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Kunimura Y, Iwata K, Ishii H, Ozawa H. Chronic estradiol exposure suppresses luteinizing hormone surge without affecting kisspeptin neurons and estrogen receptor alpha in anteroventral periventricular nucleus†. Biol Reprod 2024; 110:90-101. [PMID: 37774351 DOI: 10.1093/biolre/ioad129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/01/2023] Open
Abstract
Mammalian ovulation is induced by a luteinizing hormone surge, which is triggered by elevated plasma estrogen levels; however, chronic exposure to high levels of estradiol is known to inhibit luteinizing hormone secretion. In the present study, we hypothesized that the inhibition of the luteinizing hormone surge by chronic estradiol exposure is due to the downregulation of the estrogen receptor alpha in kisspeptin neurons at hypothalamic anteroventral periventricular nucleus, which is known as the gonadotropin-releasing hormone/luteinizing hormone surge generator. Animals exposed to estradiol for 2 days showed an luteinizing hormone surge, whereas those exposed for 14 days showed a significant suppression of luteinizing hormone. Chronic estradiol exposure did not affect the number of kisspeptin neurons and the percentage of kisspeptin neurons with estrogen receptor alpha or c-Fos in anteroventral periventricular nucleus, but it did affect the number of kisspeptin neurons in arcuate nucleus. Furthermore, chronic estradiol exposure did not affect gonadotropin-releasing hormone neurons. In the pituitary, 14-day estradiol exposure significantly reduced the expression of Lhb mRNA and LHβ-immunoreactive areas. Gonadotropin-releasing hormone-induced luteinizing hormone release was also reduced significantly by 14-day estradiol exposure. We revealed that the suppression of an luteinizing hormone surge by chronic estradiol exposure was induced in association with the significant reduction in kisspeptin neurons in arcuate nucleus, luteinizing hormone expression in the pituitary, and pituitary responsiveness to gonadotropin-releasing hormone, and this was not caused by changes in the estrogen receptor alpha-expressing kisspeptin neurons in anteroventral periventricular nucleus and gonadotropin-releasing hormone neurons, which are responsible for estradiol positive feedback.
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Affiliation(s)
- Yuyu Kunimura
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hirotaka Ishii
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
- Department of Physical Therapy, Faculty of Health Science, Bukkyo University, Kyoto, Japan
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Goto T, Hagihara M, Miyamichi K. Dynamics of pulsatile activities of arcuate kisspeptin neurons in aging female mice. eLife 2023; 12:82533. [PMID: 37223988 DOI: 10.7554/elife.82533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 05/09/2023] [Indexed: 05/26/2023] Open
Abstract
Reproductive senescence is broadly observed across mammalian females, including humans, eventually leading to a loss of fertility. The pulsatile secretion of gonadotropin-releasing hormone (GnRH), which is essential for gonad function, is primarily controlled by kisspeptin neurons in the hypothalamic arcuate nucleus (ARCkiss), the pulse generator of GnRH. The pulsatility of GnRH release, as assessed by the amount of circulating gonadotropin, is markedly reduced in aged animals, suggesting that the malfunctions of ARCkiss may be responsible for reproductive aging and menopause-related disorders. However, the activity dynamics of ARCkiss during the natural transition to reproductive senescence remain unclear. Herein, we introduce chronic in vivo Ca2+ imaging of ARCkiss in female mice by fiber photometry to monitor the synchronous episodes of ARCkiss (SEskiss), a known hallmark of GnRH pulse generator activity, from the fully reproductive to acyclic phase over 1 year. During the reproductive phase, we find that not only the frequency, but also the intensities and waveforms of individual SEskiss, vary depending on the stage of the estrus cycle. During the transition to reproductive senescence, the integrity of SEskiss patterns, including the frequency and waveforms, remains mostly unchanged, whereas the intensities tend to decline. These data illuminate the temporal dynamics of ARCkiss activities in aging female mice. More generally, our findings demonstrate the utility of fiber-photometry-based chronic imaging of neuroendocrine regulators in the brain to characterize aging-associated malfunction.
