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Kouhetsani S, Khazali H, Rajabi-Maham H. Orexin antagonism and substance-P: Effects and interactions on polycystic ovary syndrome in the wistar rats. J Ovarian Res 2023; 16:89. [PMID: 37147728 PMCID: PMC10161431 DOI: 10.1186/s13048-023-01168-4] [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: 01/26/2023] [Accepted: 04/25/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder without definitive treatments. Orexin and Substance-P (SP) neuropeptides can affect the ovarian steroidogenesis. Moreover, there are limited studies about the role of these neuropeptides in PCOS. We aimed here to clarify the effects of orexins and SP in PCOS as well as any possible interactions between them. METHODS For this purpose, the animals (n = five rats per group) received intraperitoneally a single dose of SB-334,867-A (orexin-1 receptor antagonist; OX1Ra), JNJ-10,397,049 (orexin-2 receptor antagonist; OX2Ra), and CP-96,345 (neurokinin-1 receptor antagonist; NK1Ra), alone or in combination with each other after two months of PCOS induction. The blocking of orexin and SP receptors was studied in terms of ovarian histology, hormonal changes, and gene expression of ovarian steroidogenic enzymes. RESULTS The antagonists' treatment did not significantly affect the formation of ovarian cysts. In the PCOS groups, the co-administration of OX1Ra and OX2Ra as well as their simultaneous injections with NK1Ra significantly reversed testosterone levels and Cyp19a1 gene expression when compared to the PCOS control group. There were no significant interactions between the PCOS groups that received NK1Ra together with one or both OX1R- and OX2R-antagonists. CONCLUSION The blocking of the orexin receptors modulates abnormal ovarian steroidogenesis in the PCOS model of rats. This suggests that the binding of orexin-A and -B to their receptors reduces Cyp19a1 gene expression while increasing testosterone levels.
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Affiliation(s)
- Somayeh Kouhetsani
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Homayoun Khazali
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
| | - Hassan Rajabi-Maham
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
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2
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Sardar VM, Gupta M, Korde JP, Bahiram KB, Bonde SW. Orexin system in buffalo ovarian follicles and effect of orexin on oestradiol production. Reprod Domest Anim 2023. [PMID: 36881512 DOI: 10.1111/rda.14339] [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: 01/07/2023] [Revised: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023]
Abstract
Orexin is a ligand for orexin receptors OX1R and OX2R; it is a neuropeptide with pleiotropic functions, including regulation of reproduction. The current study was carried out to investigate the mRNA expression of the prepro-orexin gene (PPO) and orexin receptors (OX1R and OX2R) in ovarian follicles during different stages of their development in the ovary of water buffalo (Bubalus bubalis) and to determine the role of orexin on oestradiol production. Ovarian follicles were classified into four groups based on size and oestradiol (E2 ) level in the follicular fluid (FF) as follows: (i) small or F1, (ii) medium or F2, (iii) large or F3, and (iv) dominant/pre-ovulatory follicle or F4. In follicles, the mRNA expression of PPO and OX1R was greater in F3 and F4 follicles in granulosa cells (GC) and theca interna (TI) cells. OX2R expression did not vary among the different follicular stages in GC. Orexin-A and orexin receptors were localized in the cytoplasm of GC and TI, and intensity was higher in F3 and F4 follicles. In addition, we cultured GC and treated them at 0.1, 1.0, and 10 ng/mL orexin-A alone or in the presence of FSH (30 ng/mL) or IGF-I (10 ng/mL) for 48 h. There was a significant (p < .05) increase in oestradiol (E2 ) secretion and cytochrome P0450 family 19 subfamily A member 1 (CYP19A1) expression from GC at 1.0 and 10.0 ng/mL orexin-A in the presence of 30 ng/mL follicle-stimulating hormone (FSH) or 10 ng/mL insulin-like growth factor-I (IGF-I). In conclusion, the present study provided evidence that the orexin system is expressed in buffalo ovarian follicles, and orexin-A in the presence of FSH and IGF-I has a stimulatory effect on oestradiol secretion from the GC of water buffalo.
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Affiliation(s)
- Vikas M Sardar
- Department of Veterinary Physiology, Nagpur Veterinary College, Nagpur, India
| | - Mahesh Gupta
- Department of Veterinary Physiology, Nagpur Veterinary College, Nagpur, India
| | - Jayant P Korde
- Department of Veterinary Physiology, Nagpur Veterinary College, Nagpur, India
| | - Krushna B Bahiram
- Department of Veterinary Physiology, Nagpur Veterinary College, Nagpur, India
| | - Sachin W Bonde
- Department of Veterinary Biochemistry, Nagpur Veterinary College, Nagpur, India
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3
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Almasi N, Zengin HY, Koç N, Uçakturk SA, İskender Mazman D, Heidarzadeh Rad N, Fisunoglu M. Leptin, ghrelin, nesfatin-1, and orexin-A plasma levels in girls with premature thelarche. J Endocrinol Invest 2022; 45:2097-2103. [PMID: 35764868 DOI: 10.1007/s40618-022-01841-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/10/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE Reducing the mean age of puberty onset in recent years has crucial public health, clinical, and social implications. This study aimed to evaluate the serum levels of appetite-related peptides (leptin, ghrelin, nesfatin-1, and orexin-A) and anthropometric data in girls with premature thelarche (PT). METHODS We enrolled 44 girls aged 4-8 years diagnosed with PT and 33 age-matched healthy girls as controls. The demographic data of the girls were obtained using a questionnaire. Anthropometric data were measured and fasting blood samples were collected. RESULTS Body weight, height, body mass index (BMI), body fat mass, and basal metabolic rate (BMR) were higher in the PT group than in the control group (p < 0.05). Serum leptin (p < 0.001), nesfatin-1 (p = 0.001), and orxein-A (p < 0.001) levels were significantly higher in the PT group than in healthy controls. However, there were no significant differences in the serum ghrelin levels between the groups (p > 0.05). The results of multivariate logistic regression revealed that serum leptin level (OR (95% CI): 42.0 (10.91, 173.06), p < 0.001), orexin-A (OR (95% CI): 1.14 (1.04, 1.24), p = 0.006), and BMI for age z-score (OR (95% CI): 6.97 (1.47, 33.4), p = 0.014) elevated the risk of incidence of PT at 4-8 girls. CONCLUSION These results suggest that in addition to serum leptin levels, serum orexin-A and nesaftin-1 can take part in the initiation of PT. Few studies have investigated the relationship between nesfatin-1 and orexin-A levels and age at onset of puberty; hence, it should be a subject for future studies.
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Affiliation(s)
- N Almasi
- Department of Nutrition and Dietetics, Hacettepe University Faculty of Health Sciences, Ankara, Turkey
| | - H Y Zengin
- Department of Biostatistics, Hacettepe University Faculty of Health Sciences, Ankara, Turkey
| | - N Koç
- Department of Child Endocrinology, Ministry of Health Ankara City Hospital, Ankara, Turkey
| | - S A Uçakturk
- Department of Child Endocrinology, Ministry of Health Ankara City Hospital, Ankara, Turkey
| | - D İskender Mazman
- Department of Child Pediatric, Ministry of Health Ankara City Hospital, Ankara, Turkey
| | - N Heidarzadeh Rad
- Department of Nutrition and Dietetics, Hacettepe University Faculty of Health Sciences, Ankara, Turkey
| | - M Fisunoglu
- Department of Nutrition and Dietetics, Hacettepe University Faculty of Health Sciences, Ankara, Turkey.
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4
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Precocious puberty in narcolepsy type 1: Orexin loss and/or neuroinflammation, which is to blame? Sleep Med Rev 2022; 65:101683. [PMID: 36096986 DOI: 10.1016/j.smrv.2022.101683] [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: 03/04/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 10/14/2022]
Abstract
Narcolepsy type 1 (NT1) is a rare neurological sleep disorder triggered by postnatal loss of the orexin/hypocretin neuropeptides. Overweight/obesity and precocious puberty are highly prevalent comorbidities of NT1, with a close temporal correlation with disease onset, suggesting a common origin. However, the underlying mechanisms remain unknown and merit further investigation. The main question we address in this review is whether the occurrence of precocious puberty in NT1 is due to the lack of orexin/hypocretin or rather to a wider hypothalamic dysfunction in the context of neuroinflammation, which is likely to accompany the disease given its autoimmune origins. Our analysis suggests that the suspected generalized neuroinflammation of the hypothalamus in NT1 would tend to delay puberty rather than hastening it. In contrast, that the brutal loss of orexin/hypocretin would favor an early reactivation of gonadotropin-releasing hormone (GnRH) secretion during the prepubertal period in vulnerable children, leading to early puberty onset. Orexin/hypocretin replacement could thus be envisaged as a potential treatment for precocious puberty in NT1. Additionally, we put forward an alternative hypothesis regarding the concomitant occurrence of sleepiness, weight gain and early puberty in NT1.
