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Soejima Y, Iwata N, Yamamoto K, Suyama A, Nakano Y, Otsuka F. Mutual Effects of Orexin and Bone Morphogenetic Proteins on Catecholamine Regulation Using Adrenomedullary Cells. Int J Mol Sci 2024; 25:1585. [PMID: 38338864 PMCID: PMC10855520 DOI: 10.3390/ijms25031585] [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: 12/22/2023] [Revised: 01/15/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Orexins are neuronal peptides that play a prominent role in sleep behavior and feeding behavior in the central nervous system, though their receptors also exist in peripheral organs, including the adrenal gland. In this study, the effects of orexins on catecholamine synthesis in the rat adrenomedullary cell line PC12 were investigated by focusing on their interaction with the adrenomedullary bone morphogenetic protein (BMP)-4. Orexin A treatment reduced the mRNA levels of key enzymes for catecholamine synthesis, including tyrosine hydroxylase (Th), 3,4-dihydroxyphenylalanie decarboxylase (Ddc) and dopamine β-hydroxylase (Dbh), in a concentration-dependent manner. On the other hand, treatment with BMP-4 suppressed the expression of Th and Ddc but enhanced that of Dbh with or without co-treatment with orexin A. Of note, orexin A augmented BMP-receptor signaling detected by the phosphorylation of Smad1/5/9 through the suppression of inhibitory Smad6/7 and the upregulation of BMP type-II receptor (BMPRII). Furthermore, treatment with BMP-4 upregulated the mRNA levels of OX1R in PC12 cells. Collectively, the results indicate that orexin and BMP-4 suppress adrenomedullary catecholamine synthesis by mutually upregulating the pathway of each other in adrenomedullary cells.
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Affiliation(s)
| | | | | | | | | | - Fumio Otsuka
- Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan; (Y.S.); (A.S.); (Y.N.)
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2
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Soejima Y, Iwata N, Nishioka R, Honda M, Nakano Y, Yamamoto K, Suyama A, Otsuka F. Interaction of Orexin and Bone Morphogenetic Proteins in Steroidogenesis by Human Adrenocortical Cells. Int J Mol Sci 2023; 24:12559. [PMID: 37628739 PMCID: PMC10454954 DOI: 10.3390/ijms241612559] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Orexins are neuropeptides that play important roles in sleep-wake regulation and food intake in the central nervous system, but their receptors are also expressed in peripheral tissues, including the endocrine system. In the present study, we investigated the functions of orexin in adrenal steroidogenesis using human adrenocortical H295R cells by focusing on its interaction with adrenocortical bone morphogenetic proteins (BMPs) that induce adrenocortical steroidogenesis. Treatment with orexin A increased the mRNA levels of steroidogenic enzymes including StAR, CYP11B2, CYP17, and HSD3B1, and these effects of orexin A were further enhanced in the presence of forskolin. Interestingly, orexin A treatment suppressed the BMP-receptor signaling detected by Smad1/5/9 phosphorylation and Id-1 expression through upregulation of inhibitory Smad7. Orexin A also suppressed endogenous BMP-6 expression but increased the expression of the type-II receptor of ActRII in H295R cells. Moreover, treatment with BMP-6 downregulated the mRNA level of OX1R, but not that of OX2R, expressed in H295R cells. In conclusion, the results indicate that both orexin and BMP-6 accelerate adrenocortical steroidogenesis in human adrenocortical cells; both pathways mutually inhibit each other, thereby leading to a fine-tuning of adrenocortical steroidogenesis.
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Affiliation(s)
| | | | | | | | | | | | | | - Fumio Otsuka
- Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan (A.S.)
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Chatterjee O, Gopalakrishnan L, Pullimamidi D, Raj C, Yelamanchi S, Gangadharappa BS, Nair B, Mahadevan A, Raju R, Keshava Prasad TS. A molecular network map of orexin-orexin receptor signaling system. J Cell Commun Signal 2023; 17:217-227. [PMID: 36480100 PMCID: PMC10030760 DOI: 10.1007/s12079-022-00700-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/04/2022] [Accepted: 09/15/2022] [Indexed: 12/13/2022] Open
Abstract
Orexins are excitatory neuropeptides, which are predominantly associated with feeding behavior, sleep-wake cycle and energy homeostasis. The orexinergic system comprises of HCRTR1 and HCRTR2, G-protein-coupled receptors of rhodopsin family and the endogenous ligands processed from HCRT pro-hormone, Orexin A and Orexin B. These neuropeptides are biosynthesized by the orexin neurons present in the lateral hypothalamus area, with dense projections to other brain regions. The orexin-receptor signaling is implicated in various metabolic as well as neurological disorders, making it a promising target for pharmacological interventions. However, there is limited information available on the collective representation of the signal transduction pathways pertaining to the orexin-orexin receptor signaling system. Here, we depict a compendium of the Orexin A/B stimulated reactions in the form of a basic signaling pathway map. This map catalogs the reactions into five categories: molecular association, activation/inhibition, catalysis, transport, and gene regulation. A total of 318 downstream molecules were annotated adhering to the guidelines of NetPath curation. This pathway map can be utilized for further assessment of signaling events associated with orexin-mediated physiological functions and is freely available on WikiPathways, an open-source pathway database ( https://www.wikipathways.org/index.php/Pathway:WP5094 ).
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Affiliation(s)
- Oishi Chatterjee
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, 690 525, Kollam, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India
| | - Lathika Gopalakrishnan
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India
- Manipal Academy of Higher Education (MAHE), 576 104, Manipal, India
| | | | - Chinmayi Raj
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
| | - Soujanya Yelamanchi
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
| | | | - Bipin Nair
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, 690 525, Kollam, India
| | - Anita Mahadevan
- Human Brain Tissue Repository, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, 560 029, Bangalore, India
- Department of Neuropathology, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, 560 029, Bangalore, India
| | - Rajesh Raju
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India.
| | - T S Keshava Prasad
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India.