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Affiliation(s)
- Teppei Goto
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Mitsue Hagihara
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Kazunari Miyamichi
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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Ono M, Ando H, Daikoku T, Fujiwara T, Mieda M, Mizumoto Y, Iizuka T, Kagami K, Hosono T, Nomura S, Toyoda N, Sekizuka-Kagami N, Maida Y, Kuji N, Nishi H, Fujiwara H. The Circadian Clock, Nutritional Signals and Reproduction: A Close Relationship. Int J Mol Sci 2023; 24:ijms24021545. [PMID: 36675058 PMCID: PMC9865912 DOI: 10.3390/ijms24021545] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
The circadian rhythm, which is necessary for reproduction, is controlled by clock genes. In the mouse uterus, the oscillation of the circadian clock gene has been observed. The transcription of the core clock gene period (Per) and cryptochrome (Cry) is activated by the heterodimer of the transcription factor circadian locomotor output cycles kaput (Clock) and brain and muscle Arnt-like protein-1 (Bmal1). By binding to E-box sequences in the promoters of Per1/2 and Cry1/2 genes, the CLOCK-BMAL1 heterodimer promotes the transcription of these genes. Per1/2 and Cry1/2 form a complex with the Clock/Bmal1 heterodimer and inactivate its transcriptional activities. Endometrial BMAL1 expression levels are lower in human recurrent-miscarriage sufferers. Additionally, it was shown that the presence of BMAL1-depleted decidual cells prevents trophoblast invasion, highlighting the importance of the endometrial clock throughout pregnancy. It is widely known that hormone synthesis is disturbed and sterility develops in Bmal1-deficient mice. Recently, we discovered that animals with uterus-specific Bmal1 loss also had poor placental development, and these mice also had intrauterine fetal death. Furthermore, it was shown that time-restricted feeding controlled the uterine clock's circadian rhythm. The uterine clock system may be a possibility for pregnancy complications, according to these results. We summarize the most recent research on the close connection between the circadian clock and reproduction in this review.
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Affiliation(s)
- Masanori Ono
- Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo 160-0023, Japan
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
- Correspondence: ; Tel.: +81-3-3342-6111
| | - Hitoshi Ando
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Takiko Daikoku
- Institute for Experimental Animals, Advanced Science Research Center, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Tomoko Fujiwara
- Department of Social Work and Life Design, Kyoto Notre Dame University, Kyoto 606-0848, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Yasunari Mizumoto
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Takashi Iizuka
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Kyosuke Kagami
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Takashi Hosono
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Satoshi Nomura
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Natsumi Toyoda
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
- Institute for Experimental Animals, Advanced Science Research Center, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Naomi Sekizuka-Kagami
- Department of Nursing, College of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Yoshiko Maida
- Department of Nursing, College of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kanazawa 920-8641, Japan
| | - Naoaki Kuji
- Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo 160-0023, Japan
| | - Hirotaka Nishi
- Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo 160-0023, Japan
| | - Hiroshi Fujiwara
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8641, Japan
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Minabe S, Iwata K, Watanabe Y, Ishii H, Ozawa H. Long-term effects of prenatal undernutrition on female rat hypothalamic KNDy neurons. Endocr Connect 2023; 12:e220307. [PMID: 36408965 PMCID: PMC9782422 DOI: 10.1530/ec-22-0307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 11/23/2022]
Abstract
The nutritional environment during development periods induces metabolic programming, leading to metabolic disorders and detrimental influences on human reproductive health. This study aimed to determine the long-term adverse effect of intrauterine malnutrition on the reproductive center kisspeptin-neurokinin B-dynorphin A (KNDy) neurons in the hypothalamic arcuate nucleus (ARC) of female offspring. Twelve pregnant rats were divided into ad-lib-fed (control, n = 6) and 50% undernutrition (UN, n = 6) groups. The UN group was restricted to 50% daily food intake of the control dams from gestation day 9 until term delivery. Differences between the two groups in terms of various maternal parameters, including body weight (BW), pregnancy duration, and litter size, as well as birth weight, puberty onset, estrous cyclicity, pulsatile luteinizing hormone (LH) secretion, and hypothalamic gene expression of offspring, were determined. Female offspring of UN dams exhibited low BW from birth to 3 weeks, whereas UN offspring showed signs of precocious puberty; hypothalamic Tac3 (a neurokinin B gene) expression was increased in prepubertal UN offspring, and the BW at the virginal opening was lower in UN offspring than that in the control group. Interestingly, the UN offspring showed significant decreases in the number of KNDy gene-expressing cells after 29 weeks of age, but the number of ARC kisspeptin-immunoreactive cells, pulsatile LH secretions, and estrous cyclicity were comparable between the groups. In conclusion, intrauterine undernutrition induced various changes in KNDy gene expression depending on the life stage. Thus, intrauterine undernutrition affected hypothalamic developmental programming in female rats.
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Affiliation(s)
- Shiori Minabe
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
- Division of Biomedical Information Analysis, Iwate Tohoku Medical Megabank Organization, Disaster Reconstruction Center, Iwate Medical University, Yahaba, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Youki Watanabe
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hirotaka Ishii
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
- Faculty of Health Science, Bukkyo University, Kyoto, Japan
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Abstract
Compared to women, increasing male age is not accompanied by such marked changes in reproductive function but changes certainly do happen. These include alterations to the hypothalamo-pituitary-testicular axis, with resultant implications for testosterone production and bioavailability as well as spermatogenesis. There is a decline in sexual function as men age, with a dramatic increase in the prevalence of erectile dysfunction after the age of 40, which is a marker for both clinically evident as well as covert coronary artery disease. Despite a quantitative decline in spermatogenesis and reduced fecundability, the male potential for fertility persists throughout adult life, however there are also increasingly recognised alterations in sperm quality and function with significant implications for offspring health. These changes are relevant to both natural and medically assisted conception.