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Soejima Y, Iwata N, Nakayama N, Hirata S, Nakano Y, Yamamoto K, Suyama A, Oguni K, Nada T, Fujisawa S, Otsuka F. Mutual Effects of Orexin and Bone Morphogenetic Proteins on Gonadotropin Expression by Mouse Gonadotrope Cells. Int J Mol Sci 2022; 23:ijms23179782. [PMID: 36077179 PMCID: PMC9456022 DOI: 10.3390/ijms23179782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/21/2022] [Accepted: 08/26/2022] [Indexed: 12/03/2022] Open
Abstract
Orexin plays a key role in the regulation of sleep and wakefulness and in feeding behavior in the central nervous system, but its receptors are expressed in various peripheral tissues including endocrine tissues. In the present study, we elucidated the effects of orexin on pituitary gonadotropin regulation by focusing on the functional involvement of bone morphogenetic proteins (BMPs) and clock genes using mouse gonadotrope LβT2 cells that express orexin type 1 (OX1R) and type 2 (OX2R) receptors. Treatments with orexin A enhanced LHβ and FSHβ mRNA expression in a dose-dependent manner in the absence of GnRH, whereas orexin A in turn suppressed GnRH-induced gonadotropin expression in LβT2 cells. Orexin A downregulated GnRH receptor expression, while GnRH enhanced OX1R and OX2R mRNA expression. Treatments with orexin A as well as GnRH increased the mRNA levels of Bmal1 and Clock, which are oscillational regulators for gonadotropin expression. Of note, treatments with BMP-6 and -15 enhanced OX1R and OX2R mRNA expression with upregulation of clock gene expression. On the other hand, orexin A enhanced BMP receptor signaling of Smad1/5/9 phosphorylation through upregulation of ALK-2/BMPRII among the BMP receptors expressed in LβT2 cells. Collectively, the results indicate that orexin regulates gonadotropin expression via clock gene expression by mutually interacting with GnRH action and the pituitary BMP system in gonadotrope cells.
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Affiliation(s)
- Yoshiaki Soejima
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Nahoko Iwata
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Nanako Nakayama
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Shinichi Hirata
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Yasuhiro Nakano
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Koichiro Yamamoto
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Atsuhito Suyama
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Kohei Oguni
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Takahiro Nada
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Satoshi Fujisawa
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
| | - Fumio Otsuka
- Department of General Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan
- Correspondence: ; Tel.: +81-86-235-7342; Fax: +81-86-235-7345
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Effects of orexin A on PTGS2, PTGES, CBR1 and PGFS mRNA transcript abundances and prostaglandin E2 and F2α concentrations in culture medium of pig uterine explants collected during early gestation and the estrogenic cycle. Anim Reprod Sci 2022; 237:106910. [DOI: 10.1016/j.anireprosci.2021.106910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/11/2022]
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7
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Zaobidna E, Kiezun M, Dobrzyn K, Szeszko K, Rytelewska E, Kisielewska K, Gudelska M, Bors K, Kopij G, Szymanska K, Kaminska B, Kaminski T, Smolinska N. The influence of orexin B on the transcriptome profile of porcine myometrial explants during early implantation. Theriogenology 2020; 156:205-213. [PMID: 32755720 DOI: 10.1016/j.theriogenology.2020.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 01/04/2023]
Abstract
This study aimed to determine the effect of orexin B (OXB) on the global expression pattern and the relationships among differentially expressed genes (DE-genes) in the transcriptome of myometrial explants during the early implantation period in the pig (day 15 of pregnancy). The changes in the transcriptome profile of the porcine myometrium were investigated using the Porcine (V2) Two-colour Gene Expression Microarray, 4 × 44. An analysis of the data from the microarray experiment revealed that 1540 DE-genes were affected by OXB, of which 1135 exhibited fold changes (FC) greater than 1.2 (P < 0.05). Among these, 576 genes were up-regulated and 559 genes were down-regulated. Among the affected biological processes in the myometrial tissue, 76 were enhanced and 31 were suppressed. Furthermore, the differential expression of nine genes, related to the regulation of reproductive functions and metabolic homeostasis, was confirmed by quantitative RT-PCR. A functional analysis of the relationships between DE-genes indicated that OXB interacts with the genes involved in the processes such as the inflammatory response, the response to interleukin-6, cytokine receptor activity, the regulation of cell activation, growth factor receptor binding, lipid modification and the steroid metabolic process. An analysis of DE-genes and their functional relationships suggests that OXB could be involved in the mechanisms such as the regulation of cell proliferation and development, inhibition of contractility, regulation of programmed cell death, and the development of blood vessels, all of which facilitate implantation.
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Affiliation(s)
- Ewa Zaobidna
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Kamil Dobrzyn
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Karol Szeszko
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Edyta Rytelewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Katarzyna Kisielewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Marlena Gudelska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Kinga Bors
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Grzegorz Kopij
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Karolina Szymanska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Barbara Kaminska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Tadeusz Kaminski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Nina Smolinska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
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Dobrzyn K, Kiezun M, Szeszko K, Kisielewska K, Rytelewska E, Gudelska M, Zaobidna E, Bors K, Kopij G, Szymanska K, Kaminska B, Kaminski T, Smolinska N. Orexin B affects the transcriptome of incubated in vitro porcine endometrial explants from the early-implantation period. Reprod Domest Anim 2020; 56:239-253. [PMID: 32402144 DOI: 10.1111/rda.13700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/23/2020] [Accepted: 05/05/2020] [Indexed: 01/11/2023]
Abstract
This study determined the effect of orexin B (OXB) on the porcine endometrial transcriptome during the embryo attachment phase. Microarray analyses of gene ontology (GO), biological pathways, networks and differentially expressed genes (DEG) were performed. Orexin B influenced the expression of 887 genes (fold change > 1.2; p < .05): 620 genes were up-regulated, and 267 were down-regulated. The analysis of the relationship between DEG revealed that OXB interacts with genes linked with processes such as cell hormone binding, regulation of hormone levels, lipid transport, steroid metabolic processes, the apoptotic signalling pathway and the acute inflammatory response, which are pivotal for reproductive success. Orexin B played a bivalent role in the early-pregnant uterus by limiting the pregnancy outcome, promoting embryo development, suppressing the immune system and, consequently, preventing embryo rejection. These findings suggest that OXB could be responsible for the proper course of gestation by adapting litter size to the metabolic status of the maternal organism.
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Affiliation(s)
- Kamil Dobrzyn
- 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
| | - Karol Szeszko
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - 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
| | - Ewa Zaobidna
- 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
| | - Grzegorz Kopij
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Karolina Szymanska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Barbara Kaminska
- 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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9
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Dobrzyn K, Kiezun M, Szeszko K, Gudelska M, Kisielewska K, Rytelewska E, Zaobidna E, Wyrebek J, Bors K, Kopij G, Kaminska B, Kaminski T, Smolinska N. The in vitro effect of orexin a on the porcine myometrial transcriptomic profile during the early-implantation period. Theriogenology 2019; 143:157-167. [PMID: 31875568 DOI: 10.1016/j.theriogenology.2019.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/20/2019] [Accepted: 12/06/2019] [Indexed: 01/11/2023]
Abstract
In pigs, early gestation is the most critical period deciding about the reproduction success, and it depends on many processes, involving a significant number of genes and their products. Myometrium was found to be an important source of factors pivotal for a proper course of gestation. The aim of the study was to determine the effect of orexin A (OXA) on the porcine transcriptome, and the determination of relationships among differentially expressed genes (DEG) in the porcine myometrium during implantation using microarray technology. The analyses of gene ontology (GO), DEG assays, biological pathways and networks were performed. OXA affected the expression of 461 genes with fold-change values greater than 1.2 (p < 0.05). The expression of 260 genes were up-regulated and 201 down-regulated in the OXA-treated myometrium. Twelve genes were selected for qPCR validation of differential expression based on their known role in angiogenesis, immune processes, steroid hormone signaling and prostaglandins synthesis. The analysis of relationship between DEG indicated that OXA interacts with genes involved in the inflammatory response, cytokine binding, cytokine activity, interleukin production, leukocyte migration, angiogenesis and embryonic hemopoiesis. The presented results suggest that OXA may play a key role in ensuring optimal conditions for implanting embryos.
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Affiliation(s)
- Kamil Dobrzyn
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Karol Szeszko
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Marlena Gudelska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Katarzyna Kisielewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Edyta Rytelewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Ewa Zaobidna
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Joanna Wyrebek
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Kinga Bors
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Grzegorz Kopij
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Barbara Kaminska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Tadeusz Kaminski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
| | - Nina Smolinska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn-Kortowo, Poland.
