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Witkowski S, White Q, Shreyer S, Garcia RL, Brown DE, Sievert LL. Acute increases in physical activity and temperature are associated with hot flash experience in midlife women. Menopause 2024; 31:600-607. [PMID: 38814193 PMCID: PMC11213681 DOI: 10.1097/gme.0000000000002373] [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] [Indexed: 05/31/2024]
Abstract
OBJECTIVE This study determined the association between acute changes in physical activity, temperature, and humidity and 24-hour subjective and objective hot flash experience. METHODS Data collection occurred during the cooler months of the year in Western Massachusetts (October-April). Women aged 45-55 across three menopause stages (n = 270) were instrumented with ambulatory monitors to continuously measure hot flashes, physical activity, temperature, and humidity for 24 hours. Objective hot flashes were assessed via sternal skin conductance, and subjective hot flashes were recorded by pressing an event marker and data logging. Physical activity was measured with wrist-worn accelerometers and used to define sleep and wake periods. Logistic multilevel modeling was used to examine the differences in physical activity, humidity, and temperature in the 10 minutes preceding a hot flash versus control windows when no hot flashes occurred. The odds of hot flashes were considered separately for objective and subjective hot flashes as well as for wake and sleep periods. RESULTS Data from 188 participants were included in the analyses. There was a significantly greater odds of a hot flash following acute increases in physical activity for objective waking hot flashes (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.17-1.47; P < 0.001) and subjective waking hot flashes (OR, 1.16; 95% CI, 1.0-1.33; P = 0.03). Acute increases in the actigraphy signal were associated with significantly higher odds of having an objective (OR, 1.17; 95% CI, 1.03-1.35; P < 0.01) or subjective (OR, 1.72; 95% CI, 1.52-2.01; P < 0.001) sleeping hot flash. Increases in temperature were significantly related to the odds of subjective sleeping hot flashes only (OR, 1.38; 95% CI, 1.15-1.62; P < 0.001). There was no evidence for a relationship between humidity and odds of experiencing any hot flashes. CONCLUSION These results indicate that acute increases in physical activity increase the odds of hot flashes that are objectively measured and subjectively reported during waking and sleeping periods. Temperature increases were only related to subjectively reported nighttime hot flashes.
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Affiliation(s)
| | - Quinn White
- Statistical & Data Sciences, Smith College, Northampton, MA
| | - Sofiya Shreyer
- Department of Anthropology, University of Massachusetts, Amherst, MA
| | - Randi L Garcia
- Statistical & Data Sciences, Smith College, Northampton, MA
| | - Daniel E Brown
- Department of Anthropology, University of Hawaii at Hilo, Hilo, HI
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Koysombat K, McGown P, Nyunt S, Abbara A, Dhillo WS. New advances in menopause symptom management. Best Pract Res Clin Endocrinol Metab 2024; 38:101774. [PMID: 37076317 DOI: 10.1016/j.beem.2023.101774] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Vasomotor symptoms (VMS) are characteristic of menopause experienced by over 75% of postmenopausal women with significant health and socioeconomic implications. Although the average duration of symptoms is seven years, 10% of women experience symptoms for more than a decade. Although menopausal hormone therapy (MHT) remains an efficacious and cost-effective treatment, its use may not be suitable in all women, such as those at an increased risk of breast cancer or gynaecological malignancy. The neurokinin B (NKB) signaling pathway, together with its intricate connection to the median preoptic nucleus (MnPO), has been postulated to provide integrated reproductive and thermoregulatory responses, with a central role in mediating postmenopausal VMS. This review describes the physiological hypothalamo-pituitary-ovary (HPO) axis, and subsequently the neuroendocrine changes that occur with menopause using evidence derived from animal and human studies. Finally, data from the latest clinical trials using novel therapeutic agents that antagonise NKB signaling are reviewed.
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Affiliation(s)
- Kanyada Koysombat
- Section of Investigative Medicine, Imperial College London, London, United Kingdom; Department of Endocrinology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Patrick McGown
- Section of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Sandhi Nyunt
- Section of Investigative Medicine, Imperial College London, London, United Kingdom; Department of Endocrinology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Ali Abbara
- Section of Investigative Medicine, Imperial College London, London, United Kingdom; Department of Endocrinology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Waljit S Dhillo
- Section of Investigative Medicine, Imperial College London, London, United Kingdom; Department of Endocrinology, Imperial College Healthcare NHS Trust, London, United Kingdom.
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3
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Johnson KA, Martin N, Nappi RE, Neal-Perry G, Shapiro M, Stute P, Thurston RC, Wolfman W, English M, Franklin C, Lee M, Santoro N. Efficacy and Safety of Fezolinetant in Moderate to Severe Vasomotor Symptoms Associated With Menopause: A Phase 3 RCT. J Clin Endocrinol Metab 2023; 108:1981-1997. [PMID: 36734148 PMCID: PMC10348473 DOI: 10.1210/clinem/dgad058] [Citation(s) in RCA: 61] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 01/22/2023] [Accepted: 01/25/2023] [Indexed: 02/04/2023]
Abstract
CONTEXT Vasomotor symptoms (VMS) are common, bothersome, and can persist for years before and after menopause. OBJECTIVE We aimed to assess efficacy/safety of fezolinetant for treatment of moderate to severe VMS associated with menopause. METHODS In this double-blind, placebo-controlled, 12-week phase 3 trial with a 40-week active treatment extension (NCT04003142; SKYLIGHT 2), women aged 40 to 65 years with minimum average 7 moderate to severe VMS/day were randomized to 12 weeks of once-daily placebo, fezolinetant 30 mg, or fezolinetant 45 mg. Completers were rerandomized to fezolinetant 30/45 mg for 40 additional weeks. Coprimary efficacy endpoints were mean daily change from baseline to week 4 (W4) and W12 in VMS frequency and severity. Safety was also assessed. RESULTS Both fezolinetant doses statistically significantly reduced VMS frequency/severity at W4 and W12 vs placebo. For VMS frequency, W4 least squares mean (SE) reduction vs placebo: fezolinetant 30 mg, -1.82 (0.46; P < .001); 45 mg, -2.55 (0.46; P < .001); W12: 30 mg, -1.86 (0.55; P < .001); 45 mg, -2.53 (0.55; P < .001). For VMS severity, W4: 30 mg, -0.15 (0.06; P < .05); 45 mg, -0.29 (0.06; P < .001); W12: 30 mg, -0.16 (0.08; P < .05); 45 mg, -0.29 (0.08; P < .001). Improvement in VMS frequency and severity was observed by W1 and maintained through W52. Serious treatment-emergent adverse events were infrequent, reported by 2%, 1%, and 0% of those receiving fezolinetant 30 mg, fezolinetant 45 mg, and placebo, respectively. CONCLUSION Daily fezolinetant 30 and 45 mg were efficacious and well tolerated for treating moderate to severe VMS associated with menopause.
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Affiliation(s)
| | - Nancy Martin
- Employee of Astellas Pharma Global Development at the Time of the Study, Northbrook, IL, USA
| | - Rossella E Nappi
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, and Research Center for Reproductive Medicine and Gynecological Endocrinology – Menopause Unit, Fondazione Policlinico IRCCS S. Matteo, Pavia 27100, Italy
| | - Genevieve Neal-Perry
- Department of Obstetrics and Gynecology, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Marla Shapiro
- Department of Family and Community Medicine, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Petra Stute
- Department of Obstetrics and Gynecology, Inselspital, Bern CH-3010, Switzerland
| | - Rebecca C Thurston
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Wendy Wolfman
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario M5G 1E2, Canada
| | - Marci English
- Global Development, Astellas Pharma Global Development, Inc., Northbrook, IL 60062, USA
| | - Catherine Franklin
- Employee of Astellas Pharma Global Development at the Time of the Study, Northbrook, IL, USA
| | - Misun Lee
- Biostatistics, Astellas Pharma Global Development, Inc., Northbrook, IL 60062, USA
| | - Nanette Santoro
- Division of Reproductive Sciences, University of Colorado School of Medicine, Aurora, CO 80045, USA
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4
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Klappenbach CM, Wang Q, Jensen AL, Glodosky NC, Delevich K. Sex and timing of gonadectomy relative to puberty interact to influence weight, body composition, and feeding behaviors in mice. Horm Behav 2023; 151:105350. [PMID: 36996734 DOI: 10.1016/j.yhbeh.2023.105350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
Gonadal sex steroids are important regulators of energy balance in adult rodents, and gonadectomy (GDX) has opposing effects on weight gain in sexually mature males and females. Puberty is associated with the emergence of sex differences in weight, body composition, and feeding behaviors, yet the role of gonadal hormones at puberty remains unclear. To address this, we performed GDX or sham surgery in male and female C57Bl/6 mice at postnatal day (P)25 (prepubertal) or P60 (postpubertal) timepoints and measured weight and body composition for 35 days, after which ad libitum and operant food intake was measured using Feeding Experimentation Device 3 (FED3s) in the home cage. Consistent with previous studies, postpubertal GDX caused weight gain in females and weight loss in males and increased adiposity in both sexes. However, prepubertal GDX decreased weight gain and altered body composition across the adolescent transition (P25 to P60) in males but had no effect in females. Despite the varied effects on weight, GDX decreased food intake and motivation for food as assessed in operant tasks regardless of sex or timing of surgery relative to puberty. Our findings indicate that GDX interacts with both sex and age at surgery to influence weight, body composition, and feeding behavior.
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Affiliation(s)
- Courtney M Klappenbach
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Qing Wang
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Allison L Jensen
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Nicholas C Glodosky
- Department of Psychology Washington State University, Pullman, WA 99164, USA
| | - Kristen Delevich
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA.
