1
|
He Y, Hou J, Qiu Y, Ouyang K, Li D, Li L. Microcystin-LR immersion caused sequential endocrine disruption and growth inhibition in zebrafish (Danio rerio) from fertilization to sexual differentiation completion. Toxicology 2023:153569. [PMID: 37295766 DOI: 10.1016/j.tox.2023.153569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/03/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023]
Abstract
Microcystin-LR (MC-LR) is a highly toxic congener and is also one of the most commonly found. Recent studies have demonstrated that MC-LR can disrupt growth and endocrine in fish, but how it works at the stage of the sex differentiation period had not been determined to date. In this study, zebrafish (Danio rerio) embryos were exposed to MC-LR (0 and 10μg/L), and sampled at 14, 28, and 42 days post fertilization (dpf), respectively. The results demonstrated that MC-LR caused the growth inhibition of zebrafish at 42 dpf. The expression levels of genes related to the growth hormone/insulin-like growth factor (GH/IGF) and hypothalamic-pituitary-thyroid (HPT) axes, as well as the levels of hormone 3,5,3'- Triiodothyronine (T3) and thyroxine (T4), were significantly decreased at all time points. A Significant decrease in the ratio of testosterone and estradiol (T/E2) were detected at 28 and 42 dpf in MC-LR group along with changes in genes related to the hypothalamic-pituitary-gonadal (HPG) axis. The result of sex ratio showed that the percentage of females was up to 61.84%, indicating a estrogenic effect induced by MC-LR. The significant changes on hormone levels and gene transcripts occurred mainly in the stage of sex differentiation. The correlation analysis further suggested that key cross-talks among three endocrine axes may be the growth hormone releasing hormone (GHRH), Transthyretin (TTR) and gonadotropin releasing hormone (GnRH) signaling molecules. Overall, our findings provide a new insight for understanding the mechanisms by which MC-LR affects fish growth and reproduction during gonadal development.
Collapse
Affiliation(s)
- Ya He
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Jie Hou
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, P.R. China
| | - Yuming Qiu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Kang Ouyang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Dapeng Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R. China; Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, P.R. China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, P.R. China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, P.R. China
| | - Li Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R. China; Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, P.R. China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, P.R. China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, P.R. China.
| |
Collapse
|
2
|
Winters SJ, Moore JP. PACAP: A regulator of mammalian reproductive function. Mol Cell Endocrinol 2020; 518:110912. [PMID: 32561449 PMCID: PMC7606562 DOI: 10.1016/j.mce.2020.110912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/14/2020] [Accepted: 06/06/2020] [Indexed: 12/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an ancestral molecule that was isolated from sheep hypothalamic extracts based on its action to stimulate cAMP production by pituitary cell cultures. PACAP is one of a number of ligands that coordinate with GnRH to control reproduction. While initially viewed as a hypothalamic releasing factor, PACAP and its receptors are widely distributed, and there is growing evidence that PACAP functions as a paracrine/autocrine regulator in the CNS, pituitary, gonads and placenta, among other tissues. This review will summarize current knowledge concerning the expression and function of PACAP in the hypothalamic-pituitary-gonadal axis with special emphasis on its role in pituitary function in the fetus and newborn.
Collapse
Affiliation(s)
- Stephen J Winters
- Division of Endocrinology, Metabolism and Diabetes, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
| | - Joseph P Moore
- Division of Endocrinology, Metabolism and Diabetes, University of Louisville School of Medicine, Louisville, KY, 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| |
Collapse
|
3
|
Zhang Q, Han X, Wu H, Zhang M, Hu G, Dong Z, Yu S. Dynamic changes in CGRP, PACAP, and PACAP receptors in the trigeminovascular system of a novel repetitive electrical stimulation rat model: Relevant to migraine. Mol Pain 2019; 15:1744806918820452. [PMID: 30799680 PMCID: PMC6365643 DOI: 10.1177/1744806918820452] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Migraine is the seventh most disabling disorder globally, with prevalence
of 11.7% worldwide. One of the prevailing mechanisms is the activation
of the trigeminovascular system, and calcitonin gene-related peptide
(CGRP) is an important therapeutic target for migraine in this system.
