PMID: 34342862 DOI: 10.1007/s40266-021-00878-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Around two-thirds of patients with Alzheimer's disease (AD) are women, which could be related to the depletion of female sexual hormones at menopause. The replacement of these hormones with hormone therapy (HT) to possibly decrease AD risk or treat AD patients has generated conflicting results in the literature. OBJECTIVE Our aim was to systematically review the relationship between HT use in postmenopausal women with AD and the risk of developing or treating AD symptoms. DATA SOURCES The PubMed, LILACS, Scopus, Scielo, and Web of Science databases were searched from January 1994 to December 2020 using the descriptors 'Alzheimer Disease OR Alzheimer's Disease' and 'Hormone Replacement Therapy OR Estrogen Replacement Therapy'. STUDY SELECTION Observational and controlled clinical trials including postmenopausal women diagnosed with AD and evaluating HT efficacy were eligible for inclusion. DATA EXTRACTION Extracted data comprise study design, covariates, inclusion criteria for sample selection, AD diagnosis criteria, biases, HT regimen, and cognitive measurement tools used. RESULTS Overall, 25 studies were selected. Among the 14 observational studies, 8 reported an improvement in cognitive function and a decrease in AD risk, especially in younger postmenopausal women. Five observational studies did not demonstrate any association between HT and AD, and one study reported an increase in AD risk, regardless of time of HT initiation. Of the 11 controlled clinical trials included, 7 showed an amelioration in cognitive function after HT. The remaining 4 trials saw no difference between HT and control. CONCLUSION Both observational and controlled clinical trials had methodological issues and discrepancies in inclusion criteria and HT protocols. These inconsistencies made it difficult to establish an association between HT and AD.
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Affiliation(s)
- Camila A E F Cardinali
- Departamento de Fisiologia e Biofisica, Universidade de Sao Paulo, Av Professor Lineu Prestes 2415, São Paulo, 05508-900, Brazil
| | - Yandara A Martins
- Departamento de Fisiologia e Biofisica, Universidade de Sao Paulo, Av Professor Lineu Prestes 2415, São Paulo, 05508-900, Brazil.
| | - Andréa S Torrão
- Departamento de Fisiologia e Biofisica, Universidade de Sao Paulo, Av Professor Lineu Prestes 2415, São Paulo, 05508-900, Brazil
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6
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Debarba LK, Jayarathne HSM, Miller RA, Garratt M, Sadagurski M. 17-a-estradiol has sex-specific effects on neuroinflammation that are partly reversed by gonadectomy. J Gerontol A Biol Sci Med Sci 2021; 77:66-74. [PMID: 34309657 DOI: 10.1093/gerona/glab216] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Indexed: 11/13/2022] Open
Abstract
17-α-estradiol (17aE2) treatment from 4-months of age extends lifespan in male mice and can reduce neuroinflammatory responses in the hypothalamus of 12-month-old males. Although 17aE2 improves longevity in males, female mice are unaffected, suggesting a sexually dimorphic pattern of lifespan regulation. We tested whether the sex-specific effects of 17aE2 on neuroinflammatory responses are affected by gonadal removal and whether hypothalamic changes extend to other brain regions in old age. We show that sex-specific effects of 17aE2 on age-associated gliosis are brain region-specific and are partially dependent on gonadectomy. 17aE2 treatment started at 4 months of age protected 25-month-old males from hypothalamic inflammation. Castration before 17aE2 exposure reduced the effect of 17aE2 on hypothalamic astrogliosis in males. By contrast, sex-specific inhibition of microgliosis generated by 17aE2 was not significantly affected by castration. In the hippocampus, gonadectomy influenced the severity of gliosis and the responsiveness to 17aE2 in a region-dependent manner. The male-specific effects of 17aE2 correlate with increases in hypothalamic ERα expression, specifically in gonadally intact males, consistent with the idea that 17aE2 might act through this receptor. Our results indicate that neuroinflammatory responses to 17aE2 are partially controlled by the presence of sex-specific gonads. Loss of gonadal function and age-associated neuroinflammation could, therefore, influence late-life health and disease onset, leading to sexual dimorphism in both aging and in response to drugs that modify the pace of aging.
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Affiliation(s)
- Lucas K Debarba
- Department of Biological Sciences, IBio (Integrative Biosciences Center), Wayne State University, Detroit, Michigan, MI
| | - Hashan S M Jayarathne
- Department of Biological Sciences, IBio (Integrative Biosciences Center), Wayne State University, Detroit, Michigan, MI
| | - Richard A Miller
- Department of Pathology and Geriatrics Center, University of Michigan, Ann Arbor, MI
| | - Michael Garratt
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, NZ
| | - Marianna Sadagurski
- Department of Biological Sciences, IBio (Integrative Biosciences Center), Wayne State University, Detroit, Michigan, MI
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7
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Meng Z, Wang X, Zhang D, Lan Z, Cai X, Bian C, Zhang J. Steroid receptor coactivator-1: The central intermediator linking multiple signals and functions in the brain and spinal cord. Genes Dis 2021; 9:1281-1289. [PMID: 35873031 PMCID: PMC9293692 DOI: 10.1016/j.gendis.2021.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/31/2021] [Accepted: 06/21/2021] [Indexed: 11/28/2022] Open
Abstract
The effects of steroid hormones are believed to be mediated by their nuclear receptors (NRs). The p160 coactivator family, including steroid receptor coactivator-1 (SRC-1), 2 and 3, has been shown to physically interact with NRs to enhance their transactivational activities. Among which SRC-1 has been predominantly localized in the central nervous system including brain and spinal cord. It is not only localized in neurons but also detectable in neuroglial cells (mainly localized in the nuclei but also detectable in the extra-nuclear components). Although the expression of SRC-1 is regulated by many steroids, it is also regulated by some non-steroidal factors such as injury, sound and light. Functionally, SRC-1 has been implied in normal function such as development and ageing, learning and memory, central regulation on reproductive behaviors, motor and food intake. Pathologically, SRC-1 may play a role in the regulation of neuropsychiatric disorders (including stress, depression, anxiety, and autism spectrum disorder), metabolite homeostasis and obesity as well as tumorigenesis. Under most conditions, the related mechanisms are far from elucidation; although it may regulate spatial memory through Rictor/mTORC2-actin polymerization related synaptic plasticity. Several inhibitors and stimulator of SRC-1 have shown anti-cancer potentials, but whether these small molecules could be used to modulate ageing and central disorder related neuropathology remain unclear. Therefore, to elucidate when and how SRC-1 is turned on and off under different stimuli is very interesting and great challenge for neuroscientists.
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Affiliation(s)
- Zhaoyou Meng
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoya Wang
- Department of Neurosurgery, Nanchong Central Hospital, the Second Clinical Medical College, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China
| | - Dongmei Zhang
- Department of Dermatology, Southwest Hospital, Army Medical University, Chongqing 400038, PR China
| | - Zhen Lan
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoxia Cai
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Chen Bian
- School of Psychology, Amy Medical University, Chongqing 400038, PR China
- Corresponding author.
| | - Jiqiang Zhang
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- Corresponding author.
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8
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Vaillant C, Gueguen MM, Feat J, Charlier TD, Coumailleau P, Kah O, Brion F, Pellegrini E. Neurodevelopmental effects of natural and synthetic ligands of estrogen and progesterone receptors in zebrafish eleutheroembryos. Gen Comp Endocrinol 2020; 288:113345. [PMID: 31812531 DOI: 10.1016/j.ygcen.2019.113345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/03/2019] [Accepted: 11/26/2019] [Indexed: 12/31/2022]
Abstract
Natural and synthetic estrogens and progestins are widely used in human and veterinary medicine and are detected in waste and surface waters. Our previous studies have clearly shown that a number of these substances targets the brain to induce the estrogen-regulated brain aromatase expression but the consequences on brain development remain virtually unexplored. The aim of the present study was therefore to investigate the effect of estradiol (E2), progesterone (P4) and norethindrone (NOR), a 19-nortestosterone progestin, on zebrafish larval neurogenesis. We first demonstrated using real-time quantitative PCR that nuclear estrogen and progesterone receptor brain expression is impacted by E2, P4 and NOR. We brought evidence that brain proliferative and apoptotic activities were differentially affected depending on the steroidal hormone studied, the concentration of steroids and the region investigated. Our findings demonstrate for the first time that steroid compounds released in aquatic environment have the capacity to disrupt key cellular events involved in brain development in zebrafish embryos further questioning the short- and long-term consequences of this disruption on the physiology and behavior of organisms.
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Affiliation(s)
- Colette Vaillant
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - Marie-Madeleine Gueguen
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - Justyne Feat
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - Thierry D Charlier
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - Pascal Coumailleau
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - Olivier Kah
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France
| | - François Brion
- Institut National de l'Environnement Industriel et des Risques INERIS, Unité d'Ecotoxicologie, 60550, Verneuil-en-Halatte, France
| | - Elisabeth Pellegrini
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000 Rennes, France.
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9
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Zhong SJ, Wang L, Gu RZ, Zhang WH, Lan R, Qin XY. Ginsenoside Rg1 ameliorates the cognitive deficits in D-galactose and AlCl 3-induced aging mice by restoring FGF2-Akt and BDNF-TrkB signaling axis to inhibit apoptosis. Int J Med Sci 2020; 17:1048-1055. [PMID: 32410834 PMCID: PMC7211162 DOI: 10.7150/ijms.43979] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022] Open
Abstract
Ginsenoside Rg1 is the main active ingredient of Panax ginseng with the activity of neuroprotective, antioxidant and strengthening the immune system. Therefore, we hypothesized that Rg1 may afford anti-aging effects although the mechanism remains to be elucidated. In this study, chemically induced aging mice were established by consecutive administration of D-galactose and AlCl3. We found that Rg1 effectively ameliorates spatial learning and memory deficits in aging mice demonstrated by their improved performance in step down avoidance tests and Morris water maze experiments. Rg1 restored aging-induced decline of FGF2 and BDNF, reactivated TrkB/Akt signaling pathways in the hippocampus and prefrontal cortex to inhibit apoptosis, for the expression of anti-apoptotic protein Bcl-2 and apoptosis promoting enzyme cleaved-Caspase3 were antagonistically restored. Therefore, these results established the anti-aging effects of Rg1, and FGF2, BDNF and associated signaling pathways might be promising targets. Our data may provide a new avenue to the pharmacological research and diet therapeutic role of ethnic products such as Rg1 in anti-aging and aging associated diseases.
