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Franssen D, Johansson HKL, Lopez-Rodriguez D, Lavergne A, Terwagne Q, Boberg J, Christiansen S, Svingen T, Parent AS. Perinatal exposure to the fungicide ketoconazole alters hypothalamic control of puberty in female rats. Front Endocrinol (Lausanne) 2023; 14:1140886. [PMID: 37077353 PMCID: PMC10108553 DOI: 10.3389/fendo.2023.1140886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/03/2023] [Indexed: 04/05/2023] Open
Abstract
INTRODUCTION Estrogenic endocrine disrupting chemicals (EDCs) such as diethylstilbestrol (DES) are known to alter the timing of puberty onset and reproductive function in females. Accumulating evidence suggests that steroid synthesis inhibitors such as ketoconazole (KTZ) or phthalates may also affect female reproductive health, however their mode of action is poorly understood. Because hypothalamic activity is very sensitive to sex steroids, we aimed at determining whether and how EDCs with different mode of action can alter the hypothalamic transcriptome and GnRH release in female rats. DESIGN Female rats were exposed to KTZ or DES during perinatal (DES 3-6-12μg/kg.d; KTZ 3-6-12mg/kg.d), pubertal or adult periods (DES 3-12-48μg/kg.d; KTZ 3-12-48mg/kg.d). RESULTS Ex vivo study of GnRH pulsatility revealed that perinatal exposure to the highest doses of KTZ and DES delayed maturation of GnRH secretion before puberty, whereas pubertal or adult exposure had no effect on GnRH pulsatility. Hypothalamic transcriptome, studied by RNAsequencing in the preoptic area and in the mediobasal hypothalamus, was found to be very sensitive to perinatal exposure to all doses of KTZ before puberty with effects persisting until adulthood. Bioinformatic analysis with Ingenuity Pathway Analysis predicted "Creb signaling in Neurons" and "IGF-1 signaling" among the most downregulated pathways by all doses of KTZ and DES before puberty, and "PPARg" as a common upstream regulator driving gene expression changes. Deeper screening ofRNAseq datasets indicated that a high number of genes regulating the activity of the extrinsic GnRH pulse generator were consistently affected by all the doses of DES and KTZ before puberty. Several, including MKRN3, DNMT3 or Cbx7, showed similar alterations in expression at adulthood. CONCLUSION nRH secretion and the hypothalamic transcriptome are highly sensitive to perinatal exposure to both DES and KTZ. The identified pathways should be exploredfurther to identify biomarkers for future testing strategies for EDC identification and when enhancing the current standard information requirements in regulation.
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Affiliation(s)
- Delphine Franssen
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
- *Correspondence: Delphine Franssen,
| | | | | | - Arnaud Lavergne
- GIGA-Bioinformatics, GIGA Institute, Université de Liège, Liège, Belgium
| | - Quentin Terwagne
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Julie Boberg
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Sofie Christiansen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Terje Svingen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Anne-Simone Parent
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liège, Liège, Belgium
- Department of Pediatrics, University Hospital Liege, Liege, Belgium
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Kraynak M, Willging MM, Kuehlmann AL, Kapoor AA, Flowers MT, Colman RJ, Levine JE, Abbott DH. Aromatase Inhibition Eliminates Sexual Receptivity Without Enhancing Weight Gain in Ovariectomized Marmoset Monkeys. J Endocr Soc 2022; 6:bvac063. [PMID: 35592515 PMCID: PMC9113444 DOI: 10.1210/jendso/bvac063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/19/2022] Open
Abstract
Context Ovarian estradiol supports female sexual behavior and metabolic function. While ovariectomy (OVX) in rodents abolishes sexual behavior and enables obesity, OVX in nonhuman primates decreases, but does not abolish, sexual behavior, and inconsistently alters weight gain. Objective We hypothesize that extra-ovarian estradiol provides key support for both functions, and to test this idea, we employed aromatase inhibition to eliminate extra-ovarian estradiol biosynthesis and diet-induced obesity to enhance weight gain. Methods Thirteen adult female marmosets were OVX and received (1) estradiol-containing capsules and daily oral treatments of vehicle (E2; n = 5); empty capsules and daily oral treatments of either (2) vehicle (VEH, 1 mL/kg, n = 4), or (3) letrozole (LET, 1 mg/kg, n = 4). Results After 7 months, we observed robust sexual receptivity in E2, intermediate frequencies in VEH, and virtually none in LET females (P = .04). By contrast, few rejections of male mounts were observed in E2, intermediate frequencies in VEH, and high frequencies in LET females (P = .04). Receptive head turns were consistently observed in E2, but not in VEH and LET females. LET females, alone, exhibited robust aggressive rejection of males. VEH and LET females demonstrated increased % body weight gain (P = .01). Relative estradiol levels in peripheral serum were E2 >>> VEH > LET, while those in hypothalamus ranked E2 = VEH > LET, confirming inhibition of local hypothalamic estradiol synthesis by letrozole. Conclusion Our findings provide the first evidence for extra-ovarian estradiol contributing to female sexual behavior in a nonhuman primate, and prompt speculation that extra-ovarian estradiol, and in particular neuroestrogens, may similarly regulate sexual motivation in other primates, including humans.