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Affiliation(s)
- Sarah Martins da Silva
- Reproductive Medicine Research Group, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, DD1 9SY, Dundee, UK
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, EH16 4TJ, Edinburgh, UK.
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Dolcetti FJC, Falomir-Lockhart E, Acuña F, Herrera ML, Cervellini S, Barbeito CG, Grassi D, Arevalo MA, Bellini MJ. IGF1 gene therapy in middle-aged female rats delays reproductive senescence through its effects on hypothalamic GnRH and kisspeptin neurons. Aging (Albany NY) 2022; 14:8615-8632. [DOI: 10.18632/aging.204360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/21/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Franco Juan Cruz Dolcetti
- Laboratorio de Bioquímica del Envejecimiento, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina
| | - Eugenia Falomir-Lockhart
- Laboratorio de Bioquímica del Envejecimiento, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina
| | - Francisco Acuña
- Laboratorio de Histología y Embriología Descriptiva, Experimental y Comparada, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina
| | - Macarena Lorena Herrera
- Laboratorio de Bioquímica del Envejecimiento, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina
- Instituto de Farmacología Experimental de Córdoba-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas, UNC-CONICET, Córdoba, Argentina
| | - Sofia Cervellini
- Laboratorio de Bioquímica del Envejecimiento, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina
| | - Claudio Gustavo Barbeito
- Laboratorio de Histología y Embriología Descriptiva, Experimental y Comparada, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina
| | - Daniela Grassi
- Department of Anatomy, Histology and Neuroscience, Autonomous University of Madrid, Madrid, España
| | - Maria-Angeles Arevalo
- Instituto Cajal, CSIC, Madrid, España
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, España
| | - María José Bellini
- Laboratorio de Bioquímica del Envejecimiento, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina
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7
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Sexual Dimorphism in Kisspeptin Signaling. Cells 2022; 11:cells11071146. [PMID: 35406710 PMCID: PMC8997554 DOI: 10.3390/cells11071146] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 02/05/2023] Open
Abstract
Kisspeptin (KP) and kisspeptin receptor (KPR) are essential for the onset of puberty, development of gonads, and maintenance of gonadal function in both males and females. Hypothalamic KPs and KPR display a high degree of sexual dimorphism in expression and function. KPs act on KPR in gonadotropin releasing hormone (GnRH) neurons and induce distinct patterns of GnRH secretion in males and females. GnRH acts on the anterior pituitary to secrete gonadotropins, which are required for steroidogenesis and gametogenesis in testes and ovaries. Gonadal steroid hormones in turn regulate the KP neurons. Gonadal hormones inhibit the KP neurons within the arcuate nucleus and generate pulsatile GnRH mediated gonadotropin (GPN) secretion in both sexes. However, the numbers of KP neurons in the anteroventral periventricular nucleus and preoptic area are greater in females, which release a large amount of KPs in response to a high estrogen level and induce the preovulatory GPN surge. In addition to the hypothalamus, KPs and KPR are also expressed in various extrahypothalamic tissues including the liver, pancreas, fat, and gonads. There is a remarkable difference in circulating KP levels between males and females. An increased level of KPs in females can be linked to increased numbers of KP neurons in female hypothalamus and more KP production in the ovaries and adipose tissues. Although the sexually dimorphic features are well characterized for hypothalamic KPs, very little is known about the extrahypothalamic KPs. This review article summarizes current knowledge regarding the sexual dimorphism in hypothalamic as well as extrahypothalamic KP and KPR system in primates and rodents.
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8
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Enomoto H, Iwata K, Matsumoto K, Otsuka M, Morita A, Ozawa H. Hypothalamic KNDy neuron expression in streptozotocin-induced diabetic female rats. J Endocrinol 2022; 253:39-51. [PMID: 35084363 PMCID: PMC8942341 DOI: 10.1530/joe-21-0169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 01/27/2022] [Indexed: 11/08/2022]
Abstract
Kisspeptin neurons, i.e. KNDy neurons, in the arcuate nucleus (ARC) coexpress neurokinin B and dynorphin and regulate gonadotropin-releasing hormone/luteinizing hormone (LH) pulses. Because it remains unclear whether these neurons are associated with reproductive dysfunction in diabetic females, we examined the expression of KNDy neurons detected by histochemistry in streptozotocin (STZ)-induced diabetic female rats 8 weeks after STZ injection. We also evaluated relevant metabolic parameters - glucose, 3-hydroxybutyrate, and non-esterified fatty acids - as indicators of diabetes progression. Severe diabetes with hyperglycemia and severe ketosis suppressed the mRNA expression of KNDy neurons, resulting in low plasma LH levels and persistent diestrus. In moderate diabetes with hyperglycemia and moderate ketosis, kisspeptin-immunoreactive cells and plasma LH levels were decreased, while the mRNA expression of KNDy neurons remained unchanged. Mild diabetes with hyperglycemia and slight ketosis did not affect KNDy neurons and plasma LH levels. The number of KNDy cells was strongly and negatively correlated with plasma 3-hydroxybutyrate levels. The vaginal smear analysis showed unclear proestrus in diabetic rats 3-5 days after STZ injection, and the mRNA expression of kisspeptin in the ARC was decreased 2 weeks after STZ injection in severely diabetic rats. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV), which induce an LH surge, were unaffected at 2 and 8 weeks after STZ injection regardless of the diabetes severity. These results suggest that diabetes mellitus progression in females may negatively affect ARC kisspeptin neurons but not AVPV kisspeptin neurons, implicating a potential role of ARC kisspeptin neurons in menstrual disorder and infertility.