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Affiliation(s)
- Si-Jia Zhong
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.,College of Economics and management, North China Electric Power University, Beijing 102206, China
| | - Lin Wang
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Run-Ze Gu
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Wen-Hao Zhang
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Rongfeng Lan
- Department of Cell Biology & Medical Genetics, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen 518060, China
| | - Xiao-Yan Qin
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
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10
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Baumgartner NE, Grissom EM, Pollard KJ, McQuillen SM, Daniel JM. Neuroestrogen-Dependent Transcriptional Activity in the Brains of ERE-Luciferase Reporter Mice following Short- and Long-Term Ovariectomy. eNeuro 2019; 6:ENEURO.0275-19.2019. [PMID: 31575604 PMCID: PMC6795557 DOI: 10.1523/eneuro.0275-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/03/2019] [Accepted: 09/22/2019] [Indexed: 12/22/2022] Open
Abstract
Previous work has demonstrated that estrogen receptors are transcriptionally active in the absence of ovarian estrogens. The current work aims to determine whether brain-derived estrogens influence estrogen receptor-dependent transcription after short- or long-term loss of ovarian function. Experiments were conducted using estrogen response element (ERE)-Luciferase reporter mice, which express the gene for luciferase driven by consensus ERE, allowing for the quantification of ERE-dependent transcription. Brain regions examined were hippocampus, cortex, and hypothalamus. In Experiment 1, short-term (10 d) ovariectomy had no impact on ERE-dependent transcription across brain regions compared with sham surgery. In Experiment 2, chronic intracerebroventricular administration of the aromatase inhibitor letrozole significantly decreased transcriptional activity in 10-d-old ovariectomized mice across brain regions, indicating that the sustained transcription in short-term ovariectomized mice is mediated at least in part via actions of neuroestrogens. Additionally, intracerebroventricular administration of estrogen receptor antagonist ICI-182,780 blocked transcription in 10-d-old ovariectomized mice across brain regions, providing evidence that sustained transcription in ovariectomized mice is estrogen receptor dependent. In Experiment 3, long-term (70 d) ovariectomy significantly decreased ERE-dependent transcription across brain regions, though some residual activity remained. In Experiment 4, chronic intracerebroventricular letrozole administration had no impact on transcription in 70 d ovariectomized mice across brain regions, indicating that the residual ERE-dependent transcription in long-term ovariectomized mice is not mediated by neuroestrogens. Overall, the results indicate that ERE-dependent transcription in the brain continues after ovariectomy and that the actions of neuroestrogens contribute to the maintenance of ERE-dependent transcription in the brain following short-term, but not long-term, loss of ovarian function.
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Affiliation(s)
| | - Elin M Grissom
- Neuroscience Program
- Department of Psychology, Tulane University, New Orleans, Louisiana 70118
| | | | | | - Jill M Daniel
- Neuroscience Program
- Tulane Brain Institute
- Department of Psychology, Tulane University, New Orleans, Louisiana 70118
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11
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S-nitrosoglutathione prevents cognitive impairment through epigenetic reprogramming in ovariectomised mice. Biochem Pharmacol 2019; 168:352-365. [DOI: 10.1016/j.bcp.2019.07.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/23/2019] [Indexed: 12/22/2022]
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12
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Lagunas N, Marraudino M, de Amorim M, Pinos H, Collado P, Panzica G, Garcia-Segura LM, Grassi D. Estrogen receptor beta and G protein-coupled estrogen receptor 1 are involved in the acute estrogenic regulation of arginine-vasopressin immunoreactive levels in the supraoptic and paraventricular hypothalamic nuclei of female rats. Brain Res 2019; 1712:93-100. [DOI: 10.1016/j.brainres.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 01/20/2023]
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13
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Wibowo E. Cognitive Impacts of Estrogen Treatment in Androgen-Deprived Males: What Needs to be Resolved. Curr Neuropharmacol 2018; 15:1043-1055. [PMID: 28294068 PMCID: PMC5652012 DOI: 10.2174/1570159x15666170313122555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 02/10/2017] [Accepted: 03/08/2017] [Indexed: 12/13/2022] Open
Abstract
Background: Many prostate cancer (PCa) patients are on androgen deprivation therapy (ADT) as part of their cancer treatments but ADT may lead to cognitive impairments. ADT depletes men of both androgen and estrogen. Whether estradiol supplementation can improve cognitive impairments in patients on ADT is understudied. Objective: To summarize data on the effects of estradiol treatment on cognitive function of androgen-deprived genetic male populations (PCa patients and male-to-female transsexuals) and castrated male animals. Method: Publications were identified by a literature search on PubMed and Google Scholar. Results: While some studies showed that estradiol improves cognitive function (most notably, spatial ability) for castrated rats, what remains uninvestigated are: 1) whether estradiol can improve cognition after long-term androgen deprivation, 2) how estradiol affects memory retention, and 3) how early vs. delayed estradiol treatment after castration influences cognition. For androgen-deprived genetic males, estradiol treatment may improve some cognitive functions (e.g., verbal and visual memory), but the findings are not consistent due to large variability in the study design between studies. Conclusion: Future studies are required to determine the best estradiol treatment protocol to maximize cognitive benefits for androgen-deprived genetic males. Tests that assess comparable cognitive domains in human and rodents are needed. What particularly under-investigated is how the effects of estradiol on cognitive ability intersect with other parameters; sleep, depression and physical fatigue. Such studies have clinical implications to improve the quality of life for both PCa patients on ADT as well as for male-to-female transsexuals.
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Affiliation(s)
- Erik Wibowo
- Level 6, 2775 Laurel Street, Gordon & Leslie Diamond Health Care Centre, Vancouver, British Columbia, V5Z 1M9. Canada
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14
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Engler-Chiurazzi EB, Brown CM, Povroznik JM, Simpkins JW. Estrogens as neuroprotectants: Estrogenic actions in the context of cognitive aging and brain injury. Prog Neurobiol 2017; 157:188-211. [PMID: 26891883 PMCID: PMC4985492 DOI: 10.1016/j.pneurobio.2015.12.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/06/2015] [Accepted: 12/10/2015] [Indexed: 12/30/2022]
Abstract
There is ample empirical evidence to support the notion that the biological impacts of estrogen extend beyond the gonads to other bodily systems, including the brain and behavior. Converging preclinical findings have indicated a neuroprotective role for estrogen in a variety of experimental models of cognitive function and brain insult. However, the surprising null or even detrimental findings of several large clinical trials evaluating the ability of estrogen-containing hormone treatments to protect against age-related brain changes and insults, including cognitive aging and brain injury, led to hesitation by both clinicians and patients in the use of exogenous estrogenic treatments for nervous system outcomes. That estrogen-containing therapies are used by tens of millions of women for a variety of health-related applications across the lifespan has made identifying conditions under which benefits with estrogen treatment will be realized an important public health issue. Here we provide a summary of the biological actions of estrogen and estrogen-containing formulations in the context of aging, cognition, stroke, and traumatic brain injury. We have devoted special attention to highlighting the notion that estrogen appears to be a conditional neuroprotectant whose efficacy is modulated by several interacting factors. By developing criteria standards for desired beneficial peripheral and neuroprotective outcomes among unique patient populations, we can optimize estrogen treatments for attenuating the consequences of, and perhaps even preventing, cognitive aging and brain injury.
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Affiliation(s)
- E B Engler-Chiurazzi
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, United States.
| | - C M Brown
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Neurobiology and Anatomy, West Virginia University, Morgantown, WV 26506, United States.
| | - J M Povroznik
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Pediatrics, West Virginia University, Morgantown, WV 26506, United States.
| | - J W Simpkins
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, United States.
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15
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Peterson RL, Parkinson KC, Mason JB. Restoration of immune and renal function in aged females by re-establishment of active ovarian function. Reprod Fertil Dev 2017; 29:2052-2059. [DOI: 10.1071/rd16333] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/14/2016] [Indexed: 01/14/2023] Open
Abstract
Proper immune functioning is necessary to maximize reproductive success. In addition, age-associated uremia in women is often associated with hypothalamic–pituitary–gonadal dysfunction. In the present experiments, we tested immune and renal function to determine if exposure of postreproductive mice to young, reproductively cycling ovaries would influence non-reproductive physiological functions. Control female CBA/J mice were evaluated at 6, 13 and 16 months of age. Additional mice received new (60-day-old) ovaries at 12 months of age and were evaluated at 16 months of age. Consequently, 6-month-old control mice and 16-month-old recipient mice both possessed 6-month-old ovaries and were reproductively cycling. A significant age-related decline in immune function (T-cell subset analysis) was found in 16-month-old mice, but was improved 64% by ovarian transplantation. Renal function (blood urea nitrogen : creatinine ratio) was also decreased with aging, but ovarian transplantation restored function to levels found in 6-month-old mice. In summary, we have shown that immune and renal function, which are negatively influenced by aging, can be positively influenced or restored by re-establishment of active ovarian function in aged female mice. These findings provide a strong incentive for further investigation of the positive influence of young ovaries on restoration of health in postreproductive females.