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Affiliation(s)
- Marissa Kraynak
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Molly M Willging
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Center for Women’s Health, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Alex L Kuehlmann
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Amita A Kapoor
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Matthew T Flowers
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Ricki J Colman
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jon E Levine
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - David H Abbott
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, WI 53715, USA
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Abstract
In primates, the gonatotropin-releasing hormone (GnRH) neurosecretory system, consisting of GnRH, kisspeptin, and neurokinin B neurons, is active during the neonatal/early infantile period. During the late infantile period, however, activity of the GnRH neurosecretory system becomes minimal as a result of gonadal steroid independent central inhibition, and this suppressed GnRH neurosecretory state continues throughout the prepubertal period. At the initiation of puberty, the GnRH neurosecretory system becomes active again because of the decrease in central inhibition. During the progress of puberty, kisspeptin and neurokinin B signaling to GnRH neurons further increases, resulting in the release of gonadotropins and subsequent gonadal maturation, and hence puberty. This review further discusses potential substrates of central inhibition and subsequent pubertal modification of the GnRH neurosecretory system by the pubertal increase in steroid hormones, which ensures the regulation of adult reproductive function.
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Affiliation(s)
- Ei Terasawa
- Department of Pediatrics and Wisconsin National Primate Research CenterUniversity of Wisconsin‐MadisonMadisonWIUSA
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4
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Brann DW, Lu Y, Wang J, Zhang Q, Thakkar R, Sareddy GR, Pratap UP, Tekmal RR, Vadlamudi RK. Brain-derived estrogen and neural function. Neurosci Biobehav Rev 2021; 132:793-817. [PMID: 34823913 PMCID: PMC8816863 DOI: 10.1016/j.neubiorev.2021.11.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023]
Abstract
Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E2) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E2 (BDE2). Much of what we know regarding the functional roles of BDE2 has come from studies using specific inhibitors of the E2 synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E2 (NDE2) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E2 (ADE2) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.
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Affiliation(s)
- Darrell W Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Jing Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Roshni Thakkar
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Gangadhara R Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Uday P Pratap
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Rajeshwar R Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Ratna K Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA; Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX, 78229, USA.
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Geddes RI, Kapoor A, Hayashi K, Rauh R, Wehber M, Bongers Q, Jansen AD, Anderson IM, Farquhar G, Vadakkadath‐Meethal S, Ziegler TE, Atwood CS. Hypogonadism induced by surgical stress and brain trauma is reversed by human chorionic gonadotropin in male rats: A potential therapy for surgical and TBI-induced hypogonadism? Endocrinol Diabetes Metab 2021; 4:e00239. [PMID: 34277964 PMCID: PMC8279618 DOI: 10.1002/edm2.239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/14/2020] [Accepted: 01/16/2021] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Hypogonadotropic hypogonadism (HH) is an almost universal, yet underappreciated, endocrinological complication of traumatic brain injury (TBI). The goal of this study was to determine whether the developmental hormone human chorionic gonadotropin (hCG) treatment could reverse HH induced by a TBI. METHODS Plasma samples were collected at post-surgery/post-injury (PSD/PID) days -10, 1, 11, 19 and 29 from male Sprague-Dawley rats (5- to 6-month-old) that had undergone a Sham surgery (craniectomy alone) or CCI injury (craniectomy + bilateral moderate-to-severe CCI injury) and treatment with saline or hCG (400 IU/kg; i.m.) every other day. RESULTS Both Sham and CCI injury significantly decreased circulating testosterone (T), 11-deoxycorticosterone (11-DOC) and corticosterone concentrations to a similar extent (79.1% vs. 80.0%; 46.6% vs. 48.4%; 56.2% vs. 32.5%; respectively) by PSD/PID 1. hCG treatment returned circulating T to baseline concentrations by PSD/PID 1 (8.9 ± 1.5 ng/ml and 8.3 ± 1.9 ng/ml; respectively) and was maintained through PSD/PID 29. hCG treatment significantly, but transiently, increased circulating progesterone (P4) ~3-fold (30.2 ± 10.5 ng/ml and 24.2 ± 5.8 ng/ml) above that of baseline concentrations on PSD 1 and PID 1, respectively. hCG treatment did not reverse hypoadrenalism following either procedure. CONCLUSIONS Together, these data indicate that (1) craniectomy is sufficient to induce persistent hypogonadism and hypoadrenalism, (2) hCG can reverse hypogonadism induced by a craniectomy or craniectomy +CCI injury, suggesting that (3) craniectomy and CCI injury induce a persistent hypogonadism by decreasing hypothalamic and/or pituitary function rather than testicular function in male rats. The potential role of hCG as a cheap, safe and readily available treatment for reversing surgery or TBI-induced hypogonadism is discussed.