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Fonseca CS, Aquino NSS, Goncalves GKN, Drummond LR, Hipolito LTM, Silva JF, Silva KSC, Henriques PC, Domingues TE, Lacerda ACR, Guatimosim S, Coimbra CC, Szawka RE, Reis AM. Norepinephrine modulation of heat dissipation in female rats lacking estrogen. J Neuroendocrinol 2022; 34:e13188. [PMID: 36306200 DOI: 10.1111/jne.13188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/10/2022] [Accepted: 07/15/2022] [Indexed: 11/27/2022]
Abstract
Postmenopausal hot flushes are caused by lack of estradiol (E2) but their neuroendocrine basis is still poorly understood. Here, we investigated the interrelationship between norepinephrine and hypothalamic neurons, with emphasis on kisspeptin neurons in the arcuate nucleus (ARC), as a regulatory pathway in the vasomotor effects of E2. Ovariectomized (OVX) rats displayed increased tail skin temperature (TST), and this increase was prevented in OVX rats treated with E2 (OVX + E2). Expression of Fos in the hypothalamus and the number of ARC kisspeptin neurons coexpressing Fos were increased in OVX rats. Likewise, brainstem norepinephrine neurons of OVX rats displayed higher Fos immunoreactivity associated with the increase in TST. In the ARC, the density of dopamine-ß-hydroxylase (DBH)-immunoreactive (ir) fibers was not altered by E2 but, importantly, DBH-ir terminals were found in close apposition to kisspeptin cells, revealing norepinephrine inputs to ARC kisspeptin neurons. Intracerebroventricular injection of the α2-adrenergic agonist clonidine (CLO) was used to reduce central norepinephrine release, confirmed by the decreased 3-methoxy-4-hydroxyphenylglycol/norepinephrine ratio in the preoptic area and ARC. Accordingly, CLO treatment in OVX rats reduced ARC Kiss1 mRNA levels and TST to the values of OVX + E2 rats. Conversely, CLO stimulated Kiss1 expression in the anteroventral periventricular nucleus (AVPV) and increased luteinizing hormone secretion. These findings provide evidence that augmented heat dissipation in OVX rats involves the increase in central norepinephrine that modulates hypothalamic areas related to thermoregulation, including ARC kisspeptin neurons. This neuronal network is suppressed by E2 and its imbalance may be implicated in the vasomotor symptoms of postmenopausal hot flushes.
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Affiliation(s)
- Cristina S Fonseca
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nayara S S Aquino
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Gleisy K N Goncalves
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lucas R Drummond
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Laisa T M Hipolito
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juneo F Silva
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Ilheus, Brazil
| | - Kaoma S C Silva
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Patricia C Henriques
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Talita E Domingues
- Faculdade de Ciencias Biologicas e da Saude, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil
| | - Ana C R Lacerda
- Faculdade de Ciencias Biologicas e da Saude, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil
| | - Silvia Guatimosim
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Candido C Coimbra
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Raphael E Szawka
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Adelina M Reis
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Zhang Z, DiVittorio JR, Joseph AM, Correa SM. The Effects of Estrogens on Neural Circuits That Control Temperature. Endocrinology 2021; 162:6262699. [PMID: 33939822 PMCID: PMC8237993 DOI: 10.1210/endocr/bqab087] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Indexed: 12/17/2022]
Abstract
Declining and variable levels of estrogens around the time of menopause are associated with a suite of metabolic, vascular, and neuroendocrine changes. The archetypal adverse effects of perimenopause are vasomotor symptoms, which include hot flashes and night sweats. Although vasomotor symptoms are routinely treated with hormone therapy, the risks associated with these treatments encourage us to seek alternative treatment avenues. Understanding the mechanisms underlying the effects of estrogens on temperature regulation is a first step toward identifying novel therapeutic targets. Here we outline findings in rodents that reveal neural and molecular targets of estrogens within brain regions that control distinct components of temperature homeostasis. These insights suggest that estrogens may alter the function of multiple specialized neural circuits to coordinate the suite of changes after menopause. Thus, defining the precise cells and neural circuits that mediate the effects of estrogens on temperature has promise to identify strategies that would selectively counteract hot flashes or other negative side effects without the health risks that accompany systemic hormone therapies.
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Affiliation(s)
- Zhi Zhang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA
- Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Johnathon R DiVittorio
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Alexia M Joseph
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Stephanie M Correa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA
- Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
- Correspondence: Stephanie Correa, Ph.D., UCLA Dept. of Integrative Biology and Physiology 2028 Terasaki Life Sciences Building, 610 Charles E Young Drive East, Box 957239 Los Angeles, CA 90095, USA.
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Depypere H, Lademacher C, Siddiqui E, Fraser GL. Fezolinetant in the treatment of vasomotor symptoms associated with menopause. Expert Opin Investig Drugs 2021; 30:681-694. [PMID: 33724119 DOI: 10.1080/13543784.2021.1893305] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Introduction: Although international clinical practice guidelines recognize a continued role for menopausal hormone therapy (HT), particularly for symptomatic women <60 years of age or within 10 years of menopause, safety and tolerability concerns have discouraged HT use due to potential links with a perceived increased risk of hormone-dependent cancers, and an established risk of stroke and venous thromboembolism. There is therefore a need for safe, effective non-hormonal therapy for relief of menopausal vasomotor symptoms (VMS).Areas covered: This narrative review summarizes the dataset accrued for fezolinetant, a neurokinin-3 receptor (NK3R) antagonist in clinical development for menopause-associated VMS.Expert opinion: Altered signaling in neuroendocrine circuits at menopause leads to VMS wherein NK3R activity plays a key role to modulate the thermoregulatory center in a manner conducive to triggering the 'hot flash' response. Thus, a new generation of NK3R antagonists has entered clinical development to specifically target the mechanistic basis of VMS. Fezolinetant is the most advanced NK3R antagonist in terms of stage of clinical development. Results to date have demonstrated rapid and substantial reduction in VMS frequency and severity and associated improvements in health-related quality of life. NK3R antagonists offer a non-hormonal alternative to HT for the treatment of menopause-related VMS.
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Affiliation(s)
- Herman Depypere
- Breast and Menopause Clinic, University Hospital, Ghent, Belgium
| | | | - Emad Siddiqui
- Medical Affairs, Astellas Pharma Medical and Development, Chertsey, UK
| | - Graeme L Fraser
- Former Chief Scientific Officer of Ogeda SA, Gosselies, Belgium and Consultant for Astellas Pharma Inc
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Santollo J, Collett JA, Edwards AA. The anti-dipsogenic and anti-natriorexigenic effects of estradiol, but not the anti-pressor effect, are lost in aged female rats. Physiol Rep 2021; 9:e14948. [PMID: 34288542 PMCID: PMC8290476 DOI: 10.14814/phy2.14948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 11/24/2022] Open
Abstract
Estradiol (E2) inhibits fluid intake in several species, which may help to defend fluid homeostasis by preventing excessive extracellular fluid volume. Although this phenomenon is well established using the rat model, it has only been studied directly in young adults. Because aging influences the neuronal sensitivity to E2 and the fluid intake effects of E2 are mediated in the brain, we tested the hypothesis that aging influences the fluid intake effects of E2 in female rats. To do so, we examined water and NaCl intake in addition to the pressor effect after central angiotensin II treatment in young (3-4 months), middle-aged (10-12 months), and old (16-18 months) ovariectomized rats treated with estradiol benzoate (EB). As expected, EB treatment reduced water and NaCl intake in young rats. EB treatment, however, did not reduce water intake in old rats, nor did it reduce NaCl intake in middle-aged or old rats. The ability of EB to reduce blood pressure was, in contrast, observed in all three age groups. Next, we also measured the gene expression of estrogen receptors (ERs) and the angiotensin type 1 receptor (AT1R) in the areas of the brain that control fluid balance. ERβ, G protein estrogen receptor (GPER), and AT1R were reduced in the paraventricular nucleus of the hypothalamus in middle-aged and old rats, compared to young rats. These results suggest the estrogenic control of fluid intake is modified by age. Older animals lost the fluid intake effects of E2, which correlated with decreased ER and AT1R expression in the hypothalamus.
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Affiliation(s)
| | - Jason A. Collett
- Department of BiologyUniversity of KentuckyLexingtonKYUSA
- Department of Anatomy, Cell Biology and PhysiologyIndiana University School of MedicineIndianapolisINUSA
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Impact of nulliparity, hypertensive disorders of pregnancy, and gestational diabetes on vasomotor symptoms in midlife women. ACTA ACUST UNITED AC 2021; 27:1363-1370. [PMID: 32796290 DOI: 10.1097/gme.0000000000001628] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine whether women with a history of nulliparity, hypertensive disorders of pregnancy (HDP), or gestational diabetes mellitus (GDM) have a higher odds of reporting vasomotor symptoms (VMS) at midlife. METHODS A longitudinal analysis was performed with 2,249 women with pregnancy history data in the Study of Women's Health Across the Nation. Women were classified as nulliparous, no HDP/GDM, or a history of HDP/GDM. VMS (hot flashes, night sweats) were assessed separately at baseline and at each follow-up visit. VMS was recorded as any versus none; 0 , 1-5 , 6+ days in past 2 weeks. Pregnancy history was examined in relation to each VMS (hot flashes, night sweats) using generalized estimating equations adjusting for age (time-varying), site, race/ethnicity, education, financial strain, smoking, and body mass index. Models excluded women with hysterectomy/bilateral oophorectomy and observations with hormone therapy use. RESULTS Women in the HDP/GDM group (n = 208, 9%) were more likely to be Black, financially strained, and overweight. Compared to women with no HDP/GDM, women with HDP/GDM had greater odds of reporting any hot flashes (OR:1.27; 95% CI:1.05-1.53). Nulliparous women had lower odds of any hot flashes (OR:0.64; 95% CI:0.51-0.80) and night sweats (OR:0.73; 95% CI:0.58-0.93) in age-adjusted models. Similar patterns were observed for frequency of hot flashes and night sweats; associations were attenuated to nonsignificance after adjusting for covariates. CONCLUSIONS History of HDP/GDM may be associated with more VMS and nulliparity with fewer VMS, but not independently of sociodemographic factors. Our findings underscore the importance of social and economic disparities in both reproductive outcomes and VMS. VIDEO SUMMARY:: http://links.lww.com/MENO/A631.
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Fleischer AW, Schalk JC, Wetzel EA, Hanson AM, Sem DS, Donaldson WA, Frick KM. Long-term oral administration of a novel estrogen receptor beta agonist enhances memory and alleviates drug-induced vasodilation in young ovariectomized mice. Horm Behav 2021; 130:104948. [PMID: 33571507 PMCID: PMC8680219 DOI: 10.1016/j.yhbeh.2021.104948] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/09/2020] [Accepted: 01/19/2021] [Indexed: 01/11/2023]
Abstract
Development of estrogen therapies targeting the β (ERβ) but not α (ERα) estrogen receptor is critically needed for the treatment of negative menopausal symptoms, as ERα activation increases health risks like cancer. Here, we determined the effects of long-term oral treatment with EGX358, a novel highly selective ERβ agonist, on memory, vasodilation, and affect in young ovariectomized mice. Mice were orally gavaged daily for 9 weeks with vehicle, 17β-estradiol (E2), the ERβ agonist diarylpropionitrile (DPN), or EGX358 at doses that enhance memory when delivered acutely. Tail skin temperature was recorded as a proxy for vasodilation following injection of vehicle or senktide, a tachykinin receptor 3 agonist used to model hot flashes. Anxiety-like behavior was assessed in the open field (OF) and elevated plus maze (EPM), and depression-like behavior was measured in the tail suspension (TST) and forced swim tests (FST). Finally, memory was assessed in object recognition (OR) and object placement (OP) tasks. E2, DPN, and EGX358 reduced senktide-mediated increases in tail skin temperature compared to vehicle. All three treatments also enhanced memory in the OR and OP tasks, whereas vehicle did not. Although E2 increased time spent in the center of the OF, no other treatment effects were observed in the OF, EPM, TST, or FST. These data suggest that long-term ERβ activation can reduce hot flash-like symptoms and enhance spatial and object recognition memories in ovariectomized mice. Thus, the highly selective ERβ agonist EGX358 may be a promising avenue for reducing menopause-related hot flashes and memory dysfunction.