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4
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Razavinia F, Tehranian N, Sadatmahalleh SJ, Kazemnejad A, Khajetash S, Daryasari SRF, Pahlavan F, Jahanfar S. The influence of mode of delivery, anthropometric indices, and infant's sex on the maternal and cord blood orexin-A levels: A cohort study. J Obstet Gynaecol Res 2021; 47:2363-2370. [PMID: 33870593 DOI: 10.1111/jog.14758] [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: 12/08/2020] [Revised: 02/17/2021] [Accepted: 03/10/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Orexin as an adipokin hormone plays an important role in appetite regulation, energy metabolism, obesity, diabetes, and cardiovascular disease. The main source of orexin secretion in nonpregnant and pregnant women is adipose tissue and placenta, respectively. This research was conducted to evaluate the association between orexin-A level and the mode of delivery, anthropometric indices, and sex of the infant. METHODS This prospective cohort study was conducted on 69 normal pregnant women. The samples of umbilical cord blood were obtained at the time of delivery, and maternal blood was taken within 24 h of delivery. Serum orexin-A levels were measured by using enzyme-linked immunosorbent assay. Statistical analyses were performed using SPSS and p < 0.05 was considered as significant. RESULTS We found a significant difference between postpartum maternal and umbilical cord orexin-A level both with the mode of delivery (p < 0.001). Also, a significant positive correlation was seen between maternal and umbilical cord serum orexin-A levels (r = -0.61, p < 0.001). There was no relationship between serum orexin-A levels with anthropometric indices and the sex of the neonate (p > 0.05). CONCLUSION Both maternal and umbilical cord serum orexin-A levels were associated with the mode of delivery. Maternal and cord blood orexin-A levels in normal vaginal delivery are higher than cesarean section.
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Affiliation(s)
- Fatemeh Razavinia
- Department of Reproductive Health and Midwifery, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Najmeh Tehranian
- Department of Reproductive Health and Midwifery, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | - Anoshirvan Kazemnejad
- Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shaghayegh Khajetash
- Counseling in Midwifery, Research Committee, School of Nursing and Midwifery Nasibeh, Sari, Iran
| | | | - Fattaneh Pahlavan
- Department of Reproductive Health and Midwifery, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shayesteh Jahanfar
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, Massachusetts, USA
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Kisielewska K, Rytelewska E, Gudelska M, Kiezun M, Dobrzyn K, Szeszko K, Bors K, Wyrebek J, Kaminski T, Smolinska N. The effect of orexin B on steroidogenic acute regulatory protein, P450 side-chain cleavage enzyme, and 3β-hydroxysteroid dehydrogenase gene expression, and progesterone and androstenedione secretion by the porcine uterus during early pregnancy and the estrous cycle. J Anim Sci 2019; 97:851-864. [PMID: 30508170 DOI: 10.1093/jas/sky458] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/29/2018] [Indexed: 01/21/2023] Open
Abstract
The aim of this study was to investigate the effect of orexin B (OXB) on progesterone (P4) and androstenedione (A4) secretion by porcine endometrial and myometrial tissue explants and on the expression of key steroidogenic proteins and enzymes involved in steroid production. The hormones secretion and the expression of steroidogenic acute regulatory protein (StAR), P450 side-chain cleavage enzyme (CYP11A1), and 3β-hydroxysteroid dehydrogenase (HSD3B1) were analyzed on days 10 to 11, 12 to 13, 15 to 16, and 27 to 28 of pregnancy and during the luteal phase of the estrous cycle (days 10 to 11). Endometrial and myometrial explants were cultured in vitro in the presence of OXB (1, 10, or 100 nM) and OXB (1, 10, or 100 nM) with 1 µM of JNJ (OX2R antagonist). Gene expression was examined by real-time PCR, and steroid secretion was determined by radioimmunoassay. Orexin B modulated StAR, CYP11A1, HSD3B1 mRNA content depending on the type of uterine tissue, the applied OXB dose, and the stage of pregnancy or the estrous cycle (P < 0.05). Orexin B increased P4 secretion in all stages of early gestation (P < 0.05). Orexin B enhanced the release of A4 on days 12 to 13, 15 to 16, and 27 to 28 of gestation, whereas on days 10 to 11 of early pregnancy, A4 secretion decreased in the endometrium and increased in the myometrium (P < 0.05). These results indicate that OXB affects the expression of key steroidogenic regulators and the secretion of steroid hormones in the porcine uterus during early pregnancy.
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Affiliation(s)
- Katarzyna Kisielewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Edyta Rytelewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Marlena Gudelska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Kamil Dobrzyn
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Karol Szeszko
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Kinga Bors
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Joanna Wyrebek
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Tadeusz Kaminski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Nina Smolinska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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6
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Effect of orexin B on CYP17A1 and CYP19A3 expression and oestradiol, oestrone and testosterone secretion in the porcine uterus during early pregnancy and the oestrous cycle. Animal 2018; 12:1921-1932. [PMID: 29366436 DOI: 10.1017/s1751731117003779] [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] [Indexed: 11/06/2022] Open
Abstract
Orexin A (OXA) and B (OXB) are hypothalamic neuropeptides identified as regulators of food intake, energy homoeostasis, sleep-wake cycle and arousal. They also create an integrative link between energy homoeostasis and reproduction. Although their functions in the ovaries and testes have been partially explored, to date, less attention has been focused on the role of the peptides in the uterus. The aim of this study was to investigate the effect of one of orexins - orexin B on oestradiol (E2), oestrone (E1) and testosterone (T) secretion by porcine endometrial and myometrial slices as well as the gene expression of key steroidogenic enzymes responsible for steroid production (CYP17A1, CYP19A3) during the luteal phase of the oestrous cycle (days 10 to 11) and early pregnancy (days 10 to 11, 12 to 13, 15 to 16, 27 to 28). Orexin B suppressed E2 secretion by endometrial slices on days 10 to 11 and 15 to 16 of pregnancy, and days 10 to 11 of the cycle. In the myometrium, OXB inhibited E2 production on days 10 to 11 of pregnancy, whereas on days 12 to 13 it enhanced steroid output. Endometrial E1 release was potentiated by the peptide during all studied periods of the cycle and pregnancy, with the exception of days 12 to 13, when an inhibitory effect was observed. Myometrial secretion of E1 was increased, except on days 27 to 28. Testosterone secretion by endometrial slices was increased on days 12 to 13 and 27 to 28 of pregnancy. On days 10 to 11 of the cycle, T release was stimulated in response to the lowest and decreased under the influence of the highest dose of OXB. In the myometrium, T production was inhibited by OXB on days 10 to 11 of pregnancy and during the corresponding period of the cycle. On days 27 to 28 of pregnancy, T release was potentiated by the lowest dose of OXB. Expression of both genes was modified by OXB depending on the period of pregnancy and the type of examined uterine tissues. Our findings suggest that OXB, through modulation of uterine steroidogenesis, may have a regulatory role in the uterus.