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Affiliation(s)
- Rastafa I. Geddes
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Amita Kapoor
- Assay Services Unit and Institute for Clinical and Translational Research Core LaboratoryNational Primate Research CenterUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Kentaro Hayashi
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Ryan Rauh
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Marlyse Wehber
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Quinn Bongers
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Alex D. Jansen
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Icelle M. Anderson
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Gabrielle Farquhar
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Sivan Vadakkadath‐Meethal
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
| | - Toni E. Ziegler
- Assay Services Unit and Institute for Clinical and Translational Research Core LaboratoryNational Primate Research CenterUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Craig S. Atwood
- Division of Geriatrics and GerontologyDepartment of MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWIUSA
- Geriatric Research, Education and Clinical CenterVeterans Administration HospitalMadisonWIUSA
- School of Exercise, Biomedical and Health SciencesEdith Cowan UniversityJoondalupAustralia
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Nguyen SM, Wiepz GJ, Schotzko M, Simmons HA, Mejia A, Ludwig KD, Zhu A, Brunner K, Hernando D, Reeder SB, Wieben O, Johnson K, Shah D, Golos TG. Impact of ferumoxytol magnetic resonance imaging on the rhesus macaque maternal-fetal interface†. Biol Reprod 2021; 102:434-444. [PMID: 31511859 DOI: 10.1093/biolre/ioz181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/05/2019] [Accepted: 09/03/2019] [Indexed: 01/26/2023] Open
Abstract
Ferumoxytol is a superparamagnetic iron oxide nanoparticle used off-label as an intravascular magnetic resonance imaging (MRI) contrast agent. Additionally, ferumoxytol-uptake by macrophages facilitates detection of inflammatory sites by MRI through ferumoxytol-induced image contrast changes. Therefore, ferumoxytol-enhanced MRI holds great potential for assessing vascular function and inflammatory response, critical to determine placental health in pregnancy. This study sought to assess the fetoplacental unit and selected maternal tissues, pregnancy outcomes, and fetal well-being after ferumoxytol administration. In initial developmental studies, seven pregnant rhesus macaques were imaged with or without ferumoxytol administration. Pregnancies went to term with vaginal delivery and infants showed normal growth rates compared to control animals born the same year that did not undergo MRI. To determine the impact of ferumoxytol on the maternal-fetal interface (MFI), fetal well-being, and pregnancy outcome, four pregnant rhesus macaques at ~100 gestational day underwent MRI before and after ferumoxytol administration. Collection of the fetoplacental unit and selected maternal tissues was performed 2-3 days following ferumoxytol administration. A control group that did not receive ferumoxytol or MRI was used for comparison. Iron levels in fetal and MFI tissues did not differ between groups, and there was no significant difference in tissue histopathology with or without exposure to ferumoxytol, and no effect on placental hormone secretion. Together, these results suggest that the use of ferumoxytol and MRI in pregnant rhesus macaques does not negatively impact the MFI and can be a valuable experimental tool in research with this important animal model.
