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Koebele SV, Mennenga SE, Poisson ML, Hewitt LT, Patel S, Mayer LP, Dyer CA, Bimonte-Nelson HA. Characterizing the effects of tonic 17β-estradiol administration on spatial learning and memory in the follicle-deplete middle-aged female rat. Horm Behav 2020; 126:104854. [PMID: 32949557 PMCID: PMC8032560 DOI: 10.1016/j.yhbeh.2020.104854] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 01/19/2023]
Abstract
17β-estradiol (E2)-containing hormone therapy is a safe, effective way to alleviate unwanted menopause symptoms. Preclinical research has focused upon the role of E2 in learning and memory using a surgically menopausal rodent model whereby the ovaries are removed. Given that most women retain their reproductive tract and undergo a natural menopause transition, it is necessary to understand how exogenous E2 impacts a structurally intact, but follicle-deplete, system. In the current study, 8 month old female rats were administered the ovatoxin 4-vinylcyclohexene diepoxide (VCD), which accelerates ovarian follicular depletion, to model the human menopause transition. After follicular depletion, at 11 months old, rats were administered Vehicle or tonic E2 treatment for 12 days prior to behavioral evaluation on spatial working and reference memory tasks. Results demonstrated that E2 had both enhancing and impairing effects on taxed working memory depending upon the learning or retention phases of the water radial-arm maze, with no impact on reference memory. Relationships between memory scores and circulating estrogen levels were specific to follicle-depleted rats without E2 treatment. Collectively, findings demonstrate the complexity of E2 administration in a follicle-depleted background, with cognitive effects specific to working memory; furthermore, E2 administration altered circulating hormonal milieu and relationships between hormone profiles and memory. In sum, menopausal etiology impacts the parameters of E2 effects on cognition, complementing prior work with other estrogen compounds. Deciphering estrogenic actions in a system wherein the reproductive tract remains intact with follicle-depleted ovaries, thus modeling the majority or menopausal women, is critical for translational perspectives.
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Affiliation(s)
- Stephanie V Koebele
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America
| | - Sarah E Mennenga
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America
| | - Mallori L Poisson
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America
| | - Lauren T Hewitt
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America
| | - Shruti Patel
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America
| | | | - Cheryl A Dyer
- FYXX Foundation, Flagstaff, AZ, United States of America
| | - Heather A Bimonte-Nelson
- Department of Psychology, Arizona State University, Tempe, AZ 85287, United States of America; Arizona Alzheimer's Consortium, Phoenix, AZ 85006, United States of America.
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Phytoestrogen genistein hinders ovarian oxidative damage and apoptotic cell death-induced by ionizing radiation: co-operative role of ER-β, TGF-β, and FOXL-2. Sci Rep 2020; 10:13551. [PMID: 32782329 PMCID: PMC7419553 DOI: 10.1038/s41598-020-70309-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 07/14/2020] [Indexed: 01/17/2023] Open
Abstract
Radiotherapy is a well-known cause of premature ovarian failure (POF). Therefore, we investigated the molecular influence of genistein (GEN) on the ovarian reserve of rats exposed to ϒ-radiation. Female Sprague Dawley rats were exposed to a 3.2 Gy γ-radiation to induce POF and/or treated with either GEN (5 mg/kg, i.p.) or Ethinyl estradiol (E2; 0.1 mg/kg, s.c.), once daily for 10 days. GEN was able to conserve primordial follicles stock and population of growing follicles accompanied with reduction in atretic follicles. GEN restored the circulating estradiol and anti-Müllerian hormone levels which were diminished after irradiation. GEN has potent antioxidant activity against radiation-mediated oxidative stress through upregulating endogenous glutathione levels and glutathione peroxidase activity. Mechanistically, GEN inhibited the intrinsic pathway of apoptosis by repressing Bax expression and augmenting Bcl-2 expression resulted in reduced Bax/Bcl-2 ratio with subsequent reduction in cytochrome c and caspase 3 expression. These promising effects of GEN are associated with improving granulosa cells proliferation. On the molecular basis, GEN reversed ovarian apoptosis through up-regulation of ER-β and FOXL-2 with downregulation of TGF-β expression, therefore inhibiting transition of primordial follicles to more growing follicles. GEN may constitute a novel therapeutic modality for safeguarding ovarian function of females' cancer survivors.