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16
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Benmansour S, Arroyo LD, Frazer A. Comparison of the Antidepressant-Like Effects of Estradiol and That of Selective Serotonin Reuptake Inhibitors in Middle-Aged Ovariectomized Rats. Front Aging Neurosci 2016; 8:311. [PMID: 28066235 PMCID: PMC5174113 DOI: 10.3389/fnagi.2016.00311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/06/2016] [Indexed: 01/04/2023] Open
Abstract
This study investigated the effect of age and that of the post-ovariectomy (OVX) time interval on the antidepressant (AD)-like effects of estradiol (E2) and selective serotonin reuptake inhibitors (SSRIs) in middle-aged (10 month) OVX rats (10m-OVX). Acute or chronic effects of these treatments in 10m-OVX were compared with those (1) in young adult (4-month) OVX rats (4m-OVX) or with older (14-month) OVX rats (14m-OVX), at a short time: 2 weeks post-OVX (+2w) and (2) in 10m-OVX rats after a longer times: 4 or 8 months post-OVX (+4m or +8m). Using in vivo chronoamperometry in the CA3 region of the hippocampus, E2 at 20 pmol, a dose shown previously to inhibit the serotonin transporter (SERT) in 4m-OVX, had no effect in 10m-OVX+2w. A higher dose of E2 (40 pmol) increased T80 value, a measure of serotonin or 5-hydroxytryptamine (5-HT) clearance, and also blocked the ability of fluvoxamine to increase T80. By contrast, estradiol had no effects on SERT function in 10m-OVX+4m, even at a higher dose than 40 pmol. Fluvoxamine slowed 5-HT clearance in 10m-OVX at +2w, +4m and +8m post-OVX as it did in the 4m-OVX. Using the forced swim test, 2 weeks treatment with E2 (5 μg/day), a dose shown previously to induce AD-like effects in 4m-OVX, had no effect in 10m-OVX+2w. However, a higher dose (10 μg/day) of E2 induced an AD-like effect as demonstrated by significantly increased swimming behavior and decreased immobility. This effect was not seen in 10m-OVX+4m. By contrast, significant AD-like effects were obtained in 14m-OVX+2w, thereby demonstrating that the lack of an AD effect of E2 is due to the 4-month hormone withdrawal and not to an age effect. After 2 weeks treatment with the SSRI sertraline, similar AD-like effects were obtained in 10m-OVX tested at +2w, +4m or +8m post-OVX as those found in 4m-OVX. Thus, the potency of estradiol to produce effects consistent with inhibition of the SERT was not only decreased in older rats but its effects were markedly diminished the longer hormonal depletion occurred. By contrast, the ability of SSRIs to inhibit the SERT was not affected either by age or the length of hormonal depletion.
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Affiliation(s)
- Saloua Benmansour
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio TX, USA
| | - Luis D Arroyo
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio TX, USA
| | - Alan Frazer
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San AntonioTX, USA; South Texas Veterans Health Care System, San AntonioTX, USA
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17
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Black KL, Witty CF, Daniel JM. Previous Midlife Oestradiol Treatment Results in Long-Term Maintenance of Hippocampal Oestrogen Receptor α Levels in Ovariectomised Rats: Mechanisms and Implications for Memory. J Neuroendocrinol 2016; 28:10.1111/jne.12429. [PMID: 27603028 PMCID: PMC5527336 DOI: 10.1111/jne.12429] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 01/28/2023]
Abstract
Ovariectomised rats that have received previous administration of oestradiol in midlife display enhanced cognition and increased hippocampal levels of oestrogen receptor (ER)α months after oestradiol treatment ended compared to ovariectomised controls. The present study aimed to investigate the mechanisms by which ERα levels are maintained following midlife oestradiol exposure and the role of ERα in memory in ageing females in the absence of circulating oestrogens. Unliganded ERα has increased interaction with the ubiquitin ligase, C-terminus of Hsc-70 interacting protein (CHIP), leading to increased degradation of the receptor. In our first experiment, we tested the hypothesis that midlife oestradiol exposure in ovariectomised rats results in decreased interaction between CHIP and hippocampal ERα, leading to increased levels of ERα. Middle-aged rats were ovariectomised and received oestradiol or vehicle implants. After 40 days, implants were removed. One month later, rats were killed and hippocampi were processed for whole protein western blotting and co-immunoprecipitation, in which ERα was immunoprecipitated from lysate. As expected, ERα protein expression was increased in rats previously treated with oestradiol compared to vehicle-treated rats. In rats treated with oestradiol, there was a decrease in CHIP-ERα interaction, suggesting that previous oestradiol treatment reduces interaction, slowing the degradation of ERα. In a second experiment, we determined the impact on memory of antagonism of ER in the absence of circulating oestrogens. Rats were ovariectomised and implanted with oestradiol capsules. Capsules were removed after 40 days. Rats received chronic i.c.v. infusion of ER antagonist, ICI 182 780, or artificial cerebrospinal fluid vehicle and were tested on a spatial memory radial-maze task. Rats treated with ICI 182 780 had significantly worse performance (more errors). These experiments provide evidence that previous midlife oestradiol treatment maintains hippocampal ERα by decreasing its interaction with CHIP and that activation of these receptors provides cognitive benefits in the absence of circulating oestrogens.
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Affiliation(s)
- K L Black
- Program in Neuroscience, Tulane University, New Orleans, LA, USA
- Brain Institute, Tulane University, New Orleans, LA, USA
| | - C F Witty
- Program in Neuroscience, Tulane University, New Orleans, LA, USA
| | - J M Daniel
- Program in Neuroscience, Tulane University, New Orleans, LA, USA.
- Brain Institute, Tulane University, New Orleans, LA, USA.
- Department of Psychology, Tulane University, New Orleans, LA, USA.
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18
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Ianov L, Kumar A, Foster TC. Epigenetic regulation of estrogen receptor α contributes to age-related differences in transcription across the hippocampal regions CA1 and CA3. Neurobiol Aging 2016; 49:79-85. [PMID: 27776265 DOI: 10.1016/j.neurobiolaging.2016.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/20/2016] [Accepted: 09/20/2016] [Indexed: 10/20/2022]
Abstract
The expression of estrogen receptor alpha (ERα) varies across brain regions and changes with age and according to the previous history of estradiol exposure. ERα is regulated by a number of mechanisms including the level of mRNA (Esr1) expression. For this study, we took advantage of regional differences in hippocampal ERα expression to investigate DNA ERα promoter methylation at CpG dinucleotide sites as a potential epigenetic mechanism for regulating gene expression. Young and aged female Fischer 344 rats were ovariectomized, and Esr1 expression and ERα promoter methylation were examined in hippocampal regions CA1 and CA3, either 3 or 14 weeks following surgery. The results indicate that reduced Esr1 expression in region CA1 relative to CA3 was associated with an increase in DNA methylation in region CA1, particularly for the first CpG site. Additionally, differential methylation of distal CpG sites, 11-17, was associated with altered Esr1 expression during aging or following long-term hormone deprivation. The results support the idea that methylation of site 1 may be the primary regulatory region for cross-regional patterns in ERα expression, while distal sites are modifiable across the life span and may act as a feedback mechanism for ERα activity.
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Affiliation(s)
- Lara Ianov
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Genetics and Genomics Program, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Genetics and Genomics Program, Genetics Institute, University of Florida, Gainesville, FL, USA.
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19
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Grissom EM, Daniel JM. Evidence for Ligand-Independent Activation of Hippocampal Estrogen Receptor-α by IGF-1 in Hippocampus of Ovariectomized Rats. Endocrinology 2016; 157:3149-56. [PMID: 27254005 PMCID: PMC4967122 DOI: 10.1210/en.2016-1197] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/26/2016] [Indexed: 11/19/2022]
Abstract
In the absence of ovarian estrogens, increased levels of estrogen receptor (ER)α in the hippocampus are associated with improvements in cognition. In vitro evidence indicates that under conditions of low estrogen, growth factors, including Insulin-Like Growth Factor 1 (IGF-1), can activate ERα and regulate ERα-mediated transcription through mechanisms that likely involve modification of phosphorylation sites on the receptor. The goal of the current work was to investigate a role for IGF-1 in ligand-independent activation of ERα in the hippocampus of female rats. Ovariectomized rats received a single intracerebroventricular infusion of IGF-1 and hippocampi were collected 1 or 24 hours later. After 1 h, IGF-1 increased hippocampal levels of phosphorylated ERα at serine 118 (S118) as revealed by Western blotting. Coimmunoprecipitation revealed that at 1 hour after infusion, IGF-1 increased association between ERα and steroid receptor coactivator 1, a histone acetyltransferase that increases transcriptional activity of phosphorylated ERα. IGF-1 infusion increased levels of the ERα-regulated proteins ERα, choline acetyltransferase, and brain-derived neurotrophic factor in the hippocampus 24 hours after infusion. Results indicate that IGF-1 activates ERα in ligand-independent manner in the hippocampus via phosphorylation at S118 resulting in increased association of ERα with steroid receptor coactivator 1 and elevation of ER-regulated proteins. To our knowledge, these data are the first in vivo evidence of ligand-independent actions of ERα and provide a mechanism by which ERα can impact memory in the absence of ovarian estrogens.