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Affiliation(s)
- Sydney M Nguyen
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA.,Obstetrics & Gynecology, University of Wisconsin Madison School of Medicine, Madison, Wisconsin, USA
| | - Gregory J Wiepz
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA
| | - Michele Schotzko
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA
| | - Heather A Simmons
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA
| | - Andres Mejia
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA
| | - Kai D Ludwig
- Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Ante Zhu
- Biomedical Engineering, University of Wisconsin Madison, Madison, Wisconsin, USA.,Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Kevin Brunner
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA.,Emergency Medicine, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Diego Hernando
- Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, USA.,Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Scott B Reeder
- Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, USA.,Biomedical Engineering, University of Wisconsin Madison, Madison, Wisconsin, USA.,Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA.,Emergency Medicine, University of Wisconsin Madison, Madison, Wisconsin, USA.,Medicine, University of Wisconsin Madison, Madison, Wisconsin, USA, and
| | - Oliver Wieben
- Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, USA.,Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Kevin Johnson
- Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, USA.,Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Dinesh Shah
- Obstetrics & Gynecology, University of Wisconsin Madison School of Medicine, Madison, Wisconsin, USA
| | - Thaddeus G Golos
- Wisconsin National Primate Research Center (WNPRC), Madison, Wisconsin, USA.,Obstetrics & Gynecology, University of Wisconsin Madison School of Medicine, Madison, Wisconsin, USA.,Comparative Biosciences, University of Wisconsin Madison, Madison, Wisconsin, USA
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Uddin MM, Ibrahim MMH, Briski KP. Sex-dimorphic neuroestradiol regulation of ventromedial hypothalamic nucleus glucoregulatory transmitter and glycogen metabolism enzyme protein expression in the rat. BMC Neurosci 2020; 21:51. [PMID: 33238883 PMCID: PMC7687823 DOI: 10.1186/s12868-020-00598-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022] Open
Abstract
Background Ventromedial hypothalamic nucleus (VMN) gluco-regulatory transmission is subject to sex-specific control by estradiol. The VMN is characterized by high levels of aromatase expression. Methods The aromatase inhibitor letrozole (LZ) was used with high-resolution microdissection/Western blot techniques to address the hypothesis that neuroestradiol exerts sex-dimorphic control of VMN neuronal nitric oxide synthase (nNOS) and glutamate decarboxylase65/67 (GAD) protein expression. Glycogen metabolism impacts VMN nNOS and GAD profiles; here, LZ treatment effects on VMN glycogen synthase (GS) and phosphorylase brain- (GPbb; glucoprivic-sensitive) and muscle (GPmm; norepinephrine-sensitive) variant proteins were examined. Results VMN aromatase protein content was similar between sexes. Intracerebroventricular LZ infusion of testes-intact male and ovariectomized, estradiol-replaced female rats blocked insulin-induced hypoglycemic (IIH) up-regulation of this profile. LZ exerted sex-contingent effects on basal VMN nNOS and GAD expression, but blocked IIH-induced NO stimulation and GAD suppression in each sex. Sex-contingent LZ effects on basal and hypoglycemic patterns of GPbb and GPmm expression occurred at distinctive levels of the VMN. LZ correspondingly down- or up-regulated baseline pyruvate recycling pathway marker protein expression in males (glutaminase) and females (malic enzyme-1), and altered INS effects on those proteins. Conclusions Results infer that neuroestradiol is required in each sex for optimal VMN metabolic transmitter signaling of hypoglycemic energy deficiency. Sex differences in VMN GP variant protein levels and sensitivity to aromatase may correlate with sex-dimorphic glycogen mobilization during this metabolic stress. Neuroestradiol may also exert sex-specific effects on glucogenic amino acid energy yield by actions on distinctive enzyme targets in each sex.
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Affiliation(s)
- Md Main Uddin
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Mostafa M H Ibrahim
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Karen P Briski
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA.
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Schmidt JK, Strelchenko N, Park MA, Kim YH, Mean KD, Schotzko ML, Kang HJ, Golos TG, Slukvin II. Genome editing of CCR5 by CRISPR-Cas9 in Mauritian cynomolgus macaque embryos. Sci Rep 2020; 10:18457. [PMID: 33116147 DOI: 10.1038/s41598-020-75295-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
The discovery that CCR5 serves as an R5-HIV-1 co-receptor, coupled with findings of protection from HIV infection in individuals lacking CCR5, led to the exploration of novel therapeutic strategies for HIV infection based on genome editing of CCR5. Advancing translation of CCR5-mutant-based cellular therapies for HIV requires development of novel physiologically relevant animal models. Mauritian cynomolgus macaques (MCMs), with high degree of MHC allele sharing, are valuable models for HIV-1 research and stem cell therapies. To facilitate the generation of a CCR5-mutant MHC-defined MCM model, we explored editing the CCR5 gene in MCM embryos via CRISPR-Cas9. We refined ovarian stimulation and in vitro fertilization (IVF) methods established for Chinese cynomolgus macaques to generate in vitro MCM embryos. Time-lapse embryo imaging was performed to assess the timing of MCM embryonic developmental events in control and CRISPR-Cas9 microinjected embryos. Using a dual-guide gene targeting approach, biallelic deletions in the CCR5 gene were introduced into ~ 23–37% of MCM embryos. In addition, single blastomere PCR analysis revealed mosaicism in CCR5 editing within the same embryo. Successful development of IVF and CCR5 editing protocols in MCM embryos lays a foundation for the creation of CCR5-mutant MCMs to assess novel stem cell-based HIV therapeutics.