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Affiliation(s)
- Aaron W Fleischer
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, United States of America.
| | - Jayson C Schalk
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, United States of America.
| | - Edward A Wetzel
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881, United States of America.
| | - Alicia M Hanson
- Department Pharmaceutical Sciences, Concordia University Wisconsin, Mequon, WI 53097, United States of America; Center for Structure-Based Drug Design and Development, Concordia University Wisconsin, Mequon, WI 53097, United States of America.
| | - Daniel S Sem
- Department Pharmaceutical Sciences, Concordia University Wisconsin, Mequon, WI 53097, United States of America; Center for Structure-Based Drug Design and Development, Concordia University Wisconsin, Mequon, WI 53097, United States of America.
| | - William A Donaldson
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881, United States of America.
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, United States of America.
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Virtual Screening of Cablin Patchouli Herb as a Treatment for Heat Stress: A Study Based on Network Pharmacology, Molecular Docking, and Experimental Verification. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:8057587. [PMID: 33777163 PMCID: PMC7969090 DOI: 10.1155/2021/8057587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 02/21/2021] [Accepted: 02/26/2021] [Indexed: 11/18/2022]
Abstract
Heat-related diseases have long been known to damage the structure and function of essential macromolecules such as proteins, lipids, and nucleic acids, thereby compromising the integrity of cells and tissues and the physiological functions of the entire organism. Heat stress is the physical discomfort caused by overheating the body and is also the initial manifestation of heat-related diseases. Cablin patchouli herb (CPB) has been used in China for two thousand years and has been used to treat heat stress, but to date, no related mechanistic research is available. In this study, KEGG and PPI networks and the TCMSP and GEO databases were used to explore the components of CPB in relation to heat stress: quercetin, genkwanin, irisolidone, 3,23-dihydroxy-12-oleanen-28-oic acid, and quercetin 7-O-β-D-glucoside. The targets identified were EGFR, NCOA1, FOS, HIF1A, NFKBIA, and NCOA2; these proteins were verified by molecular docking and experimental verification. In short, our research represents the first report on the use of the traditional Chinese medicine CPB to treat heat stress and thus has pioneering significance.
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Rheum rhaponticum Root Extract Improves Vasomotor Menopausal Symptoms and Estrogen-Regulated Targets in Ovariectomized Rat Model. Int J Mol Sci 2021; 22:ijms22031032. [PMID: 33494167 PMCID: PMC7864327 DOI: 10.3390/ijms22031032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 11/16/2022] Open
Abstract
Ovarian insufficiency and ovariectomy are characterized by deregulated heat loss mechanisms. Unlike hormone therapy, ERr 731 (a standardized botanical extract of Siberian rhubarb Rheum rhaponticum L. high in rhaponticin) acts like a selective estrogen receptor modulator for ERβ receptors and may offer a higher degree of safety while maintaining the desired efficacy profile. In this study, we examined the relationship between oral administration of ERr 731 and the underlying components of skin vasomotion responses in an ovariectomized (OVX) rat model. ERr 731 dose-dependently reduced tail skin temperature (Tskin) values by an average of 1 °C. The rapid onset of this effect was observed in 1 and 3 mg/kg/day ERr 731 groups as early as day 2 of administration, and remained in place for the duration of the treatment (2 weeks). Substituting ERr 731 after E2 withdrawal helped maintain body temperature similarly to E2 alone, suggesting the usefulness of ERr 731 for replacing existing hormonal therapy in humans. ERr 731 also acted as a highly selective agonist for ERβ in the hypothalamus of OVX rats, as well as in ERα/β cell-based reporter assays. These data validate the OVX/Tskin rat model as a suitable screening platform to evaluate botanical and pharmaceutical treatments of menopause, while providing further evidence for the efficacy of ERr 731 towards alleviating vasomotor menopausal symptoms and improving wellbeing during the menopausal transition.
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Zhang Z, Reis FMCV, He Y, Park JW, DiVittorio JR, Sivakumar N, van Veen JE, Maesta-Pereira S, Shum M, Nichols I, Massa MG, Anderson S, Paul K, Liesa M, Ajijola OA, Xu Y, Adhikari A, Correa SM. Estrogen-sensitive medial preoptic area neurons coordinate torpor in mice. Nat Commun 2020; 11:6378. [PMID: 33311503 PMCID: PMC7732979 DOI: 10.1038/s41467-020-20050-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/12/2020] [Indexed: 12/15/2022] Open
Abstract
Homeotherms maintain a stable internal body temperature despite changing environments. During energy deficiency, some species can cease to defend their body temperature and enter a hypothermic and hypometabolic state known as torpor. Recent advances have revealed the medial preoptic area (MPA) as a key site for the regulation of torpor in mice. The MPA is estrogen-sensitive and estrogens also have potent effects on both temperature and metabolism. Here, we demonstrate that estrogen-sensitive neurons in the MPA can coordinate hypothermia and hypometabolism in mice. Selectively activating estrogen-sensitive MPA neurons was sufficient to drive a coordinated depression of metabolic rate and body temperature similar to torpor, as measured by body temperature, physical activity, indirect calorimetry, heart rate, and brain activity. Inducing torpor with a prolonged fast revealed larger and more variable calcium transients from estrogen-sensitive MPA neurons during bouts of hypothermia. Finally, whereas selective ablation of estrogen-sensitive MPA neurons demonstrated that these neurons are required for the full expression of fasting-induced torpor in both female and male mice, their effects on thermoregulation and torpor bout initiation exhibit differences across sex. Together, these findings suggest a role for estrogen-sensitive MPA neurons in directing the thermoregulatory and metabolic responses to energy deficiency.
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Affiliation(s)
- Zhi Zhang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Fernando M C V Reis
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Yanlin He
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Jae W Park
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Johnathon R DiVittorio
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Nilla Sivakumar
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - J Edward van Veen
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Shum
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - India Nichols
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Megan G Massa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Shawn Anderson
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ketema Paul
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Marc Liesa
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Avishek Adhikari
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Stephanie M Correa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA.
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA.
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Marui S, Masuda Y, Kato I, Nagashima K. Influence of exogenous and endogenous estrogen on thermoregulatory responses to mild heat and the interaction with light and dark phases. J Physiol Sci 2020; 70:56. [PMID: 33256597 PMCID: PMC10717522 DOI: 10.1186/s12576-020-00782-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/11/2020] [Indexed: 11/10/2022]
Abstract
The present study aimed to determine the influence of estradiol (E2) and the interaction with circadian phases on thermoregulatory responses to mild heat in female rats. Heat loss and production during 3-h exposure to the environment at an ambient temperature of 28-34 °C were assessed by measuring abdominal temperature (Tabd), tail skin temperature, and oxygen consumption in ovariectomized rats with and without E2 replacement (OVX + E2 and OVX, respectively) and in control rats in the proestrus (P) and diestrus (D) phases. In the light phase, Tabd remained unchanged in all groups. Tabd increased in the dark phase, but was lower in the OVX + E2 and P groups than in the OVX and D groups. Oxygen consumption decreased at 34 °C, but to a lesser extent in the OVX + E2 group than in the OVX group. These results suggest that E2 activates thermoregulation in mild heat in the dark phase.
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Affiliation(s)
- Shuri Marui
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
| | - Yuta Masuda
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
- Graduate School of Human Sciences, Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Issei Kato
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
- Graduate School of Human Sciences, Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Kei Nagashima
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan.
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Krajewski-Hall SJ, Miranda Dos Santos F, McMullen NT, Blackmore EM, Rance NE. Glutamatergic Neurokinin 3 Receptor Neurons in the Median Preoptic Nucleus Modulate Heat-Defense Pathways in Female Mice. Endocrinology 2019; 160:803-816. [PMID: 30753503 PMCID: PMC6424091 DOI: 10.1210/en.2018-00934] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/04/2019] [Indexed: 01/06/2023]
Abstract
We have proposed that arcuate neurons coexpressing kisspeptin, neurokinin B, and dynorphin (KNDy neurons) contribute to hot flushes via projections to neurokinin 3 receptor (NK3R)-expressing neurons in the median preoptic nucleus (MnPO). To characterize the thermoregulatory role of MnPO NK3R neurons in female mice, we ablated these neurons using injections of saporin toxin conjugated to a selective NK3R agonist. Loss of MnPO NK3R neurons increased the core temperature (TCORE) during the light phase, with the frequency distributions indicating a regulated shift in the balance point. The increase in TCORE in the ablated mice occurred despite changes in the ambient temperature and regardless of estrogen status. We next determined whether an acute increase in ambient temperature or higher TCORE would induce Fos in preoptic enhanced green fluorescent protein (EGFP)-immunoreactive neurons in Tacr3-EGFP mice. Fos activation was increased in the MnPO but no induction of Fos was found in NK3R (EGFP-immunoreactive) neurons. Thus, MnPO NK3R neurons are not activated by warm thermosensors in the skin or viscera and are not warm-sensitive neurons. Finally, RNAscope was used to determine whether Tacr3 (NK3R) mRNA was coexpressed with vesicular glutamate transporter 2 or vesicular γ-aminobutyric acid (GABA) transporter mRNA, markers of glutamatergic and GABAergic neurotransmission, respectively. In the MnPO, 94% of NK3R neurons were glutamatergic, but in the adjacent medial preoptic area, 97% of NK3R neurons were GABAergic. Thus, NK3R neurons in the MnPO are glutamatergic and play a role in reducing TCORE but are not activated by warm thermal stimuli (internal or external). These findings suggest that KNDy neurons modulate thermosensory pathways for heat defense indirectly via a subpopulation of glutamatergic MnPO neurons that express NK3R.