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Cao LB, Liu HB, Lu G, Lv Y, Leung CK, Du YZ, Wang WM, Xiong ZQ, Su XW, Li HJ, Chen ZJ, Ma JL, Chan WY. Hormone-Like Effects of 4-Vinylcyclohexene Diepoxide on Follicular Development. Front Cell Dev Biol 2020; 8:587. [PMID: 32850784 PMCID: PMC7412635 DOI: 10.3389/fcell.2020.00587] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/17/2020] [Indexed: 12/31/2022] Open
Abstract
Background 4-vinylcyclohexene diepoxide (VCD) has long been considered a hazardous occupational chemical that promotes ovarian failure. However, VCD is also used as a research compound to chemically induce animal models of premature ovarian insufficiency (POI), and in related work we unexpectedly found that VCD apparently exhibits both dose- and duration-dependent opposing, hormone-like effects on the maintenance of the primordial follicle pool, follicle development, and ovulation induction. Results We conducted experiments with cultured murine ovaries and performed transplantation experiments using postnatal day (PD) 2 and PD12 mice and found that low-dose, short-term exposure to VCD (VCDlow) actually protects the primordial/primary follicle pool and improves the functional ovarian reserve (FOR) by disrupting follicular atresia. VCDlow inhibits follicular apoptosis and regulates the Pten-PI3K-Foxo3a pathway. Short-term VCD exposure in vivo (80 mg/kg, 5 days) significantly increases the number of superovulated metaphase II oocytes, preovulatory follicles, and corpus luteum in middle-aged mice with diminished ovarian reserve (DOR). We demonstrate that low-dose but not high-dose VCD promotes aromatase levels in granulosa cells (GCs), thereby enhancing the levels of estradiol secretion. Conclusion Our study illustrates a previously unappreciated, hormone-like action for the occupational “ovotoxin” molecule VCD and strongly suggests that VCDlow should be explored for its potential utility for treating human ovarian follicular development disorders, including subfertility in perimenopausal women.
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Affiliation(s)
- Lian Bao Cao
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
| | - Hong Bin Liu
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
| | - Gang Lu
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
| | - Yue Lv
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
| | - Chi Kwan Leung
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,SDIVF R&D Centre, Hong Kong Science and Technology Parks, Sha Tin, China
| | - Yan Zhi Du
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,Center for Reproductive Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wu Ming Wang
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
| | - Zhi Qiang Xiong
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,SDIVF R&D Centre, Hong Kong Science and Technology Parks, Sha Tin, China
| | - Xian Wei Su
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,SDIVF R&D Centre, Hong Kong Science and Technology Parks, Sha Tin, China
| | - Hong Jian Li
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,SDIVF R&D Centre, Hong Kong Science and Technology Parks, Sha Tin, China
| | - Zi-Jiang Chen
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,Center for Reproductive Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jin Long Ma
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.,SDIVF R&D Centre, Hong Kong Science and Technology Parks, Sha Tin, China
| | - Wai Yee Chan
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
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Battiston FG, Dos Santos C, Barbosa AM, Sehnem S, Leonel ECR, Taboga SR, Anselmo-Franci JA, Lima FB, Rafacho A. Glucose homeostasis in rats treated with 4-vinylcyclohexene diepoxide is not worsened by dexamethasone treatment. J Steroid Biochem Mol Biol 2017; 165:170-181. [PMID: 27264932 DOI: 10.1016/j.jsbmb.2016.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/19/2022]
Abstract
4-vinilcyclohexene diepoxide (4-VCD) causes premature ovarian failure and may result in estrogen deficiency, characterizing the transition to estropause in rodents (equivalent to menopause in women). Estropause/menopause is associated with metabolic derangements such as glucose intolerance and insulin resistance. Glucocorticoids (GCs) are known to exert diabetogenic effects. Thus, we aimed to investigate whether rats with premature ovarian failure are more prone to the diabetogenic effects of GC. For this, immature female rats received daily injections of 4-VCD [160mg/kg body weight (b.w.), intraperitoneally (i.p.)] for 15 consecutive days, whereas control rats received vehicle. After 168days of the completion of 4-VCD administration, rats were divided into 4 groups: CTL-received daily injections of saline (1mL/kg, b.w., i.p.) for 5days; DEX-received daily injections of dexamethasone (1mg/kg, b.w., i.p.) for 5days; VCD-treated as CTL group; VCD+DEX-treated as DEX group. Experiments and euthanasia occurred one day after the last dexamethasone injection. 