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Dees WL, Hiney JK, Srivastava VK. Regulation of prepubertal dynorphin secretion in the medial basal hypothalamus of the female rat. J Neuroendocrinol 2019; 31:e12810. [PMID: 31715027 PMCID: PMC6916394 DOI: 10.1111/jne.12810] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/21/2019] [Accepted: 11/08/2019] [Indexed: 11/27/2022]
Abstract
The onset of puberty is the result of an increase in secretion of hypothalamic gonadotrophin-releasing hormone (GnRH). This action is a result of not only the development of stimulatory inputs to its release, but also the gradual decrease in inhibitory inputs that restrain release of the peptide prior to pubertal onset. Dynorphin (DYN) is one of the inhibitory inputs produced in the medial basal hypothalamus (MBH); however, little is known about what substance(s) control its prepubertal synthesis and release. Because neurokinin B (NKB) increases in the hypothalamus as puberty approaches, we considered it a candidate for such a role. An initial study investigated the acute effects of an NKB agonist, senktide, on the secretion of DYN from MBH tissues incubated in vitro. In other experiments, central injections of senktide were administered to animals for 4 days then MBHs were collected for assessment of DYN synthesis or for the in vitro secretion of both DYN and GnRH. Because insulin-like growth factor (IGF)-1 has been shown to play an important role at puberty, additional animals received central injections of this peptide for 4 days to assess NKB and DYN synthesis or the in vitro secretion of NKB. The results obtained show that senktide administration up-regulates the NKB receptor protein, at the same time as suppressing the DYN and its receptor. Senktide consistently suppressed DYN and elevated GnRH secretion in the same tissue incubates from both the acute and chronic studies. IGF-1 administration caused an increase in NKB protein, at the same time as decreasing DYN protein. Furthermore, the central administration of IGF-1 caused an increase in NKB release, an action blocked by the IGF-1 receptor blocker, JB-1. These results indicate that the IGF-1/NKB pathway contributes to suppressing the DYN inhibitory tone on prepubertal GnRH secretion and thus facilitates the puberty-related increase in the release of GnRH to accelerate the onset of puberty.
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Affiliation(s)
- William L. Dees
- Department of Veterinary Integrative BiosciencesCollege of Veterinary MedicineTexas A&M UniversityCollege StationTXUSA
| | - Jill K. Hiney
- Department of Veterinary Integrative BiosciencesCollege of Veterinary MedicineTexas A&M UniversityCollege StationTXUSA
| | - Vinod K. Srivastava
- Department of Veterinary Integrative BiosciencesCollege of Veterinary MedicineTexas A&M UniversityCollege StationTXUSA
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Sarkar M, Lai JC, Sawinski D, Zeigler TE, Cedars M, Forde KA. Sex hormone levels by presence and severity of cirrhosis in women with chronic hepatitis C virus infection. J Viral Hepat 2019; 26:258-262. [PMID: 30339729 PMCID: PMC6345586 DOI: 10.1111/jvh.13027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/01/2018] [Accepted: 09/23/2018] [Indexed: 12/12/2022]
Abstract
Cirrhosis is associated with hormonal dysregulation, as evidenced by secondary amenorrhoea in reproductive-aged women, and feminization of cirrhotic men. Whether hormone levels vary by severity of cirrhosis in women is not known. If identified, such changes may have important clinical relevance, particularly, as low sex hormone binding globulin (SHBG) and follicle stimulating hormone (FSH) are known to promote metabolic and cardiovascular disease in women. In a cohort of post-menopausal women with chronic hepatitis C virus (HCV) infection, we compared comprehensive sex hormone levels by presence of cirrhosis, as well as across Child-Turcotte-Pugh (CTP) class. Results: There were n = 18 cirrhotic and n = 21 noncirrhotic women with a median age of 57 years (interquartile range [IQR] 53-62). Compared to noncirrhotics, cirrhotic women had higher oestradiol (11.0 vs 6.0 pg/mL, P = 0.05) and oestrone levels (32.0 vs 8.0 ng/mL, P < 0.001), and lower sex hormone binding globulin (SHBG) (69.2 vs 155.6 nmol/L, P = 0.001), and FSH levels (4.9 vs 89.6 mIU/mL, P < 0.001). Among cirrhotic women, there was a progressive decline in FSH and SHBG and concurrent rise in oestrone levels from CTP class A to C (test of trend, P values ≤0.02). Cirrhosis is associated with lower FSH and SHBG levels in cirrhotic compared to noncirrhotic women with HCV infection. In cirrhotic women, these levels demonstrate steady decline by disease severity. Given known associations of low SHBG and FSH with cardio-metabolic disease, the clinical implications of hormonal changes by cirrhosis severity in HCV-infected women warrants investigation.