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10
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Rytelewska E, Kisielewska K, Gudelska M, Kiezun M, Dobrzyn K, Bors K, Wyrebek J, Kaminska B, Kaminski T, Smolinska N. The effect of orexin a on the StAR, CYP11A1 and HSD3B1 gene expression, as well as progesterone and androstenedione secretion in the porcine uterus during early pregnancy and the oestrous cycle. Theriogenology 2019; 143:179-190. [PMID: 31733930 DOI: 10.1016/j.theriogenology.2019.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 09/24/2019] [Accepted: 10/13/2019] [Indexed: 12/16/2022]
Abstract
Orexin A (OXA) is primarily known for its involvement in the regulation of feeding behaviour, energy metabolism and sleep/wake cycle. Nevertheless, studies indicate its engagement in the regulation of the porcine reproductive system. Therefore, the aim of this study was to investigate OXA effect (1, 10, 100 nM), in the presence or absence of the selective orexin receptor type 1 antagonist (SB-3348667; 1 μM), on the gene expression of key steroidogenic enzymes: steroidogenic acute regulatory protein (StAR), P450 side-chain cleavage enzyme (CYP11A1) and 3β-hydroxysteroid dehydrogenase (HSD3B1), as well as on progesterone (P4) and androstenedione (A4) secretion. Endometrial and myometrial tissue explants were collected from gilts on days 10 to 11, 12 to 13, 15 to 16 and 27 to 28 of pregnancy, and on days 10 to 11 of the oestrous cycle (n = 5 per studied period of pregnancy or mid-luteal phase of the oestrous cycle). Gene expression was evaluated by real-time PCR. The level of steroid hormones secreted into the culture medium was examined by radioimmunoassay (RIA). In the present study, in the endometrium, OXA significantly stimulated StAR expression on days 12 to 13, CYP11A1 expression on days 27 to 28 and HSD3B1 expression on days 15 to 16 of pregnancy. Further, in this tissue, OXA decreased StAR mRNA level on days 10 to 11, CYP11A1 mRNA level on days 15 to 16, as well as HSD3B1 mRNA level on days 10 to 11 and 12 to 13 of gestation. Regarding the myometrium, OXA stimulated CYP11A1 gene expression on days 15 to 16 of pregnancy. In this tissue, OXA decreased StAR transcript content on days 15 to 16 and CYP11A1 mRNA level on days 27 to 28. We also demonstrated that OXA alone enhanced P4 secretion in the endometrium on days 10 to 11 and 12 to 13 of gestation. OXA alone has no significant effect on endometrial and myometrial A4 secretion, whereas OXA in combination with OX1R antagonist increased this hormone secretion during all studied stages of pregnancy. Therefore, we can conclude that OXA may affect de novo synthesis and secretion of P4 and A4 in the porcine uterus via participating in the regulation of key steroidogenic enzymes gene expression, as well as modulating steroid hormones secretion during early pregnancy and mid-luteal phase of the oestrous cycle in pigs. However, further research is required to explain the exact role of OXA in the porcine uterus.
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Affiliation(s)
- Edyta Rytelewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Katarzyna Kisielewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Marlena Gudelska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Kamil Dobrzyn
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Kinga Bors
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Joanna Wyrebek
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Barbara Kaminska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Tadeusz Kaminski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
| | - Nina Smolinska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-718, Olsztyn, Poland.
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11
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Dobrzyn K, Szeszko K, Kiezun M, Kisielewska K, Rytelewska E, Gudelska M, Wyrebek J, Bors K, Kaminski T, Smolinska N. In vitro effect of orexin A on the transcriptomic profile of the endometrium during early pregnancy in pigs. Anim Reprod Sci 2019; 200:31-42. [DOI: 10.1016/j.anireprosci.2018.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/25/2018] [Accepted: 11/16/2018] [Indexed: 01/04/2023]
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12
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Hosseini A, Khazali H. Central Orexin A Affects Reproductive Axis by Modulation of Hypothalamic Kisspeptin/Neurokinin B/Dynorphin Secreting Neurons in the Male Wistar Rats. Neuromolecular Med 2018; 20:525-536. [PMID: 30218420 DOI: 10.1007/s12017-018-8506-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/10/2018] [Indexed: 02/08/2023]
Abstract
It is an established fact that orexin plays an important role in regulating the reproductive axis and the secretions of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH). However, its precise cellular and molecular mechanisms are not fully recognized. Accordingly, the aim of the present study is to find out whether the central injection of orexin A (OXA) and its antagonists, SB-334867 (as orexin receptor antagonist 1; OX1RA) and JNJ-10397049 (as orexin receptor antagonist 2; OX2RA), either alone or in combination, can leave any impact on the reproductive axis (either hormonal or behavioral) in the male Wistar rats. Furthermore, in order to see whether OXA signals can be relayed through the pathway of kisspeptin/neurokinin B/dynorphin (known as KNDy neurons, a neural network which works upstream of GnRH neurons) or not, the relative gene expression of these neuropeptides were measured. Overall, the data from radioimmunoassay revealed that OXA significantly decreases the mean serum level of LH and testosterone and, in a similar vein, its antagonists neutralize this impact. Moreover, data from real-time quantitative PCR indicated that OXA has significantly reduced the hypothalamic expression of Gnrh. In this line, the gene expressions of Kisspeptin and Neurokinin b decreased. However, OXA antagonists neutralize this impact. Also, the expression of Dynorphin gene was upregulated by the following application of the OXA. The results of this study are related to the impact of orexin on the reproductive axis. It is recommended that KNDy neurons as the interneural pathway relay the information of orexin to the GnRH neurons.
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Affiliation(s)
- Abdolkarim Hosseini
- Department of Animal Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Homayoun Khazali
- Department of Animal Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
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13
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Grafe LA, Bhatnagar S. The contribution of orexins to sex differences in the stress response. Brain Res 2018; 1731:145893. [PMID: 30081036 DOI: 10.1016/j.brainres.2018.07.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/22/2018] [Accepted: 07/12/2018] [Indexed: 02/07/2023]
Abstract
Women are twice as likely as men to suffer from stress-related psychiatric disorders, such as post-traumatic stress disorder (PTSD) and Major Depressive Disorder (MDD), however, the biological basis of these sex differences is not fully understood. Interestingly, orexins are known to be dysregulated in these disorders. This review first discusses the important role of orexins regulating the response to stress. Next, we review the evidence for sex differences in the orexin system, in which the majority of both preclinical and clinical studies have reported higher orexin system expression in females. Finally, we discuss the functional consequences of these sex differences in orexin expression. Most importantly, the preclinical literature reveals that higher orexin system activity in females contributes to exaggerated neuroendocrine and behavioral responses to stress. In sum, the available data suggests that orexins may be important in the etiology of stress-related psychiatric disorders that present differently in men and women. Thus, targeting orexins could potentially ameliorate many phenotypes of stress-related illness in a sex-specific way.
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Affiliation(s)
- Laura A Grafe
- Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Seema Bhatnagar
- Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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14
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Linehan V, Hirasawa M. Electrophysiological Properties of Melanin-Concentrating Hormone and Orexin Neurons in Adolescent Rats. Front Cell Neurosci 2018; 12:70. [PMID: 29662440 PMCID: PMC5890094 DOI: 10.3389/fncel.2018.00070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 02/27/2018] [Indexed: 01/05/2023] Open
Abstract
Orexin and melanin-concentrating hormone (MCH) neurons have complementary roles in various physiological functions including energy balance and the sleep/wake cycle. in vitro electrophysiological studies investigating these cells typically use post-weaning rodents, corresponding to adolescence. However, it is unclear whether these neurons are functionally mature at this period and whether these studies can be generalized to adult cells. Therefore, we examined the electrophysiological properties of orexin and MCH neurons in brain slices from post-weaning rats and found that MCH neurons undergo an age-dependent reduction in excitability, but not orexin neurons. Specifically, MCH neurons displayed an age-dependent hyperpolarization of the resting membrane potential (RMP), depolarizing shift of the threshold, and decrease in excitatory transmission, which reach the adult level by 7 weeks of age. In contrast, basic properties of orexin neurons were stable from 4 weeks to 14 weeks of age. Furthermore, a robust short-term facilitation of excitatory synapses was found in MCH neurons, which showed age-dependent changes during the post-weaning period. On the other hand, a strong short-term depression was observed in orexin neurons, which was similar throughout the same period. These differences in synaptic responses and age dependence likely differentially affect the network activity within the lateral hypothalamus where these cells co-exist. In summary, our study suggests that orexin neurons are electrophysiologically mature before adolescence whereas MCH neurons continue to develop until late adolescence. These changes in MCH neurons may contribute to growth spurts or consolidation of adult sleep patterns associated with adolescence. Furthermore, these results highlight the importance of considering the age of animals in studies involving MCH neurons.