4-VCD-treated rats exhibited ovary hypotrophy and reduced number of preantral follicles (p<0.05). Premature ovarian failure had no impact on the body weight gain or food intake, but both were reduced by the effects of dexamethasone. The increase in blood glucose, plasma insulin and triacylglycerol levels as well as the reduction in insulin sensitivity caused by dexamethasone treatment was not exacerbated in the VCD+DEX group of rats. Premature ovarian failure did change neither the hepatic content of glycogen and triacylglycerol nor the glycerol release from perigonadal adipose tissue. Glucose intolerance was observed in the VCD group after an ipGTT (p<0.05), but not after an oral glucose challenge. Glucose intolerance and compensatory pancreatic β-cell mass caused by GC were not modified by ovarian failure in the VCD+DEX group. We conclude that reduced ovarian function has no major implications on the diabetogenic effects promoted by GC treatment, indicating that other factors related to aging may make rats more vulnerable to GC side effects on glucose metabolism.
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Affiliation(s)
- Francielle Garghetti Battiston
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil
| | - Cristiane Dos Santos
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil
| | - Amanda Marreiro Barbosa
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil
| | - Sibele Sehnem
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil
| | - Ellen Cristina Rivas Leonel
- Department of Biology, Institute of Biosciences, Letters and Exact Sciences, Univ. Estadual Paulista-IBILCE/UNESP, São José do Rio Preto, SP, Brazil
| | - Sebastião Roberto Taboga
- Department of Biology, Institute of Biosciences, Letters and Exact Sciences, Univ. Estadual Paulista-IBILCE/UNESP, São José do Rio Preto, SP, Brazil
| | - Janete A Anselmo-Franci
- Department of Morphology, Center of Biological Sciences, School of Dentistry of Ribeirão Preto, São Paulo University-USP, Ribeirão Preto, SP, Brazil
| | - Fernanda Barbosa Lima
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil
| | - Alex Rafacho
- Department of Physiological Sciences and Multicenter Graduate Program in Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina-UFSC, Florianópolis, Brazil.
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5
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Devine PJ, Perreault SD, Luderer U. Roles of reactive oxygen species and antioxidants in ovarian toxicity. Biol Reprod 2012; 86:27. [PMID: 22034525 PMCID: PMC3290661 DOI: 10.1095/biolreprod.111.095224] [Citation(s) in RCA: 277] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 09/20/2011] [Accepted: 10/06/2011] [Indexed: 12/22/2022] Open
Abstract
Proper functioning of the ovary is critical to maintain fertility and overall health, and ovarian function depends on the maintenance and normal development of ovarian follicles. This review presents evidence about the potential impact of oxidative stress on the well-being of primordial, growing and preovulatory follicles, as well as oocytes and early embryos, examining cell types and molecular targets. Limited data from genetically modified mouse models suggest that several antioxidant enzymes that protect cells from reactive oxygen species (ROS) may play important roles in follicular development and/or survival. Exposures to agents known to cause oxidative stress, such as gamma irradiation, chemotherapeutic drugs, or polycyclic aromatic hydrocarbons, induce rapid primordial follicle loss; however, the mechanistic role of ROS has received limited attention. In contrast, ROS may play an important role in the initiation of apoptosis in antral follicles. Depletion of glutathione leads to atresia of antral follicles in vivo and apoptosis of granulosa cells in cultured antral follicles. Chemicals, such as cyclophosphamide, dimethylbenzanthracene, and methoxychlor, increase proapoptotic signals, preceded by increased ROS and signs of oxidative stress, and cotreatment with antioxidants is protective. In oocytes, glutathione levels change rapidly during progression of meiosis and early embryonic development, and high oocyte glutathione at the time of fertilization is required for male pronucleus formation and for embryonic development to the blastocyst stage. Because current evidence suggests that oxidative stress can have significant negative impacts on female fertility and gamete health, dietary or pharmacological intervention may prove to be effective strategies to protect female fertility.