Recent studies suggested an emerging role of pituitary adenylate
cyclase-activating peptide (PACAP) in migraine. However, the relation
between CGRP and PACAP and the role of PACAP in migraine remain
undefined. In this study, we established a novel repetitive (one,
three, and seven days) electrical stimulation model by stimulating
dura mater in conscious rats. Then, we determined expression patterns
in the trigeminal ganglion and the trigeminal nucleus caudalis of the
trigeminovascular system. Electrical stimulation decreased facial
mechanical thresholds, and the order of sensitivity was as follows:
vibrissal pad >inner canthus >outer canthus (P < 0.001). The
electrical stimulation group exhibited head-turning and head-flicks
(P < 0.05) nociceptive behaviors. Importantly, electrical
stimulation increased the expressions of CGRP, PACAP, and the
PACAP-preferring type 1 (PAC1) receptor in both trigeminal ganglion
and trigeminal nucleus caudalis (P < 0.05). The expressions of two
vasoactive intestinal peptide (VIP)-shared type 2 (VPAC1 and VPAC2)
receptors were increased in the trigeminal ganglion, whereas in the
trigeminal nucleus caudalis, their increases were peaked on Day 3 and
then decreased by Day 7. PACAP was colocalized with NEUronal Nuclei
(NeuN), PAC1, and CGRP in both trigeminal ganglion and the trigeminal
nucleus caudalis. Our results demonstrate that the repetitive
electrical stimulation model can simulate the allodynia during the
migraine chronification, and PACAP plays a role in the pathogenesis of
migraine potentially via PAC1 receptor.
Collapse
Affiliation(s)
- Qing Zhang
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China.,2 Townsend Family Laboratories, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xun Han
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| | - Hangfei Wu
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| | - Mingjie Zhang
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| | - Guanqun Hu
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| | - Zhao Dong
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| | - Shengyuan Yu
- 1 Department of Neurology, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
4
|
Tumurbaatar T, Kanasaki H, Oride A, Okada H, Hara T, Tumurgan Z, Kyo S. Effect of pituitary adenylate cyclase-activating polypeptide (PACAP) in the regulation of hypothalamic kisspeptin expression. Gen Comp Endocrinol 2019; 270:60-66. [PMID: 30316762 DOI: 10.1016/j.ygcen.2018.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/20/2018] [Accepted: 10/09/2018] [Indexed: 10/28/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor are broadly distributed in the brain, and PACAP is known to work as a multifunctional peptide. However, it is still largely unknown how PACAP affects the hypothalamic-pituitary-gonadal (HPG) axis. In this study, we examined the effect of PACAP on hypothalamic kisspeptin expression, a known regulator of gonadotropin-releasing hormone. We used two hypothalamic cell models, mHypoA-50 and mHypoA-55, which were originated from kisspeptin-expressing neuron in anterioventral periventricular nucleus and arcuate nucleus regions in the hypothalamus, respectively. Expression of Kiss-1 gene, which encodes kisspeptin, was significantly increased by PACAP stimulation in both mHypoA-50 and mHypoA-55 cells, by up to 2.69 ± 0.93-fold and 4.89 ± 1.13-fold, respectively. PACAP6-38, a PACAP receptor antagonist did not antagonize the action of PACAP on Kiss-1 gene expression but increased Kiss-1 gene by itself in these cells. PACAP-induced Kiss-1 gene expression in both mHypoA-50 and mHypoA-55 cells was almost completely prevented in the presence of H89, a protein kinase A inhibitor. PACAP was expressed in both these hypothalamic cell models and its expression was up-regulated by estradiol in mHypoA-50 cells but not in mHypoA-55 cells. Stimulation of mHypoA-50 and mHypoA-55 cells with PACAP increased the expression levels of corticotropin-releasing hormone and neurotensin, both of which could modulate HPG axis. Our present observations suggest that hypothalamic PACAP might modulate the HPG axis by directly or indirectly modulating Kiss-1 gene expression.