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Affiliation(s)
| | | | - Nathaniel T McMullen
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, Arizona
| | - Elise M Blackmore
- Department of Pathology, University of Arizona College of Medicine, Tucson, Arizona
| | - Naomi E Rance
- Department of Pathology, University of Arizona College of Medicine, Tucson, Arizona
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, Arizona
- Department of Neurology, University of Arizona College of Medicine, Tucson, Arizona
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, Arizona
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Modi M, Dhillo WS. Neurokinin 3 Receptor Antagonism: A Novel Treatment for Menopausal Hot Flushes. Neuroendocrinology 2019; 109:242-248. [PMID: 30504731 DOI: 10.1159/000495889] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/25/2018] [Indexed: 11/19/2022]
Abstract
Menopause is associated with significant symptomatic burden, with approximately two-thirds of postmenopausal women suffering from vasomotor symptoms, hot flushes, and night sweats. The mainstay of treatment for hot flushes continues to be hormone replacement therapy. However, as hormone replacement therapy is contraindicated in some cases, alternative, efficacious treatment options are also required. Hot flushes are thought to arise as a result of significant changes in the neuroendocrine circuitry underpinning the reproductive axis during menopause. This includes reduced circulating ovarian oestrogens, hypersecretion of gonadotropins, and increased expression of kisspeptin and neurokinin B (NKB) within the infundibular nucleus of the hypothalamus. In recent years, NKB, predominantly acting via the neurokinin 3 receptor (NK3R), has emerged as an important player in the development of menopausal hot flushes. Antagonism of NK3R has garnered much interest as a novel therapeutic target to help ameliorate hot flush symptoms. Improvements in hot flush frequency, severity, and quality of life have been demonstrated in a number of clinical trials using novel NK3R antagonists in postmenopausal women. Within this review, we will explore the growing body of evidence supporting antagonism of NK3R as a potentially promising treatment for menopausal hot flushes.
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Affiliation(s)
- Manish Modi
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | - Waljit S Dhillo
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom,
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Adverse Effects of Aromatase Inhibition on the Brain and Behavior in a Nonhuman Primate. J Neurosci 2018; 39:918-928. [PMID: 30587540 PMCID: PMC6382974 DOI: 10.1523/jneurosci.0353-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 11/12/2018] [Accepted: 11/17/2018] [Indexed: 01/12/2023] Open
Abstract
Breast cancer patients using aromatase inhibitors (AIs) as an adjuvant therapy often report side effects, including hot flashes, mood changes, and cognitive impairment. Despite long-term use in humans, little is known about the effects of continuous AI administration on the brain and cognition. We used a primate model of human cognitive aging, the common marmoset, to examine the effects of a 4-week daily administration of the AI letrozole (20 μg, p.o.) on cognition, anxiety, thermoregulation, brain estrogen content, and hippocampal pyramidal cell physiology. Letrozole treatment was administered to both male and female marmosets and reduced peripheral levels of estradiol (E2), but unexpectedly increased E2 levels in the hippocampus. Spatial working memory and intrinsic excitability of hippocampal neurons were negatively affected by the treatment possibly due to increased hippocampal E2. While no changes in hypothalamic E2 were observed, thermoregulation was disrupted by letrozole in females only, indicating some impact on hypothalamic activity. These findings suggest adverse effects of AIs on the primate brain and call for new therapies that effectively prevent breast cancer recurrence while minimizing side effects that further compromise quality of life.SIGNIFICANCE STATEMENT Aromatase inhibitors (AIs) are used as an adjuvant therapy for estrogen-receptor-positive breast cancer and are associated with side effects, including hot flashes, depression/anxiety, and memory deficits severe enough for many women to discontinue this life-saving treatment. AIs are also used by men, yet sex differences in the reported side effects have not been systematically studied. We show that AI-treated male and female marmosets exhibit behavioral changes consistent with these CNS symptoms, as well as elevated hippocampal estradiol and compromised hippocampal physiology. These findings illustrate the need for (1) a greater understanding of the precise mechanisms by which AIs impact brain function and (2) the development of new treatment approaches for breast cancer patients that minimize adverse effects on the brain.
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18
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Miragem AA, Homem de Bittencourt PI. Nitric oxide-heat shock protein axis in menopausal hot flushes: neglected metabolic issues of chronic inflammatory diseases associated with deranged heat shock response. Hum Reprod Update 2018; 23:600-628. [PMID: 28903474 DOI: 10.1093/humupd/dmx020] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/28/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Although some unequivocal underlying mechanisms of menopausal hot flushes have been demonstrated in animal models, the paucity of similar approaches in humans impedes further mechanistic outcomes. Human studies might show some as yet unexpected physiological mechanisms of metabolic adaptation that permeate the phase of decreased oestrogen levels in both symptomatic and asymptomatic women. This is particularly relevant because both the severity and time span of hot flushes are associated with increased risk of chronic inflammatory disease. On the other hand, oestrogen induces the expression of heat shock proteins of the 70 kDa family (HSP70), which are anti-inflammatory and cytoprotective protein chaperones, whose expression is modulated by different types of physiologically stressful situations, including heat stress and exercise. Therefore, lower HSP70 expression secondary to oestrogen deficiency increases cardiovascular risk and predisposes the patient to senescence-associated secretory phenotype (SASP) that culminates in chronic inflammatory diseases, such as obesities, type 2 diabetes, neuromuscular and neurodegenerative diseases. OBJECTIVE AND RATIONALE This review focuses on HSP70 and its accompanying heat shock response (HSR), which is an anti-inflammatory and antisenescent pathway whose intracellular triggering is also oestrogen-dependent via nitric oxide (NO) production. The main goal of the manuscript was to show that the vasomotor symptoms that accompany hot flushes may be a disguised clue for important neuroendocrine alterations linking oestrogen deficiency to the anti-inflammatory HSR. SEARCH METHODS Results from our own group and recent evidence on hypothalamic control of central temperature guided a search on PubMed and Google Scholar websites. OUTCOMES Oestrogen elicits rapid production of the vasodilatory gas NO, a powerful activator of HSP70 expression. Whence, part of the protective effects of oestrogen over cardiovascular and neuroendocrine systems is tied to its capacity of inducing the NO-elicited HSR. The hypothalamic areas involved in thermoregulation (infundibular nucleus in humans and arcuate nucleus in other mammals) and whose neurons are known to have their function altered after long-term oestrogen ablation, particularly kisspeptin-neurokinin B-dynorphin neurons, (KNDy) are the same that drive neuroprotective expression of HSP70 and, in many cases, this response is via NO even in the absence of oestrogen. From thence, it is not illogical that hot flushes might be related to an evolutionary adaptation to re-equip the NO-HSP70 axis during the downfall of circulating oestrogen. WIDER IMPLICATIONS Understanding of HSR could shed light on yet uncovered mechanisms of menopause-associated diseases as well as on possible manipulation of HSR in menopausal women through physiological, pharmacological, nutraceutical and prebiotic interventions. Moreover, decreased HSR indices (that can be clinically determined with ease) in perimenopause could be of prognostic value in predicting the moment and appropriateness of starting a HRT.
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Affiliation(s)
- Antônio Azambuja Miragem
- Laboratory of Cellular Physiology, Department of Physiology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, ICBS, 2nd Floor, Suite 350, Porto Alegre, RS 90050-170, Brazil.,Federal Institute of Education, Science and Technology 'Farroupilha', Rua Uruguai 1675, Santa Rosa, RS 98900-000, Brazil
| | - Paulo Ivo Homem de Bittencourt
- Laboratory of Cellular Physiology, Department of Physiology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, ICBS, 2nd Floor, Suite 350, Porto Alegre, RS 90050-170, Brazil
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Sun Y, Qin LH, Chen X, Yan X, Mao L, Bai W, Kang J. Effects of black cohosh and estrogen on core body and tail-skin temperatures in ovariectomized rats by telemetric monitoring with dual thermistor probes. Climacteric 2018; 21:153-159. [PMID: 29323578 DOI: 10.1080/13697137.2017.1415320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To investigate the effects of black cohosh and estrogen on the temperature in ovariectomized rats, the core body temperature (CBT) and tail-skin temperature (TST) were simultaneously monitored and the relationship between these two temperatures was explored. METHODS Twenty-four female Sprague-Dawley rats aged 8 weeks were randomly divided into four groups: sham-operated (SHAM), ovariectomized (OVX), OVX treated with estradiol valerate (OVX + E), and OVX treated with isopropanolic black cohosh extract (OVX + ICR). Rats were sham-operated or ovariectomized and were implanted with telemetry transmitters with dual thermistor probes. Two weeks after surgery, the animals were treated with drugs for 4 weeks. During the last week of the treatments, the dynamic temperature profiles of the CBT and TST were collected. RESULTS The average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation were significantly higher in OVX than in SHAM rats. In addition, dramatic fluctuations of TST in OVX rats occurred at the time points of the day when the CBTs were lower in OVX rats than in SHAM rats. Treatment of OVX rats with estradiol valerate or isopropanolic black cohosh extract markedly decreased the average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation. Moreover, CBT was found to be significantly higher, while TST was lower in OVX + E than in OVX + ICR rats. CONCLUSIONS Both black cohosh and estradiol treatments ameliorated the abnormal thermoregulation in OVX rats. In particular, black cohosh reduced CBT better than estradiol and estradiol reduced TST better than black cohosh.
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Affiliation(s)
- Y Sun
- a Department of Obstetrics and Gynecology , Beijing Shijitan Hospital, Capital Medical University , Beijing , China
| | - L H Qin
- b Department of Anatomy and Embryology , Peking University Health Science Center , Beijing , China
| | - X Chen
- c Department of Obstetrics and Gynecology , Peking University First Hospital , Beijing , China
| | - X Yan
- d Department of Clinical Research Institute , Peking University Health Science Center , Beijing , China
| | - L Mao
- c Department of Obstetrics and Gynecology , Peking University First Hospital , Beijing , China
| | - W Bai
- a Department of Obstetrics and Gynecology , Beijing Shijitan Hospital, Capital Medical University , Beijing , China
| | - J Kang
- e Department of Physiology and Pathophysiology, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China
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Krajewski-Hall SJ, Blackmore EM, McMinn JR, Rance NE. Estradiol alters body temperature regulation in the female mouse. Temperature (Austin) 2017; 5:56-69. [PMID: 29687044 DOI: 10.1080/23328940.2017.1384090] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 10/18/2022] Open
Abstract
Hot flushes are due to estrogen withdrawal and characterized by the episodic activation of heat dissipation effectors. Recent studies (in humans and rats) have implicated neurokinin 3 (NK3) receptor signaling in the genesis of hot flushes. Although transgenic mice are increasingly used for biomedical research, there is limited information on how 17β-estradiol and NK3 receptor signaling alters thermoregulation in the mouse. In this study, a method was developed to measure tail skin temperature (TSKIN) using a small data-logger attached to the surface of the tail, which, when combined with a telemetry probe for core temperature (TCORE), allowed us to monitor thermoregulation in freely-moving mice over long durations. We report that estradiol treatment of ovariectomized mice reduced TCORE during the light phase (but not the dark phase) while having no effect on TSKIN or activity. Estradiol also lowered TCORE in mice exposed to ambient temperatures ranging from 20 to 36°C. Unlike previous studies in the rat, estradiol treatment of ovariectomized mice did not reduce TSKIN during the dark phase. Subcutaneous injections of an NK3 receptor agonist (senktide) in ovariectomized mice caused an acute increase in TSKIN and a reduction in TCORE, consistent with the activation of heat dissipation effectors. These changes were reduced by estradiol, suggesting that estradiol lowers the sensitivity of central thermoregulatory pathways to NK3 receptor activation. Overall, we show that estradiol treatment of ovariectomized mice decreases TCORE during the light phase, reduces the thermoregulatory effects of senktide and modulates thermoregulation differently than previously described in the rat.