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Affiliation(s)
- Monika Sarkar
- University of California, San Francisco, Department of Medicine, Division of Gastroenterology and Hepatology
| | - Jennifer C. Lai
- University of California, San Francisco, Department of Medicine, Division of Gastroenterology and Hepatology
| | - Deirdre Sawinski
- University of Pennsylvania, Department of Medicine, Renal Electrolyte and Hypertension Division
| | - Toni E. Zeigler
- University of Wisconsin-Madison, National Primate Research Center
| | - Marcelle Cedars
- University of California, San Francisco, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility
| | - Kimberly A. Forde
- University of Pennsylvania, Department of Medicine, Division of Gastroenterology,University of Pennsylvania, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine
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11
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Abstract
Contribution to Special Issue on Fast effects of steroids. The concept that the positive feedback effect of ovarian estradiol (E2) results in GnRH and gonadotropin surges is a well-established principle. However, a series of studies investigating the rapid action of E2 in female rhesus monkeys has led to a new concept that neuroestradiol, synthesized and released in the hypothalamus, also contributes to regulation of the preovulatory GnRH surge. This unexpected finding started from our surprising observation that E2 induces rapid stimulatory action in GnRH neurons in vitro. Subsequently, we confirmed that a similar rapid stimulatory action of E2 occurs in vivo. Unlike subcutaneous injection of E2 benzoate (EB), a brief (10-20 min), direct infusion of EB into the median eminence in ovariectomized (OVX) female monkeys rapidly stimulates release of GnRH and E2 in a pulsatile manner, and the EB-induced GnRH and E2 release is blocked by simultaneous infusion of the aromatase inhibitor, letrozole. This suggests that stimulated release of E2 is of hypothalamic origin. To further determine the role of neuroestradiol we examined the effects of letrozole on EB-induced GnRH and LH surges in OVX females. Results indicate that letrozole treatment greatly attenuated the EB-induced GnRH and LH surges. Collectively, neuroestradiol released from the hypothalamus appears to be necessary for the positive feedback effect of E2 on the GnRH/LH surge.
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Affiliation(s)
- Ei Terasawa
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI 53715, United States; Department of Pediatrics, University of Wisconsin, Madison, WI 53706, United States.
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Terasawa E, Garcia JP, Seminara SB, Keen KL. Role of Kisspeptin and Neurokinin B in Puberty in Female Non-Human Primates. Front Endocrinol (Lausanne) 2018; 9:148. [PMID: 29681889 PMCID: PMC5897421 DOI: 10.3389/fendo.2018.00148] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/20/2018] [Indexed: 11/25/2022] Open
Abstract
In human patients, loss-of-function mutations in the genes encoding kisspeptin (KISS1) and neurokinin B (NKB) and their receptors (KISS1R and NK3R, respectively) result in an abnormal timing of puberty or the absence of puberty. To understand the neuroendocrine mechanism of puberty, we investigated the contribution of kisspeptin and NKB signaling to the pubertal increase in GnRH release using rhesus monkeys as a model. Direct measurements of GnRH and kisspeptin in the median eminence of the hypothalamus with infusion of agonists and antagonists for kisspeptin and NKB reveal that kisspeptin and NKB signaling stimulate GnRH release independently or collaboratively by forming kisspeptin and NKB neuronal networks depending on the developmental age. For example, while in prepubertal females, kisspeptin and NKB signaling independently stimulate GnRH release, in pubertal females, the formation of a collaborative kisspeptin and NKB network further accelerates the pubertal increase in GnRH release. It is speculated that the collaborative mechanism between kisspeptin and NKB signaling to GnRH neurons is necessary for the complex reproductive function in females.
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Affiliation(s)
- Ei Terasawa
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, United States
- Department of Pediatrics, University of Wisconsin, Madison, WI, United States
- *Correspondence: Ei Terasawa,
| | - James P. Garcia
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, United States
| | - Stephanie B. Seminara
- Reproductive Endocrine Unit and the Harvard Reproductive Sciences Center, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Kim L. Keen
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, United States
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13
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Cornil CA. On the role of brain aromatase in females: why are estrogens produced locally when they are available systemically? J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:31-49. [PMID: 29086012 DOI: 10.1007/s00359-017-1224-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 01/27/2023]
Abstract
The ovaries are often thought of as the main and only source of estrogens involved in the regulation of female behavior. However, aromatase, the key enzyme for estrogen synthesis, although it is more abundant in males, is expressed and active in the brain of females where it is regulated by similar mechanisms as in males. Early work had shown that estrogens produced in the ventromedial hypothalamus are involved in the regulation of female sexual behavior in musk shrews. However, the question of the role of central aromatase in general had not received much attention until recently. Here, I will review the emerging concept that central aromatization plays a role in the regulation of physiological and behavioral endpoints in females. The data support the notion that in females, brain aromatase is not simply a non-functional evolutionary vestige, and provide support for the importance of locally produced estrogens for brain function in females. These observations should also have an impact for clinical research.
