Morphometric and Myelin Basic Protein Expression Changes in Arcuate Nucleus Kisspeptin Neurons Underlie Activation of Hypothalamic Pituitary Gonadal-axis in Monkeys (Macaca Mulatta) during the Breeding Season.
Hira Zubair, Shazia Shamas, Hamid Ullah, Ghulam Nabi, Tanzeel Huma, Rahim Ullah, Rashad Hussain, Muhammad Shahab
{"title":"Morphometric and Myelin Basic Protein Expression Changes in Arcuate Nucleus Kisspeptin Neurons Underlie Activation of Hypothalamic Pituitary Gonadal-axis in Monkeys (<i>Macaca Mulatta</i>) during the Breeding Season.","authors":"Hira Zubair, Shazia Shamas, Hamid Ullah, Ghulam Nabi, Tanzeel Huma, Rahim Ullah, Rashad Hussain, Muhammad Shahab","doi":"10.1080/07435800.2022.2102649","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>Kisspeptin is involved in the hypothalamic pituitary gonadal-axis' seasonal regulation in rodents and sheep. Studies of kisspeptin signaling in regulating the transition between breeding and nonbreeding seasons have focused on kisspeptin expression, myelin basic protein (MBP) expression around kisspeptin-ir cells, and quantifying the synaptic connections between kisspeptin and gonadotropin-releasing hormone (GnRH) neurons in various animal models; however, the role of kisspeptin in regulating the seasonal breeding of primates has not been explored yet.</p><p><strong>Objective: </strong>This study investigated changes in kisspeptin signaling during breeding and a non-breeding season in a non-human primate model, the rhesus monkey.</p><p><strong>Methods: </strong>Three adult male monkeys (n = 3) from the breeding season and two monkeys (n = 2) from the non-breeding season were used in this study. After measuring the testicular volume and collecting a single blood sample, all animals were humanely euthanized under controlled conditions, and their hypothalami were collected and processed. Two 20 µm thick hypothalamic sections (mediobasal hypothalamus) from each animal were processed for kisspeptin-MBP and kisspeptin-GnRH immunohistochemistry (IHC). One section from each animal was used as a primary antibody omitted control to check the nonspecific binding in each IHC.</p><p><strong>Results: </strong>Compared to the non-breeding season, plasma testosterone levels and testicular volumes were significantly higher in monkeys during the breeding season. Furthermore, compared to the non-breeding season, increased kisspeptin expression and a higher number of synaptic contacts between kisspeptin fibers and GnRH cell bodies were observed in the arcuate nucleus of the breeding season monkeys. In contrast, enlarged kisspeptin soma and higher MBP expression were observed in non-breeding monkeys.</p><p><strong>Conclusion: </strong>Our results indicated enhanced kisspeptin signaling in primate hypothalamus during the breeding season. These findings support the idea that kisspeptin acts as a mediator for the seasonal regulation of the reproductive axis in higher primates.</p>","PeriodicalId":11601,"journal":{"name":"Endocrine Research","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Endocrine Research","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1080/07435800.2022.2102649","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/7/22 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 1
Abstract
Introduction: Kisspeptin is involved in the hypothalamic pituitary gonadal-axis' seasonal regulation in rodents and sheep. Studies of kisspeptin signaling in regulating the transition between breeding and nonbreeding seasons have focused on kisspeptin expression, myelin basic protein (MBP) expression around kisspeptin-ir cells, and quantifying the synaptic connections between kisspeptin and gonadotropin-releasing hormone (GnRH) neurons in various animal models; however, the role of kisspeptin in regulating the seasonal breeding of primates has not been explored yet.
Objective: This study investigated changes in kisspeptin signaling during breeding and a non-breeding season in a non-human primate model, the rhesus monkey.
Methods: Three adult male monkeys (n = 3) from the breeding season and two monkeys (n = 2) from the non-breeding season were used in this study. After measuring the testicular volume and collecting a single blood sample, all animals were humanely euthanized under controlled conditions, and their hypothalami were collected and processed. Two 20 µm thick hypothalamic sections (mediobasal hypothalamus) from each animal were processed for kisspeptin-MBP and kisspeptin-GnRH immunohistochemistry (IHC). One section from each animal was used as a primary antibody omitted control to check the nonspecific binding in each IHC.
Results: Compared to the non-breeding season, plasma testosterone levels and testicular volumes were significantly higher in monkeys during the breeding season. Furthermore, compared to the non-breeding season, increased kisspeptin expression and a higher number of synaptic contacts between kisspeptin fibers and GnRH cell bodies were observed in the arcuate nucleus of the breeding season monkeys. In contrast, enlarged kisspeptin soma and higher MBP expression were observed in non-breeding monkeys.
Conclusion: Our results indicated enhanced kisspeptin signaling in primate hypothalamus during the breeding season. These findings support the idea that kisspeptin acts as a mediator for the seasonal regulation of the reproductive axis in higher primates.
期刊介绍:
This journal publishes original articles relating to endocrinology in the broadest context. Subjects of interest include: receptors and mechanism of action of hormones, methodological advances in the detection and measurement of hormones; structure and chemical properties of hormones. Invitations to submit Brief Reviews are issued to specific authors by the Editors.