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Affiliation(s)
- Patrick J. Devine
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts
| | - Sally D. Perreault
- Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Ulrike Luderer
- Division of Occupational and Environmental Medicine, Department of Medicine, School of Medicine, University of California Irvine, Irvine, California
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, California
- Program in Public Health, University of California Irvine, Irvine, California
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6
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Stanley JA, Lee J, Nithy TK, Arosh JA, Burghardt RC, Banu SK. Chromium-VI arrests cell cycle and decreases granulosa cell proliferation by down-regulating cyclin-dependent kinases (CDK) and cyclins and up-regulating CDK-inhibitors. Reprod Toxicol 2011; 32:112-23. [PMID: 21621607 DOI: 10.1016/j.reprotox.2011.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 04/14/2011] [Accepted: 05/12/2011] [Indexed: 11/28/2022]
Abstract
Environmental contamination with hexavalent chromium (CrVI) has been increasing in the drinking water of the USA and developing countries. CrVI causes various health problems including menstrual disorders and infertility. Recently, we reported that CrVI causes granulosa cell apoptosis through the intrinsic apoptotic pathway. Our previous studies showed that postnatal exposure to CrVI arrests follicle development. In order to explore the underlying mechanism, primary and immortalized granulosa cells from rats were treated with 10 μM potassium dichromate and analyses of the cell cycle, and cell cycle regulatory proteins were performed. CrVI decreased cell proliferation as a result of cell cycle arrest and down-regulated cyclin-dependent kinases (CDK), cyclins, and PCNA while up-regulating CDK-inhibitors and down-regulating FSH receptor and ERβ. Vitamin C mitigated the effects of CrVI. This study shows that CrVI causes cell cycle arrest in granulosa cells by altering cell cycle regulatory proteins with potential intervention by vitamin C.
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Affiliation(s)
- Jone A Stanley
- Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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7
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Van Kempen TA, Milner TA, Waters EM. Accelerated ovarian failure: a novel, chemically induced animal model of menopause. Brain Res 2011; 1379:176-87. [PMID: 21211517 PMCID: PMC3078694 DOI: 10.1016/j.brainres.2010.12.064] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 12/17/2010] [Accepted: 12/20/2010] [Indexed: 10/18/2022]
Abstract
Current rodent models of menopause fail to adequately recapitulate the menopause transition. The intact aging model fails to achieve very low estrogen levels, and the ovariectomy model lacks a perimenopause phase. A new rodent model of accelerated ovarian failure (AOF) successfully replicates human perimenopause and postmenopause, including estrous acyclicity and fluctuating, followed by undetectable, estrogen levels, and allows for the dissociation of the effects of hormone levels from the effects of aging. In this model, an ovotoxic chemical, 4-vinylcyclohexene diepoxide (VCD), selective for primary and primordial follicles, is injected intraperitonelly in animals for 15 days. As the mature follicle population is depleted through natural cycling, ovarian failure follows increasing periods of acyclity. Administered at low doses, VCD specifically causes apoptotic cell death of primordial follicles but does not affect other peripheral tissues, including the liver and spleen, nor does it affect brain inflammation markers. In addition to reducing confounds associated with genetic and surgical manipulations, the AOF model maintains the presence of ovarian tissue which importantly parallels to the menopause transition in humans. The VCD injection procedure can be applied to studies using transgenic or knockout mice strains, or in other disease-state models (e.g., ischemia, atherosclerosis, or diabetes). This AOF model of menopause will generate new insights into women's health particularly in determining the critical periods (i.e., a window of opportunity) during perimenopause for restoring ovarian hormones for the most efficacious effect on memory and mood disorders as well as other menopausal symptoms.