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Affiliation(s)
- Sally J Krajewski-Hall
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Elise M Blackmore
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Jessi R McMinn
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Naomi E Rance
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
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A low degree of high ambient temperature decreased food intake and activated median preoptic and arcuate nuclei. Physiol Behav 2017; 181:16-22. [DOI: 10.1016/j.physbeh.2017.08.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/27/2022]
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Uchida Y, Nagashima K, Yuri K. Systemic estradiol administration to ovariectomized rats facilitates thermoregulatory behavior in a cold environment. Brain Res 2017; 1670:125-134. [PMID: 28602745 DOI: 10.1016/j.brainres.2017.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/05/2017] [Accepted: 06/06/2017] [Indexed: 11/29/2022]
Abstract
Rats place their tails underneath their bodies in the cold (tail-hiding behavior), which is a behavioral indicator of thermoregulation. The aim of the present study was to elucidate the effect of estradiol (E2) on tail-hiding behavior and neural activity assessed by immunohistochemistry. Ovariectomized rats were implanted with a silastic tube with or without E2 underneath the dorsal skin (E2(-) and E2(+) groups), and exposed to 27°C, 16°C, and 10°C for 2h with continuous body temperature (Tb), tail skin temperature (Ttail), and behavioral measurements. cFos immunoreactive (cFos-IR) cells in the insula, secondary somatosensory cortex, medial preoptic nucleus, parastrial nucleus, amygdala, and lateral parabrachial nucleus were counted. Tb and Ttail were not different between the E2(-) and E2(+) groups. At 16°C, the duration and the onset of tail-hiding behavior in the E2(+) group were greater than that in the E2(-) group. The number of cFos-IR cells in the insula of the E2(-) group was greater than that of the E2(+) group in rats kept at 16°C. E2 might modulate tail-hiding behavior of female rats at 16°C, and the insula may be involved in the response.
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Affiliation(s)
- Yuki Uchida
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Kochi, Japan.
| | - Kei Nagashima
- Laboratory of Integrative Physiology (Body Temperature and Fluid Laboratory), Faculty of Human Sciences, Waseda University, Saitama, Japan; Institute of Applied Brain Sciences, Waseda University, Saitama, Japan
| | - Kazunari Yuri
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Kochi, Japan
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Zhang J, Bai W, Wang W, Jiang H, Jin B, Liu Y, Liu S, Wang K, Jia J, Qin L. Mechanisms underlying alterations in norepinephrine levels in the locus coeruleus of ovariectomized rats: Modulation by estradiol valerate and black cohosh. Neuroscience 2017; 354:110-121. [PMID: 28457819 DOI: 10.1016/j.neuroscience.2017.04.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/02/2017] [Accepted: 04/20/2017] [Indexed: 11/30/2022]
Abstract
Hot flushes are common in menopause. Norepinephrine (NE), primarily synthesized in the locus coeruleus (LC), plays a major role in central thermoregulation. Furthermore, we previously observed decreased dopamine beta hydroxylase (DβH), a key enzyme in NE synthesis, in LC neurons following ovariectomy. In this study, we explore the mechanisms underlying decreased NE levels in the LC (LC-NE) in ovariectomized (OVX) rats, and the modulating effects of estradiol valerate (E2) and black cohosh (ICR). We used high-performance liquid chromatography to detect LC-NE in SHAM, OVX, OVX-E2, and OVX-ICR groups. Western blotting and immunohistochemistry were performed to investigate the expression of NE metabolic enzymes, the NE reuptake transporter (NET), and estrogen receptors (ERs) in the LC. We observed significant LC-NE decreases in the OVX group. E2 and ICR enhanced LC-NE but did not restore them to SHAM levels. Ovariectomy affected NE synthesis, degradation, and reuptake. Levels of NE catabolic enzymes monoamine oxidase A (MAOA) and catechol-O-methyltransferase (COMT) decreased, while NET expression increased. E2 restored MAOA and COMT to SHAM levels but had no effect on NET. ICR restored COMT and NET to SHAM levels but had no effect on MAOA. Moreover, the OVX group also exhibited decreased expression of ERα and ERβ. E2 enhanced the expression of ERα and ERβ, while ICR only enhanced ERβexpression. Taken together, reduced NE in OVX rats resulted from reduced synthesis and increased degradation and reuptake. E2 and ICR may regulate these processes in different ways through various ERs.
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Affiliation(s)
- Jing Zhang
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wenpei Bai
- Obstetrics and Gynecology Department, Beijing Shijitan Hospital, Beijing 100083, China
| | - Wenjuan Wang
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Hai Jiang
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Biao Jin
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yao Liu
- Department of Cardiology, Peking University People's Hospital, Beijing 100044, China
| | - Shuya Liu
- Department of Stomatology, General Hospital of Armed Police, Beijing 100039, China
| | - Ke Wang
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Jia
- Department of Stomatology, General Hospital of Armed Police, Beijing 100039, China
| | - Lihua Qin
- Anatomy and Embryology Department, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
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Sturdee DW, Hunter MS, Maki PM, Gupta P, Sassarini J, Stevenson JC, Lumsden MA. The menopausal hot flush: a review. Climacteric 2017; 20:296-305. [DOI: 10.1080/13697137.2017.1306507] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- D. W. Sturdee
- Department of Gynaecology, Solihull Hospital, Birmingham, UK
| | - M. S. Hunter
- Unit of Psychology, Institute of Psychiatry (at Guy's), King's College London, London, UK
| | - P. M. Maki
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA
| | - P. Gupta
- Women's Unit, Solihull Hospital, Birmingham Heartlands & Solihull NHS Trust, Birmingham, UK
| | - J. Sassarini
- Department of Obstetrics & Gynaecology, University of Glasgow, College of Medicine, Western Infirmary, Glasgow, UK
| | - J. C. Stevenson
- National Heart & Lung Institute, Royal Brompton Hospital, London, UK
| | - M. A. Lumsden
- Reproductive and Maternal Medicine, University of Glasgow, Glasgow, UK
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The middle-aged ovariectomized marmoset (Callithrix jacchus) as a model of menopausal symptoms: Preliminary evidence. Neuroscience 2016; 337:1-8. [PMID: 27619737 DOI: 10.1016/j.neuroscience.2016.08.056] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/24/2022]
Abstract
Menopausal women often suffer from hot flashes and sleep disturbances that significantly impact their quality of life. Both human and animal studies suggest that loss of estrogens during menopause contribute to these symptoms. In the female rat, both core body temperature (CBT) and sleep are sensitive to 17β-estradiol (E2) levels, but important differences between the rat and the human patterns limit the interpretation of the results. The sleep and thermoregulation of the common marmoset (Callithrix jacchus) more closely resemble human patterns. However, no study to date has examined whether E2 influences sleep and thermoregulation in this species. The main goal of the present study was to investigate the suitability of the ovariectomized (OVX) marmoset for studying two major menopausal symptoms experienced by women, sleep disturbance and thermodysregulation. Two middle-aged OVX marmosets (6years old) were implanted with a telemeter that records electroencephalograms (EEG), electromyograms (EMG), and CBT. Sleep patterns and CBT were recorded under baseline, two E2 replacement (6 and 12μg/kg/day, p.o.) conditions and two E2 withdrawal conditions. Relative to both baseline and withdrawal, high E2 replacement was associated with lower nighttime CBT. In addition, fewer nighttime arousals were observed under low E2 replacement compared to baseline. Higher delta power was observed under both E2 replacement conditions suggesting enhanced sleep quality. These preliminary results suggest that E2 modulates sleep and thermoregulation in the OVX marmoset, making it a promising model for studying menopausal symptoms.
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Abegg K, Corteville C, Bueter M, Lutz TA. Alterations in energy expenditure in Roux-en-Y gastric bypass rats persist at thermoneutrality. Int J Obes (Lond) 2016; 40:1215-21. [PMID: 27102054 DOI: 10.1038/ijo.2016.55] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 01/08/2016] [Accepted: 02/11/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND The compensatory decrease in energy expenditure (EE) in response to body weight loss is attenuated by Roux-en-Y gastric bypass (RYGB) surgery in rats. The thermoneutral zone (TNZ) is at higher temperatures in rodents than in humans. Consequently, rodents may be under moderate cold stress if EE is measured at room temperature, leading to increased EE due to adaptive thermogenesis. We speculated that the reported alterations in EE of RYGB rats at room temperature are caused by higher adaptive thermogenesis and are therefore not present at thermoneutrality. METHODS Male Wistar rats were randomized for RYGB or sham surgery. Some sham rats were body weight matched (BWM) to the RYGB rats by food restriction, the others received ad libitum access to food (AL). EE, body temperature, physical activity and food intake were measured at ambient temperatures between 22 and 32 °C to determine the TNZ. Adaptive thermogenesis requires β3-adrenergic receptor-mediated uncoupling protein-1 (UCP-1) expression in brown adipose tissue (BAT). The in vivo thermogenic capacity of BAT was determined by administering the β3-adrenergic agonist CL316,243, and UCP-1 protein expression was measured at room temperature. RESULTS The TNZ was between 28 and 30 °C for AL and RYGB and between 30 and 32 °C for BWM rats, respectively. In contrast to AL and BWM rats, EE was not significantly higher at room temperature than at thermoneutrality in RYGB rats, reflecting a lack of adaptive thermogenesis. Consistently, both the thermogenic capacity of BAT and UCP-1 expression were decreased in RYGB compared with AL rats at room temperature. CONCLUSIONS Our data confirm that the decrease in EE after body weight loss is attenuated by RYGB surgery and show that this effect persists at thermoneutrality. Contrary to our hypothesis, we found that adaptive thermogenesis at room temperature is reduced in RYGB rats.