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Affiliation(s)
- Hiroyuki Enomoto
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
- Department of Neurosurgery, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
- Correspondence should be addressed to K Iwata:
| | - Keisuke Matsumoto
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Mai Otsuka
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Akio Morita
- Department of Neurosurgery, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
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9
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Ozawa H. Kisspeptin neurons as an integration center of reproductive regulation: Observation of reproductive function based on a new concept of reproductive regulatory nervous system. Reprod Med Biol 2021; 21:e12419. [PMID: 34934400 PMCID: PMC8656200 DOI: 10.1002/rmb2.12419] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 11/29/2022] Open
Abstract
Background Regulation of the reproductive system has been explained by the actions and feedback of gonadotropin releasing hormone‐luteinizing hormone/follicle stimulating hormone (GnRH‐LH/FSH) ‐sex steroids; however, the discovery of kisspeptin neurons and a kisspeptin‐GnRH‐LH/FSH axis has prompted this regulation to be reviewed. Methods We investigated changes in kisspeptin neurons and associated changes in the hypothalamic‐pituitary‐gonadal (HPG) axis under various situations and experimental conditions using histochemical methods. Main findings (Results) Kisspeptin neurons play an important role in receiving and integrating information from internal and external environmental factors and communicating it to the conventional HPG axis. Conclusion The recently described Kisspeptin‐GnRH‐LH/FSH‐gonad system regulates reproductive function via mechanisms that until recently were not completely understood.
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Affiliation(s)
- Hitoshi Ozawa
- Department of Anatomy and Neurobiology Graduate School of Medicine Nippon Medical School Tokyo Japan
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López-Trinidad BP, Vigueras-Villaseñor RM, Konigsberg M, Ávalos-Rodríguez A, Rodríguez-Tobón A, Cortés-Barberena E, Arteaga-Silva M, Arenas-Ríos E. Alterations in epididymal sperm maturation caused by ageing. Reprod Fertil Dev 2021; 33:855-864. [PMID: 34844664 DOI: 10.1071/rd21081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 10/05/2021] [Indexed: 11/23/2022] Open
Abstract
The epididymis is an organ that performs all the biochemical changes responsible for sperm maturation. During ageing, histological alterations in the epididymis and decreased protein synthesis have been found. This might affect the sperm maturation process. The aim of this study was to determine if the changes in the epididymis during ageing might cause alterations in sperm maturation. Wistar rats of 3-4months old (young) and 18-21months old (old) were used. The testosterone concentration was determined and the epididymides were dissected and divided in three regions: caput, corpus, and cauda. The tissues were used for histological processing and sperm extraction. Testosterone concentration decreased 34% in the old animals compared to the young ones. The distribution of mannose, sialic acid, and N-acetylglucosamine in the glycocalyx of the sperm membrane of old animals was different from that of young animals. The same occurred with phosphatidylserine externalisation and protein phosphorylation at tyrosine residues. Epididymis histology in old animals showed tubular and cellular degeneration. Our results suggest that ageing affects maturational markers, likely due to alterations in the epididymis as a result of the testosterone decrease associated with ageing.