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Affiliation(s)
- Victoria Linehan
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John's, NL, Canada
| | - Michiru Hirasawa
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John's, NL, Canada
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Affiliation(s)
- Olaf Jöhren
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
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16
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Cataldi NI, Lux-Lantos VA, Libertun C. Perinatal programming of the orexinergic (hypocretinergic) system in hypothalamus and anterior pituitary by testosterone. Peptides 2018; 99:117-127. [PMID: 28442349 DOI: 10.1016/j.peptides.2017.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 01/12/2023]
Abstract
Orexins A/B derived from hypothalamic prepro-orexin (PPO) are agonists for orexin receptors 1 (OX1) and 2 (OX2). Previously, we showed clear sex differences in the hypothalamic-pituitary-gonadal orexinergic system in adult rodents. Here, we studied the effect of sexual brain differentiation on the orexinergic system in neuroendocrine structures regulating reproduction. We evaluated: a: proestrous and neonatally androgenized female rats; b: adult males, untreated or gonadectomized in adulthood and injected with oil or estradiol and progesterone (E2/P4); c: control and demasculinized males (perinatally treated with flutamide and later castration) injected either with oil or E2/P4 in adulthood. Rats were sacrificed at 12:00 and 18:00h; blood samples and brains were collected. Hormones were measured using radioimmunoassay. PPO, OX1 and OX2 mRNAs were quantified by qPCR in medial basal hypothalamus, anterior hypothalamus, adenohypophysis, and cortex. Western blots for OX1 were done in the same structures. In normal females, gonadotropins surged at 18:00h coinciding with significant elevations of PPO, OX1 and OX2 mRNAs and OX1 protein in hypothalamus and pituitary; no increases were observed at noon. Afternoon changes were absent in masculinized females. Demasculinized males when treated with E2/P4 showed high PPO, OX1 and OX2 mRNAs and OX1 protein expression in hypothalamus and pituitary at 12:00 and 18:00h compared vehicle-treated controls. The same steroid treatment was ineffective in males with normal brain masculinization. Here we show that neonatal testosterone shapes the sexual differences in the hypothalamic-pituitary orexinergic system in synchronicity to establishing the brain sex differences of the reproductive axis. The female brain controls gonadotropin surges and concurrent elevations of all studied components of the orexinergic system, suggesting its participation as a possible link between food intake, behavior and hormonal control of reproduction.
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Affiliation(s)
| | | | - Carlos Libertun
- Instituto de Biología y Medicina Experimental-CONICET, Argentina; Universidad de Buenos Aires, Facultad de Medicina, Departamento de Fisiología y Biofísica, Buenos Aires, Argentina.
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17
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Activation of 5-HT 2A receptor disrupts rat maternal behavior. Neuropharmacology 2017; 128:96-105. [PMID: 28965828 DOI: 10.1016/j.neuropharm.2017.09.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/26/2017] [Accepted: 09/26/2017] [Indexed: 11/21/2022]
Abstract
Serotonin 5-HT2A receptor is widely distributed in the central nervous system and plays an important role in sensorimotor function, emotion regulation, motivation, executive control, learning and memory. We investigated its role in rat maternal behavior, a naturalistic behavior encompassing many psychological functions that the 5-HT2A receptor is involved in. We first showed that activation of 5-HT2A receptor by TCB-2 (a highly selective 5-HT2A agonist, 1, 2.5 or 5.0 mg/kg) disrupted maternal behavior dose-dependently, and this effect was reduced by pretreatment with a 5-HT2A receptor antagonist MDL 100907, but exacerbated by pretreatment with a 5-HT2C receptor antagonist SB242084 and a 5-HT2C receptor agonist MK212, indicating that the maternal disruptive effect of 5-HT2A activation is receptor-specific and can be modulated by 5-HT2C receptor bidirectionally. We then microinjected TCB-2 into two brain regions important for the normal expression of maternal behavior: the medial prefrontal cortex (mPFC) and the medial preoptic area (mPOA) and found that only acute intra-mPFC infusion of TCB-2 suppressed pup retrieval, whereas intra-mPOA had no effect. Finally, using c-Fos immunohistochemistry, we identified that the ventral bed nucleus of stria terminalis (vBNST), the central amygdala (CeA), and the dorsal raphe (DR) were additionally involved in the maternal-disruptive effect of TCB-2. These findings suggest that the 5-HT2A receptor in the mPFC and other maternally related regions is required for the normal expression of maternal behavior through its intrinsic action or interactions with other receptors (e.g. 5-HT2C). Functional disruption of this neuroreceptor system might contribute to postpartum mental disorders (e.g. depression and psychosis) that impair the quality of maternal care.
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18
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Fernandez MO, Hsueh K, Park HT, Sauceda C, Hwang V, Kumar D, Kim S, Rickert E, Mahata S, Webster NJG. Astrocyte-Specific Deletion of Peroxisome-Proliferator Activated Receptor- γ Impairs Glucose Metabolism and Estrous Cycling in Female Mice. J Endocr Soc 2017; 1:1332-1350. [PMID: 29264458 PMCID: PMC5686676 DOI: 10.1210/js.2017-00242] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/15/2017] [Indexed: 01/21/2023] Open
Abstract
Mice lacking peroxisome-proliferator activated receptor-γ (PPARγ) in neurons do not become leptin resistant when placed on a high-fat diet (HFD). In male mice, this results in decreased food intake and increased energy expenditure, causing reduced body weight, but this difference in body weight is not observed in female mice. In addition, estrous cycles are disturbed and the ovaries present with hemorrhagic follicles. We observed that PPARγ was more highly expressed in astrocytes than neurons, so we created an inducible, conditional knockout of PPARγ in astrocytes (AKO). The AKO mice had impaired glucose tolerance and hepatic steatosis that did not worsen with HFD. Expression of gluconeogenic genes was elevated in the mouse livers, as was expression of several genes involved in lipogenesis, lipid transport, and storage. The AKO mice also had a reproductive phenotype with fewer estrous cycles, elevated plasma testosterone levels, reduced corpora lutea formation, and alterations in hypothalamic and ovarian gene expression. Thus, the phenotypes of the AKO mice were very different from those seen in the neuronal knockout mice, suggesting distinct roles for PPARγ in these two cell types.
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Affiliation(s)
- Marina O Fernandez
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093.,Laboratory of Neuroendocrinology, Instituto de Biología y Medicina Experimental, CONICET. Vuelta de Obligado 2490, C1428ADN, Buenos Aires, Argentina
| | - Katherine Hsueh
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Hyun Tae Park
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093.,Department of Obstetrics and Gynecology, Korea University Anam Hospital, Seoul 136-705, Korea
| | - Consuelo Sauceda
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Vicky Hwang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Deepak Kumar
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Sun Kim
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Emily Rickert
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Sumana Mahata
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Nicholas J G Webster
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093.,Medical Research Service, VA San Diego Healthcare System, San Diego, California 92161.,Moores Cancer Center, University of California San Diego, La Jolla, California 92093
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19
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Joshi D, Singh SK. Localization and expression of Orexin A and its receptor in mouse testis during different stages of postnatal development. Gen Comp Endocrinol 2017; 241:50-56. [PMID: 27174745 DOI: 10.1016/j.ygcen.2016.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/29/2016] [Accepted: 05/06/2016] [Indexed: 11/25/2022]
Abstract
Orexin A (OXA), a hypothalamic neuropeptide, is involved in regulation of various biological functions and its actions are mediated through G-protein-coupled receptor, OX1R. This neuropeptide has emerged as a central neuroendocrine modulator of reproductive functions. Both OXA and OX1R have been shown to be expressed in peripheral organs such as gastrointestinal and genital tracts. In the present study, localization and expression of OXA and OX1R in mouse testis during different stages of postnatal development have been investigated. Immunohistochemical results demonstrated localization of OXA and OX1R in both the interstitial and the tubular compartments of the testis throughout the period of postnatal development. In testicular sections on 0day postpartum (dpp), gonocytes, Sertoli cells and foetal Leydig cells showed OXA and OX1R-immunopositive signals. At 10dpp, Sertoli cells, spermatogonia, early spermatocytes and Leydig cells showed immunopositive signals for both, the ligand and the receptor. On 30 and 90dpp, the spermatogonia, Sertoli cells, spermatocytes, spermatids and Leydig cells showed the OXA and OX1R-immunopositive signals. At 90dpp, strong OXA-positive signals were seen in Leydig cells, primary spermatocytes and spermatogonia, while OX1R-immunopositive intense signals were observed in Leydig cells and elongated spermatids. Further, semiquantitative RT-PCR and immunoblot analyses showed that OXA and OX1R were expressed in the testis both at transcript and protein levels during different stages of postnatal development. The expression of OXA and OX1R increased progressively from day of birth (0dpp) until adulthood (90dpp), with maximal expression at 90 dpp. The results suggest that OXA and OX1R are expressed in the testis and that they may help in proliferation and development of germ cells, Leydig cells and Sertoli cells, and in the spermatogenic process and steroidogenesis.