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Koesema E, Kodadek T. Global analysis of gene expression mediated by OX1 orexin receptor signaling in a hypothalamic cell line. PLoS One 2017; 12:e0188082. [PMID: 29145494 PMCID: PMC5690679 DOI: 10.1371/journal.pone.0188082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 10/31/2017] [Indexed: 01/23/2023] Open
Abstract
The orexins and their cognate G-protein coupled receptors have been widely studied due to their associations with various behaviors and cellular processes. However, the detailed downstream signaling cascades that mediate these effects are not completely understood. We report the generation of a neuronal model cell line that stably expresses the OX1 orexin receptor (OX1) and an RNA-Seq analysis of changes in gene expression seen upon receptor activation. Upon treatment with orexin, several families of related transcription factors are transcriptionally regulated, including the early growth response genes (Egr), the Kruppel-like factors (Klf), and the Nr4a subgroup of nuclear hormone receptors. Furthermore, some of the transcriptional effects observed have also been seen in data from in vivo sleep deprivation microarray studies, supporting the physiological relevance of the data set. Additionally, inhibition of one of the most highly regulated genes, serum and glucocorticoid-regulated kinase 1 (Sgk1), resulted in the diminished orexin-dependent induction of a subset of genes. These results provide new insight into the molecular signaling events that occur during OX1 signaling and support a role for orexin signaling in the stimulation of wakefulness during sleep deprivation studies.
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Affiliation(s)
- Eric Koesema
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, FL, United States of America
| | - Thomas Kodadek
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, FL, United States of America
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8
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Liguori G, Squillacioti C, Assisi L, Mirabella N, Langella E, Costagliola A, Vittoria A. Localization of orexin B and receptor 2 for orexins in testicular cytotypes of the camelid alpaca (Vicugna pacos
). Reprod Domest Anim 2017; 52:452-458. [DOI: 10.1111/rda.12931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/21/2016] [Indexed: 11/26/2022]
Affiliation(s)
- G Liguori
- Department of Veterinary Medicine and Animal Productions; University of Naples Federico II; Naples Italy
| | - C Squillacioti
- Department of Veterinary Medicine and Animal Productions; University of Naples Federico II; Naples Italy
| | - L Assisi
- Department of Biology; University of Naples Federico II; Naples Italy
| | - N Mirabella
- Department of Veterinary Medicine and Animal Productions; University of Naples Federico II; Naples Italy
| | - E Langella
- School of Agricultural, Forestry, Food and Environmental Sciences; University of Basilicata; Potenza Italy
| | - A Costagliola
- Department of Veterinary Medicine and Animal Productions; University of Naples Federico II; Naples Italy
| | - A Vittoria
- Department of Veterinary Medicine and Animal Productions; University of Naples Federico II; Naples Italy
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Czerwinska J, Chojnowska K, Kaminski T, Bogacka I, Smolinska N, Kaminska B. Orexin receptor expression in the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes of free-living European beavers (Castor fiber L.) in different periods of the reproductive cycle. Gen Comp Endocrinol 2017; 240:103-113. [PMID: 27664717 DOI: 10.1016/j.ygcen.2016.09.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/07/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023]
Abstract
Orexins are hypothalamic neuropeptides acting via two G protein-coupled receptors in mammals: orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R). In European beavers, which are seasonally breeding animals, the presence and functions of orexins and their receptors remain unknown. Our study aimed to determine the expression of OXR mRNAs and the localization of OXR proteins in hypothalamic-pituitary-adrenal/gonadal (HPA/HPG) axes in free-living beavers. The expression of OXR genes (OX1R, OX2R) and proteins was found in all analysed tissues during three periods of beavers' reproductive cycle (April, July, November). The expression of OXR mRNAs in the beaver HPA axis varied seasonally (P<0.05). The levels of OX1R mRNA also differed between the sexes (P<0.05). In the mediobasal hypothalamus, OX1R transcript content increased in pregnant females in April (P<0.05) and OX2R expression increased in males in July (P<0.05). In the pituitary and adrenals, OX1R mRNA levels were relatively constant in females and peaked in July in males (P<0.05), whereas the OX2R was most highly expressed in males in November and in females in April (P<0.05). In gonads, OX1R expression did not fluctuate between seasons or sexes, but transcript levels were elevated in the testes in November and in the ovaries in July (P<0.05). In turn, OX2R mRNA levels varied between the sexes (P<0.05) and were higher in females (July and November) than in males (P<0.05). The circannual variations in OXR mRNA levels in HPA and HPG axes suggest that the expression of these receptors is associated with sex-specific changes in beavers' reproductive activity and their environmental adaptations.
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Affiliation(s)
- Joanna Czerwinska
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland.
| | - Katarzyna Chojnowska
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland
| | - Tadeusz Kaminski
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland
| | - Iwona Bogacka
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland
| | - Nina Smolinska
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland
| | - Barbara Kaminska
- University of Warmia and Mazury in Olsztyn, Faculty of Biology and Biotechnology, Department of Animal Physiology, Oczapowskiego 1A Street, 10-719 Olsztyn, Poland
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10
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Chang X, Zhao Y, Ju S, Guo L. Orexin-A stimulates 3β-hydroxysteroid dehydrogenase expression and cortisol production in H295R human adrenocortical cells through the AKT pathway. Int J Mol Med 2014; 34:1523-8. [PMID: 25319929 DOI: 10.3892/ijmm.2014.1959] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 09/23/2014] [Indexed: 11/05/2022] Open
Abstract
Orexin-A is a regulatory peptide involved in the regulation of food intake, sleep-wakefulness, and it has various endocrine and metabolic functions. It orchestrates diverse central and peripheral processes through the stimulation of two G-protein coupled receptors, orexin receptor type 1 (OX1 receptor) and orexin receptor type 2 (OX2 receptor). In this study, human adrenocortical cells (NCI-H295R cells) were incubated with various concentrations of orexin-A (10-10 to 10-6 M) in vitro, and the mRNA and protein expression of OX1 receptor was determined in the cells. In addition, NCI-H295R cells treated with 10-6 M orexin-A were then treated with or without OX1 receptor specific antagonist (SB334867), AKT antagonist (PF-04691502), or a combination of both. Subsequently, cell proliferation, the cortisol content in the medium and the mRNA and protein expression expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) were analyzed. The activity of the AKT signaling pathway was also determined in the NCI-H295R cells. We observed that the increase in the mRNA and protein expression of OX1 receptor was orexin-A concentration-dependent, with 10-6 M orexin-A exerting the most potent effect. Orexin-A enhanced cell proliferation and cortisol production, and increased the mRNA and protein expression of 3β-HSD in the NCI-H295R cells; however, these effects were partly blocked by the OX1 receptor antagonist, the AKT antagonist and the combination of both. Furthermore, orexin-A significantly increased the phosphorylation of AKT, with the levels of total AKT protein remaining unaltered. This effect was blocked in the presence of PF-04691502 (10-6 M), SB334867 (10-6 M) and the combination of both. On the whole, our data demonstrate that the effects of orexin-A on the survival and function of human adrenocortical cells are mediated through the AKT signaling pathway.