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Affiliation(s)
- B P López-Trinidad
- Doctorado en Biología Experimental. Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México; and Laboratorio de Morfofisiología y Bioquímica del Espermatozoide, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
| | - R M Vigueras-Villaseñor
- Laboratorio de Biología de la Reproducción, Instituto Nacional de Pediatría, Ciudad de México, México
| | - M Konigsberg
- Laboratorio de Bioenergética y envejecimiento Celular, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
| | - A Ávalos-Rodríguez
- Laboratorio de Bioquímica de la Reproducción, Universidad Autónoma Metropolitana. Unidad Xochimilco. Ciudad de México, México
| | - A Rodríguez-Tobón
- Laboratorio de Ecología y Biología de Mamíferos, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México; and Laboratorio de Morfofisiología y Bioquímica del Espermatozoide, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
| | - E Cortés-Barberena
- Laboratorio de Biología Celular y Citometría de Flujo, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
| | - M Arteaga-Silva
- Laboratorio de Neuroendocrinología Reproductiva, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
| | - E Arenas-Ríos
- Laboratorio de Morfofisiología y Bioquímica del Espermatozoide, Universidad Autónoma Metropolitana. Unidad Iztapalapa. Ciudad de México, México
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11
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Mattam U, Talari NK, Thiriveedi VR, Fareed M, Velmurugan S, Mahadev K, Sepuri NBV. Aging reduces kisspeptin receptor (GPR54) expression levels in the hypothalamus and extra-hypothalamic brain regions. Exp Ther Med 2021; 22:1019. [PMID: 34373705 DOI: 10.3892/etm.2021.10451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 03/03/2021] [Indexed: 12/31/2022] Open
Abstract
Aging leads to the diminished pulsatile secretion of hypothalamic gonadotropin-releasing hormone (GnRH). Kisspeptin (Kp), the upstream regulator of the hypothalamic-pituitary-gonadal (HPG) axis, regulates GnRH synthesis and release through its cognate receptor, G-protein coupled receptor 54 (GPR54). In turn, GnRH regulates GPR54 expression. GnRH administration into the third ventricle has been shown to induce neurogenesis in different brain regions in old age. However, aging-associated changes in hypothalamic and extra-hypothalamic GPR54 expression were unclear. Therefore, the expression levels of GPR54 were evaluated in various brain regions of adult (age, 3-4 months) and old (age, 20-24 months) male Wistar rats in the present study. In the hypothalamus, mRNA and protein levels of Kp and GPR54 were identified to be significantly decreased in old age. Furthermore, GnRH1 expression in the hypothalamus was analyzed to observe the functional consequence of a reduced Kp-GPR54 system in the hypothalamus. It was found that hypothalamic GnRH1 levels were significantly decreased in old age. As GnRH regulates GPR54 levels, GPR54 was examined in extra-hypothalamic regions. GPR54 levels were found to be significantly decreased in the hippocampus and medulla and pons in old-age rats when compared to adult rats. Notably, GPR54 expression was observed in the frontal lobe, cortex, midbrain and cerebellum of adult and old-age rats; however, the difference between the two groups was not statistically significant. To the best of our knowledge, this is the first study that provides the quantitative distribution of GPR54 in different brain regions during aging. Thus, the reduced levels of Kp and its receptor, GPR54 in the hypothalamus could be cumulatively responsible for reduced levels of GnRH observed in old age.
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Affiliation(s)
- Ushodaya Mattam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Noble Kumar Talari
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Venkata Ramana Thiriveedi
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Mohammed Fareed
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Sathya Velmurugan
- National Institute of Animal Biotechnology, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Kalyankar Mahadev
- School of Medical Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Naresh Babu V Sepuri
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
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Han A, Kim JY, Kwak-Kim J, Lee SK. Menopause is an inflection point of age-related immune changes in women. J Reprod Immunol 2021; 146:103346. [PMID: 34147765 DOI: 10.1016/j.jri.2021.103346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 10/21/2022]
Abstract
Elevated proinflammatory cytokines in postmenopausal women is considered as one of the causes increasing the incidence of chronic inflammatory diseases. However, the details of postmenopausal immune changes have not yet been fully revealed. Thus, we investigated age-related immune changes in women and compared immune responses in postmenopausal and reproductive-age women. A total of 34 postmenopausal women and 91 reproductive-age women were included in the study. After isolating peripheral blood mononuclear cells, analysis of immunophenotypes and intracellular cytokine profiles were done. The proportion of natural killer (NK) cells was significantly higher, and the ratio of TNF-α- to IL-10-producing CD3+CD4 + T cells (Th1 to Th2) and the ratio of Th17 cells to CD4+CD25+Foxp3+ regulatory T (Treg) cells (Th17 to Treg) were higher, in postmenopausal women than in reproductive-age women. The Treg cell proportion was negatively correlated with the Th1 and Th2 cell proportions in reproductive-age women but not in postmenopausal women. As age increased, the proportion of Tregs was increased in reproductive-age women (r = 0.302, p = 0.004), whereas the proportion of Th1 cells was increased in postmenopausal women (r = 0.466, p = 0.005). FSH levels showed a positive correlation with Fopx3+ T cell and Treg cell (p = 0.04, 0.053, respectively), whereas Th17/Treg ratio and Th1 cell showed negative correlation with FSH.(p = 0.045, 0.024, respectively). In conclusion, postmenopausal women have higher proinflammatory immune statuses, as demonstrated by increased proportions of NK, Th1, and Th17 cells, altered correlations among NK and T cell subsets, and compromised balances between effector T cell subsets.