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Affiliation(s)
- Elin M Grissom
- Department of Psychology and Program in Neuroscience, Tulane University, New Orleans, Louisiana 70118
| | - Jill M Daniel
- Department of Psychology and Program in Neuroscience, Tulane University, New Orleans, Louisiana 70118
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20
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Mason JB, Terry BC, Merchant SS, Mason HM, Nazokkarmaher M. Manipulation of Ovarian Function Significantly Influenced Trabecular and Cortical Bone Volume, Architecture and Density in Mice at Death. PLoS One 2015; 10:e0145821. [PMID: 26717576 PMCID: PMC4696788 DOI: 10.1371/journal.pone.0145821] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/09/2015] [Indexed: 01/06/2023] Open
Abstract
Previously, transplantation of ovaries from young, cycling mice into old, postreproductive-age mice increased life span and decreased cardiomyopathy at death. We anticipated that the same factors that increased life span and decreased cardiomyopathy could also influence the progression of orthopedic disease. At 11 months of age, prepubertally ovariectomized and ovary-intact mice (including reproductively cycling and acyclic mice) received new 60-day-old ovaries. At death, epiphyseal bone in the proximal tibia and the distal femur and mid-shaft tibial and femoral diaphyseal bone was analyzed with micro-computed tomography. For qualitative analysis of osteophytosis, we also included mineralized connective tissue within the stifle joint. Prepubertal ovariectomy had the greatest influence on bone volume, ovarian transplantation had the greatest influence on bone architecture and both treatments influenced bone density. Ovarian transplantation increased cortical, but not trabecular bone density and tended to increase osteophytosis and heterotopic mineralization, except in acyclic recipients. These effects may have been dictated by the timing of the treatments, with ovariectomy appearing to influence early development and ovarian transplantation limited to influencing only the postreproductive period. However, major differences observed between cycling, acyclic and ovariectomized recipients of new ovaries may have been, in part due to differences in the levels of hormone receptors present and the responsiveness of specific bone processes to hormone signaling. Changes that resulted from these treatments may represent a compensatory response to normal age-associated, negative, orthopedic changes. Alternatively, differences between treatments may simply be the 'preservation' of unblemished orthopedic conditions, prior to the influence of negative, age-associated effects. These findings may suggest that in women, tailoring hormone replacement therapy to the patient's current reproductive status may improve therapy effectiveness and that beginning therapy earlier may help preserve trabecular bone mineral density that would otherwise be lost during perimenopause.
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Affiliation(s)
- Jeffrey B. Mason
- Department of Animal, Dairy and Veterinary Sciences, Center for Integrated BioSystems, School of Veterinary Medicine, Utah State University, Logan, UT, United States of America
| | - Boston C. Terry
- Department of Bioengineering, College of Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Samer S. Merchant
- Department of Bioengineering, College of Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Holly M. Mason
- Department of Animal, Dairy and Veterinary Sciences, Center for Integrated BioSystems, School of Veterinary Medicine, Utah State University, Logan, UT, United States of America
| | - Mahdi Nazokkarmaher
- Department of Animal, Dairy and Veterinary Sciences, Center for Integrated BioSystems, School of Veterinary Medicine, Utah State University, Logan, UT, United States of America
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21
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Koebele SV, Bimonte-Nelson HA. Trajectories and phenotypes with estrogen exposures across the lifespan: What does Goldilocks have to do with it? Horm Behav 2015; 74:86-104. [PMID: 26122297 PMCID: PMC4829405 DOI: 10.1016/j.yhbeh.2015.06.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 05/14/2015] [Accepted: 06/04/2015] [Indexed: 01/04/2023]
Abstract
This article is part of a Special Issue "Estradiol and cognition". Estrogens impact the organization and activation of the mammalian brain in both sexes, with sex-specific critical windows. Throughout the female lifespan estrogens activate brain substrates previously organized by estrogens, and estrogens can induce non-transient brain and behavior changes into adulthood. Therefore, from early life through the transition to reproductive senescence and beyond, estrogens are potent modulators of the brain and behavior. Organizational, reorganizational, and activational hormone events likely impact the trajectory of brain profiles during aging. A "brain profile," or quantitative brain measurement for research purposes, is typically a snapshot in time, but in life a brain profile is anything but static--it is in flux, variable, and dynamic. Akin to this, the only thing continuous and consistent about hormone exposures across a female's lifespan is that they are noncontinuous and inconsistent, building and rebuilding on past exposures to create a present brain and behavioral landscape. Thus, hormone variation is especially rich in females, and is likely the destiny for maximal responsiveness in the female brain. The magnitude and direction of estrogenic effects on the brain and its functions depend on a myriad of factors; a "Goldilocks" phenomenon exists for estrogens, whereby if the timing, dose, and regimen for an individual are just right, markedly efficacious effects present. Data indicate that exogenously-administered estrogens can bestow beneficial cognitive effects in some circumstances, especially when initiated in a window of opportunity such as the menopause transition. Could it be that the age-related reduction in efficacy of estrogens reflects the closure of a late-in-life critical window occurring around the menopause transition? Information from classic and contemporary works studying organizational/activational estrogen actions, in combination with acknowledging the tendency for maximal responsiveness to cyclicity, will elucidate ways to extend sensitivity and efficacy into post-menopause.
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Affiliation(s)
- Stephanie V Koebele
- Department of Psychology, Arizona State University, Tempe, AZ 85287, USA; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, USA
| | - Heather A Bimonte-Nelson
- Department of Psychology, Arizona State University, Tempe, AZ 85287, USA; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, USA.
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22
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Duarte-Guterman P, Yagi S, Chow C, Galea LAM. Hippocampal learning, memory, and neurogenesis: Effects of sex and estrogens across the lifespan in adults. Horm Behav 2015; 74:37-52. [PMID: 26122299 DOI: 10.1016/j.yhbeh.2015.05.024] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/29/2015] [Accepted: 05/26/2015] [Indexed: 01/12/2023]
Abstract
This article is part of a Special Issue "Estradiol and Cognition". There are sex differences in hippocampus-dependent cognition and neurogenesis suggesting that sex hormones are involved. Estrogens modulate certain forms of spatial and contextual memory and neurogenesis in the adult female rodent, and to a lesser extent male, hippocampus. This review focuses on the effects of sex and estrogens on hippocampal learning, memory, and neurogenesis in the young and aged adult rodent. We discuss how factors such as the type of estrogen, duration and dose of treatment, timing of treatment, and type of memory influence the effects of estrogens on cognition and neurogenesis. We also address how reproductive experience (pregnancy and mothering) and aging interact with estrogens to modulate hippocampal cognition and neurogenesis in females. Given the evidence that adult hippocampal neurogenesis plays a role in long-term spatial memory and pattern separation, we also discuss the functional implications of regulating neurogenesis in the hippocampus.
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Affiliation(s)
- Paula Duarte-Guterman
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Shunya Yagi
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Carmen Chow
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Liisa A M Galea
- Department of Psychology, Centre for Brain Health, Program in Neuroscience, University of British Columbia, Vancouver, Canada.
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23
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Daniel JM, Witty CF, Rodgers SP. Long-term consequences of estrogens administered in midlife on female cognitive aging. Horm Behav 2015; 74:77-85. [PMID: 25917862 PMCID: PMC4573273 DOI: 10.1016/j.yhbeh.2015.04.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/08/2015] [Accepted: 04/12/2015] [Indexed: 12/15/2022]
Abstract
This article is part of a Special Issue "Estradiol and cognition". Many of the biochemical, structural, and functional changes that occur as the female brain ages are influenced by changes in levels of estrogens. Administration of estrogens begun during a critical window near menopause is hypothesized to prevent or delay age-associated cognitive decline. However, due to potential health risks women often limit use of estrogen therapy to a few years to treat menopausal symptoms. The long-term consequences for the brain of short-term use of estrogens are unknown. Interestingly, there are preliminary data to suggest that short-term use of estrogens during the menopausal transition may afford long-term cognitive benefits to women as they age. Thus, there is the intriguing possibility that short-term estrogen therapy may provide lasting benefits to the brain and cognition. The focus of the current review is an examination of the long-term impact for cognition of midlife use of estrogens. We review data from our lab and others indicating that the ability of midlife estrogens to impact estrogen receptors in the hippocampus may contribute to its ability to exert lasting impacts on cognition in aging females.
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Affiliation(s)
- Jill M Daniel
- Department of Psychology, Tulane University New Orleans, LA 70118, USA; Program in Neuroscience, Tulane University New Orleans, LA 70118, USA.
| | - Christine F Witty
- Program in Neuroscience, Tulane University New Orleans, LA 70118, USA
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24
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Bastos CP, Pereira LM, Ferreira-Vieira TH, Drumond LE, Massensini AR, Moraes MFD, Pereira GS. Object recognition memory deficit and depressive-like behavior caused by chronic ovariectomy can be transitorialy recovered by the acute activation of hippocampal estrogen receptors. Psychoneuroendocrinology 2015; 57:14-25. [PMID: 25867995 DOI: 10.1016/j.psyneuen.2015.03.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/18/2015] [Accepted: 03/21/2015] [Indexed: 01/29/2023]
Abstract
It is well known that estradiol (E2) replacement therapy is effective on restoring memory deficits and mood disorders that may occur during natural menopause or after surgical ovarian removal (ovariectomy, OVX). However, it is still unknown the effectiveness of acute and localized E2 administration on the effects of chronic OVX. Here we tested the hypothesis that the intra-hippocampal E2 infusion, as well as specific agonists of estrogen receptors (ERs) alpha (ERα) and beta (ERβ), are able to mend novel object recognition (NOR) memory deficit and depressive-like behavior caused by 12 weeks of OVX. We found that both ERα and ERβ activation, at earlier stages of consolidation, recovered the NOR memory deficit caused by 12 w of OVX. Conversely, only the ERβ activation was effective in decreasing the depressive-like behavior caused by 12 w of OVX. Furthermore, we investigated the effect of OVX on hippocampal volume and ERs expression. The structural MRI showed no alteration in the hippocampus volume of 12 w OVX animals. Interestingly, ERα expression in the hippocampus decreased after one week of OVX, but increased in 12 w OVX animals. Overall, we may conclude that the chronic estrogen deprivation, induced by 12 weeks of OVX, modulates the hippocampal ERα expression and induces NOR memory deficit and depressive-like behaviors. Nonetheless, it is noteworthy that the acute effects of E2 on NOR memory and depressive-like behavior are still apparent even after 12 weeks of OVX.