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Affiliation(s)
- Xiaocen Chang
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuyan Zhao
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Shujing Ju
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lei Guo
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
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11
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Nitkiewicz A, Smolinska N, Maleszka A, Chojnowska K, Kaminski T. Expression of orexins and their precursor in the porcine ovary and the influence of orexins on ovarian steroidogenesis in pigs. Anim Reprod Sci 2014; 148:53-62. [PMID: 24916957 DOI: 10.1016/j.anireprosci.2014.03.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 03/16/2014] [Accepted: 03/23/2014] [Indexed: 11/30/2022]
Abstract
Orexins A and B are hypothalamic neuropeptides associated with homeostasis and the reproductive system. The aim of the study was to compare the expression of the prepro-orexin gene and the intensity of orexins immunoreactivity in the porcine ovary (corpora lutea, granulosa and theca interna cells) during four different stages of the oestrous cycle (days: 2-3, 10-12, 14-16 and 17-19) and to examine the in vitro effect of orexins on the secretion of steroid hormones by porcine luteal, granulosa and theca interna cells. The highest expression of prepro-orexin mRNA was observed in theca interna cells on days 17-19 of the oestrous cycle. The highest content of immunoreactive orexin A was noted in corpora lutea on days 10-12 and the highest level of immunoreactive orexin B on days 14-16 of the cycle. Immunoreactive orexin A concentrations were higher in theca interna cells than in granulosa cells, whereas similar levels of immunoreactive orexin B were observed in both cell types. Under in vitro conditions, at the concentration of 10 nM, orexins A and B inhibited FSH-induced oestradiol secretion by granulosa cells. The obtained results suggest that the pattern of orexin peptide expression in the porcine ovary is related to the animals' hormonal status. Our findings imply that orexins can affect porcine reproductive functions through modulation of ovarian steroidogenesis.
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Affiliation(s)
- Anna Nitkiewicz
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Nina Smolinska
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Anna Maleszka
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Katarzyna Chojnowska
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Tadeusz Kaminski
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland.
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Patel AX, Miller SR, Nathan PJ, Kanakaraj P, Napolitano A, Lawrence P, Koch A, Bullmore ET. Neuroendocrine and sympathetic responses to an orexin receptor antagonist, SB-649868, and alprazolam following insulin-induced hypoglycemia in humans. Psychopharmacology (Berl) 2014; 231:3817-28. [PMID: 24770625 PMCID: PMC4159598 DOI: 10.1007/s00213-014-3520-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 02/24/2014] [Indexed: 02/02/2023]
Abstract
RATIONALE The orexin-hypocretin system is important for translating peripheral metabolic signals and central neuronal inputs to a diverse range of behaviors, from feeding, motivation and arousal, to sleep and wakefulness. Orexin signaling is thus an exciting potential therapeutic target for disorders of sleep, feeding, addiction, and stress. OBJECTIVES/METHODS Here, we investigated the low dose pharmacology of orexin receptor antagonist, SB-649868, on neuroendocrine, sympathetic nervous system, and behavioral responses to insulin-induced hypoglycemic stress, in 24 healthy male subjects (aged 18-45 years; BMI 19.0-25.9 kg/m(2)), using a randomized, double-blind, placebo-controlled, within-subject crossover design. Alprazolam, a licensed benzodiazepine anxiolytic, was used as a positive comparator, as it has previously been validated using the insulin tolerance test (ITT) model in humans. RESULTS Of the primary endpoints, ITT induced defined increases in pulse rate, plasma cortisol, and adrenocorticotropic hormone in the placebo condition, but these responses were not significantly impacted by alprazolam or SB-649868 pre-treatment. Of the secondary endpoints, ITT induced a defined increase in plasma concentrations of adrenaline, noradrenaline, growth hormone (GH), and prolactin in the placebo condition. Alprazolam pre-treatment significantly reduced the GH response to ITT (p < 0.003), the peak electromyography (p < 0.0001) and galvanic skin response (GSR, p = 0.04) to acoustic startle, the resting GSR (p = 0.01), and increased appetite following ITT (p < 0.0005). SB-649868 pre-treatment produced no significant results. CONCLUSION We concluded that the ITT model may be informative for assessing the effects of drugs directly acting on the neuroendocrine or sympathetic nervous systems, but could not be validated for studying low dose orexin antagonist activity.
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Affiliation(s)
- Ameera X. Patel
- Brain Mapping Unit, Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB UK
| | - Sam R. Miller
- Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK
| | - Pradeep J. Nathan
- Brain Mapping Unit, Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB UK ,Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK ,School of Psychology and Psychiatry, Monash University, Melbourne, Australia
| | - Ponmani Kanakaraj
- Quantitative Sciences India, GlaxoSmithKline Pharmaceuticals Ltd, Bangalore, India
| | - Antonella Napolitano
- Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK
| | - Philip Lawrence
- Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK
| | - Annelize Koch
- Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK
| | - Edward T. Bullmore
- Brain Mapping Unit, Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB UK ,Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Centre for Clinical Investigation, Cambridge, UK
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Russo F, Maruccio L, Calamo A, de Girolamo P, Varricchio E. Orexin 1 receptor in the seminiferous tubules of boar testis: an immunohistochemical study. Acta Histochem 2014; 116:286-8. [PMID: 23746541 DOI: 10.1016/j.acthis.2013.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 11/26/2022]
Abstract
Orexin receptor 1 (OX₁R) and orexin receptor 2 (OX₂R) are two G-protein-coupled receptors that bind their ligands, orexin A (OXA) and B (OXB), with different affinities. The male genital system represents an important target for OXA, which appears to play a role in the control of steroidogenesis and germ cell development in the testis. It is known that among domestic breeding animals, in the boar the number of Leydig cells is very high and OXA appears to have stimulatory activity on testosterone production. In this study, we aimed to evaluate the presence of OX₁R in the boar testis in order to extend our knowledge concerning the distribution and a potential functional role of the orexinergic system in the male reproductive tract of farm animals. The presence of OX₁R immunopositive cells in seminiferous tubules of the boar testis enables us to hypothesize a possible role of OXA on male germ cells cycle in pig. Further investigations, involving functional and ultrastructural analysis, may contribute to our understanding of the role of orexins in the boar genital system.
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Leonard CS, Kukkonen JP. Orexin/hypocretin receptor signalling: a functional perspective. Br J Pharmacol 2014; 171:294-313. [PMID: 23848055 PMCID: PMC3904253 DOI: 10.1111/bph.12296] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 06/17/2013] [Accepted: 07/03/2013] [Indexed: 10/26/2022] Open
Abstract
Multiple homeostatic systems are regulated by orexin (hypocretin) peptides and their two known GPCRs. Activation of orexin receptors promotes waking and is essential for expression of normal sleep and waking behaviour, with the sleep disorder narcolepsy resulting from the absence of orexin signalling. Orexin receptors also influence systems regulating appetite/metabolism, stress and reward, and are found in several peripheral tissues. Nevertheless, much remains unknown about the signalling pathways and targets engaged by native receptors. In this review, we integrate knowledge about the orexin receptor signalling capabilities obtained from studies in expression systems and various native cell types (as presented in Kukkonen and Leonard, this issue of British Journal of Pharmacology) with knowledge of orexin signalling in different tissues. The tissues reviewed include the CNS, the gastrointestinal tract, the pituitary gland, pancreas, adrenal gland, adipose tissue and the male reproductive system. We also summarize the findings in different native and recombinant cell lines, especially focusing on the different cascades in CHO cells, which is the most investigated cell line. This reveals that while a substantial gap exists between what is known about orexin receptor signalling and effectors in recombinant systems and native systems, mounting evidence suggests that orexin receptor signalling is more diverse than originally thought. Moreover, rather than being restricted to orexin receptor 'overexpressing' cells, this signalling diversity may be utilized by native receptors in a site-specific manner.