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Affiliation(s)
- Aera Han
- Konyang University Myunggok Research Institute, Republic of Korea
| | - Jee Yun Kim
- Department of Obstetrics and Gynecology, Konyang University College of Medicine, Daejeon, Republic of Korea
| | - Joanne Kwak-Kim
- Reproductive Medicine and Immunology, Department of Obstetrics and Gynecology, Chicago Medical School at Rosalind Franklin University of Medicine and Science, Vernon Hills, USA; Department of Microbiology and Immunology, Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Sung Ki Lee
- Konyang University Myunggok Research Institute, Republic of Korea; Department of Obstetrics and Gynecology, Konyang University College of Medicine, Daejeon, Republic of Korea.
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Abstract
This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY, 11367, United States.
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15
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Iwata K, Kunimura Y, Ozawa H. Hypothalamic Kisspeptin Expression in Hyperandrogenic Female Rats and Aging Rats. Acta Histochem Cytochem 2019; 52:85-91. [PMID: 31777408 PMCID: PMC6872488 DOI: 10.1267/ahc.19013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/05/2019] [Indexed: 01/29/2023] Open
Abstract
Hypothalamic kisspeptin neurons stimulate gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) release. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) of rats induce an LH surge for ovulation, and those in the arcuate nucleus (ARC) regulate pulsatile LH secretion for follicle development and spermatogenesis. Dysfunction of kisspeptin neurons thus reduces the reproductive function. This review focuses on the effect of androgen or aging on kisspeptin expression in rats. Although androgen directly suppresses ARC kisspeptin neurons in female rats, the AVPV kisspeptin neurons are hardly affected. In rats, plasma LH concentrations decrease in both sexes with aging, and ARC kisspeptin expression also decreases in old rats compared with young rats. In addition, kisspeptin neurons may be associated with hyperprolactinemia in old female rats because they are known to release prolactin through hypothalamic tuberoinfundibular dopaminergic (TIDA) neurons. Hypothalamic kisspeptin neurons are thus the main regulator to secrete LH, and inhibition of kisspeptin expression leads to various kinds of reproductive dysfunction.
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Affiliation(s)
- Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School
| | - Yuyu Kunimura
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School
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16
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Bahougne T, Angelopoulou E, Jeandidier N, Simonneaux V. Individual evaluation of luteinizing hormone in aged C57BL/6 J female mice. GeroScience 2019; 42:323-331. [PMID: 31641925 DOI: 10.1007/s11357-019-00104-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/12/2019] [Indexed: 12/23/2022] Open
Abstract
In female mammals, reproductive senescence is a complex process involving progressive ovarian dysfunction associated with an altered central control of the hypothalamic-pituitary axis. The objective of this study was to compare the longitudinal change in preovulatory luteinizing hormone (LH) secretion as well as estrous cycle in individual C57BL/6 J female mice at 3, 6, 9 and 12 months. Amplitude and timing of LH secretion at the surge were similar from 3 to 9 months but were altered in 12-month old mice with a significant decrease of more than 50% of peak LH value and a 2 h delay in the occurrence of the LH surge as compared to younger mice. The analysis of two to three successive LH surges at 3, 6, 9 and 12 months showed low and similar intra-individual variability at all ages. The estrous cycle length and intra/inter variability were stable over the age. This study shows that female mice in regular environmental conditions display stable LH surge timing and amplitude up to 9 months, but at 12 months, the LH surge is delayed with a reduced amplitude, however without overt modification in the estrous cycles. Analysis of individual preovulatory LH secretion and estrous cycle indicates that mice can be followed up to 9 months to investigate the detrimental effects of various parameters on mouse reproductive activity.
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Affiliation(s)
- Thibault Bahougne
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France. .,Service d'Endocrinologie et Diabète, Hôpitaux Universitaires de Strasbourg, 1 place de l'hôpital, 67000, Strasbourg, France.
| | - Eleni Angelopoulou
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France
| | - Nathalie Jeandidier
- Service d'Endocrinologie et Diabète, Hôpitaux Universitaires de Strasbourg, 1 place de l'hôpital, 67000, Strasbourg, France
| | - Valérie Simonneaux
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France
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17
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Kaufman JM, Lapauw B, Mahmoud A, T'Sjoen G, Huhtaniemi IT. Aging and the Male Reproductive System. Endocr Rev 2019; 40:906-972. [PMID: 30888401 DOI: 10.1210/er.2018-00178] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/27/2018] [Indexed: 12/21/2022]
Abstract
This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.