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Affiliation(s)
- Cristiane P Bastos
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil
| | - Luciana M Pereira
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil
| | - Talita H Ferreira-Vieira
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil
| | - Luciana E Drumond
- Centro de Tecnologia e Pesquisa em Magneto-Ressonância, CTPMAG, Universidade Federal de Minas Gerais, Brazil; Universidade Federal de São João Del Rey, Brazil
| | - André R Massensini
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil
| | - Márcio F D Moraes
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil; Centro de Tecnologia e Pesquisa em Magneto-Ressonância, CTPMAG, Universidade Federal de Minas Gerais, Brazil
| | - Grace S Pereira
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Brazil.
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25
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Wibowo E, Calich HJ, Currie RW, Wassersug RJ. Prolonged androgen deprivation may influence the autoregulation of estrogen receptors in the brain and pelvic floor muscles of male rats. Behav Brain Res 2015; 286:128-35. [PMID: 25746452 DOI: 10.1016/j.bbr.2015.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 02/24/2015] [Accepted: 03/02/2015] [Indexed: 12/18/2022]
Abstract
Androgen deprivation in males has detrimental effects on various tissues and bodily functions, some of which can be restored by estradiol (E2) administration. We investigated how the duration of androgen deprivation affects the autoregulation of estrogen receptors (ERs) levels in core brain areas associated with sexual behavior and cognition, as well as in pelvic floor muscles (PFM). We also measured c-Fos levels in brain areas associated with sexual behavior shortly after the rats mated. Prolonged castration increases ERα levels in the preoptic area (POA) and E2 treatment reverses these effects. In the POA, c-Fos levels after mating are not affected by the duration of androgen deprivation and/or E2 treatment. ERβ levels in the POA as well as c-Fos levels in the POA and the core area of nucleus accumbens correlate with the mounting frequency for E2-treated Short-Term castrates. Additionally, ERβ levels in the medial amygdala are positively correlated with the mounting frequency of Long-Term castrates that received E2 treatment. In the hippocampus, ERs are downregulated only when E2 is administered early after castration, whereas downregulation of ERα in the prefrontal cortex only occurs with delayed E2 treatment. Early, but not delayed, E2 treatment after castration increases ERβ levels in the bulbocavernosus and ERα levels in the levator ani of male rats. Our data suggest that the duration of androgen deprivation may influence the autoregulation of ERs by E2 treatment in select brain areas and pelvic floor muscles of male rats.
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Affiliation(s)
- Erik Wibowo
- Department of Medical Neuroscience, 5850 College Street, PO Box 15000, Halifax, NS B3H 4R2, Canada; Vancouver Prostate Centre, Vancouver General Hospital, 2775 Laurel St., University of British Columbia, Vancouver, BC V5Z 1M9, Canada.
| | - Hannah J Calich
- Department of Medical Neuroscience, 5850 College Street, PO Box 15000, Halifax, NS B3H 4R2, Canada.
| | - R William Currie
- Department of Medical Neuroscience, 5850 College Street, PO Box 15000, Halifax, NS B3H 4R2, Canada.
| | - Richard J Wassersug
- Department of Medical Neuroscience, 5850 College Street, PO Box 15000, Halifax, NS B3H 4R2, Canada; Department of Urologic Sciences, Gordon & Leslie Diamond Care Centre, 2775 Laurel St., University of British Columbia, Vancouver, BC V5Z 1M9, Canada; Australian Research Centre in Sex, Health and Society, La Trobe University 215 Franklin Street, Melbourne, Victoria 3000, Australia.
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26
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Luine VN. Estradiol and cognitive function: past, present and future. Horm Behav 2014; 66:602-18. [PMID: 25205317 PMCID: PMC4318702 DOI: 10.1016/j.yhbeh.2014.08.011] [Citation(s) in RCA: 294] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/26/2014] [Accepted: 08/29/2014] [Indexed: 12/13/2022]
Abstract
A historical perspective on estradiol's enhancement of cognitive function is presented, and research, primarily in animals, but also in humans, is reviewed. Data regarding the mechanisms underlying the enhancements are discussed. Newer studies showing rapid effects of estradiol on consolidation of memory through membrane interactions and activation of inter-cellular signaling pathways are reviewed as well as studies focused on traditional genomic mechanisms. Recent demonstrations of intra-neuronal estradiol synthesis and possible actions as a neurosteroid to promote memory are discussed. This information is applied to the critical issue of the current lack of effective hormonal (or other) treatments for cognitive decline associated with menopause and aging. Finally, the critical period hypothesis for estradiol effects is discussed along with novel strategies for hormone/drug development. Overall, the historical record documents that estradiol positively impacts some aspects of cognitive function, but effective therapeutic interventions using this hormone have yet to be realized.
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Affiliation(s)
- Victoria N Luine
- Department of Psychology, Hunter College of CUNY, New York, NY, USA.
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27
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Fortress AM, Kim J, Poole RL, Gould TJ, Frick KM. 17β-Estradiol regulates histone alterations associated with memory consolidation and increases Bdnf promoter acetylation in middle-aged female mice. ACTA ACUST UNITED AC 2014; 21:457-67. [PMID: 25128537 PMCID: PMC4138358 DOI: 10.1101/lm.034033.113] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Histone acetylation is essential for hippocampal memory formation in young adult rodents. Although dysfunctional histone acetylation has been associated with age-related memory decline in male rodents, little is known about whether histone acetylation is altered by aging in female rodents. In young female mice, the ability of 17β-estradiol (E2) to enhance object recognition memory consolidation requires histone H3 acetylation in the dorsal hippocampus. However, the extent to which histone acetylation is regulated by E2 in middle-aged females is unknown. The mnemonic benefits of E2 in aging females appear to be greatest in middle age, and so pinpointing the molecular mechanisms through which E2 enhances memory at this age could lead to the development of safer and more effective treatments for maintaining memory function without the side effects of current therapies. Here, we show that dorsal hippocampal infusion of E2 rapidly enhanced object recognition and spatial memory, and increased histone H3 acetylation in the dorsal hippocampus, while also significantly reducing levels of histone deacetylase (HDAC2 and HDAC3) proteins. E2 specifically increased histone H3 acetylation at Bdnf promoters pII and pIV in the dorsal hippocampus of both young and middle-aged mice, despite age-related decreases in pI and pIV acetylation. Furthermore, levels of mature BDNF and pro-BDNF proteins in the dorsal hippocampus were increased by E2 in middle-aged females. Together, these data suggest that the middle-aged female dorsal hippocampus remains epigenetically responsive to E2, and that E2 may enhance memory in middle-aged females via epigenetic regulation of Bdnf.
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Affiliation(s)
- Ashley M Fortress
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | - Jaekyoon Kim
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | - Rachel L Poole
- Department of Psychology, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Thomas J Gould
- Department of Psychology, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
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28
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Regulation of object recognition and object placement by ovarian sex steroid hormones. Behav Brain Res 2014; 285:140-57. [PMID: 25131507 DOI: 10.1016/j.bbr.2014.08.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 07/29/2014] [Accepted: 08/01/2014] [Indexed: 12/26/2022]
Abstract
The ovarian hormones 17β-estradiol (E2) and progesterone (P4) are potent modulators of hippocampal memory formation. Both hormones have been demonstrated to enhance hippocampal memory by regulating the cellular and molecular mechanisms thought to underlie memory formation. Behavioral neuroendocrinologists have increasingly used the object recognition and object placement (object location) tasks to investigate the role of E2 and P4 in regulating hippocampal memory formation in rodents. These one-trial learning tasks are ideal for studying acute effects of hormone treatments on different phases of memory because they can be administered during acquisition (pre-training), consolidation (post-training), or retrieval (pre-testing). This review synthesizes the rodent literature testing the effects of E2 and P4 on object recognition (OR) and object placement (OP), and the molecular mechanisms in the hippocampus supporting memory formation in these tasks. Some general trends emerge from the data. Among gonadally intact females, object memory tends to be best when E2 and P4 levels are elevated during the estrous cycle, pregnancy, and in middle age. In ovariectomized females, E2 given before or immediately after testing generally enhances OR and OP in young and middle-aged rats and mice, although effects are mixed in aged rodents. Effects of E2 treatment on OR and OP memory consolidation can be mediated by both classical estrogen receptors (ERα and ERβ), and depend on glutamate receptors (NMDA, mGluR1) and activation of numerous cell signaling cascades (e.g., ERK, PI3K/Akt, mTOR) and epigenetic processes (e.g., histone acetylation, DNA methylation). Acute P4 treatment given immediately after training also enhances OR and OP in young and middle-aged ovariectomized females by activating similar cell signaling pathways as E2 (e.g., ERK, mTOR). The few studies that have administered both hormones in combination suggest that treatment can enhance OR and OP, but that effects are highly dependent on factors such as dose and timing of administration. In addition to providing more detail on these general conclusions, this review will discuss directions for future avenues of research into the hormonal regulation of object memory.