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Affiliation(s)
- K Abegg
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - C Corteville
- Department of Surgery I, University of Wurzburg, Wurzburg, Germany
| | - M Bueter
- Division of Visceral and Transplantation Surgery, Department of Surgery, University Hospital Zurich, Zurich, Switzerland.,Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - T A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Zingue S, Michel T, Tchatchou J, Chantal Beatrice Magne N, Winter E, Monchot A, Awounfack CF, Djiogue S, Clyne C, Fernandez X, Creczynski-Pasa TB, Njamen D. Estrogenic effects of Ficus umbellata Vahl. (Moraceae) extracts and their ability to alleviate some menopausal symptoms induced by ovariectomy in Wistar rats. JOURNAL OF ETHNOPHARMACOLOGY 2016; 179:332-344. [PMID: 26771069 DOI: 10.1016/j.jep.2016.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 12/30/2015] [Accepted: 01/02/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ficus umbellata Vahl. (Moraceae) is a medicinal plant used in Cameroon to treat amenorrhea as well as other physiological disorders related to menopause. AIM OF STUDY In order to justify scientifically its traditional use, the estrogen-like properties of the aqueous (AE) and methanol (MeOH) extracts of F. umbellata were investigated. MATERIAL AND METHODS In vitro, the ability of different extracts of F. umbellata to activate estrogen receptors α (ERα) and β (ERβ) in cell-based reporter gene assays using human embryonic kidney (HEK293T) cells transfected with ERs was tested. In vivo, a 3-day uterotrophic assay and the capacity of the extracts to alleviate hot flushes in ovariectomized adult rats were tested. Using a bioassay-guided fractionation the major compound of F. umbellata was isolated and tested in vitro on HEK293T-ERα and ERβ cells. RESULTS AE and MeOH extracts significantly altered ERα as well as ERβ activities. In vivo, both extracts significantly increase the uterine and vaginal epithelium thickness, and uterine total protein levels in a dose dependent manner. Interestingly, both extracts of F. umbellata at the dose of 100 mg/kg BW significantly decreased the total number, average duration as well as frequency of hot flushes in experimental rats compared to age-matched OVX controls. Finally, 7-methylumbelliferone, a coumarin was characterized as the major compound of F. umbellata; however this compound did not transactivate ERα as well ERβ in vitro. CONCLUSION These aforementioned results suggest that F. umbellata extracts as used by the traditional practitioner have estrogen-like effects and may alleviate some menopausal problems such as vaginal dryness and hot flushes.
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Affiliation(s)
- Stéphane Zingue
- Department of Life and Earth Sciences, Higher Teachers' Training College, University of Maroua, P.O. Box 55, Maroua, Cameroon; Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
| | - Thomas Michel
- Institute of Chemistry of Nice, Faculty of Science, University Nice Sophia-Antipolis, UMR CNRS 7272, Valrose Park, F-06108 Nice Cedex 2, Nice, France
| | - Jules Tchatchou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
| | | | - Evelyn Winter
- Department of Pharmaceutical Sciences, Health Sciences Centre, Federal University of Santa Catarina, CEP 88040-900 Florianópolis, SC, Brazil
| | - André Monchot
- Institute of Chemistry of Nice, Faculty of Science, University Nice Sophia-Antipolis, UMR CNRS 7272, Valrose Park, F-06108 Nice Cedex 2, Nice, France
| | - Charline Florence Awounfack
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
| | - Sefirin Djiogue
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
| | - Colin Clyne
- Hudson Institute of Medical Research, 27-31 Wright Street Clayton, VIC 3168, Australia
| | - Xavier Fernandez
- Institute of Chemistry of Nice, Faculty of Science, University Nice Sophia-Antipolis, UMR CNRS 7272, Valrose Park, F-06108 Nice Cedex 2, Nice, France
| | - Tânia Beatriz Creczynski-Pasa
- Department of Pharmaceutical Sciences, Health Sciences Centre, Federal University of Santa Catarina, CEP 88040-900 Florianópolis, SC, Brazil
| | - Dieudonné Njamen
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
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28
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Mittelman-Smith MA, Krajewski-Hall SJ, McMullen NT, Rance NE. Neurokinin 3 Receptor-Expressing Neurons in the Median Preoptic Nucleus Modulate Heat-Dissipation Effectors in the Female Rat. Endocrinology 2015; 156:2552-62. [PMID: 25825817 PMCID: PMC4475724 DOI: 10.1210/en.2014-1974] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
KNDy neurons facilitate tail skin vasodilation and modulate the effects of estradiol on thermoregulation. We hypothesize that KNDy neurons influence cutaneous vasodilation via projections to neurons in the median preoptic nucleus (MnPO) that express the neurokinin 3 receptor (NK3R). In support of this hypothesis, focal microinjections of senktide, an NK3R agonist, into the MnPO lowers core temperature (TCORE) in the female rat. To further study the role of MnPO NK3R neurons in thermoregulation, these neurons were specifically ablated using a conjugate of a selective NK3R agonist and saporin (NK3-SAP). NK3-SAP or blank-SAP (control) was injected into the MnPO/medial septum. Tail skin temperature (TSKIN) and TCORE were measured in ovariectomized rats exposed to 3 ambient temperatures (TAMBIENT) before and after estradiol-17β (E2) treatment. Before killing, we injected senktide (sc), monitored TCORE for 70 minutes, and harvested brains for Fos immunohistochemistry. Ablation of MnPO NK3R neurons lowered TSKIN at neutral and subneutral TAMBIENT regardless of E2 treatment. However, ablation did not prevent the effects of E2 on TCORE and TSKIN. In control rats, senktide injections induced hypothermia with numerous Fos-immunoreactive cells in the MnPO. In contrast, in NK3-SAP rats, senktide did not alter TCORE and minimal Fos-immunoreactive neurons were identified in the MnPO. These data show that NK3R neurons in the MnPO are required for the hypothermic effects of senktide but not for the E2 modulation of thermoregulation. The lower TSKIN in NK3-SAP-injected rats suggests that MnPO NK3R neurons, like KNDy neurons, facilitate cutaneous vasodilation, an important heat-dissipation effector.
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Affiliation(s)
- Melinda A Mittelman-Smith
- Departments of Pathology (M.A.M.-S., S.J.K.-H., N.E.R.), Cellular and Molecular Medicine (N.T.M., N.E.R.), and Neurology (N.E.R.), and the Evelyn F. McKnight Brain Institute (N.E.R.), University of Arizona College of Medicine, Tucson, Arizona 85724
| | - Sally J Krajewski-Hall
- Departments of Pathology (M.A.M.-S., S.J.K.-H., N.E.R.), Cellular and Molecular Medicine (N.T.M., N.E.R.), and Neurology (N.E.R.), and the Evelyn F. McKnight Brain Institute (N.E.R.), University of Arizona College of Medicine, Tucson, Arizona 85724
| | - Nathaniel T McMullen
- Departments of Pathology (M.A.M.-S., S.J.K.-H., N.E.R.), Cellular and Molecular Medicine (N.T.M., N.E.R.), and Neurology (N.E.R.), and the Evelyn F. McKnight Brain Institute (N.E.R.), University of Arizona College of Medicine, Tucson, Arizona 85724
| | - Naomi E Rance
- Departments of Pathology (M.A.M.-S., S.J.K.-H., N.E.R.), Cellular and Molecular Medicine (N.T.M., N.E.R.), and Neurology (N.E.R.), and the Evelyn F. McKnight Brain Institute (N.E.R.), University of Arizona College of Medicine, Tucson, Arizona 85724
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Estrogen deprivation does not affect vascular heat shock response in female rats: a comparison with oxidative stress markers. Mol Cell Biochem 2015; 407:239-49. [PMID: 26045174 DOI: 10.1007/s11010-015-2472-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/30/2015] [Indexed: 10/23/2022]
Abstract
Hot flashes, which involve a tiny rise in core temperature, are the most common complaint of peri- and post-menopausal women, being tightly related to decrease in estrogen levels. On the other hand, estradiol (E2) induces the expression of HSP72, a member of the 70 kDa family of heat shock proteins (HSP70), which are cytoprotective, cardioprotective, and heat inducible. Since HSP70 expression is compromised in age-related inflammatory diseases, we argued whether the capacity of triggering a robust heat shock (HS) response would be still present after E2 withdrawal. Hence, we studied the effects of HS treatment (hot tub) in female Wistar rats subjected to bilateral ovariectomy (OVX) after a 7-day washout period. Twelve h after HS, the animals were killed and aortic arches were surgically excised for molecular analyses. The results were compared with oxidative stress markers in the plasma (superoxide dismutase, catalase, and lipoperoxidation) because HSP70 expression is also sensitive to redox regulation. Extracellular (plasma) to intracellular HSP70 ratio, an index of systemic inflammatory status, was also investigated. The results showed that HS response was preserved in OVX animals, as inferred from HSP70 expression (up to 40% rise, p < 0.01) in the aortas, which was accompanied by no further alterations in oxidative stress, hematological parameters, and glycemic control either. This suggests that the lack of estrogen per se could not be solely ascribed as the unique source of low HSP70 expression as observed in long-term post-menopausal individuals. As a consequence, periodic evaluation of HSP70 status (iHSP70 vs. eHSP70) may be of clinical relevance because decreased HS response capacity is at the center of the onset of menopause-related dysfunctions.
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Standard sub-thermoneutral caging temperature influences radiosensitivity of hematopoietic stem and progenitor cells. PLoS One 2015; 10:e0120078. [PMID: 25793392 PMCID: PMC4368554 DOI: 10.1371/journal.pone.0120078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/19/2015] [Indexed: 11/19/2022] Open
Abstract
The production of new blood cells relies on a hierarchical network of hematopoietic stem and progenitor cells (HSPCs). To maintain lifelong hematopoiesis, HSPCs must be protected from ionizing radiation or other cytotoxic agents. For many years, murine models have been a valuable source of information regarding factors that either enhance or reduce the survival of HSPCs after exposure of marrow to ionizing radiation. In a recent series of studies, however, it has become clear that housing-related factors such as the cool room temperature required for laboratory mice can exert a surprising influence on the outcome of experiments. Here we report that the mild, but chronic cold-stress endured by mice housed under these conditions exerts a protective effect on HSPCs after both non-lethal and lethal doses of total body irradiation (TBI). Alleviation of this cold-stress by housing mice at a thermoneutral temperature (30°C) resulted in significantly greater baseline radiosensitivity to a lethal dose of TBI with more HSPCs from mice housed at thermoneutral temperature undergoing apoptosis following non-lethal TBI. Cold-stressed mice have elevated levels of norepinephrine, a key molecule of the sympathetic nervous system that binds to β-adrenergic receptors. We show that blocking this signaling pathway in vivo through use of the β-blocker propanolol completely mitigates the protective effect of cold-stress on HSPC apoptosis. Collectively this study demonstrates that chronic stress endured by the standard housing conditions of laboratory mice increases the resistance of HSPCs to TBI-induced apoptosis through a mechanism that depends upon β-adrenergic signaling. Since β-blockers are commonly prescribed to a wide variety of patients, this information could be important when predicting the clinical impact of HSPC sensitivity to TBI.