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Affiliation(s)
- Deepanshu Joshi
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India
| | - Shio Kumar Singh
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India.
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20
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Joshi D, Singh SK. Localization, expression and role of Orexin A and its receptor in testes of neonatal mice. Gen Comp Endocrinol 2016; 239:62-70. [PMID: 26562300 DOI: 10.1016/j.ygcen.2015.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 11/02/2015] [Accepted: 11/08/2015] [Indexed: 11/26/2022]
Abstract
Orexin A (OXA), a hypothalamic neuropeptide, and its receptor (OX1R) are primarily expressed in lateral hypothalamus and are involved in the control of various biological functions. Expressions of OXA and OX1R have also been reported in peripheral organs like gastrointestinal and genital tracts. In the present study, expressions of OXA and OX1R have been observed in the testis of Parkes strain neonatal mice by semi-quantitative RT-PCR and western blot analyses. Immunohistochemical study also revealed their presence on spermatogonia, Sertoli cells and in the interstitium of the testis. In order to understand the role of OXA and OX1R in testicular development, an in vitro study was also performed. For this, binding of OXA to OX1R was blocked using OX1R specific antagonist, SB-334867. Eighteen mice were sacrificed and their testes were cultured in complete media containing vehicle and two doses (0.1 and 4.0μg/ml media) of SB-334867 for 72h in CO2 incubator at 37°C. At the end of culture period, testes were used for western blot and RT-PCR analyses to study the expression of various markers of gonadal development, such as steroidogenic factor 1 (SF-1), Wilms' tumor 1 (Wt1), Mullerian inhibiting substance (MIS) and stem cell factor (SCF). Further, expressions of OXA, OX1R and glucose transporter 3 (GLUT 3) were also studied. A marked increase in the expression of SF-1 and a decrease in the expression of Wt1 at both transcript and protein levels were noted, while there was a decrease in the expression of SCF and MIS at transcript level at both doses of the antagonist; this suggests that blockage of OXA binding to OX1R by SB-334867 affects testicular development. The decrease in expressions of OXA, OX1R and GLUT 3 in the test is in response to both doses of the antagonist points to their down-regulation causing inefficient uptake of glucose by the testicular cells, thereby affecting gonadal development. In conclusion, our results suggest that the binding of OXA to OX1R is important for the development of the testis.
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Affiliation(s)
- Deepanshu Joshi
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India
| | - Shio Kumar Singh
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India.
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21
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The effect of orexin A on CYP17A1 and CYP19A3 expression and on oestradiol, oestrone and testosterone secretion in the porcine uterus during early pregnancy and the oestrous cycle. Theriogenology 2016; 90:129-140. [PMID: 28166959 DOI: 10.1016/j.theriogenology.2016.11.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/20/2016] [Accepted: 11/26/2016] [Indexed: 11/20/2022]
Abstract
Orexin A (OXA) is a hypothalamic neuropeptide known for its role in the regulation of food intake and arousal. It is also considered as a link between energy homeostasis and reproduction. Nevertheless, very little is known on the role of this peptide in the uterus. The objective of this study was to investigate OXA effect on oestradiol (E2), oestrone (E1), and testosterone (T) secretion by porcine endometrial and myometrial explants and gene expression of key steroidogenic enzymes involved in steroid production, namely cytochrome P450c17 (CYP17A1) and cytochrome P450 aromatase (CYP19A3), on days 10-11, 12 to 13, 15 to 16 and 27 to 28 of pregnancy and on days 10-11 of the cycle. In endometrium, OXA increased E1 secretion on days 10-11 and 15 to 27 of gestation, and T release on days 12-13. A decrease in E2, E1 and T secretion was noted on days 27-28, 12 to 13 and 10 to 11 of gestation, respectively. OXA enhanced CYP17A1 and CYP19A3 expression on days 15-28 of pregnancy, whereas decreased their expression on days 10-13. In the myometrium, OXA increased E1 secretion on days 10-16 of pregnancy, whereas inhibited the release of E2 and T on days 10-11. CYP17A1 and CYP19A3 genes expression was enhanced on days 27-28 and 12 to 13 of pregnancy, respectively. The expression of both genes was suppressed on days 10-11 and 15 to 16 of pregnancy (P < 0.05). Our findings suggest that OXA, via its influence on steroidogenesis, may play a regulatory role in the uterus.
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Behavioral, pharmacological and neuroanatomical analysis of serotonin 2C receptor agonism on maternal behavior in rats. Psychoneuroendocrinology 2016; 73:252-262. [PMID: 27566488 PMCID: PMC5048576 DOI: 10.1016/j.psyneuen.2016.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/28/2016] [Accepted: 08/15/2016] [Indexed: 01/23/2023]
Abstract
As a highly motivated social behavior, maternal behavior in rats has been routinely used to study psychoactive drugs for clinical, neuroscience and pharmacological purposes. Recent evidence indicates that acute activation of serotonin 2C (5-HT2C) receptors causes a disruption of rat maternal behavior. The present study was designed to elucidate the behavioral, pharmacological mechanisms and neuroanatomical basis of this 5-HT2C effect. First, we replicated the finding that acute MK212 injection (2.0mg/kg, a highly selective 5-HT2C agonist) disrupts maternal behavior, especially on pup retrieval. Interestingly, this disruption was significantly attenuated by 4-h pup separation (a procedure putatively increased maternal motivation). MK212 also suppressed food retrieval, indicating that it has a general effect on motivated behaviors. Second, we showed that MK212 disrupts maternal behavior by specifically activating 5-HT2C receptor, as pretreatment with a 5-HT2C receptor antagonist SB242084 (0.6 and 1.0mg/kg) alleviated MK212-induced disruption on pup retrieval. Third, we microinjected MK212 into various brain regions implicated in the regulation of maternal behavior: nucleus accumbens shell (25, 75, 250ng/0.5μl/side), medial prefrontal cortex (25 and 250ng, 1, 2 and 5μg/0.5μl/side), and medial preoptic area (MPOA, 75ng, 1 and 5μg/0.5μl/side). Pup retrieval and other maternal responses were not affected by any of these manipulations. Finally, we used c-Fos immunohistochemistry to identify the central mechanisms of the acute and repeated MK212 effects on maternal behavior. Acute MK212 (2.0mg/kg) disrupted pup retrieval and concurrently decreased c-Fos expression in the ventral part of lateral septal nucleus (LSv), MPOA, dentate gyrus (DG) and dorsal raphe (DR), but increased it in the central amygdala (CeA). Five days of repeated MK212 (2.0mg/kg) treatment produced a persistent disruption of pup retrieval and only decreased c-Fos expression in the DR. These findings not only confirm a role of 5-HT2C receptor in rat maternal behavior, but also suggest that the coordinated 5-HT2C activity in various limbic (e.g., LSv, DG, CeA), hypothalamic regions (e.g., MPOA) and brainstem areas (e.g. DR), is likely involved in the mediation of important psychological processes (e.g. motor function, motivation) necessary for the normal expression of maternal behavior.
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Zhao Y, Singh C, Prober DA, Wayne NL. Morphological and Physiological Interactions Between GnRH3 and Hypocretin/Orexin Neuronal Systems in Zebrafish (Danio rerio). Endocrinology 2016; 157:4012-4020. [PMID: 27533887 PMCID: PMC5045510 DOI: 10.1210/en.2016-1381] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/11/2016] [Indexed: 01/11/2023]
Abstract
GnRH neurons integrate internal and external cues to control sexual maturation and fertility. Homeostasis of energy balance and food intake correlates strongly with the status of reproduction. Neuropeptides secreted by the hypothalamus involved in modulating energy balance and feeding may play additional roles in the regulation of reproduction. Hypocretin (Hcrt) (also known as orexin) is one such peptide, primarily controlling sleep/wakefulness, food intake, and reward processing. There is a growing body of evidence indicating that Hcrt/orexin (Hcrt) modulates reproduction through interacting with the hypothalamo-pituitary-gonadal axis in mammals. To explore potential morphological and functional interactions between the GnRH and Hcrt neuronal systems, we employed a variety of experimental approaches including confocal imaging, immunohistochemistry, and electrophysiology in transgenic zebrafish, in which fluorescent proteins are genetically expressed in GnRH3 and Hcrt neurons. Our imaging data revealed close apposition and direct connection between GnRH3 and Hcrt neuronal systems in the hypothalamus during larval development through adulthood. Furthermore, the Hcrt receptor (HcrtR) is expressed in GnRH3 neurons. Electrophysiological data revealed a reversible inhibitory effect of Hcrt on GnRH3 neuron electrical activity, which was blocked by the HcrtR antagonist almorexant. In addition, Hcrt had no effect on the electrical activity of GnRH3 neurons in the HcrtR null mutant zebrafish (HcrtR-/-). Our findings demonstrate a close anatomical and functional relationship between Hcrt and GnRH neuronal systems in zebrafish. It is the first demonstration of a link between neuronal circuits controlling sleeping/arousal/feeding and reproduction in zebrafish, an important animal model for investigating the molecular genetics of development.