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Affiliation(s)
- C S Leonard
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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15
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Xu TR, Yang Y, Ward R, Gao L, Liu Y. Orexin receptors: Multi-functional therapeutic targets for sleeping disorders, eating disorders, drug addiction, cancers and other physiological disorders. Cell Signal 2013; 25:2413-23. [DOI: 10.1016/j.cellsig.2013.07.025] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 07/26/2013] [Indexed: 12/29/2022]
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16
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Kukkonen JP. Physiology of the orexinergic/hypocretinergic system: a revisit in 2012. Am J Physiol Cell Physiol 2012; 304:C2-32. [PMID: 23034387 DOI: 10.1152/ajpcell.00227.2012] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The neuropeptides orexins and their G protein-coupled receptors, OX(1) and OX(2), were discovered in 1998, and since then, their role has been investigated in many functions mediated by the central nervous system, including sleep and wakefulness, appetite/metabolism, stress response, reward/addiction, and analgesia. Orexins also have peripheral actions of less clear physiological significance still. Cellular responses to the orexin receptor activity are highly diverse. The receptors couple to at least three families of heterotrimeric G proteins and other proteins that ultimately regulate entities such as phospholipases and kinases, which impact on neuronal excitation, synaptic plasticity, and cell death. This article is a 10-year update of my previous review on the physiology of the orexinergic/hypocretinergic system. I seek to provide a comprehensive update of orexin physiology that spans from the molecular players in orexin receptor signaling to the systemic responses yet emphasizing the cellular physiological aspects of this system.
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Affiliation(s)
- Jyrki P Kukkonen
- Dept. of Veterinary Biosciences, University of Helsinki, Finland.
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17
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Abstract
In 1998, our group discovered a cDNA that encoded the precursor of two putative neuropeptides that we called hypocretins for their hypothalamic expression and their similarity to the secretin family of neuropeptides. In the past 15 years, numerous studies have placed the hypocretin system as an integrator of homeostatic functions with a crucial, nonredundant function as an arousal stabilizer. Here, we discuss some of the data that have accumulated over the years on the integrating capacity of these hypothalamic neurons and their role on sleep-to-wake transitions.
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Affiliation(s)
- Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA.
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18
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Shahid IZ, Rahman AA, Pilowsky PM. Orexin and Central Regulation of Cardiorespiratory System. SLEEP HORMONES 2012; 89:159-84. [DOI: 10.1016/b978-0-12-394623-2.00009-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tsunematsu T, Yamanaka A. The Role of Orexin/Hypocretin in the Central Nervous System and Peripheral Tissues. SLEEP HORMONES 2012; 89:19-33. [DOI: 10.1016/b978-0-12-394623-2.00002-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Kagerer SM, Eichholz C, Jöhren O. Orexins/hypocretins increase the promoter activity of selective steroidogenic enzymes. Peptides 2011; 32:839-43. [PMID: 21256172 DOI: 10.1016/j.peptides.2011.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
Abstract
Orexins (hypocretins) regulate multiple physiological functions, including central regulation of energy homeostasis and sleep-wake behavior but also peripheral hormonal actions. Recent data suggest specific effects of orexins at adrenal glands. To further assess the mechanism by which orexins regulate steroidogenesis we analyzed the effect of orexin A and B on the transcriptional activity of the luciferase reporter gene driven by the human steroid 21-hydroxylase (CYP21), 3β-hydroxysteroid dehydrogenase (HSD3B2), 11β-hydroxylase (CYP11B1), and aldosterone synthase (CYP11B2) gene promoter regions. After transient transfection of the reporter gene constructs into human NCI H295R cells, treatment with orexin A and B for 6 and 12h increased the promoter activity of the CYP11B2, HSD3B2 and, to a lesser extend, CYP21 genes. The activity of the CYP11B1 was increased by both orexins after 3h of treatment. Compared to the effects of forskolin or angiotensin II, however, the effect of orexins on the transcriptional activity of the steroidogenic enzyme genes was moderate. Our results suggest that orexins increase the expression of steroidogenic enzymes at the transcriptional level and that orexins play a role in the long term regulation of adrenal steroid production.
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Affiliation(s)
- Sonja M Kagerer
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany
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Novikova NS, Perekrest SV, Shainidze KZ, Korneva EA. Hypothalamic Orexin-Containing Neurons in the Hypothalamus on Exposure to Antigenic and Non-Antigenic Stimuli. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s11055-011-9399-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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22
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López M, Tena-Sempere M, Diéguez C. Cross-talk between orexins (hypocretins) and the neuroendocrine axes (hypothalamic-pituitary axes). Front Neuroendocrinol 2010; 31:113-27. [PMID: 19654017 DOI: 10.1016/j.yfrne.2009.07.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 07/28/2009] [Accepted: 07/29/2009] [Indexed: 02/06/2023]
Abstract
Lesioning and electrical stimulation experiments carried out during the first half of the twentieth century showed that the lateral hypothalamic area (LHA) is involved in the neuroendocrine control of hormone secretion. However, the molecular basis of this phenomenon remained unclear until fifty years later when in 1998, two different laboratories discovered a new family of hypothalamic neuropeptides, the orexins or hypocretins (OX-A/Hcrt1 and OX-B/Hcrt2). Since then, remarkable evidence has revealed that orexins/hypocretins play a prominent role in regulating virtually all the neuroendocrine axes, acting as pivotal signals in the coordination of endocrine responses with regards to sleep, arousal and energy homeostasis. The clinical relevance of these actions is supported by human data showing impairment of virtually all the neuroendocrine axes in orexin/hypocretin-deficient narcoleptic patients. Here, we summarize more than ten years of knowledge about the orexins/hypocretins with particular focus on their role as neuroendocrine regulators. Understanding this aspect of orexin/hypocretin physiology could open new therapeutic possibilities in the treatment of sleep, energy homeostasis and endocrine pathologies.
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Affiliation(s)
- Miguel López
- Department of Physiology, School of Medicine, University of Santiago de Compostela - Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain.