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Messmer MN, Kokolus KM, Eng JWL, Abrams SI, Repasky EA. Mild cold-stress depresses immune responses: Implications for cancer models involving laboratory mice. Bioessays 2014; 36:884-91. [PMID: 25066924 DOI: 10.1002/bies.201400066] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Physiologically accurate mouse models of cancer are critical in the pre-clinical development of novel cancer therapies. However, current standardized animal-housing temperatures elicit chronic cold-associated stress in mice, which is further increased in the presence of tumor. This cold-stress significantly impacts experimental outcomes. Data from our lab and others suggest standard housing fundamentally alters murine physiology, and this can produce altered immune baselines in tumor and other disease models. Researchers may thus underestimate the efficacy of therapies that are benefitted by immune responses. A potential mediator, norepinephrine, also underlies stress pathways common in mice and humans. Therefore, research into mechanisms connecting cold-stress and norepinephrine signaling with immune depression in mice could highlight new combination therapies for humans to simultaneously target stress while stimulating anti-tumor immunity.
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Affiliation(s)
- Michelle N Messmer
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY, USA
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32
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McGregor C, Sau A, Ruddy SC, Leung D, Webb M, Durst T, Wright JS, Lagace D, Pratt MAC. Novel ligands balance estrogen receptor β and α agonism for safe and effective suppression of the vasomotor response in the ovariectomized female rat model of menopause. Endocrinology 2014; 155:2480-91. [PMID: 24823389 DOI: 10.1210/en.2013-1976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Vasomotor thermo-dysregulation (hot flashes) are an often debilitating symptom of menopause. Effective treatment is achieved primarily through activation of the estrogen receptor (ER)α with estrogens but is also associated with increased risk for breast and uterine cancer. In this study, we have tested novel compounds lacking the B ring of 17-hydroxy-β-estradiol (E2) (A-CD compounds) with differing ratios of ERα:ERβ binding affinities for the ability to reduce diurnal/nocturnal tail-skin temperatures (TSTs) in the ovariectomized female rat menopausal hot flash model. Normal mammary tissue expresses the predominantly antiproliferative ERβ. Therefore, we hypothesized that a preferential ERβ agonist with fractional ERα activity would safely reduce TSTs. The A-CD compound, L17, is a preferential ERβ agonist that has a ratio of ERβ:ERα binding affinity relative to E2 of 9.3 (where ERβ:ERα for E2, 1.0). In the ovariectomized rat, daily administration of low doses (1 mg/kg) of the A-CD compound TD81 (ERα:ERβ relative affinity, 15.2) was ineffective in temperature regulation, whereas L17 showed a trend toward TST reduction. Both E2 and the A-CD compound, TD3 (ERβ:ERα relative affinity, 5.0), also reduced TSTs but had marked proliferative effects on mammary and uterine tissues. At 2 mg/kg, L17 strongly reduced TSTs even more effectively than E2 but, importantly, had only minimal effect on uterine weight and mammary tissues. Both E2- and L17-treated rats showed similar weight reduction over the treatment period. E2 is rapidly metabolized to highly reactive quinones, and we show that L17 has 2-fold greater metabolic stability than E2. Finally, L17 and E2 similarly mediated induction of c-fos expression in neurons within the rat thermoregulatory hypothalamic median preoptic nucleus. Thus, the A-CD compound, L17, may represent a safe and effective approach to the treatment of menopausal hot flashes.
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Affiliation(s)
- Chelsea McGregor
- Department of Cellular and Molecular Medicine (C.M., A.S., S.C.R., D.La., M.A.C.P.), and University of Ottawa Neuroscience Institute (D.La.), University of Ottawa, Ottawa, Ontario, Canada K1H 8M5; Centre for Drug Research and Development (D.Le., M.W.), Vancouver, British Columbia, Canada V6T 1Z3; Department of Chemistry (T.D.), University of Ottawa, Ottawa, Ontario, Canada K1N 6N5; and Department of Chemistry (J.S.W.), Carleton University, Ottawa, Ontario, K1S 5B6 Canada
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Herndon JM, Cholanians AB, Lizarraga LE, Lau SS, Monks TJ. Catechol-o-methyltransferase and 3,4-({+/-})-methylenedioxymethamphetamine toxicity. Toxicol Sci 2014; 139:162-73. [PMID: 24591155 DOI: 10.1093/toxsci/kfu035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Metabolism of 3,4-(±)-methylenedioxymethamphetamine (MDMA) is necessary to elicit its neurotoxic effects. Perturbations in phase I and phase II hepatic enzymes can alter the neurotoxic profile of systemically administered MDMA. In particular, catechol-O-methyltransferase (COMT) plays a critical role in determining the fraction of MDMA that is converted to potentially neurotoxic metabolites. Thus, cytochrome P450 mediated demethylenation of MDMA, or its N-demethylated metabolite, 3,4-(±)-methylenedioxyamphetamine, give rise to the catechols, N-methyl-α-methyldopamine and α-methyldopamine, respectively. Methylation of these catechols by COMT limits their oxidation and conjugation to glutathione, a process that ultimately gives rise to neurotoxic metabolites. We therefore determined the effects of modulating COMT, a critical enzyme involved in determining the fraction of MDMA that is converted to potentially neurotoxic metabolites, on MDMA-induced toxicity. Pharmacological inhibition of COMT in the rat potentiated MDMA-induced serotonin deficits and exacerbated the acute MDMA-induced hyperthermic response. Using a genetic mouse model of COMT deficiency, in which mice lack a functional COMT gene, such mice displayed greater reductions in dopamine concentrations relative to their wild-type (WT) counterparts. Neither WT nor COMT deficient mice were susceptible to MDMA-induced decreases in serotonin concentrations. Interestingly, mice devoid of COMT were far more susceptible to the acute hyperthermic effects of MDMA, exhibiting greater increases in body temperature that ultimately resulted in death. Our findings support the view that COMT plays a pivotal role in determining the toxic response to MDMA.
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Affiliation(s)
- Joseph M Herndon
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
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Rance NE, Dacks PA, Mittelman-Smith MA, Romanovsky AA, Krajewski-Hall SJ. Modulation of body temperature and LH secretion by hypothalamic KNDy (kisspeptin, neurokinin B and dynorphin) neurons: a novel hypothesis on the mechanism of hot flushes. Front Neuroendocrinol 2013; 34:211-27. [PMID: 23872331 PMCID: PMC3833827 DOI: 10.1016/j.yfrne.2013.07.003] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/31/2022]
Abstract
Despite affecting millions of individuals, the etiology of hot flushes remains unknown. Here we review the physiology of hot flushes, CNS pathways regulating heat-dissipation effectors, and effects of estrogen on thermoregulation in animal models. Based on the marked changes in hypothalamic kisspeptin, neurokinin B and dynorphin (KNDy) neurons in postmenopausal women, we hypothesize that KNDy neurons play a role in the mechanism of flushes. In the rat, KNDy neurons project to preoptic thermoregulatory areas that express the neurokinin 3 receptor (NK3R), the primary receptor for NKB. Furthermore, activation of NK₃R in the median preoptic nucleus, part of the heat-defense pathway, reduces body temperature. Finally, ablation of KNDy neurons reduces cutaneous vasodilatation and partially blocks the effects of estrogen on thermoregulation. These data suggest that arcuate KNDy neurons relay estrogen signals to preoptic structures regulating heat-dissipation effectors, supporting the hypothesis that KNDy neurons participate in the generation of flushes.
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Affiliation(s)
- Naomi E Rance
- Department of Pathology and the Evelyn F. McKnight Brain Research Institute, University of Arizona College of Medicine, Tucson, AZ 85724, USA.
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Role for kisspeptin/neurokinin B/dynorphin (KNDy) neurons in cutaneous vasodilatation and the estrogen modulation of body temperature. Proc Natl Acad Sci U S A 2012; 109:19846-51. [PMID: 23150555 DOI: 10.1073/pnas.1211517109] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Estrogen withdrawal in menopausal women leads to hot flushes, a syndrome characterized by the episodic activation of heat dissipation effectors. Despite the extraordinary number of individuals affected, the etiology of flushes remains an enigma. Because menopause is accompanied by marked alterations in hypothalamic kisspeptin/neurokinin B/dynorphin (KNDy) neurons, we hypothesized that these neurons could contribute to the generation of flushes. To determine if KNDy neurons participate in the regulation of body temperature, we evaluated the thermoregulatory effects of ablating KNDy neurons by injecting a selective toxin for neurokinin-3 expressing neurons [NK(3)-saporin (SAP)] into the rat arcuate nucleus. Remarkably, KNDy neuron ablation consistently reduced tail-skin temperature (T(SKIN)), indicating that KNDy neurons facilitate cutaneous vasodilatation, an important heat dissipation effector. Moreover, KNDy ablation blocked the reduction of T(SKIN) by 17β-estradiol (E(2)), which occurred in the environmental chamber during the light phase, but did not affect the E(2) suppression of T(SKIN) during the dark phase. At the high ambient temperature of 33 °C, the average core temperature (T(CORE)) of ovariectomized (OVX) control rats was significantly elevated, and this value was reduced by E(2) replacement. In contrast, the average T(CORE) of OVX, KNDy-ablated rats was lower than OVX control rats at 33 °C, and not altered by E(2) replacement. These data provide unique evidence that KNDy neurons promote cutaneous vasodilatation and participate in the E(2) modulation of body temperature. Because cutaneous vasodilatation is a cardinal sign of a hot flush, these results support the hypothesis that KNDy neurons could play a role in the generation of flushes.