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Affiliation(s)
- Yali Zhao
- Department of Physiology (Y.Z., N.L.W.), David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095; and Division of Biology and Biological Engineering (C.S., D.P.), California Institute of Technology, Pasadena, California 91125
| | - Chanpreet Singh
- Department of Physiology (Y.Z., N.L.W.), David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095; and Division of Biology and Biological Engineering (C.S., D.P.), California Institute of Technology, Pasadena, California 91125
| | - David A Prober
- Department of Physiology (Y.Z., N.L.W.), David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095; and Division of Biology and Biological Engineering (C.S., D.P.), California Institute of Technology, Pasadena, California 91125
| | - Nancy L Wayne
- Department of Physiology (Y.Z., N.L.W.), David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095; and Division of Biology and Biological Engineering (C.S., D.P.), California Institute of Technology, Pasadena, California 91125
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Salimi M, Alishah Z, Khazali H, Mahmoudi F. Orexin Decreases Aromatase Gene Expression in The Hypothalamus of Androgenized Female Rats. INTERNATIONAL JOURNAL OF FERTILITY & STERILITY 2016; 10:190-5. [PMID: 27441052 PMCID: PMC4948071 DOI: 10.22074/ijfs.2016.4909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 07/11/2015] [Indexed: 11/04/2022]
Abstract
BACKGROUND Orexin is a hypothalamic orexigenic neuropeptide, which third cerebral injection of it mainly exerts inhibitory effects on reproductive functions. It increases significantly the Aromatase (Cyp19) gene expression in the hypothalamus of male rats. Aromatase is an enzyme which converts androgens to estradiol in the hypothalamus of rats. Prenatal or neonatal exposure of females to testosterone masculinizes the pattern of Cyp19 mRNA levels in adulthood. In the present study the effects of central injections of orexin-A on hypothalamic Cyp19 gene expression of adult female rats were investigated, while they had been androgenized on third day of postnatal life. MATERIALS AND METHODS In this experimental study, twenty female Wistar rats received subcutaneous injections of testosterone propionate (50 µg/100 µl) on their third day of postnatal life. Adult androgenized rats weighing 180-220 g, received either 3 µl saline or one of 2, 4 or 8 µg/3 µl concentration of orexin via third cerebral ventricle. Five non-androgenized rats, as control group, received intra cerebral ventricle (ICV) injection of 3 µl saline. The hypothalamuses were dissected out and mean Cyp19 mRNA levels were determined by semi-quantitative real time-polymerase chain reaction (PCR) method. Data were analyzed by unpaired t test and one-way ANOVA using SPSS software, version 16. RESULTS Mean relative Cyp19 mRNA level was significantly increased in the hypothalamus of androgenized compared to non-androgenized female rats. Central injec- tions of 2, 4 or 8 µg/3 µl orexin decreased significantly the hypothalamic Cyp19 mRNA level of androgenized rats compared to androgenized-control groups. CONCLUSION The results suggested that the orexin may exert inhibitory effects on the gene expression of Cyp19 in the hypothalamus of neonatal androgenized female rats in adulthood.
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Affiliation(s)
- Maliheh Salimi
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Zahra Alishah
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Homayoun Khazali
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Fariba Mahmoudi
- Department of Biology, Facualty of Basic Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
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Pace M, Baracchi F, Gao B, Bassetti C. Identification of Sleep-Modulated Pathways Involved in Neuroprotection from Stroke. Sleep 2015; 38:1707-18. [PMID: 26085290 DOI: 10.5665/sleep.5148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/13/2015] [Indexed: 12/21/2022] Open
Abstract
STUDY OBJECTIVES Sleep deprivation (SDp) performed before stroke induces an ischemic tolerance state as observed in other forms of preconditioning. As the mechanisms underlying this effect are not well understood, we used DNA oligonucleotide microarray analysis to identify the genes and the gene-pathways underlying SDp preconditioning effects. DESIGN Gene expression was analyzed 3 days after stroke in 4 experimental groups: (i) SDp performed before focal cerebral ischemia (IS) induction; (ii) SDp performed before sham surgery; (iii) IS without SDp; and (iv) sham surgery without SDp. SDp was performed by gentle handling during the last 6 h of the light period, and ischemia was induced immediately after. SETTINGS Basic sleep research laboratory. MEASUREMENTS AND RESULTS Stroke induced a massive alteration in gene expression both in sleep deprived and non-sleep deprived animals. However, compared to animals that underwent ischemia alone, SDp induced a general reduction in transcriptional changes with a reduction in the upregulation of genes involved in cell cycle regulation and immune response. Moreover, an upregulation of a new neuroendocrine pathway which included melanin concentrating hormone, glycoprotein hormones-α-polypeptide and hypocretin was observed exclusively in rats sleep deprived before stroke. CONCLUSION Our data indicate that sleep deprivation before stroke reprogrammed the signaling response to injury. The inhibition of cell cycle regulation and inflammation are neuroprotective mechanisms reported also for other forms of preconditioning treatment, whereas the implication of the neuroendocrine function is novel and has never been described before. These results therefore provide new insights into neuroprotective mechanisms involved in ischemic tolerance mechanisms.
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Affiliation(s)
- Marta Pace
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Francesca Baracchi
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland
| | - Bo Gao
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland
| | - Claudio Bassetti
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
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Skrapits K, Kanti V, Savanyú Z, Maurnyi C, Szenci O, Horváth A, Borsay BÁ, Herczeg L, Liposits Z, Hrabovszky E. Lateral hypothalamic orexin and melanin-concentrating hormone neurons provide direct input to gonadotropin-releasing hormone neurons in the human. Front Cell Neurosci 2015; 9:348. [PMID: 26388735 PMCID: PMC4559643 DOI: 10.3389/fncel.2015.00348] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 08/20/2015] [Indexed: 12/03/2022] Open
Abstract
Hypophysiotropic projections of gonadotropin-releasing hormone (GnRH)-synthesizing neurons form the final common output way of the hypothalamus in the neuroendocrine control of reproduction. Several peptidergic neuronal systems of the medial hypothalamus innervate human GnRH cells and mediate crucially important hormonal and metabolic signals to the reproductive axis, whereas much less is known about the contribution of the lateral hypothalamic area to the afferent control of human GnRH neurons. Orexin (ORX)- and melanin-concentrating hormone (MCH)-synthesizing neurons of this region have been implicated in diverse behavioral and autonomic processes, including sleep and wakefulness, feeding and other functions. In the present immunohistochemical study, we addressed the anatomical connectivity of these neurons to human GnRH cells in post-mortem hypothalamic samples obtained from autopsies. We found that 38.9 ± 10.3% and 17.7 ± 3.3% of GnRH-immunoreactive (IR) perikarya in the infundibular nucleus of human male subjects received ORX-IR and MCH-IR contacts, respectively. On average, each 1 mm segment of GnRH dendrites received 7.3 ± 1.1 ORX-IR and 3.7 ± 0.5 MCH-IR axo-dendritic appositions. Overall, the axo-dendritic contacts dominated over the axo-somatic contacts and represented 80.5 ± 6.4% of ORX-IR and 76.7 ± 4.6% of MCH-IR inputs to GnRH cells. Based on functional evidence from studies of laboratory animals, the direct axo-somatic and axo-dendritic input from ORX and MCH neurons to the human GnRH neuronal system may convey critical metabolic and other homeostatic signals to the reproducive axis. In this study, we also report the generation and characterization of new antibodies for immunohistochemical detection of GnRH neurons in histological sections.