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23
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Nurmio M, Tena-Sempere M, Toppari J. Orexins and the regulation of the hypothalamic-pituitary-testicular axis. Acta Physiol (Oxf) 2010; 198:349-54. [PMID: 19476455 DOI: 10.1111/j.1748-1716.2009.02006.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Orexins (OX), OX-A and OX-B, were initially identified as hypothalamic neuropeptides primarily involved in the control of food intake and states of arousal. Thereafter, orexins have been substantiated as putative pleiotropic regulators of a wide diversity of biological systems, including different neuroendocrine axes. Among the latter, compelling experimental evidence has recently been documented that orexins, mainly OX-A, may act at different levels of the hypothalamic-pituitary-gonadal (HPG) axis to modulate reproductive function. These actions are likely to include regulatory effects on the hypothalamic centres governing the HPG axis, as well as direct actions at the gonadal level. We review herein the experimental evidence, gathered in recent years, supporting a reproductive 'facet' of orexins, with special emphasis on our current knowledge of their patterns of expression and potential functional roles in the testis. Overall, the available data strongly suggest that, by acting at different levels of the HPG axis, orexins may operate as putative neuroendocrine and autocrine/paracrine regulators of gonadal function.
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Affiliation(s)
- M Nurmio
- Department of Physiology, University of Turku, Turku, Finland
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24
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Abstract
The neuropeptides orexin A and B (hypocretin-1 and -2) are involved in numerous central regulation processes such as energy homeostasis, sleeping behaviour and addiction. The expression of orexins and orexin receptors in a variety of tissues outside the brain and the presence of orexin A in the circulation indicate the existence of an additional peripheral orexin system. Furthermore, it is well established that orexins exert an influence on the regulation of the hypothalamus-pituitary-adrenal axis, acting both on its central and peripheral branch. In rat and human adrenal cortices the expression of both orexin receptors has been verified with a predominance of OX(2)R. The local expression of orexin receptors was observed to be gender specific and to be modified by plasma glucose and insulin concentrations, nutritional status as well as gonadal steroids. Various studies consistently demonstrated orexin A to enhance glucocorticoid secretion of rat and human adrenal cortices, while orexin B was found to be either less potent or ineffective. On the contrary, the influence of orexins on adrenocortical aldosterone production and cell proliferation is still more controversial. Recent findings indicate that orexins stimulate adrenocortical steroidogenesis by augmenting transcription of selective steroidogenic enzymes and proteins such as steroidogenic acute regulatory protein. Both, G(q) and G(s), signalling pathways with a downstream activation of MAP kinases appear to be involved in this regulation.
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Affiliation(s)
- S M Kagerer
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
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25
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Wenzel J, Grabinski N, Knopp CA, Dendorfer A, Ramanjaneya M, Randeva HS, Ehrhart-Bornstein M, Dominiak P, Jöhren O. Hypocretin/orexin increases the expression of steroidogenic enzymes in human adrenocortical NCI H295R cells. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1601-9. [PMID: 19793950 DOI: 10.1152/ajpregu.91034.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypocretins/orexins act through two receptor subtypes: OX(1) and OX(2). Outside the brain, orexin receptors are expressed in adrenal glands, where orexins stimulate the release of glucocorticoids. To further address the regulation of steroidogenesis, we analyzed the effect of orexins on the expression of steroidogenic enzymes in human adrenocortical National Cancer Institute (NCI) H295R cells by qPCR. In NCI H295R cells, OX(2) receptors were highly expressed, as they were in human adrenal glands. After treatment of NCI H295R cells with orexin A for 12-24 h, the cortisol synthesis rate was significantly increased, whereas 30 min of treatment showed no effect. While CYP11B1 and CYP11B2 mRNA levels were increased already at earlier time points, the expression of HSD3B2 and CYP21 mRNA was significantly up-regulated after treatment with orexin A for 12 h. Likewise, orexin B increased CYP21 and HSD3B2 mRNA levels showing, however, a lower potency compared with orexin A. The mRNA levels of CYP11A and CYP17 were unaffected by orexin A. OX(2) receptor mRNA levels were down-regulated after 12 and 24 h of orexin A treatment. Orexin A increased intracellular Ca(2+) but not cAMP concentrations in NCI H295R cells. Furthermore, inhibition of PKC and MAPK kinase/ERK kinase (MEK1/2) prevented the increase of HSD3B2 expression by orexin A. Accordingly, orexin A treatment of NCI H295R cells markedly enhanced ERK1/2 phosphorylation that was prevented by PKC and, in part, PKA inhibition. In conclusion, orexins may influence adrenal steroidogenesis by differential regulation of the expression of steroidogenic enzymes involving Ca(2+), as well as PKC-ERK1/2 signaling.
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Affiliation(s)
- Jan Wenzel
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
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Chen XW, Huang W, Yan JA, Fan HX, Guo N, Lü J, Xiu Y, Gu JL, Zhang CX, Ruan HZ, Hu ZA, Yu ZP, Zhou Z. Reinvestigation of the effect of orexin A on catecholamine release from adrenal chromaffin cells. Neurosci Lett 2008; 436:181-4. [DOI: 10.1016/j.neulet.2008.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 02/26/2008] [Accepted: 03/07/2008] [Indexed: 11/16/2022]
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Abstract
Orexin A (OXA) and orexin B were originally isolated as hypothalamic peptides regulating sleep, wakefulness and feeding. However, growing evidence suggests that orexins have major functions also in the peripheral tissues. Central orexigenic pathways originating from medulla activate the hypothalamus-pituitary axis and can influence the sympathetic tone. Orexins and their receptors are widely dispersed throughout the intestine, where orexin receptors are regulated by the nutritional status, affect insulin secretion and intestinal motility. Although the primary source of the peptide has not been elucidated, OXA is detected in plasma and its level varies in response to the metabolic state. In this review, we focus on the current knowledge on peripheral functions of orexins and discuss possible endocrine, paracrine and neurocrine roles.