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Sinchak K, Wagner EJ. Estradiol signaling in the regulation of reproduction and energy balance. Front Neuroendocrinol 2012; 33:342-63. [PMID: 22981653 PMCID: PMC3496056 DOI: 10.1016/j.yfrne.2012.08.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/18/2012] [Accepted: 08/22/2012] [Indexed: 12/14/2022]
Abstract
Our knowledge of membrane estrogenic signaling mechanisms and their interactions that regulate physiology and behavior has grown rapidly over the past three decades. The discovery of novel membrane estrogen receptors and their signaling mechanisms has started to reveal the complex timing and interactions of these various signaling mechanisms with classical genomic steroid actions within the nervous system to regulate physiology and behavior. The activation of the various estrogenic signaling mechanisms is site specific and differs across the estrous cycle acting through both classical genomic mechanisms and rapid membrane-initiated signaling to coordinate reproductive behavior and physiology. This review focuses on our current understanding of estrogenic signaling mechanisms to promote: (1) sexual receptivity within the arcuate nucleus of the hypothalamus, (2) estrogen positive feedback that stimulates de novo neuroprogesterone synthesis to trigger the luteinizing hormone surge important for ovulation and estrous cyclicity, and (3) alterations in energy balance.
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Affiliation(s)
- Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840-9502, United States.
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Girbig D, Keller K, Prelle K, Patchev V, Vonk R, Igl BW. A dynamic model of circadian rhythms in rodent tail skin temperature for comparison of drug effects. J Circadian Rhythms 2012; 10:1. [PMID: 22221596 PMCID: PMC3398330 DOI: 10.1186/1740-3391-10-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 01/05/2012] [Indexed: 11/10/2022] Open
Abstract
Menopause-associated thermoregulatory dysfunction can lead to symptoms such as hot flushes severely impairing quality of life of affected women. Treatment effects are often assessed by the ovariectomized rat model providing time series of tail skin temperature measurements in which circadian rhythms are a fundamental ingredient. In this work, a new statistical strategy is presented for analyzing such stochastic-dynamic data with the aim of detecting successful drugs in hot flush treatment. The circadian component is represented by a nonlinear dynamical system which is defined by the van der Pol equation and provides well-interpretable model parameters. Results regarding the statistical evaluation of these parameters are presented.
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Affiliation(s)
- Dorothee Girbig
- Global Drug Discovery Statistics and Experimental Medicine Statistics, Bayer HealthCare, Berlin, Germany.
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Dacks PA, Krajewski SJ, Rance NE. Activation of neurokinin 3 receptors in the median preoptic nucleus decreases core temperature in the rat. Endocrinology 2011; 152:4894-905. [PMID: 22028440 PMCID: PMC3230049 DOI: 10.1210/en.2011-1492] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 09/22/2011] [Indexed: 11/19/2022]
Abstract
Estrogens have pronounced effects on thermoregulation, as illustrated by the occurrence of hot flushes secondary to estrogen withdrawal in menopausal women. Because neurokinin B (NKB) gene expression is markedly increased in the infundibular (arcuate) nucleus of postmenopausal women, and is modulated by estrogen withdrawal and replacement in multiple species, we have hypothesized that NKB neurons could play a role in the generation of flushes. There is no information, however, on whether the primary NKB receptor [neurokinin 3 receptor (NK(3)R)] modulates body temperature in any species. Here, we determine the effects of microinfusion of a selective NK(3)R agonist (senktide) into the rat median preoptic nucleus (MnPO), an important site in the heat-defense pathway. Senktide microinfusion into the rat MnPO decreased core temperature in a dose-dependent manner. The hypothermia induced by senktide was similar in ovariectomized rats with and without 17β-estradiol replacement. The hypothermic effect of senktide was prolonged in rats exposed to an ambient temperature of 29.0 C, compared with 21.5 C. Senktide microinfusion also altered tail skin vasomotion in rats exposed to an ambient temperature of 29.0 but not 21.5 C. Comparisons of the effects of senktide at different ambient temperatures indicated that the hypothermia was not secondary to thermoregulatory failure or a reduction in cold-induced thermogenesis. Other than a very mild increase in drinking, senktide microinfusion did not affect behavior. Terminal fluorescent dextran microinfusion showed targeting of the MnPO and adjacent septum, and immunohistochemical studies revealed that senktide induced a marked increase in Fos-activation in the MnPO. Because MnPO neurons expressed NK(3)R-immunoreactivity, the induction of MnPO Fos by senktide is likely a direct effect. By demonstrating that NK(3)R activation in the MnPO modulates body temperature, these studies support the hypothesis that hypothalamic NKB neurons could be involved in the generation of menopausal flushes.
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Affiliation(s)
- Penny A Dacks
- Department of Pathology, University of Arizona College of Medicine, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA
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Dacks PA, Krajewski SJ, Rance NE. Ambient temperature and 17β-estradiol modify Fos immunoreactivity in the median preoptic nucleus, a putative regulator of skin vasomotion. Endocrinology 2011; 152:2750-9. [PMID: 21521752 PMCID: PMC3115603 DOI: 10.1210/en.2010-1230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 03/31/2011] [Indexed: 11/19/2022]
Abstract
Estrogen has pronounced effects on thermoregulation, but the anatomic sites of integration between the reproductive and thermoregulatory axes are unknown. In this study, we tested whether estradiol-17β (E(2)) treatment would alter the activity of thermoregulatory brain regions responding to mild changes in ambient temperature (T(AMBIENT)). Core and tail skin temperatures were recorded at the ambient temperatures of 20, 24, or 31 C in ovariectomized (OVX) rats with and without E(2). Neuronal activity was evaluated by counting the number of Fos-immunoreactive cells in the brains of rats killed 90 min after exposure to one of the three ambient temperatures. Of 14 brain areas examined, the median preoptic nucleus (MnPO) was the only site that exhibited increased Fos immunoreactivity at the high T(AMBIENT) of 31 C. At 24 C, OVX rats exhibited increased numbers of MnPO Fos-immunoreactive cells, compared with OVX + E(2) rats. Interestingly, tail skin vasomotion and MnPO Fos expression were affected in a similar manner by T(AMBIENT) and E(2) treatment. In the arcuate nucleus and anteroventral periventricular nucleus (AVPV), Fos immunoreactivity was highest at the low T(AMBIENT) of 20 C, with inhibitory (arcuate nucleus) and stimulatory (AVPV) effects of E(2). No other areas responded to both T(AMBIENT) and E(2) treatment. These results implicate the MnPO, the arcuate nucleus, and the AVPV as sites of integration between the reproductive and thermoregulatory axes. Combined with studies showing the importance of MnPO neurons in heat-defense pathways, the MnPO emerges as a likely site for E(2) modulation of thermoregulatory vasomotion.
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Affiliation(s)
- Penny A Dacks
- Department of Pathology, University of Arizona College of Medicine, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA
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Williams H, Dacks PA, Rance NE. An improved method for recording tail skin temperature in the rat reveals changes during the estrous cycle and effects of ovarian steroids. Endocrinology 2010; 151:5389-94. [PMID: 20861232 PMCID: PMC2954718 DOI: 10.1210/en.2010-0630] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the rat, tail skin vasomotion is a primary heat loss mechanism that can be monitored by changes in tail skin temperature (T(SKIN)). Previous studies showed that ovariectomy and estrogen replacement modify T(SKIN) in the rat. Based on these findings, the ovariectomized (OVX) rat has been used as a model to study the mechanisms and treatment of menopausal hot flushes. It is not known, however, if T(SKIN) changes across the estrous cycle in intact rats. Here, we describe an improved method for monitoring T(SKIN) in freely moving rats using a SubCue Mini datalogger mounted on the ventral surface of the tail. This method is noninvasive, cost-effective, and does not require restraints or tethering. We observed a distinct pattern of T(SKIN) across the estrous cycle characterized by low T(SKIN) on proestrous night. To determine whether this pattern was secondary to secretion of ovarian steroids, we monitored the thermoregulatory effects of 17β-estradiol (E(2)) and E(2) plus progesterone, administered via SILASTIC capsules to OVX rats. E(2) treatment of OVX rats significantly reduced T(SKIN) in the dark phase from 2 to 21 d after hormone treatment. The T(SKIN) of E(2)-treated OVX animals was not significantly different from OVX rats receiving E(2) plus progesterone. These data provide evidence that the reduction in T(SKIN) on proestrous night was secondary to elevated levels of ovarian estrogens. This study provides the first description of T(SKIN) changes with the estrous cycle and supports the role of estrogens in normal thermoregulation in the rat.
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Affiliation(s)
- Hemalini Williams
- Department of Pathology, Evelyn F. McKnight Brain Research Institute, University of Arizona College of Medicine, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA
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Uchida Y, Tokizawa K, Nakamura M, Mori H, Nagashima K. Estrogen in the medial preoptic nucleus of the hypothalamus modulates cold responses in female rats. Brain Res 2010; 1339:49-59. [PMID: 20416284 DOI: 10.1016/j.brainres.2010.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 04/08/2010] [Accepted: 04/09/2010] [Indexed: 12/01/2022]
Abstract
The present study examined the effect of the central administration of estrogen on responses to the cold. Estrogen or cholesterol was applied locally to the medial preoptic nucleus (MPO) or dorsomedial hypothalamic nucleus (DMH) of the hypothalamus in free-moving ovariectomized rats. Forty-eight hours after the application, rats had 2-h exposure at 10 or 25 degrees C. Body temperature (T(b)) and the tail surface temperature (T(tail)) were continuously measured by telemetry and thermography, respectively. The change of T(b) at 10 degrees C from the 25 degrees C baseline was higher in the estrogen application in the MPO than that in the cholesterol application; however, such difference was not observed in the DMH application. The uncoupling 1 protein mRNA level in the interscapular brown adipose tissue involved in non-shivering thermogenesis was not different between the estrogen and cholesterol applications in the MPO and DMH. T(tail) decreased in the cold, which was greater after the estrogen application in the MPO than after the cholesterol application. These results show that estrogen affects the MPO in female rats, changing T(b) in the cold. Moreover, suppression of heat loss from the tail may be involved in the mechanism.
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Affiliation(s)
- Yuki Uchida
- Faculty of Human Sciences, Waseda University, Tokorozawa, Saitama, Japan
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Romanovsky AA, Garami A. Prostaglandin riddles in energy metabolism: E is for excess, D is for depletion. Focus on "Food deprivation alters thermoregulatory responses to lipopolysaccharide by enhancing cryogenic inflammatory signaling via prostaglandin D2". Am J Physiol Regul Integr Comp Physiol 2010; 298:R1509-11. [PMID: 20410482 DOI: 10.1152/ajpregu.00253.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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