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Affiliation(s)
- Tracey A Van Kempen
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA.
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8
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Tamoxifen decreases ovarian follicular loss from experimental toxicant DMBA and chemotherapy agents cyclophosphamide and doxorubicin in the rat. J Assist Reprod Genet 2010; 27:591-7. [PMID: 20711751 DOI: 10.1007/s10815-010-9463-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 07/23/2010] [Indexed: 10/19/2022] Open
Abstract
INTRODUCTION we serendipitously observed a protective effect of tamoxifen against depletion of ovarian follicles by 7,12-dimethylbenzanthracene (DMBA), a chemical carcinogen, during a cancer prevention study. Such ovarian protection is being sought as an alternative approach to fertility preservation in human cancer patients. METHODS rats received tamoxifen (0, 1 mg or 2.5 mg/kg/d) and DMBA (0, 1, 2 mg/kg/wk) or cyclophosphamide (0, 35, 50 mg/kg/wk). Ovarian follicles were quantified and effects on fertility and litter size were tested. Cultured oocytes were exposed to chemotherapy drug doxorubicin, with or without 4-hydroxytamoxifen (4HT). RESULTS DMBA and cyclophosphamide decreased the number of primordial and total follicles, and this reduction was prevented by tamoxifen. Cyclophosphamide tended to reduce fertility and lessened neonatal survival. Tamoxifen reversed these defects. Doxorubicin caused oocyte fragmentation which was prevented by 4HT. CONCLUSIONS tamoxifen decreases follicle loss and improves reproductive function following exposure to ovarian toxicants including chemotherapy drugs in the female rat.
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Albrecht ED, Pepe GJ. Estrogen regulation of placental angiogenesis and fetal ovarian development during primate pregnancy. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2010; 54:397-408. [PMID: 19876841 DOI: 10.1387/ijdb.082758ea] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During human and nonhuman primate pregnancy, an extensive blood vessel network is established within the villous placenta to support fetal growth and follicles develop within the fetal ovary to provide a pool of oocytes for reproductive function in adulthood. These two important developmental events occur in association with a progressive increase in placental estrogen production and levels. This review will describe the developmental processes required for placental vascularization and fetal follicular maturation and recent studies which show that estrogen has an important role in regulating these events.
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Affiliation(s)
- Eugene D Albrecht
- Department of Obstetrics, Gynecology and Reproductive Sciences, Center for Studies in Reproduction, University of Maryland School of Medicine, Baltimore, Maryland, USA.
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10
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Neuroprotection against excitotoxic brain injury in mice after ovarian steroid depletion. Brain Res 2009; 1265:37-46. [PMID: 19236850 DOI: 10.1016/j.brainres.2009.02.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 02/10/2009] [Indexed: 11/21/2022]
Abstract
Ovarian steroid hormones influence not only seizure phenomena, but also the neuronal cell death that follows. In the present study, we applied two models of ovarian steroid loss, ovariectomy and chemically-induced ovarian failure, to evaluate kainate-induced seizure activity and the susceptibility of hippocampal neurons to seizure-induced neurodegeneration. Young adult female FVB/NJ mice were ovariectomized with (OVX+E, n=6) or without (OVX, n=8) estrogen replacement. A separate group of females received the ovotoxin, 4-vinylcyclohexene diepoxide (VCD, n=8) to deplete ovarian follicles. Mice underwent kainate-induced status epilepticus and were evaluated for seizure activity (3 h) and delayed hippocampal neuronal injury (7 days). While there were no differences in latency or duration of severe seizures among control, OVX and VCD-treated mice, OVX+E mice exhibited seizures of a significantly longer duration. However, both VCD-induced ovarian failure and OVX led to a dramatic reduction in the extent of excitotoxic cell death, with slightly greater effects observed in VCD-treated mice. Estradiol administration to OVX mice also exerted a significant neuroprotective effect against kainate-induced cell death. These results support and extend earlier findings suggesting that the hormonal milieu may have differential effects on seizure susceptibility that are separate and distinct from those influencing hippocampal neuronal vulnerability. Collectively, these findings highlight the complex interactions among the loss of ovarian steroid hormones, estrogen replacement, seizures, and seizure-induced cell death.