Collapse
Affiliation(s)
- Tuvshintugs Tumurbaatar
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Haruhiko Kanasaki
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan.
| | - Aki Oride
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Hiroe Okada
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Tomomi Hara
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Zolzaya Tumurgan
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Satoru Kyo
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| |
Collapse
|
5
|
Oride A, Kanasaki H, Kyo S. Role of pituitary adenylate cyclase-activating polypeptide in modulating hypothalamic-pituitary system. Reprod Med Biol 2018; 17:234-241. [PMID: 30013423 PMCID: PMC6046521 DOI: 10.1002/rmb2.12094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 02/01/2018] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional peptide that is isolated and identified from the ovine hypothalamus, whose effects and mechanisms have been elucidated in numerous studies. The PACAP and its receptor are widely expressed, not only in the hypothalamus but also in peripheral organs. METHODS The studies on the role of PACAP in the hypothalamic-pituitary system, including those by the authors, were summarized. RESULTS In the pituitary gonadotrophs, PACAP increases the gonadotrophin α-, luteinizing hormoneβ-, and follicle-stimulating hormone β-subunit expression and the expression of gonadotropin-releasing hormone (GnRH) receptor and its own receptor, PAC1R. Moreover, a low-frequency GnRH pulse increases the expression of PACAP and PAC1R more than a high-frequency GnRH pulse in the gonadotrophs. The PACAP stimulates prolactin synthesis and secretion and increases PAC1R in the lactotrophs. In the hypothalamus, PACAP increases the expression of the GnRH receptors, although it is unable to increase the expression of GnRH in the GnRH-producing neurons. CONCLUSION The PACAP not only acts directly in each hormone-producing cell, it possibly might regulate hormone synthesis via the expression of its own receptors or those of other hormones.
Collapse
Affiliation(s)
- Aki Oride
- Department of Obstetrics and GynecologyFaculty of MedicineShimane UniversityIzumo CityJapan
| | - Haruhiko Kanasaki
- Department of Obstetrics and GynecologyFaculty of MedicineShimane UniversityIzumo CityJapan
| | - Satoru Kyo
- Department of Obstetrics and GynecologyFaculty of MedicineShimane UniversityIzumo CityJapan
| |
Collapse
|
6
|
Kanasaki H, Oride A, Mijiddorj T, Sukhbaatar U, Kyo S. How is GnRH regulated in GnRH-producing neurons? Studies using GT1-7 cells as a GnRH-producing cell model. Gen Comp Endocrinol 2017; 247:138-142. [PMID: 28131616 DOI: 10.1016/j.ygcen.2017.01.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/05/2017] [Accepted: 01/23/2017] [Indexed: 12/24/2022]
Abstract
Hypothalamic secretion of gonadotropin-releasing hormone (GnRH) has been established as a principle pathway for initiating and integrating female reproductive function. GnRH stimulates the release of two gonadotropins-luteinizing hormone and follicle-stimulating hormone-from the anterior pituitary, which eventually stimulate the synthesis of sex steroids in association with follicular growth and ovulation. This reproductive control of the hypothalamic-pituitary-gonadal (HPG) axis also mediates gonadal feedback mechanisms. Although GnRH neurons certainly play a pivotal role in the HPG axis, the detailed mechanisms of their functional network, including regulatory systems, remain unknown. After the discovery of the indispensable role of kisspeptin in the development of human reproductive functions, our understanding of the neuroendocrine regulation of the HPG axis was revolutionized, and it is now recognized that kisspeptin acts upstream of GnRH and is responsible for sex steroid feedback mechanisms. Kisspeptin can stimulate gonadotropin release from the pituitary gland by stimulating GnRH release and GnRH antagonists prevent kisspeptin-induced gonadotropin release. Furthermore, it has been shown that GnRH neurons express kisspeptin receptors. Nevertheless, the detailed mechanisms underlying the regulation of homogeneous populations of GnRH neurons are still largely unknown because of the limitations of experimental models used for investigation. The hypothalamus consists of a complex network of distinct neuronal cells, and it is difficult to isolate single-cell populations of GnRH neurons. The establishment of GnRH-expressing cell lines has allowed us to examine the events happening at the single-cell level. In this review, we describe in vitro studies using a GnRH-producing cell model, GT1-7 cells, which have been used to examine how GnRH-producing cells respond to hypothalamic factors and how they are involved in GnRH synthesis.