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29
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Xu XB, He Y, Song C, Ke X, Fan SJ, Peng WJ, Tan R, Kawata M, Matsuda KI, Pan BX, Kato N. Bisphenol a regulates the estrogen receptor alpha signaling in developing hippocampus of male rats through estrogen receptor. Hippocampus 2014; 24:1570-80. [DOI: 10.1002/hipo.22336] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Xiao-Bin Xu
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
| | - Ye He
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
- Department of Pharmacology; Nanchang University; Nanchang 330031 China
| | - Chen Song
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
| | - Xin Ke
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
| | - Shi-Jun Fan
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
| | - Wei-Jie Peng
- Department of Pharmacology; Nanchang University; Nanchang 330031 China
| | - Ruei Tan
- Department of Psychiatry; School of Medicine; Showa University. 6-11-11; Tokyo 157-8577 Japan
| | - Mitsuhiro Kawata
- Department of Anatomy and Neurobiology; Kyoto Prefectural University of Medicine; Kyoto 602-8566 Japan
| | - Ken-Ichi Matsuda
- Department of Anatomy and Neurobiology; Kyoto Prefectural University of Medicine; Kyoto 602-8566 Japan
| | - Bing-Xing Pan
- Laboratory of Fear and Anxiety Disorder; Institute of Life Science, Nanchang University; Nanchang 330031 China
| | - Nobumasa Kato
- Department of Psychiatry; School of Medicine; Showa University. 6-11-11; Tokyo 157-8577 Japan
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30
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Zhou L, Fester L, Haghshenas S, de Vrese X, von Hacht R, Gloger S, Brandt N, Bader M, Vollmer G, Rune GM. Oestradiol-induced synapse formation in the female hippocampus: roles of oestrogen receptor subtypes. J Neuroendocrinol 2014; 26:439-47. [PMID: 24779550 DOI: 10.1111/jne.12162] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 04/22/2014] [Accepted: 04/26/2014] [Indexed: 01/09/2023]
Abstract
During the oestrus cycle, varying spine synapse density correlates positively with varying local synthesis of oestradiol in the hippocampus. In this context, the roles of the oestrogen receptor (ER) subtypes ERα and β are not fully understood. In the present study, we used neonatal hippocampal slice cultures from female rats because these cultures synthesise oestradiol and express both receptor subtypes, and inhibition of oestradiol synthesis in these cultures results in spine synapse loss. Using electron microscopy, we tested the effects on spine synapse density in response to agonists of both ERα and ERβ. Application of agonists to the cultures had no effect. After inhibition of oestradiol synthesis, however, agonists of ERα induced spine synapse formation, whereas ERβ agonists led to a reduction in spine synapse density in the CA1 region of these cultures. Consistently, up-regulation of ERβ in the hippocampus of adult female aromatase-deficient mice is paralleled by hippocampus-specific spine synapse loss in this mutant. Finally, we found an increase in spine synapses in the adult female ERβ knockout mouse, but no effect in the adult female ERα knockout mouse. Our data suggest antagonistic roles of ERβ and ERα in spine synapse formation in the female hippocampus, which may contribute to oestrus cyclicity of spine synapse density in the hippocampus.
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Affiliation(s)
- L Zhou
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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31
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Vedder LC, Bredemann TM, McMahon LL. Estradiol replacement extends the window of opportunity for hippocampal function. Neurobiol Aging 2014; 35:2183-92. [PMID: 24813636 DOI: 10.1016/j.neurobiolaging.2014.04.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 01/27/2023]
Abstract
We previously reported that treating aged female rats, ovariectomized (OVX) as young adults, with acute proestrous levels of 17β estradiol (E2) increases CA1 spine density, NMDAR to AMPAR ratio, GluN2B-mediated NMDAR current, and long-term potentiation at CA3-CA1 synapses if administered by 15, but not at 19-month post-OVX, defining the critical window of opportunity. Importantly, when rats are aged with ovaries intact until OVX at 20 months, hippocampal E2 responsiveness is maintained, indicating the deficit at 19-month post-OVX is a consequence of the duration of hormone deprivation and not chronological age. Here, we find the beneficial effect of E2 on novel object recognition in OVX rats was constrained by the same critical window. Furthermore, chronic low-level E2 replacement, commenced by 11-month post-OVX using subcutaneous capsules removed 2 weeks before acute proestrous E2 treatment, prevents the loss of hippocampal responsiveness at 19-month post-OVX. These data define the dynamic nature of the critical window showing that chronic replacement with physiological E2 levels within a certain period post-OVX can lengthen the window.
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Affiliation(s)
- Lindsey C Vedder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Teruko M Bredemann
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lori L McMahon
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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32
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Wang TJ, Chen JR, Wang WJ, Wang YJ, Tseng GF. Genistein partly eases aging and estropause-induced primary cortical neuronal changes in rats. PLoS One 2014; 9:e89819. [PMID: 24587060 PMCID: PMC3934964 DOI: 10.1371/journal.pone.0089819] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 01/26/2014] [Indexed: 01/11/2023] Open
Abstract
Gonadal hormones can modulate brain morphology and behavior. Recent studies have shown that hypogonadism could result in cortical function deficits. To this end, hormone therapy has been used to ease associated symptoms but the risk may outweigh the benefits. Here we explored whether genistein, a phytoestrogen, is effective in restoring the cognitive and central neuronal changes in late middle age and surgically estropause female rats. Both animal groups showed poorer spatial learning than young adults. The dendritic arbors and spines of the somatosensory cortical and CA1 hippocampal pyramidal neurons were revealed with intracellular dye injection and analyzed. The results showed that dendritic spines on these neurons were significantly decreased. Remarkably, genistein treatment rescued spatial learning deficits and restored the spine density on all neurons in the surgically estropause young females. In late middle age females, genistein was as effective as estradiol in restoring spines; however, the recovery was less thorough than on young OHE rats. Neither genistein nor estradiol rectified the shortened dendritic arbors of the aging cortical pyramidal neurons suggesting that dendritic arbors and spines are differently modulated. Thus, genistein could work at central level to restore excitatory connectivity and appears to be potent alternative to estradiol for easing aging and menopausal syndromes.
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Affiliation(s)
- Tsyr-Jiuan Wang
- Department of Nursing, National Taichung University of Science and Technology, Taichung, Taiwan
| | - Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Wen-Jay Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
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33
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Estrogen-dependent changes in estrogen receptor-β mRNA expression in middle-aged female rat brain. Brain Res 2013; 1543:49-57. [PMID: 24239930 DOI: 10.1016/j.brainres.2013.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/06/2013] [Accepted: 11/07/2013] [Indexed: 01/21/2023]
Abstract
During aging, estrogen production and circulating levels of estrogen are markedly decreased in females. Although several differences exist in the process of reproductive aging between women and female rats, the results of many studies suggest that the female rat, especially the middle-aged or aged ovariectomized female, is an important animal model of hormone loss in women. In target tissues including the brain, the actions of estrogen are mediated mainly via the alpha and beta subtypes of the estrogen receptor (ER-α and ER-β). Estrogen treatment is known to change the expression of ER-α mRNA and protein in specific regions of the brain in middle-aged female rodents. In contrast, we do not know if estrogen regulates the expression of ER-β in the brain at this stage of life. In the present study, we performed in situ hybridization on brain sections of ovariectomized and estrogen-treated middle-aged female rats to reveal the effects of estrogen on the expression of ER-β throughout the brain. Our results showed that estrogen treatment decreased the number of ER-β mRNA-positive cells in the mitral cell and external plexiform layers of the olfactory bulb, central amygdaloid nucleus, medial geniculate nucleus, posterior hypothalamic nucleus, suprachiasmatic nucleus, and reticular part of the substantia nigra. As compared to the results of previous studies of young females, our data revealed that the regions in which expression of ER-β mRNA expression is affected by estrogen differ in middle age. These results suggest that the effects of estrogen on ER-β expression change with age.
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34
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Vermeer LMM, Gregory E, Winter MK, McCarson KE, Berman NEJ. Exposure to bisphenol A exacerbates migraine-like behaviors in a multibehavior model of rat migraine. Toxicol Sci 2013; 137:416-27. [PMID: 24189132 DOI: 10.1093/toxsci/kft245] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Migraine is a common and debilitating neurological disorder suffered worldwide. Women experience this condition 3 times more frequently than men, with estrogen strongly implicated to play a role. Bisphenol A (BPA), a highly prevalent xenoestrogen, is known to have estrogenic activity and may have an effect in migraine onset, intensity, and duration through estrogen receptor signaling. It was hypothesized that BPA exposure exacerbates migraine symptoms through estrogen signaling and downstream activation of nociception related pathways. Utilizing a multibehavior model of migraine in ovariectomized female rats, changes in locomotion, light and sound sensitivity, grooming, and acoustic startle were examined. Furthermore, changes in the expression of genes related to estrogen (ERα, GPR30), and nociception (extracellular signal regulated kinase, ERK, sodium gated channel, Nav1.8, and fatty acid amide hydrolase, FAAH) were studied following behavioral experiments. The following results were obtained: BPA treatment significantly exacerbated migraine-like behaviors in rats. Rats exposed to BPA demonstrated decreased locomotion, exacerbated light and sound aversion, altered grooming habits, and enhanced startle reflexes. Furthermore, BPA exposure increased mRNA expression of estrogen receptors, total ERK mRNA and ERK activation, as well as Nav1.8, and FAAH mRNA, indicative of altered estrogen signaling and altered nociception. These results show that BPA, an environmentally pervasive xenoestrogen, exacerbates migraine-like behavior in a rat model and alters expression of estrogen and nociception-related genes.