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11
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Affiliation(s)
- Jonathan L Tilly
- Vincent Center for Reproductive Biology, Department of Obstetrics and Gynecology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts 02114, USA.
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12
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Hu X, Flaws JA, Sipes IG, Hoyer PB. Activation of mitogen-activated protein kinases and AP-1 transcription factor in ovotoxicity induced by 4-vinylcyclohexene diepoxide in rats. Biol Reprod 2002; 67:718-24. [PMID: 12193377 DOI: 10.1095/biolreprod.102.004259] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Previous studies have demonstrated that ovotoxicity induced in small preantral (primordial and primary) ovarian follicles by 4-vinylcyclohexene diepoxide (VCD) in rats is likely via acceleration of the normal process of atresia (apoptosis). This acceleration is associated with increased activities of caspase cascades, changes in subcellular distribution of Bcl-2 family members, and alteration of estrogen receptor-mediated signaling pathways. The present study was designed to investigate possible effects of VCD dosing on the mitogen-activated protein kinases (MAPK)/AP-1 signaling pathways in rat ovarian small follicles. Female F344 rats were given a single dose of VCD (80 mg/kg i.p., 1 day--a time when ovotoxicity has not been initiated) or dosed daily for 10 or 15 days (80 mg/kg i.p.; 10 days--a time when the earliest signs of impending follicular destruction is seen, 15 days--a time when significant ovotoxicity is underway). Four hours following the final dose, ovaries and livers were collected. Ovarian small (25-100 microm) and large (100-250 microm) preantral follicles were isolated, and cytosolic or nuclear extracts were prepared from follicles and livers for analyses. Activities of MAPKs, including extracellular signal-regulated kinase, c-Jun N-terminal protein kinase (JNK), and p38 kinase, were determined in follicular and liver cytosolic extracts, and AP-1 DNA binding activity was determined in follicular and liver nuclear extracts. Compared with control, a single dose of VCD caused a decrease in JNK activity and an increase of AP-1 binding activity in isolated small ovarian follicles. After repeated daily dosing with VCD for 10 or 15 days, JNK and p38 kinase activities in small ovarian follicles were increased (p38 kinase: 1.64 +/- 0.14 for 10 days, 1.48 +/- 0.11 for 15 days, VCD/control, P < 0.01; JNK: 1.44 +/- 0.11 for 10 days, 1.37 +/- 0.06 for 15 days, VCD/control, P < 0.01) and AP-1 binding activity in small ovarian follicles was decreased (10 days, 0.29 +/- 0.04; 15 days, 0.51 +/- 0.04, VCD/control, P < 0.01). VCD did not affect any of these measurements in large preantral follicles or liver. Phosphorylation status of c-Jun protein as measured by Western blotting was increased (1.22 +/- 0.1, VCD/control, P < 0.05) after the 15-day daily dosing with VCD, but total c-Jun protein levels were unaffected. Using antibodies against c-Jun or phospho-c-Jun for supershift DNA binding assay, c-Jun and phospho-c-Jun were identified in the AP-1-DNA binding complex, and the binding activity was reduced in tissues with increased phospho-c-Jun protein levels. Taken together, these data provide evidence that accelerated atretic signals induced by VCD is associated with MAPK/AP-1 signaling pathways and phosphorylation of c-Jun plays a significant role in transmitting the apoptotic signals.
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Affiliation(s)
- Xiaoming Hu
- Department of Physiology, The University of Arizona, Tucson, Arizona 85724, USA
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