Collapse
Affiliation(s)
- Haruhiko Kanasaki
- Department of Obstetrics and Gynecology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan.
| | - Aki Oride
- Department of Obstetrics and Gynecology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan
| | - Tselmeg Mijiddorj
- Department of Obstetrics and Gynecology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan
| | - Unurjargal Sukhbaatar
- Department of Obstetrics and Gynecology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan
| | - Satoru Kyo
- Department of Obstetrics and Gynecology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan
| |
Collapse
|
7
|
Song H, Wang M, Wang Z, Liu J, Qi J, Zhang Q. Characterization of kiss2 and kissr2 genes and the regulation of kisspeptin on the HPG axis in Cynoglossus semilaevis. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:731-753. [PMID: 28120214 DOI: 10.1007/s10695-016-0328-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/11/2016] [Indexed: 06/06/2023]
Abstract
Reproduction allows organisms to produce offspring. Animals shift from immature juveniles into mature adults and become capable of sexual reproduction during puberty, which culminates in the first spermiation and sperm hydration or ovulation. Reproduction is closely related to the precise control of the hypothalamic-pituitary-gonadal (HPG) axis. Kisspeptin peptides are considered as the important regulator of HPG axis in mammalian. However, the current understanding of kisspeptin in flatfish is not comprehensive. In this study, we cloned and analyzed the kiss2 and kissr2 genes in Cynoglossus semilaevis. Interesting alternative splicing in the 5'-untranslated regions (UTR) of the Cskissr2 gene was found. The expression profiles of Cskiss2 and Cskissr2 showed relative high messenger RNA (mRNA) levels at the late gastrula stage during embryonic development, at total length = 40 mm during early gonadal differentiation, and in the brains and gonads of all investigated tissues. These results suggested that the kisspeptin system participated in embryogenesis and in the regulation of gonadal differentiation and development. Considering that the control and regulatory mechanisms of kisspeptin in the central reproductive axis are still unclear, we documented that the intramuscular injection of kisspeptin caused different sGnRH and cGnRH mRNA levels in a dose- and tissue-dependent manner. The mRNA expressions of FSH and LH were stimulated in the ovary and were inhibited in the testis under the kisspeptin treatments. These results provided foundations for understanding the roles of kisspeptin in the neuroendocrine system in fish. The manipulation of the kisspeptin system may provide new opportunities to control the gonadal development and even reproduction in fish.
Collapse
Affiliation(s)
- Huayu Song
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Mengxun Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Zhongkai Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Jinxiang Liu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Jie Qi
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Quanqi Zhang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, People's Republic of China.
| |
Collapse
|
8
|
Role of PACAP and Its PACAP Type I Receptor in the Central Control of Reproductive Hormones. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/978-3-319-35135-3_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
|
9
|
Interactions between Two Different G Protein-Coupled Receptors in Reproductive Hormone-Producing Cells: The Role of PACAP and Its Receptor PAC1R. Int J Mol Sci 2016; 17:ijms17101635. [PMID: 27681724 PMCID: PMC5085668 DOI: 10.3390/ijms17101635] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/10/2016] [Accepted: 09/19/2016] [Indexed: 12/22/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) and gonadotropins are indispensable hormones for maintaining female reproductive functions. In a similar manner to other endocrine hormones, GnRH and gonadotropins are controlled by their principle regulators. Although it has been previously established that GnRH regulates the synthesis and secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—both gonadotropins—from pituitary gonadotrophs, it has recently become clear that hypothalamic GnRH is under the control of hypothalamic kisspeptin. Prolactin, which is also known as luteotropic hormone and is released from pituitary lactotrophs, stimulates milk production in mammals. Prolactin is also regulated by hypothalamic factors, and it is thought that prolactin synthesis and release are principally under inhibitory control by dopamine through the dopamine D2 receptor. In addition, although it remains unknown whether it is a physiological regulator, thyrotropin-releasing hormone (TRH) is a strong secretagogue for prolactin. Thus, GnRH, LH and FSH, and prolactin are mainly regulated by hypothalamic kisspeptin, GnRH, and TRH, respectively. However, the synthesis and release of these hormones is also modulated by other neuropeptides in the hypothalamus. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a hypothalamic peptide that was first isolated from sheep hypothalamic extracts based on its ability to stimulate cAMP production in anterior pituitary cells. PACAP acts on GnRH neurons and pituitary gonadotrophs and lactotrophs, resulting in the modulation of their hormone producing/secreting functions. Furthermore, the presence of the PACAP type 1 receptor (PAC1R) has been demonstrated in these cells. We have examined how PACAP and PAC1R affect GnRH- and pituitary hormone-secreting cells and interact with their principle regulators. In this review, we describe our understanding of the role of PACAP and PAC1R in the regulation of GnRH neurons, gonadotrophs, and lactotrophs, which are regulated mainly by kisspeptin, GnRH, and TRH, respectively.