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Affiliation(s)
- M V Heinonen
- Department of Biotechnology and Molecular Medicine, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland
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Hirota K, Kushikata T, Yoshida H, Kudo M, Kudo T. Role of the orexinergic system in acute haemorrhage in the rat. Neurosci Lett 2008; 432:162-6. [DOI: 10.1016/j.neulet.2007.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 11/22/2007] [Accepted: 12/10/2007] [Indexed: 11/28/2022]
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Nishino S. The hypocretin/orexin receptor: therapeutic prospective in sleep disorders. Expert Opin Investig Drugs 2007; 16:1785-97. [DOI: 10.1517/13543784.16.11.1785] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Spinazzi R, Andreis PG, Rossi GP, Nussdorfer GG. Orexins in the regulation of the hypothalamic-pituitary-adrenal axis. Pharmacol Rev 2006; 58:46-57. [PMID: 16507882 DOI: 10.1124/pr.58.1.4] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Orexin-A and orexin-B are hypothalamic peptides that act via two G protein-coupled receptors, named orexin type 1 and type 2 receptors (OX1-Rs and OX2-Rs). The most studied biological functions of orexins are the central control of feeding and sleep, but in the past few years findings that orexin system modulates the hypothalamic-pituitary-adrenal (HPA) axis, acting on both its central and peripheral branches, have accumulated. Orexins and their receptors are expressed in the hypothalamic paraventricular nucleus and median eminence and orexin receptors in pituitary corticotropes, adrenal cortex, and medulla. Whereas the effects of orexins on adrenal aldosterone secretion are doubtful, compelling evidence indicates that these peptides enhance glucocorticoid production in rats and humans. This effect involves a 2-fold mechanism: 1) stimulation of the adrenocorticotropin-releasing hormone-mediated pituitary release of adrenocorticotropin, which in turn raises adrenal glucocorticoid secretion; and 2) direct stimulation of adrenocortical cells via OX1-Rs coupled to the adenylate cyclase-dependent cascade. The effects of orexins on catecholamine release from adrenal medulla are unclear and probably of minor relevance, but there are indications that orexins can stimulate in vitro secretion of human pheochromocytoma cells via OX2-Rs coupled to the phospholipase C-dependent cascade. Evidence is also available that orexins enhance the growth in vitro of adrenocortical cells, mainly acting via OX2-Rs. Moreover, findings suggest that the orexin system may favor HPA axis responses to stresses and play a role in the pathophysiology of cortisol-secreting adrenal adenomas.
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Affiliation(s)
- Raffaella Spinazzi
- Department of Human Anatomy and Physiology, School of Medicine, University of Padua, Italy
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Winsky-Sommerer R, Boutrel B, de Lecea L. Stress and arousal: the corticotrophin-releasing factor/hypocretin circuitry. Mol Neurobiol 2006; 32:285-94. [PMID: 16385142 DOI: 10.1385/mn:32:3:285] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Accepted: 05/31/2005] [Indexed: 11/11/2022]
Abstract
The hypocretins (also know as orexins) are two neuropeptides now commonly described as critical components for maintaining and regulating the stability of arousal. Several lines of evidence have raised the hypothesis that hypocretin-producing neurons are part of the circuitries that mediate the hypothalamic response to acute stress. New data indicate that the corticotrophin-releasing factor (CRF) peptidergic system directly innervates hypocretin-expressing neurons. CRF depolarizes hypocretin neurons, and this effect is blocked by a CRF-R1 antagonist. Furthermore, activation of hypocretinergic neurons by stress is impaired in CRF-R1 knockout mice. These data suggest that CRF-R1 receptor mediates the stress-induced activation of the hypocretinergic system. A significant amount of evidence also indicates that hypocretin cells connect reciprocally to the CRF system. We propose that upon stressor stimuli, CRF activates the hypocretin system, which relays these signals to brain stem nuclei involved in the modulation of arousal as well as to the extended amygdala, a structure involved in the negative motivational state that drives addiction.
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Ziolkowska A, Spinazzi R, Albertin G, Nowak M, Malendowicz LK, Tortorella C, Nussdorfer GG. Orexins stimulate glucocorticoid secretion from cultured rat and human adrenocortical cells, exclusively acting via the OX1 receptor. J Steroid Biochem Mol Biol 2005; 96:423-9. [PMID: 16157481 DOI: 10.1016/j.jsbmb.2005.05.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 05/17/2005] [Indexed: 11/23/2022]
Abstract
Orexins A and B are hypothalamic peptides, that act via two subtypes of receptors, named OX1-R and OX2-R. Rat and human adrenal cortexes are provided with both OX1-R and OX2-R, and we have previously shown that orexin-A, but not orexin-B, enhances glucocorticoid secretion from dispersed adrenocortical cells. Since OX1-Rs preferentially bind orexin-A and OX2-Rs are non-selective for both orexins, the hypothesis has been advanced that the secretagogue effect of orexin-A is exclusively mediated by the OX1-R. Here, we aimed to verify this contention and to gain insight into the signaling mechanism(s) underlying the secretagogue effect of orexins using primary cultures of rat and human adrenocortical cells. Reverse transcription-polymerase chain reaction showed that cultured cells, as freshly dispersed cells, expressed both OX1-R and OX2-R mRNAs. Orexin-A, but not orexin-B, concentration-dependently increased corticosterone and cortisol secretion from cultured rat and human adrenocortical cells, respectively. The blockade of OX1-Rs by selective antibodies abrogated the secretagogue effect of orexin-A, while the immuno-blockade of OX2-Rs was ineffective. The glucocorticoid response of cultured cells to orexin-A was annulled by the adenylate cyclase and protein kinase (PK) A inhibitors SQ-22536 and H-89, and unaffected by the phospholipase C and PKC inhibitors U-73122 and calphostin-C. Orexin-A, but not orexin-B, enhanced cyclic-AMP production from cultured cells, and did not alter inositol-3-phosphate release. Collectively, our present results allow us to conclude that orexins stimulate glucocorticoid secretion from rat and human adrenocortical cells, exclusively acting through OX1-Rs coupled to the adenylate cyclase/PKA-dependent signaling cascade.
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Affiliation(s)
- Agnieszka Ziolkowska
- Department of Histology and Embryology, Poznan School of Medicine, PL-60781 Poznan, Poland
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Spinazzi R, Rucinski M, Neri G, Malendowicz LK, Nussdorfer GG. Preproorexin and orexin receptors are expressed in cortisol-secreting adrenocortical adenomas, and orexins stimulate in vitro cortisol secretion and growth of tumor cells. J Clin Endocrinol Metab 2005; 90:3544-9. [PMID: 15797953 DOI: 10.1210/jc.2004-2385] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Orexins A and B are hypothalamic peptides that originate from the proteolytic cleavage of preproorexin and act through two subtypes of receptors, named OX1-R and OX2-R. OX1-R almost exclusively binds orexin-A, whereas OX2-R is nonselective for both orexins. We previously found that orexin-A, via the OX1-R, stimulates cortisol secretion from dispersed human adrenocortical cells. In this study, we demonstrate that six of eight cortisol-secreting adenomas expressed preproorexin mRNA, and seven of 10 adenomas contained measurable amounts of orexin-A but not orexin-B. Normal adrenal cortexes neither expressed preproorexin nor contained orexins. All adenomas expressed OX1-R and OX2-R mRNAs, and real-time PCR showed that the expression of both receptors was up-regulated in adenomas, compared with normal adrenal cortex. Orexin-A concentration-dependently raised basal cortisol secretion from freshly dispersed normal and adenomatous cells, minimal and maximal effective concentrations being 10(-10) and 10(-8) m, and the peptide efficacy (percent increase elicited by 10(-8) m orexin-A) was significantly higher in adenomas than in the normal adrenal cortex. Orexin-B was ineffective, thereby indicating that orexin secretagogue action is mediated by the OX1-R. In contrast, both orexins (10(-8) m) raised the proliferative activity of cultured normal and adenomatous cells, suggesting that this effect is mediated by OX2-R or both receptor subtypes. Collectively, our findings allow us to conclude that the orexin system is overexpressed in cortisol-secreting adenomas and suggest that orexin-A may act as an autocrine-paracrine regulator of the secretory activity and growth of some of these adrenal tumors.