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Affiliation(s)
- Katalin Skrapits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Vivien Kanti
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Zsófia Savanyú
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Csilla Maurnyi
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Ottó Szenci
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University Üllő, Hungary ; MTA-SZIE Large Animal Clinical Research Group, Dóra major Üllő, Hungary
| | - András Horváth
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University Üllő, Hungary
| | - Beáta Á Borsay
- Department of Forensic Medicine, Faculty of Medicine of the University of Debrecen Debrecen, Hungary
| | - László Herczeg
- Department of Forensic Medicine, Faculty of Medicine of the University of Debrecen Debrecen, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary ; Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University Budapest, Hungary
| | - Erik Hrabovszky
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
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Roa J, Tena-Sempere M. Connecting metabolism and reproduction: roles of central energy sensors and key molecular mediators. Mol Cell Endocrinol 2014; 397:4-14. [PMID: 25289807 DOI: 10.1016/j.mce.2014.09.027] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/26/2014] [Accepted: 09/26/2014] [Indexed: 12/15/2022]
Abstract
It is well established that pubertal activation of the reproductive axis and maintenance of fertility are critically dependent on the magnitude of body energy reserves and the metabolic state of the organism. Hence, conditions of impaired energy homeostasis often result in deregulation of puberty and reproduction, whereas gonadal dysfunction can be associated with the worsening of the metabolic profile and, eventually, changes in body weight. While much progress has taken place in our knowledge about the neuroendocrine mechanisms linking metabolism and reproduction, our understanding of how such dynamic interplay happens is still incomplete. As paradigmatic example, much has been learned in the last two decades on the reproductive roles of key metabolic hormones (such as leptin, insulin and ghrelin), their brain targets and the major transmitters and neuropeptides involved. Yet, the molecular mechanisms whereby metabolic information is translated and engages into the reproductive circuits remain largely unsolved. In this work, we will summarize recent developments in the characterization of the putative central roles of key cellular energy sensors, such as mTOR, in this phenomenon, and will relate these with other molecular mechanisms likely contributing to the brain coupling of energy balance and fertility. In doing so, we aim to provide an updated view of an area that, despite still underdeveloped, may be critically important to fully understand how reproduction and metabolism are tightly connected in health and disease.
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Affiliation(s)
- Juan Roa
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Hospital Universitario Reina Sofia, 14004 Córdoba, Spain
| | - Manuel Tena-Sempere
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Hospital Universitario Reina Sofia, 14004 Córdoba, Spain.
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Li J, Hu Z, de Lecea L. The hypocretins/orexins: integrators of multiple physiological functions. Br J Pharmacol 2014; 171:332-50. [PMID: 24102345 DOI: 10.1111/bph.12415] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 07/16/2013] [Accepted: 08/02/2013] [Indexed: 12/28/2022] Open
Abstract
The hypocretins (Hcrts), also known as orexins, are two peptides derived from a single precursor produced in the posterior lateral hypothalamus. Over the past decade, the orexin system has been associated with numerous physiological functions, including sleep/arousal, energy homeostasis, endocrine, visceral functions and pathological states, such as narcolepsy and drug abuse. Here, we review the discovery of Hcrt/orexins and their receptors and propose a hypothesis as to how the orexin system orchestrates these multifaceted physiological functions.
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Affiliation(s)
- Jingcheng Li
- Department of Physiology, Third Military Medical University, Chongqing, China
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29
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Clarke IJ. Interface between metabolic balance and reproduction in ruminants: focus on the hypothalamus and pituitary. Horm Behav 2014; 66:15-40. [PMID: 24568750 DOI: 10.1016/j.yhbeh.2014.02.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 01/24/2023]
Abstract
This article is part of a Special Issue "Energy Balance". The interface between metabolic regulators and the reproductive system is reviewed with special reference to the sheep. Even though sheep are ruminants with particular metabolic characteristics, there is a broad consensus across species in the way that the reproductive system is influenced by metabolic state. An update on the neuroendocrinology of reproduction indicates the need to account for the way that kisspeptin provides major drive to gonadotropin releasing hormone (GnRH) neurons and also mediates the feedback effects of gonadal steroids. The way that kisspeptin function is influenced by appetite regulating peptides (ARP) is considered. Another newly recognised factor is gonadotropin inhibitory hormone (GnIH), which has a dual function in that it suppresses reproductive function whilst also acting as an orexigen. Our understanding of the regulation of food intake and energy expenditure has expanded exponentially in the last 3 decades and historical perspective is provided. The function of the regulatory factors and the hypothalamic cellular systems involved is reviewed with special reference to the sheep. Less is known of these systems in the cow, especially the dairy cow, in which a major fertility issue has emerged in parallel with selection for increased milk production. Other endocrine systems--the hypothalamo-pituitary-adrenal axis, the growth hormone (GH) axis and the thyroid hormones--are influenced by metabolic state and are relevant to the interface between metabolic function and reproduction. Special consideration is given to issues such as season and lactation, where the relationship between metabolic hormones and reproductive function is altered.
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Affiliation(s)
- Iain J Clarke
- Monash University, Department of Physiology, Wellington Road, Clayton 3168, Australia.
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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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Duncan MJ, Franklin KM, Peng X, Yun C, Legan SJ. Circadian rhythm disruption by a novel running wheel: roles of exercise and arousal in blockade of the luteinizing hormone surge. Physiol Behav 2014; 131:7-16. [PMID: 24727338 DOI: 10.1016/j.physbeh.2014.04.006] [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: 09/06/2013] [Revised: 03/26/2014] [Accepted: 04/03/2014] [Indexed: 11/24/2022]
Abstract
Exposure of proestrous Syrian hamsters to a new room, cage, and novel running wheel blocks the luteinizing hormone (LH) surge until the next day in ~75% of hamsters [1]. The studies described here tested the hypotheses that 1) exercise and/or 2) orexinergic neurotransmission mediate novel wheel blockade of the LH surge and circadian phase advances. Female hamsters were exposed to a 14L:10D photoperiod and activity rhythms were monitored with infra-red detectors. In Expt. 1, to test the effect of exercise, hamsters received jugular cannulae and on the next day, proestrus (Day 1), shortly before zeitgeber time 5 (ZT 5, 7h before lights-off) the hamsters were transported to the laboratory. After obtaining a blood sample at ZT 5, the hamsters were transferred to a new cage with a novel wheel that was either freely rotating (unlocked), or locked until ZT 9, and exposed to constant darkness (DD). Blood samples were collected hourly for 2days from ZT 5-11 under red light for determination of plasma LH levels by radioimmunoassay. Running rhythms were monitored continuously for the next 10-14days. The locked wheels were as effective as unlocked wheels in blocking LH surges (no Day 1 LH surge in 6/9 versus 8/8 hamsters, P>0.05) and phase advances in the activity rhythms did not differ between the groups (P=0.28), suggesting that intense exercise is not essential for novel wheel blockade and phase advance of the proestrous LH surge. Expt. 2 tested whether orexin neurotransmission is essential for these effects. Hamsters were treated the same as those in Expt. 1 except that they were injected (i.p.) at ZT 4.5 and 5 with either the orexin 1 receptor antagonist SB334867 (15mg/kg per injection) or vehicle (25% DMSO in 2-hydroxypropyl-beta-cyclodextrin (HCD)). SB-334867 inhibited novel wheel blockade of the LH surge (surges blocked in 2/6 SB334867-injected animals versus 16/18 vehicle-injected animals, P<0.02) and also inhibited wheel running and circadian phase shifts, indicating that activation of orexin 1 receptors is necessary for these effects. Expt. 3 tested the hypothesis that novel wheel exposure activates orexin neurons. Proestrous hamsters were transferred at ZT 5 to a nearby room within the animal facility and were exposed to a new cage with a locked or unlocked novel wheel or left in their home cages. At ZT 8, the hamsters were anesthetized, blood was withdrawn, they were perfused with fixative and brains were removed for immunohistochemical localization of Fos, GnRH, and orexin. Exposure to a wheel, whether locked or unlocked, suppressed circulating LH concentrations at ZT 8, decreased the proportion of Fos-activated GnRH neurons, and increased Fos-immunoreactive orexin cells. Unlocked wheels had greater effects than locked wheels on all three endpoints. Thus in a familiar environment, exercise potentiated the effect of the novel wheel on Fos expression because a locked wheel was not a sufficient stimulus to block the LH surge. In conclusion, these studies indicate that novel wheel exposure activates orexin neurons and that blockade of orexin 1 receptors prevents novel wheel blockade of the LH surge. These findings are consistent with a role for both exercise and arousal in mediating novel wheel blockade of the LH surge.