Collapse
|
10
|
Oride A, Kanasaki H, Mijiddorj T, Sukhbaatar U, Yamada T, Kyo S. Expression and Regulation of Pituitary Adenylate Cyclase-Activating Polypeptide in Rat Placental Cells. Reprod Sci 2016; 23:1080-6. [PMID: 26880766 DOI: 10.1177/1933719116630421] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) was first identified as a hypophysiotropic factor that regulates pituitary cell functions and has been subsequently shown to be widely distributed and have multiple functions. The PACAP is known to be expressed in placental tissues and is suggested to have a critical role in physiological function of the placenta. In addition to PACAP, the hypothalamic peptides kisspeptin and gonadotropin-releasing hormone (GnRH) are also expressed in placental cells. In this study, we used primary cultures of placental tissues from rats of 16 to 18 days gestation and examined the regulation and function of PACAP. The PACAP messenger RNA (mRNA) expression and PACAP-immunoreactive cells were detected in primary cultures of rat placental cells. The PACAP mRNA expression in placental cells was upregulated in the presence of the sex steroids estradiol and progesterone; however, their combined treatment failed to enhance their individual effects. When the cells were stimulated with kisspeptin, PACAP mRNA expression was increased. Similarly, GnRH had a stimulatory effect on PACAP expression. Conversely, kisspeptin expression in placental cells was increased by PACAP stimulation, whereas PACAP failed to stimulate GnRH mRNA expression in these cells. Finally, we found that PACAP had a stimulatory effect on human chorionic gonadotropin expression in placental cells. Our current observations suggest that the hypothalamic peptides PACAP, kisspeptin, and GnRH are interrelated and maintain placental functions.
Collapse
Affiliation(s)
- Aki Oride
- Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, Shimane, Japan
| | - Haruhiko Kanasaki
- Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, Shimane, Japan
| | - Tselmeg Mijiddorj
- Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, Shimane, Japan
| | - Unurjargal Sukhbaatar
- Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, Shimane, Japan
| | - Takaya Yamada
- Department of Experimental Animals, Interdisciplinary Center for Science Research, Organization for Research, Shimane University, Shimane, Japan
| | - Satoru Kyo
- Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, Shimane, Japan
| |
Collapse
|
11
|
Nakajima KI, Cui Z, Li C, Meister J, Cui Y, Fu O, Smith AS, Jain S, Lowell BB, Krashes MJ, Wess J. Gs-coupled GPCR signalling in AgRP neurons triggers sustained increase in food intake. Nat Commun 2016; 7:10268. [PMID: 26743492 PMCID: PMC4729878 DOI: 10.1038/ncomms10268] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 11/24/2015] [Indexed: 01/06/2023] Open
Abstract
Agouti-related peptide (AgRP) neurons of the hypothalamus play a key role in regulating food intake and body weight, by releasing three different orexigenic molecules: AgRP; GABA; and neuropeptide Y. AgRP neurons express various G protein-coupled receptors (GPCRs) with different coupling properties, including Gs-linked GPCRs. At present, the potential role of Gs-coupled GPCRs in regulating the activity of AgRP neurons remains unknown. Here we show that the activation of Gs-coupled receptors expressed by AgRP neurons leads to a robust and sustained increase in food intake. We also provide detailed mechanistic data linking the stimulation of this class of receptors to the observed feeding phenotype. Moreover, we show that this pathway is clearly distinct from other GPCR signalling cascades that are operative in AgRP neurons. Our data suggest that drugs able to inhibit this signalling pathway may become useful for the treatment of obesity. Hypothalamic Agouti-related peptide (AgRP) neurons play a key role in regulating food intake. Here, the authors report a novel pathway in which activation of Gs-coupled receptors on AgRP neurons leads to robust, sustained increase in food intake.