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Affiliation(s)
- Jean-Marc Kaufman
- Department of Endocrinology, Ghent University Hospital, Ghent, Belgium
| | - Bruno Lapauw
- Department of Endocrinology, Ghent University Hospital, Ghent, Belgium
| | - Ahmed Mahmoud
- Department of Endocrinology, Ghent University Hospital, Ghent, Belgium
| | - Guy T'Sjoen
- Department of Endocrinology, Ghent University Hospital, Ghent, Belgium
| | - Ilpo Tapani Huhtaniemi
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, London, United Kingdom.,Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland
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18
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Herbison AE. The Gonadotropin-Releasing Hormone Pulse Generator. Endocrinology 2018; 159:3723-3736. [PMID: 30272161 DOI: 10.1210/en.2018-00653] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 08/20/2018] [Indexed: 12/18/2022]
Abstract
The pulsatile release of GnRH and LH secretion is essential for fertility in all mammals. Pulses of LH occur approximately every hour in follicular-phase females and every 2 to 3 hours in luteal-phase females and males. Many studies over the last 50 years have sought to identify the nature and mechanism of the "GnRH pulse generator" responsible for pulsatile LH release. This review examines the characteristics of pulsatile hormone release and summarizes investigations that have led to our present understanding of the GnRH pulse generator. There is presently little compelling evidence for an intrinsic mechanism of pulse generation involving interactions between GnRH neuron cell bodies. Rather, data support the presence of an extrinsic pulse generator located within the arcuate nucleus, and attention has focused on the kisspeptin neurons and their projections to GnRH neuron dendrons concentrated around the median eminence. Sufficient evidence has been gathered in rodents to conclude that a subpopulation of arcuate kisspeptin neurons is, indeed, the GnRH pulse generator. Findings in other species are generally compatible with this view and suggest that arcuate/infundibular kisspeptin neurons represent the mammalian GnRH pulse generator. With hindsight, it is likely that past arcuate nucleus multiunit activity recordings have been from kisspeptin neurons. Despite advances in identifying the cells forming the pulse generator, almost nothing is known about their mechanisms of synchronicity and the afferent hormonal and transmitter modulation required to establish the normal patterns of LH pulsatility in mammals.
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Affiliation(s)
- Allan E Herbison
- Centre for Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Kanaya M, Iwata K, Ozawa H. Distinct dynorphin expression patterns with low- and high-dose estrogen treatment in the arcuate nucleus of female rats. Biol Reprod 2018; 97:709-718. [PMID: 29069289 DOI: 10.1093/biolre/iox131] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/20/2017] [Indexed: 01/25/2023] Open
Abstract
Kisspeptin (KISS1; encoded by Kiss1) neurons in the arcuate nucleus (ARC) coexpress tachykinin 3 (TAC3; also known as neurokinin B) and dynorphin A (PDYN). Accordingly, they are termed KNDy neurons and considered to be crucial in generating pulsatile release of gonadotropin-releasing hormone. Accumulating evidence suggests that Kiss1 and Tac3 are negatively regulated by estrogen. However, it has not been fully determined whether and how estrogen modulates Pdyn and PDYN. Here, we examined the expression of Pdyn mRNA and PDYN by in situ hybridization and immunohistochemistry, respectively, in the ARC of female rats after ovariectomy (OVX) and OVX plus low- or high-dose beta-estradiol (E2) replacement. We also investigated the effect of E2 on expression of Kiss1, KISS1, Tac3, and TAC3. Furthermore, colocalization of PDYN and estrogen receptor alpha (ESR1) was determined. Subsequently, we found that low-dose E2 treatment had no effect on Pdyn mRNA-expressing cells, but increased PDYN-immunoreactive (ir) cell numbers. In contrast, high-dose E2 treatment resulted in prominent reductions in both Pdyn mRNA-expressing and PDYN-ir cell numbers. Changes induced by low or high doses of E2 were similarly observed in the expression of Kiss1, KISS1, Tac3, and TAC3. The majority of PDYN-ir neurons coexpressed ESR1 in all groups. Our results indicate that E2 regulates the expression of PDYN, as well as KISS1 and TAC3, with regulation by E2 differing according to its levels.
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Affiliation(s)
- Moeko Kanaya
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
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Saedi S, Khoradmehr A, Mohammad Reza JS, Tamadon A. The role of neuropeptides and neurotransmitters on kisspeptin/kiss1r-signaling in female reproduction. J Chem Neuroanat 2018; 92:71-82. [PMID: 30008384 DOI: 10.1016/j.jchemneu.2018.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 06/01/2018] [Accepted: 07/02/2018] [Indexed: 01/08/2023]
Abstract
Reproductive function is regulated by the hypothalamic-pituitary-gonads (HPG) axis. Hypothalamic neurons synthesizing kisspeptin play a fundamental role in the central regulation of the timing of puberty onset and reproduction in mammals. Kisspeptin is a regulator of gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH). In female rodent, the kisspeptin (encoded by kiss1 gene), neurokinin B (Tac3) and dynorphin neurons form the basis for the "KNDy neurons" in the arcuate nucleus and play a fundamental role in the regulation of GnRH/LH release. Furthermore, various factors including neurotransmitters and neuropeptides may cooperate with kisspeptin signaling to modulate GnRH function. Many neuropeptides including proopiomelanocortin, neuropeptide Y, agouti-related protein, and other neuropeptides, as well as neurotransmitters, dopamine, norepinephrine and γ-aminobutyric acid are suggested to control feeding and HPG axis, the underlying mechanisms are not well known. Nonetheless, to date, information about the neurochemical factors of kisspeptin neurons remains incomplete in rodent. This review is intended to provide an overview of KNDy neurons; major neuropeptides and neurotransmitters interfere in kisspeptin signaling to modulate GnRH function for regulation of puberty onset and reproduction, with a focus on the female rodent.