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35
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Frick KM. Epigenetics, oestradiol and hippocampal memory consolidation. J Neuroendocrinol 2013; 25:1151-62. [PMID: 24028406 PMCID: PMC3943552 DOI: 10.1111/jne.12106] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 08/13/2013] [Accepted: 09/05/2013] [Indexed: 02/02/2023]
Abstract
Epigenetic alterations of histone proteins and DNA are essential for hippocampal synaptic plasticity and cognitive function, and contribute to the aetiology of psychiatric disorders and neurodegenerative diseases. Hippocampal memory formation depends on histone alterations and DNA methylation, and increasing evidence suggests that the regulation of these epigenetic processes by modulatory factors, such as environmental enrichment, stress and hormones, substantially influences memory function. Recent work from our laboratory suggests that the ability of the sex-steroid hormone 17β-oestradiol (E2 ) to enhance novel object recognition memory consolidation in young adult female mice is dependent on histone H3 acetylation and DNA methylation in the dorsal hippocampus. Our data also suggest that enzymes mediating DNA methylation and histone acetylation work in concert to regulate the effects of E2 on memory consolidation. These findings shed light on the epigenetic mechanisms that influence hormonal modulation of cognitive function, and may have important implications for understanding how hormones influence cognition in adulthood and ageing. The present review provides a brief overview of the literature on epigenetics and memory, describes in detail our findings demonstrating that epigenetic alterations regulate E2 -induced memory enhancement in female mice, and discusses future directions for research on the epigenetic regulation of E2 -induced memory enhancement.
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Affiliation(s)
- Karyn M. Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
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36
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Galea LAM, Wainwright SR, Roes MM, Duarte-Guterman P, Chow C, Hamson DK. Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications. J Neuroendocrinol 2013; 25:1039-61. [PMID: 23822747 DOI: 10.1111/jne.12070] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 06/23/2013] [Accepted: 06/29/2013] [Indexed: 12/12/2022]
Abstract
The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress.
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Affiliation(s)
- L A M Galea
- Department of Psychology, University of British Columbia, Vancouver, Canada
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37
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Acosta JI, Hiroi R, Camp BW, Talboom JS, Bimonte-Nelson HA. An update on the cognitive impact of clinically-used hormone therapies in the female rat: models, mazes, and mechanisms. Brain Res 2013; 1514:18-39. [PMID: 23333453 PMCID: PMC3739440 DOI: 10.1016/j.brainres.2013.01.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/09/2013] [Indexed: 01/05/2023]
Abstract
In women, ovarian hormone loss associated with menopause has been related to cognitive decline. Hormone therapy (HT) may ameliorate some of these changes. Understanding the cognitive impact of female steroids, including estrogens, progestogens, and androgens, is key to discovering treatments that promote brain health in women. The preclinical literature has presented elegant and methodical experiments allowing a better understanding of parameters driving the cognitive consequences of ovarian hormone loss and HT. Animal models have been a valuable tool in this regard, and will be vital to future discoveries. Here, we provide an update on the literature evaluating the impact of female steroid hormones on cognition, and the putative mechanisms mediating these effects. We focus on preclinical work that was done with an eye toward clinical realities. Parameters that govern the cognitive efficacy of HT, from what we know thus far, include but are not limited to: type, dose, duration, and route of HT, age at HT initiation, timing of HT relative to ovarian hormone loss, memory type examined, menopause history, and hormone receptor status. Researchers have identified intricate relationships between some of these factors by studying their individual effects on cognition. As of late, there is increased focus on studying interactions between these variables as well as multiple hormone types when administered concomitantly. This is key to translating preclinical data to the clinic, wherein women typically have concurrent exposure to endogenous ovarian hormones as well as exogenous combination HTs, which include both estrogens and progestins. Gains in understanding the parameters of HT effects on cognition provide exciting novel avenues that can inform clinical treatments, eventually expanding the window of opportunity to optimally enhance cognition and brain health in aging women. This article is part of a Special Issue entitled Hormone Therapy.
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Affiliation(s)
- J I Acosta
- Department of Psychology, Arizona State University, Tempe, AZ 85287, USA
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38
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Schreihofer DA, Ma Y. Estrogen receptors and ischemic neuroprotection: Who, what, where, and when? Brain Res 2013; 1514:107-22. [DOI: 10.1016/j.brainres.2013.02.051] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 02/08/2023]
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39
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Han X, Aenlle KK, Bean LA, Rani A, Semple-Rowland SL, Kumar A, Foster TC. Role of estrogen receptor α and β in preserving hippocampal function during aging. J Neurosci 2013; 33:2671-83. [PMID: 23392694 PMCID: PMC3692013 DOI: 10.1523/jneurosci.4937-12.2013] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 11/21/2012] [Accepted: 11/26/2012] [Indexed: 11/21/2022] Open
Abstract
The expression of the ERα and ERβ estrogen receptors in the hippocampus may be important in the etiology of age-related cognitive decline. To examine the role of ERα and ERβ in regulating transcription and learning, ovariectomized wild-type (WT) and ERα and ERβ knockout (KO) mice were used. Hippocampal gene transcription in young ERαKO mice was similar to WT mice 6 h after a single estradiol treatment. In middle-age ERαKO mice, hormone deprivation was associated with a decrease in the expression of select genes associated with the blood-brain barrier; cyclic estradiol treatment increased transcription of these select genes and improved learning in these mice. In contrast to ERαKO mice, ERβKO mice exhibited a basal hippocampal gene profile similar to WT mice treated with estradiol and, in the absence of estradiol treatment, young and middle-age ERβKO mice exhibited preserved learning on the water maze. The preserved memory performance of middle-age ERβKO mice could be reversed by lentiviral delivery of ERβ to the hippocampus. These results suggest that one function of ERβ is to regulate ERα-mediated transcription in the hippocampus. This model is supported by our observations that knockout of ERβ under conditions of low estradiol allowed ERα-mediated transcription. As estradiol levels increased in the absence of ERα, we observed that other mechanisms, likely including ERβ, regulated transcription and maintained hippocampal-dependent memory. Thus, our results indicate that ERα and ERβ interact with hormone levels to regulate transcription involved in maintaining hippocampal function during aging.
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Affiliation(s)
- Xiaoxia Han
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
| | - Kristina K. Aenlle
- Department of Veterans Affairs Medical Center, Geriatric Research, Education and Clinical Center, Miami, Florida 33125
| | - Linda A. Bean
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
| | - Susan L. Semple-Rowland
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
| | - Thomas C. Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, and
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Witty CF, Gardella LP, Perez MC, Daniel JM. Short-term estradiol administration in aging ovariectomized rats provides lasting benefits for memory and the hippocampus: a role for insulin-like growth factor-I. Endocrinology 2013; 154:842-52. [PMID: 23264616 DOI: 10.1210/en.2012-1698] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We previously demonstrated that aged ovariectomized rats that had received prior estradiol treatment in middle age exhibited enhanced spatial memory and increased levels of estrogen receptor (ER)-α in the hippocampus long after estradiol treatment was terminated. The implication for cognition of increased levels of ERα resulting from prior estradiol exposure is unknown. In the absence of estrogens, growth factors, including IGF-I, can induce ERα-mediated transcription through ligand-independent mechanisms. Our current goal was to determine whether IGF-I mediates the ability of short-term exposure to estradiol to exert long-term effects on cognition and the hippocampus of aging females. Ovariectomized middle-aged rats were implanted with estradiol or cholesterol vehicle capsules. After 40 days, all capsules were removed and drug treatments were initiated. Half of each hormone treatment group received chronic intracerebroventricular delivery of the IGF-I receptor antagonist JB1, and the other half received artificial cerebrospinal fluid vehicle. Rats were tested on a spatial memory radial-arm maze task and hippocampi were immunostained for proteins of interest by Western blotting. As expected, previous treatment with estradiol enhanced spatial memory and increased levels of ERα in the hippocampus. JB1 reversed these effects. Previous treatment with estradiol resulted in lasting increases in levels of IGF-I receptors and phosphorylation of ERK/MAPK, a downstream signaling molecule of both ERα and IGF-I receptors, and increased levels of the ERα-regulated protein, choline acetyltransferase. JB1 blocked effects on ERK/MAPK and choline acetyltransferase. Results indicate that activation of IGF-I receptors is necessary for prior estradiol exposure to exert lasting impact on the hippocampus and memory.
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Does the timing of estrogen administration after castration affect its ability to preserve sexual interest in male rats? — Exploring the critical period hypothesis. Physiol Behav 2013; 110-111:63-72. [DOI: 10.1016/j.physbeh.2012.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/12/2012] [Accepted: 12/20/2012] [Indexed: 01/20/2023]
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Velíšková J, Desantis KA. Sex and hormonal influences on seizures and epilepsy. Horm Behav 2013; 63:267-77. [PMID: 22504305 PMCID: PMC3424285 DOI: 10.1016/j.yhbeh.2012.03.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 11/20/2022]
Abstract
Epilepsy is the third most common chronic neurological disorder. Clinical and experimental evidence supports the role of sex and influence of sex hormones on seizures and epilepsy as well as alterations of the endocrine system and levels of sex hormones by epileptiform activity. Conversely, seizures are sensitive to changes in sex hormone levels, which in turn may affect the seizure-induced neuronal damage. The effects of reproductive hormones on neuronal excitability and seizure-induced damage are complex to contradictory and depend on different mechanisms, which have to be accounted for in data interpretation. Both estradiol and progesterone/allopregnanolone may have beneficial effects for patients with epilepsy. Individualized hormonal therapy should be considered as adjunctive treatment in patients with epilepsy to improve seizure control as well as quality of life.
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Affiliation(s)
- Jana Velíšková
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA.