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Affiliation(s)
- R Spinazzi
- Department of Human Anatomy and Physiology, Section of Anatomy, University of Padova, Via Gabelli 65, I-35121 Padova, Italy
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Kok SW, Roelfsema F, Overeem S, Lammers GJ, Frölich M, Meinders AE, Pijl H. Pulsatile LH release is diminished, whereas FSH secretion is normal, in hypocretin-deficient narcoleptic men. Am J Physiol Endocrinol Metab 2004; 287:E630-6. [PMID: 15172887 DOI: 10.1152/ajpendo.00060.2004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypocretin (orexin) peptides are involved in the regulation of energy balance and pituitary hormone release. Narcolepsy is a sleep disorder characterized by disruption of hypocretin neurotransmission. Pituitary LH secretion is diminished in hypocretin-deficient animal models, and intracerebroventricular administration of hypocretin-1 activates the hypothalamo-pituitary-gonadal axis in rats. We evaluated whether hypocretin deficiency affects gonadotropin release in humans. To this end, we deconvolved 24-h serum concentrations of LH and FSH in seven hypocretin-deficient narcoleptic males (N) and seven controls (C) matched for age, body mass index, and sex. Basal plasma concentrations of testosterone, estradiol, and sex hormone-binding globulin were similar in both groups. Mean 24-h LH concentration was significantly lower in narcolepsy patients [3.0 +/- 0.4 (N) vs. 4.2 +/- 0.3 (C) U/l, P = 0.01], which was primarily due to a reduction of pulsatile LH secretion [23.5 +/- 1.6 (N) vs. 34.3 +/- 4.9 (C) U.l(-1).24 h(-1), P = 0.02]. The orderliness of LH and FSH secretion, quantitated by the approximate entropy statistic, was greater in patients than in controls. In contrast, all other features of FSH release were similar in narcoleptic and control groups. Also, LH and FSH secretions in response to intravenous administration of 100 microg of GnRH were similar in patients and controls. These data indicate that endogenous hypocretins are involved in the regulation of the hypothalamo-pituitary-gonadal axis activity in humans. In particular, reduced LH release in the face of normal pituitary responsivity to GnRH stimulation in narcoleptic men suggests that hypocretins promote endogenous GnRH secretion.
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Affiliation(s)
- S W Kok
- Leiden University Medical Center, Department of General Internal Medicine, 2300 RC, The Netherlands
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Barreiro ML, Pineda R, Navarro VM, Lopez M, Suominen JS, Pinilla L, Señaris R, Toppari J, Aguilar E, Diéguez C, Tena-Sempere M. Orexin 1 receptor messenger ribonucleic acid expression and stimulation of testosterone secretion by orexin-A in rat testis. Endocrinology 2004; 145:2297-306. [PMID: 14764632 DOI: 10.1210/en.2003-1405] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Orexins are hypothalamic neuropeptides primarily involved in the regulation of food intake and arousal states. In addition, a role for orexins as central neuroendocrine modulators of reproductive function has recently emerged. Prepro-orexin and orexin type-1 receptor mRNAs have been detected in the rat testis. This raises the possibility of additional peripheral actions of orexins in the control of reproductive axis, which remains so far unexplored. To analyze the biological effects and mechanisms of action of orexins in the male gonad, we evaluated testicular expression of orexin receptor 1 (OX(1)R) and orexin receptor 2 (OX(2)R) mRNAs in different experimental settings and the effect of orexin-A on testicular testosterone (T) secretion. Persistent expression of OX(1)R mRNA was demonstrated in the rat testis throughout postnatal development. In contrast, OX(2)R transcript was not detected at any developmental stage. Expression of OX(1)R mRNA persisted after selective elimination of mature Leydig cells and was detected in isolated seminiferous tubules at defined stages of the seminiferous epithelial cycle. In addition, testicular OX(1)R mRNA expression appeared to be under hormonal regulation; it was reduced by long-term hypophysectomy and partially restored by FSH replacement, whereas down-regulation was observed after exposure to increasing doses of the ligand in vitro. Moreover, OX(1)R mRNA expression was sensitive to neonatal imprinting by estrogen. Finally, orexin-A, in a dose-dependent manner, significantly increased basal, but not human choriogonadotropin-stimulated, T secretion in vitro. A similar stimulatory effect was observed in vivo after intratesticular administration of orexin-A. In conclusion, our present results provide the first evidence for the regulated expression of OX(1)R mRNA and functional role of orexin-A in the rat testis. Overall, our data are suggestive of a novel site of action of orexins in the control of male reproductive axis.
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Affiliation(s)
- M L Barreiro
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, 14004 Córdoba, Spain
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Kukkonen JP, Holmqvist T, Ammoun S, Akerman KEO. Functions of the orexinergic/hypocretinergic system. Am J Physiol Cell Physiol 2002; 283:C1567-91. [PMID: 12419707 DOI: 10.1152/ajpcell.00055.2002] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Orexin A and orexin B are hypothalamic peptides that act on their targets via two G protein-coupled receptors (OX1 and OX2 receptors). In the central nervous system, the cell bodies producing orexins are localized in a narrow region within the lateral hypothalamus and project mainly to regions involved in feeding, sleep, and autonomic functions. Via putative pre- and postsynaptic effects, orexins increase synaptic activity in these regions. In isolated neurons and cells expressing recombinant receptors orexins cause Ca2+ elevation, which is mainly dependent on influx. The activity of orexinergic cells appears to be controlled by feeding- and sleep-related signals via a variety of neurotransmitters/hormones from the brain and other tissues. Orexins and orexin receptors are also found outside the central nervous system, particularly in organs involved in feeding and energy metabolism, e.g., gastrointestinal tract, pancreas, and adrenal gland. In the present review we focus on the physiological properties of the cells that secrete or respond to orexins.
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Affiliation(s)
- Jyrki P Kukkonen
- Laboratory of Cell Physiology, Department of Neuroscience, Division of Physiology, Uppsala University, Biomedical Center, SE-75123 Uppsala, Sweden.
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