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Affiliation(s)
- Saman Saedi
- Department of Animal Science, College of Agriculture, Shiraz University, Shiraz, Iran.
| | - Arezoo Khoradmehr
- Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
| | | | - Amin Tamadon
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.
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21
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Kim K, Choe HK. Role of hypothalamus in aging and its underlying cellular mechanisms. Mech Ageing Dev 2018; 177:74-79. [PMID: 29729230 DOI: 10.1016/j.mad.2018.04.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/20/2018] [Accepted: 04/30/2018] [Indexed: 02/06/2023]
Abstract
Aging is characterized by a progressive loss of several physiological functions that can cause various age-related disorders. Several factors have been identified as causes of aging to elucidate the decline in functions. Various aspects of physiological deterioration are controlled by the hypothalamus, a critical brain region that connects the neuroendocrine system to physiological functions. In addition, functional alterations in a set of agouti-related peptide/neuropeptide Y (AgRP/NPY) and pro-opiomelanocortin (POMC) neurons, a set of growth hormone-releasing hormone (GHRH) and somatostatin (SST) neurons, a set of arginine vasopressin (AVP) and vasoactive intestinal peptide (VIP) neurons, and a set of gonadotropin-releasing hormone (GnRH) and kisspeptin/neurokinin B/dynorphin (KNDy) neurons contribute to age-related physiological decline in energy metabolism, hormone regulation, circadian rhythm, and reproduction, respectively. The underlying cellular mechanism for the hypothalamus-mediated aging progression comprises dysregulation of nutrient sensing, altered intercellular communication, stem cell exhaustion, loss of proteostasis, and epigenetic alterations. Furthermore, mammalian target of rapamycin (mTOR), NF-kB, hypothalamic stem cell, autophagy, and SIRT1 have been recognized as critical factors or pathways mediating the mechanism. Perhaps, further dissection of these pathways or components could provide the potential for developing a therapeutic intervention for age-related diseases or the extension of healthy lifespan.
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Affiliation(s)
- Keetae Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea.
| | - Han Kyoung Choe
- Department of Brain and Cognitive Sciences, DGIST, Daegu, 42988, Republic of Korea.
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Nakao K, Iwata K, Takeshita T, Ozawa H. Expression of hypothalamic kisspeptin, neurokinin B, and dynorphin A neurons attenuates in female Zucker fatty rats. Neurosci Lett 2017; 665:135-139. [PMID: 29203206 DOI: 10.1016/j.neulet.2017.12.002] [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: 11/07/2017] [Revised: 11/25/2017] [Accepted: 12/01/2017] [Indexed: 10/18/2022]
Abstract
Zucker fatty (ZF) rats are considered to be an obese model due to leptin receptor abnormality and such rats show infertility. Pulsatile gonadotropin-releasing hormone/luteinizing hormone (LH) secretion, which is important for follicular development in females, is considered to be controlled by KNDy neurons coexpressing kisspeptin, neurokinin B (NKB), and dynorphin A (DynA), encoded by Kiss1, Tac3, and Pdyn, respectively, in the hypothalamic arcuate nucleus (ARC). The purpose of this study is to examine the expression of KNDy neurons in female ZF rats by histochemical approach because pulsatile LH secretion is suppressed. Zucker lean (ZL) rats served as a control group. Animals were ovariectomized and subcutaneously implanted with a silicon tube containing estradiol to produce plasma level of estradiol during diestrus. Plasma LH levels decreased in ZF rats compared with ZL rats. The expressions of each mRNA (Kiss1, Tac3, and Pdyn) and each peptide (kisspeptin, NKB, and DynA) in the ARC significantly decreased in ZF rats compared with ZL rats. However, the number of Kiss1 neurons in the anterior ventral periventricular nucleus did not significantly differ between the two groups. These results suggest that dysfunction of leptin signaling negatively affects KNDy neurons in the ARC, resulting in reproductive dysfunction caused by suppression of the LH pulse.
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Affiliation(s)
- Kimihiko Nakao
- Department of Reproductive Medicine, Perinatology and Gynecologic Oncology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Kinuyo Iwata
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Toshiyuki Takeshita
- Department of Reproductive Medicine, Perinatology and Gynecologic Oncology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan.
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