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Garcia JP, Guerriero KA, Keen KL, Kenealy BP, Seminara SB, Terasawa E. Kisspeptin and Neurokinin B Signaling Network Underlies the Pubertal Increase in GnRH Release in Female Rhesus Monkeys. Endocrinology 2017; 158:3269-3280. [PMID: 28977601 PMCID: PMC5659687 DOI: 10.1210/en.2017-00500] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/20/2017] [Indexed: 11/19/2022]
Abstract
Loss-of-function or inactivating mutations in the genes coding for kisspeptin and its receptor (KISS1R) or neurokinin B (NKB) and the NKB receptor (NK3R) in humans result in a delay in or the absence of puberty. However, precise mechanisms of kisspeptin and NKB signaling in the regulation of the pubertal increase in gonadotropin-releasing hormone (GnRH) release in primates are unknown. In this study, we conducted a series of experiments infusing agonists and antagonists of kisspeptin and NKB into the stalk-median eminence, where GnRH, kisspeptin, and NKB neuroterminal fibers are concentrated, and measuring GnRH release in prepubertal and pubertal female rhesus monkeys. Results indicate that (1) similar to those previously reported for GnRH stimulation by the KISS1R agonist (i.e., human kisspeptin-10), the NK3R agonist senktide stimulated GnRH release in a dose-responsive manner in both prepubertal and pubertal monkeys; (2) the senktide-induced GnRH release was blocked in the presence of the KISS1R antagonist peptide 234 in pubertal but not prepubertal monkeys; and (3) the kisspeptin-induced GnRH release was blocked in the presence of the NK3R antagonist SB222200 in the pubertal but not prepubertal monkeys. These results are interpreted to mean that although, in prepubertal female monkeys, kisspeptin and NKB signaling to GnRH release is independent, in pubertal female monkeys, a reciprocal signaling mechanism between kisspeptin and NKB neurons is established. We speculate that this cooperative mechanism by the kisspeptin and NKB network underlies the pubertal increase in GnRH release in female monkeys.
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Affiliation(s)
- James P. Garcia
- Wisconsin National Primate Research Center, Madison, Wisconsin 53715
| | | | - Kim L. Keen
- Wisconsin National Primate Research Center, Madison, Wisconsin 53715
| | - Brian P. Kenealy
- Wisconsin National Primate Research Center, Madison, Wisconsin 53715
| | - Stephanie B. Seminara
- Reproductive Endocrine Unit and the Harvard Reproductive Sciences Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Ei Terasawa
- Wisconsin National Primate Research Center, Madison, Wisconsin 53715
- Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin 53706
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15
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Geddes RI, Hayashi K, Bongers Q, Wehber M, Anderson IM, Jansen AD, Nier C, Fares E, Farquhar G, Kapoor A, Ziegler TE, VadakkadathMeethal S, Bird IM, Atwood CS. Conjugated Linoleic Acid Administration Induces Amnesia in Male Sprague Dawley Rats and Exacerbates Recovery from Functional Deficits Induced by a Controlled Cortical Impact Injury. PLoS One 2017; 12:e0169494. [PMID: 28125600 PMCID: PMC5268708 DOI: 10.1371/journal.pone.0169494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/16/2016] [Indexed: 12/05/2022] Open
Abstract
Long-chain polyunsaturated fatty acids like conjugated linoleic acids (CLA) are required for normal neural development and cognitive function and have been ascribed various beneficial functions. Recently, oral CLA also has been shown to increase testosterone (T) biosynthesis, which is known to diminish traumatic brain injury (TBI)-induced neuropathology and reduce deficits induced by stroke in adult rats. To test the impact of CLA on cognitive recovery following a TBI, 5-6 month old male Sprague Dawley rats received a focal injury (craniectomy + controlled cortical impact (CCI; n = 17)) or Sham injury (craniectomy alone; n = 12) and were injected with 25 mg/kg body weight of Clarinol® G-80 (80% CLA in safflower oil; n = 16) or saline (n = 13) every 48 h for 4 weeks. Sham surgery decreased baseline plasma progesterone (P4) by 64.2% (from 9.5 ± 3.4 ng/mL to 3.4 ± 0.5 ng/mL; p = 0.068), T by 74.6% (from 5.9 ± 1.2 ng/mL to 1.5 ± 0.3 ng/mL; p < 0.05), 11-deoxycorticosterone (11-DOC) by 37.5% (from 289.3 ± 42.0 ng/mL to 180.7 ± 3.3 ng/mL), and corticosterone by 50.8% (from 195.1 ± 22.4 ng/mL to 95.9 ± 2.2 ng/mL), by post-surgery day 1. CCI injury induced similar declines in P4, T, 11-DOC and corticosterone (58.9%, 74.6%, 39.4% and 24.6%, respectively) by post-surgery day 1. These results suggest that both Sham surgery and CCI injury induce hypogonadism and hypoadrenalism in adult male rats. CLA treatment did not reverse hypogonadism in Sham (P4: 2.5 ± 1.0 ng/mL; T: 0.9 ± 0.2 ng/mL) or CCI-injured (P4: 2.2 ± 0.9 ng/mL; T: 1.0 ± 0.2 ng/mL, p > 0.05) animals by post-injury day 29, but rapidly reversed by post-injury day 1 the hypoadrenalism