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Daniel JM. Estrogens, estrogen receptors, and female cognitive aging: the impact of timing. Horm Behav 2013; 63:231-7. [PMID: 22587940 DOI: 10.1016/j.yhbeh.2012.05.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 05/04/2012] [Accepted: 05/07/2012] [Indexed: 10/28/2022]
Abstract
Estrogens have been shown to be protective agents against neurodegeneration and associated cognitive decline in aging females. However, clinical data have been equivocal as to the benefits to the brain and cognition of estrogen therapy in postmenopausal women. One factor that is proposed to be critical in determining the efficacy of hormone therapy is the timing of its initiation. The critical period or window of opportunity hypothesis proposes that following long-term ovarian hormone deprivation, the brain and cognition become insensitive to exogenously administered estrogens. In contrast, if estrogens are administered during a critical period near the time of cessation of ovarian function, they will exert beneficial effects. The focus of the current review is the examination of evidence from rodent models investigating the critical period hypothesis. A growing body of experimental data indicates that beneficial effects of 17β-estradiol (estradiol) on cognition and on cholinergic function and hippocampal plasticity, both of which have been linked to the ability of estradiol to exert beneficial effects on cognition, are attenuated if estradiol is administered following a period of long-term ovarian hormone deprivation. Further, emerging data implicate loss of estrogen receptor alpha (ERα) in the brain resulting from long-term hormone deprivation as a basis for the existence of the critical period. A unifying model is proposed by which the presence or absence of estrogens during a critical period following the cessation of ovarian function permanently alters the system resulting in decreased or increased risk, respectively, of neurodegeneration and cognitive decline.
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Affiliation(s)
- Jill M Daniel
- Department of Psychology and Program in Neuroscience, Tulane University, New Orleans, LA 70118, USA.
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Buwalda B, Schagen SB. Is basic research providing answers if adjuvant anti-estrogen treatment of breast cancer can induce cognitive impairment? Life Sci 2013; 93:581-8. [PMID: 23353876 DOI: 10.1016/j.lfs.2012.12.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/27/2012] [Accepted: 12/21/2012] [Indexed: 12/23/2022]
Abstract
Adjuvant treatment of cancer by chemotherapy is associated with cognitive impairment in some cancer survivors. Breast cancer patients are frequently also receiving endocrine therapy with selective estrogen receptor modulators (SERMs) and/or aromatase inhibitors (AIs) to suppress the growth of estradiol sensitive breast tumors. Estrogens are well-known, however, to target brain areas involved in the regulation of cognitive behavior. In this review clinical and basic preclinical research is reviewed on the actions of estradiol, SERMs and AIs on brain and cognitive functioning to see if endocrine therapy potentially induces cognitive impairment and in that respect may contribute to the detrimental effects of chemotherapy on cognitive performance in breast cancer patients. Although many clinical studies may be underpowered to detect changes in cognitive function, current basic and clinical reports suggest that there is little evidence that AIs may have a lasting detrimental effect on cognitive performance in breast cancer patients. The clinical data on SERMs are not conclusive, but some studies do suggest that tamoxifen administration may form a risk for cognitive functioning particularly in older women. An explanation may come from basic preclinical research which indicates that tamoxifen often acts agonistic in the absence of estradiol but antagonistic in the presence of endogenous estradiol. It could be hypothesized that the negative effects of tamoxifen in older women is related to the so-called window of opportunity for estrogen. Administration of SERMs beyond this so-called window of opportunity may not be effective or might even have detrimental effects similar to estradiol.
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Affiliation(s)
- Bauke Buwalda
- Behavioral Physiology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
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45
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Witty CF, Foster TC, Semple-Rowland SL, Daniel JM. Increasing hippocampal estrogen receptor alpha levels via viral vectors increases MAP kinase activation and enhances memory in aging rats in the absence of ovarian estrogens. PLoS One 2012; 7:e51385. [PMID: 23240018 PMCID: PMC3519866 DOI: 10.1371/journal.pone.0051385] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 11/02/2012] [Indexed: 11/23/2022] Open
Abstract
We previously demonstrated that aged ovariectomized rats that had received prior estradiol treatment in middle-age exhibited increased levels of estrogen receptor alpha (ERα) in the hippocampus as well as enhanced hippocampal dependent memory as compared to aged rats that had not received mid-life estradiol treatment. These effects persisted long after the estradiol treatment had been terminated. The goal of the current experiment was to determine if increased expression of ERα in the hippocampus, in the absence of exogenously administered estrogens, can impact the hippocampus and cognitive function in aging ovariectomized rats. Middle-aged rats were trained for 24 days on an eight-arm radial maze spatial memory task. All rats were then ovariectomized. Forty days later, rats received either lentiviral delivery to the hippocampus of the gene encoding ERα (lenti-ERα) or a control virus. Rats were tested on delay trials in the radial-maze in which delays of varying lengths were imposed between the fourth and fifth arm choices. Following behavior testing, hippocampi were immunostained using western blotting for ERα, the ERα-regulated protein choline acetyltransferase, and phosphorylation of the ERα-regulated kinases, ERK/MAPK and Akt. Results revealed that aging ovariectomized rats that received delivery of lenti-ERα to the hippocampus exhibited enhanced spatial memory as indicated by increased arm-choice accuracy across delays as compared to ovariectomized rats that received control virus. Western blot data revealed that lenti-ERα delivery significantly increased levels of ERα and phosphorylated ERK/MAPK and had no impact on levels of ChAT or phosphorylation of Akt. Results indicate that increasing hippocampal levels of ERα in aging females in the absence of ovarian or exogenously administered estrogens leads to increases in phosphorylation of ERK/MAPK as well as in enhanced memory.
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Affiliation(s)
- Christine F. Witty
- Neuroscience Program, Tulane University, New Orleans, Louisiana, United States of America
| | - Thomas C. Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
| | - Susan L. Semple-Rowland
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
| | - Jill M. Daniel
- Neuroscience Program, Tulane University, New Orleans, Louisiana, United States of America
- Department of Psychology, Tulane University, New Orleans, Louisiana, United States of America
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46
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Are the neuroprotective effects of estradiol and physical exercise comparable during ageing in female rats? Biogerontology 2012; 13:413-27. [DOI: 10.1007/s10522-012-9386-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/07/2012] [Indexed: 12/19/2022]
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47
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Bian C, Zhu K, Yang L, Lin S, Li S, Su B, Zhang J. Gonadectomy differentially regulates steroid receptor coactivator-1 and synaptic proteins in the hippocampus of adult female and male C57BL/6 mice. Synapse 2012; 66:849-57. [PMID: 22623226 DOI: 10.1002/syn.21574] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/14/2012] [Indexed: 02/06/2023]
Abstract
Hippocampus is one of the most important structures that mediates learning and memory, cognition, and mental behaviors and profoundly regulated by sex hormones in a sex-specific manner, but the mechanism of underlying sex differences regulation is still unclear. We have previously reported that in the male and female mice, steroid receptor coactivator-1 (SRC-1) and some key synaptic proteins share similar developmental profile in the hippocampus, but how circulating sex hormones affect hippocampal SRC-1 as well as these synaptic proteins remain unclear. In this study, we examined how gonad sex hormones regulate hippocampal SRC-1, synaptophysin, PSD-95, and AMPA receptor subtype GluR1 by using immunohistochemistry and Western blot. The results showed that in the female mice, ovariectomy affected hippocampal SRC-1 and GluR1 were only detected at 2 weeks post operation, then it recovered to sham level; synaptophysin was unaffected at any timepoint examined; significant decrease of PSD-95 was only detected at 4 weeks post operation. However, in the male hippocampus, SRC-1 and PSD-95 were decreased from one week and lasted to 4 weeks after orchidectomy, GluR1 decreased from 2 weeks after orchidectomy, but synaptophysin remained unchanged as in the females. Correlation analysis showed the profiles of SRC-1 were positively correlated with GluR1 of the females, PSD-95 and GluR1 of the males, respectively. The above results suggested a distinct regulatory mode between female and male gonad hormones in the regulation of hippocampal SRC-1 and synaptic proteins, which may be one of the mechanisms contributing to the dimorphism of hippocampus during development and ageing.
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Affiliation(s)
- Chen Bian
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
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48
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Foster TC. Role of estrogen receptor alpha and beta expression and signaling on cognitive function during aging. Hippocampus 2012; 22:656-69. [PMID: 21538657 PMCID: PMC3704216 DOI: 10.1002/hipo.20935] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2011] [Indexed: 12/24/2022]
Abstract
This review presents evidence for the idea that the expression of estrogen receptor alpha and beta (ERα and ERβ) interacts with the level of estradiol (E2) to influence the etiology of age-related cognitive decline and responsiveness to E2 treatments. There is a nonmonotonic dose response curve for E2 influences on behavior and transcription. Evidence is mounting to indicate that the dose response curve is shifted according to the relative expression of ERα and ERβ. Recent work characterizing age-related changes in the expression of ERα and ERβ in the hippocampus, as well as studies using mutant mice, and viral mediated delivery of estrogen receptors indicate that an age-related shift in ERα/ERβ expression, combined with declining gonadal E2 can impact transcription, cell signaling, neuroprotection, and neuronal growth. Finally, the role of ERα/ERβ on rapid E2 signaling and synaptogenesis as it relates to hippocampal aging is discussed.
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Affiliation(s)
- Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA.
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49
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Estrogen effects on the forced swim test differ in two outbred rat strains. Physiol Behav 2012; 106:81-6. [PMID: 22266677 DOI: 10.1016/j.physbeh.2012.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 12/31/2022]
Abstract
Changes in reproductive hormones, such as estrogen, play a role in mood regulation. The present study examined strain differences (Long-Evans vs. Wistar-Hannover) in the behavioral and biochemical effects of estrogen manipulation. Adult ovariectomized female rats were treated with estradiol, vehicle, or withdrawn from estradiol. The two strains demonstrated differential behavioral responses to short-term estradiol administration in the forced swim test; estradiol induced an antidepressant-like effect in Long-Evans rats but not in Wistar rats. Conversely, withdrawal from estradiol resulted in a depressive-like state in the Wistar rats but not in the Long-Evans rats. Western blot analyses found no differences in estrogen receptors α and β within the hippocampus or the frontal cortex, two brain areas strongly implicated in affective disorders. These data demonstrate the importance of strain as a variable when interpreting behavioral effects of estrogen.
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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
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 153-8902 Japan
| | - Christian J. Pike
- USC Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089 USA
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