Collapse
Affiliation(s)
- Ken-ichiro Nakajima
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Zhenzhong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Chia Li
- Diabetes Endocrine and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Ou Fu
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 1138657, Japan
| | - Adam S Smith
- Section on Neural Gene Expression, National Institute of Mental Health, Bethesda, Maryland 20892, USA
| | - Shalini Jain
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Bradford B Lowell
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Michael J Krashes
- Diabetes Endocrine and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
| |
Collapse
|
12
|
Sukhbaatar U, Mijiddorj T, Oride A, Kanasaki H. Stimulation of δ subunit-containing GABAA receptor by DS1 increases GnRH receptor expression but reduces GnRH mRNA expression in GnRH-producing GT1-7 cells. Endocrine 2015; 49:222-30. [PMID: 25355308 DOI: 10.1007/s12020-014-0464-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 10/23/2014] [Indexed: 12/23/2022]
Abstract
Acting via ionotropic GABAA receptors, the neurotransmitter γ-aminobutyric acid (GABA) is an important modulator of gonadotropin-releasing hormone (GnRH) neurons. In the present study, we examined the effect of DS1, a GABAA α4β3δ receptor agonist, on a strain of mouse hypothalamic immortalized GnRH neuronal cells, the GT1-7 cell line. DS1 increased the activities of serum-response element (SRE) and cAMP-response element (CRE) promoters, which reflect the activities of extracellular signal-regulated kinase and cAMP/protein kinase A (PKA) pathways, respectively. In G protein-coupled receptor 54 (GPR54)-overexpressing GT1-7 cells, both DS1 and kisspeptin-10 stimulated SRE promoter activity, and combined treatment with DS1 and kisspeptin further increased SRE promoter activity compared with DS1 or kisspeptin alone. Pituitary adenylate cyclase-activating polypeptide (PACAP) increased CRE promoter activity in PACAP type I receptor-overexpressing GT1-7 cells, with an effect similar to that of DS1 alone, and combined stimulation with PACAP and DS1 potentiated their individual effects. DS1 stimulated the transcriptional activity of GnRH receptor, and DS1 induced GnRH receptor mRNA and protein expression. PACAP-increased GnRH receptor expression was enhanced in the presence of DS1. However, DS1 significantly inhibited the basal expression of GnRH mRNA in GT1-7 cells. Our current observations suggest that DS1 exerts its stimulatory effect on the intracellular signal transduction system via GABAA α4β3δ receptors in GnRH-producing neurons. Stimulation with DS1 increased the expression of GnRH receptor but decreased the basal expression of GnRH mRNA.
Collapse
Affiliation(s)
- Unurjargal Sukhbaatar
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, 89-1 Enya, Izumo City, Shimane Prefecture, 693-8501, Japan
| | | | | | | |
Collapse
|
13
|
Kanasaki H, Oride A, Kyo S. Role of pituitary adenylate cyclase-activating polypeptide in modulating hypothalamus-pituitary neuroendocrine functions in mouse cell models. J Neuroendocrinol 2015; 27:1-7. [PMID: 25303162 DOI: 10.1111/jne.12230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 09/10/2014] [Accepted: 10/03/2014] [Indexed: 12/15/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) was originally identified as a hypothalamic activator of cyclic adenosine monophosphate production in pituitary cells. PACAP and its receptor are expressed not only in the central nervous system, but also in peripheral organs, and function to stimulate pituitary hormone synthesis and secretion as both a hypothalamic-pituitary-releasing factor and an autocrine-paracrine factor within the pituitary. PACAP stimulates the expression of the gonadotrophin α, luteinising hormone (LH) β and follicle-stimulating hormone (FSH) β subunits, as well as the gonadotrophin-releasing hormone (GnRH) receptor and its own PACAP type I receptor (PAC1R) in gonadotrophin-secreting pituitary cells. In turn, GnRH, which is known to be a crucial component of gonadotrophin secretion, stimulates the expression of PACAP and PAC1R in gonadotrophs. In addition, PAC1R and PACAP modulate the functions of GnRH-producing neurones in the hypothalamus. This review summarises the current understanding of the possible roles of PACAP and PAC1R in modulating hypothalamus and pituitary neuroendocrine cells in the mouse models.
Collapse
Affiliation(s)
- H Kanasaki
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo, Japan
| | | | | |
Collapse
|