in Sham (11-DOC: 372.6 ± 36.6 ng/mL; corticosterone: 202.6 ± 15.6 ng/mL) and CCI-injured (11-DOC: 384.2 ± 101.3 ng/mL; corticosterone: 234.6 ± 43.8 ng/mL) animals. In Sham surgery animals, CLA did not alter body weight, but did markedly increase latency to find the hidden Morris Water Maze platform (40.3 ± 13.0 s) compared to saline treated Sham animals (8.8 ± 1.7 s). In CCI injured animals, CLA did not alter CCI-induced body weight loss, CCI-induced cystic infarct size, or deficits in rotarod performance. However, like Sham animals, CLA injections exacerbated the latency of CCI-injured rats to find the hidden MWM platform (66.8 ± 10.6 s) compared to CCI-injured rats treated with saline (30.7 ± 5.5 s, p < 0.05). These results indicate that chronic treatment of CLA at a dose of 25 mg/kg body weight in adult male rats over 1-month 1) does not reverse craniectomy- and craniectomy + CCI-induced hypogonadism, but does reverse craniectomy- and craniectomy + CCI-induced hypoadrenalism, 2) is detrimental to medium- and long-term spatial learning and memory in craniectomized uninjured rats, 3) limits cognitive recovery following a moderate-severe CCI injury, and 4) does not alter body weight.
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Affiliation(s)
- Rastafa I. Geddes
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Kentaro Hayashi
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Quinn Bongers
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Marlyse Wehber
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Icelle M. Anderson
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Alex D. Jansen
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Chase Nier
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Emily Fares
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Gabrielle Farquhar
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Amita Kapoor
- Assay Services Unit and Institute for Clinical and Translational Research Core Laboratory, National Primate Research Center, University of Wisconsin-Madison, Wisconsin, United States of America
| | - Toni E. Ziegler
- Assay Services Unit and Institute for Clinical and Translational Research Core Laboratory, National Primate Research Center, University of Wisconsin-Madison, Wisconsin, United States of America
| | - Sivan VadakkadathMeethal
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Ian M. Bird
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
| | - Craig S. Atwood
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Wisconsin, United States of America
- Geriatric Research, Education and Clinical Center, Veterans Administration Hospital, Madison, Wisconsin, United States of America
- School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
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16
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Abstract
PURPOSE OF REVIEW The mechanism of puberty initiation remains an enigma, despite extensive research in the field. Pulsatile pituitary gonadotropin secretion under the guidance of hypothalamic gonadotropin-releasing hormone (GnRH) constitutes a sine qua non for pubertal onset. In turn, the secretion of GnRH in the human hypothalamus is regulated by kisspeptin and its receptor as well as by permissive or opposing signals mediated by neurokinin B and dynorphin acting on their respective receptors. These three supra-GnRH regulators compose the Kisspeptin, Neurokinin B and Dynorhin neurons (KNDy) system, a key player in pubertal onset and progression. RECENT FINDINGS The recent discovery that makorin ring finger protein 3 is also involved in puberty initiation provided further insights into the regulation of the KNDy pathway. In fact, the inhibitory (γ-amino butyric acid, neuropeptide Y, and RFamide-related peptide-3) and stimulatory signals (glutamate) acting upstream of KNDy called into question the role of makorin ring finger protein 3 as the gatekeeper of puberty. Meanwhile, the findings that 'neuroestradiol' produced locally and endocrine disruptors from the environment may influence GnRH secretion is intriguing. Finally, epigenetic mechanisms have been implicated in pubertal onset through recently discovered mechanisms. SUMMARY The exact molecular machinery underlying puberty initiation in humans is under intensive investigation. In this review, we summarize research evidence in the field, while emphasizing the areas of uncertainty and underlining the impact of current information on the evolving theory regarding this fascinating phenomenon.
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MacLusky NJ. Curiouser and Curiouser: The Evolving Story of the Mechanisms Involved in Puberty. Endocrinology 2016; 157:42-3. [PMID: 26717471 PMCID: PMC5398640 DOI: 10.1210/en.2015-1985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Neil J MacLusky
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, ON, Canada N1G 2W1
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