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Affiliation(s)
- Marilyn J Duncan
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, United States.
| | - Kathleen M Franklin
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, United States
| | - Xiaoli Peng
- Department of Physiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, United States
| | - Christopher Yun
- Department of Physiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, United States
| | - Sandra J Legan
- Department of Physiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, United States
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The effect of the estrous cycle on the expression of prepro-orexin gene and protein and the levels of orexin A and B in the porcine pituitary. Animal 2014; 8:300-7. [DOI: 10.1017/s1751731113002152] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Orexin A and B in vitro modify orexins receptors expression and gonadotropins secretion of anterior pituitary cells of proestrous rats. ACTA ACUST UNITED AC 2013; 188:25-30. [PMID: 24333629 DOI: 10.1016/j.regpep.2013.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 11/27/2013] [Accepted: 12/04/2013] [Indexed: 11/22/2022]
Abstract
AIM Orexin A and orexin B (hypocretins) are neuropeptides synthesized mainly by neurons located in the lateral hypothalamus and projections throughout the brain. They are agonists at both the orexin 1 and orexin 2G protein-coupled receptors. They have been related to arousal, sleep and feeding, autonomic and neuroendocrine functions. Their role in the brain control of gonadotropins secretion was postulated in rodents and humans. Previously, we demonstrated the participation of the orexinergic system in attaining successful reproduction in in vivo studies. METHODS We studied in vitro the effects of both neuropeptides, in the presence or absence of selective antagonists, on the mRNA expression of orexin 1 and orexin 2 receptors in anterior pituitary cells of proestrous rats, as well as the direct effects on FSH and LH secretion. RESULTS Both orexin A and orexin B increased FSH and LH secretion; these effects were suppressed by the orexin 1 receptor blocking agent SB-334867 and the orexin 2 receptor antagonists JNJ-10397049. Orexin A and orexin B decreased OX1 receptor mRNA expression and this effect was modified only when both blocking agents were present. Neither orexin A nor the blocking drugs by themselves modified OX2 receptor mRNA expression. Orexin B treatment increased the mRNA expression of OX2 receptor. The effect was abolished only by the OX2 receptor antagonist. CONCLUSION In an in vitro model, we demonstrated a direct effect of orexins on gonadotropins release and orexins receptors expression, underlining the hypothesis that orexins participate in the brain control of pituitary functions.
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Álvarez-Crespo M, Martínez-Sánchez N, Ruíz-Pino F, Garcia-Lavandeira M, Alvarez CV, Tena-Sempere M, Nogueiras R, Diéguez C, López M. The orexigenic effect of orexin-A revisited: dependence of an intact growth hormone axis. Endocrinology 2013; 154:3589-98. [PMID: 23861376 DOI: 10.1210/en.2013-1251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fifteen years ago orexins were identified as central regulators of energy homeostasis. Since then, that concept has evolved considerably and orexins are currently considered, besides orexigenic neuropeptides, key modulators of sleep-wake cycle and neuroendocrine function. Little is known, however, about the effect of the neuroendocrine milieu on orexins' effects on energy balance. We therefore investigated whether hypothalamic-pituitary axes have a role in the central orexigenic action of orexin A (OX-A) by centrally injecting hypophysectomized, adrenalectomized, gonadectomized (male and female), hypothyroid, and GH-deficient dwarf rats with OX-A. Our data showed that the orexigenic effect of OX-A is fully maintained in adrenalectomized and gonadectomized (females and males) rats, slightly reduced in hypothyroid rats, and totally abolished in hypophysectomized and dwarf rats when compared with their respective vehicle-treated controls. Of note, loss of the OX-A effect on feeding was associated with a blunted OX-A-induced increase in the expression of either neuropeptide Y or its putative regulator, the transcription factor cAMP response-element binding protein, as well as its phosphorylated form, in the arcuate nucleus of the hypothalamus of hypophysectomized and dwarf rats. Overall, this evidence suggests that the orexigenic action of OX-A depends on an intact GH axis and that this neuroendocrine feedback loop may be of interest in the understanding of orexins action on energy balance and GH deficiency.
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Affiliation(s)
- Mayte Álvarez-Crespo
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain.
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Naufahu J, Cunliffe AD, Murray JF. The roles of melanin-concentrating hormone in energy balance and reproductive function: Are they connected? Reproduction 2013; 146:R141-50. [PMID: 23884861 DOI: 10.1530/rep-12-0385] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Melanin-concentrating hormone (MCH) is an anabolic neuropeptide with multiple and diverse physiological functions including a key role in energy homoeostasis. Rodent studies have shown that the ablation of functional MCH results in a lean phenotype, increased energy expenditure and resistance to diet-induced obesity. These findings have generated interest among pharmaceutical companies vigilant for potential anti-obesity agents. Nutritional status affects reproductive physiology and behaviours, thereby optimising reproductive success and the ability to meet energetic demands. This complex control system entails the integration of direct or indirect peripheral stimuli with central effector systems and involves numerous mediators. A role for MCH in the reproductive axis has emerged, giving rise to the premise that MCH may serve as an integratory mediator between those discrete systems that regulate energy balance and reproductive function. Hence, this review focuses on published evidence concerning i) the role of MCH in energy homoeostasis and ii) the regulatory role of MCH in the reproductive axis. The question as to whether the MCH system mediates the integration of energy homoeostasis with the neuroendocrine reproductive axis and, if so, by what means has received limited coverage in the literature; evidence to date and current theories are summarised herein.
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Affiliation(s)
- Jane Naufahu
- Department of Human and Health Sciences, School of Life Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK and
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Wang W, Pan Y, Li Q, Wang L. Orexin: a potential role in the process of obstructive sleep apnea. Peptides 2013; 42:48-54. [PMID: 23313149 DOI: 10.1016/j.peptides.2013.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 12/28/2012] [Accepted: 01/02/2013] [Indexed: 02/07/2023]
Abstract
Obstructive sleep apnea (OSA) is a complicated disease with an unrecognized mechanism. Obesity, sex, age, and smoking have been found to be independent correlates of OSA. Orexin (also named hypocretin) mainly secreted by lateral hypothalamus neurons has a wide array of biological functions like regulating sleep, energy levels and breathing. Several clinical studies found ties between orexin and OSA. Because of the close correlation between orexin and obesity, sex, age and smoking (which are the key risk factors for OSA patients), we hypothesize that orexin may play a key role in the pathogenesis of OSA.
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Affiliation(s)
- Wei Wang
- Institute of Stomatology, Nanjing Medical University, Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China
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Zhang XY, Yu L, Zhuang QX, Zhu JN, Wang JJ. Central functions of the orexinergic system. Neurosci Bull 2013; 29:355-65. [PMID: 23299718 DOI: 10.1007/s12264-012-1297-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/18/2012] [Indexed: 10/27/2022] Open
Abstract
The neuropeptide orexin is synthesized by neurons exclusively located in the hypothalamus. However, these neurons send axons over virtually the entire brain and spinal cord and therefore constitute a unique central orexinergic system. It is well known that central orexin plays a crucial role in the regulation of various basic non-somatic and somatic physiological functions, including feeding, energy homeostasis, the sleep/wake cycle, reward, addiction, and neuroendocrine, as well as motor control. Moreover, the absence of orexin results in narcolepsy-cataplexy, a simultaneous somatic and non-somatic dysfunction. In this review, we summarize these central functions of the orexinergic system and associated diseases, and suggest that this system may hold a key position in somatic-non-somatic integration.
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Affiliation(s)
- Xiao-Yang Zhang
- Department of Biological Science and Technology and State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210093, China
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Nitkiewicz A, Smolinska N, Maleszka A, Kiezun M, Kaminski T. Localization of orexin A and orexin B in the porcine uterus. Reprod Biol 2012; 12:135-55. [PMID: 22850467 DOI: 10.1016/s1642-431x(12)60082-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The presence of orexins and their receptors in gonads indicate that these hormones participate in the control of reproductive functions. The aim of the study was to compare the expression of the prepro-orexin (PPO) gene in porcine endometrium and myometrium and the intensity of OXA- and OXB-immunoreactivity in the following uterine structures: endometrial glandular and luminal epithelium and stroma as well as the myometrial longitudinal and circular muscles during the four stages (days 2-3, 10-12, 14-16, 17-19) of the estrous cycle. The highest expression of PPO mRNA was observed in the endometrium and the myometrium on days 14-16 of the cycle. The expression of the PPO gene on days 2-3 was more pronounced in the myometrium than in the endometrium, whereas on days 17-19 the gene expression was markedly higher in the endometrium. The OXA signal intensity was highest on days 2-3 in the luminal epithelium and on days 2-3 and 10-12 in the stroma. In circular muscles of the myometrium, the highest immunoreactivity was found on days 2-3 and 10-12, while in longitudinal muscles on days 2-3. OXB-immunoreactivity was highest on days 10-12 in longitudinal muscles, on days 17-19 in glandular epithelium and stroma, and on days 10-12 and 14-16 in luminal epithelium. Our results suggest that orexin A and B are produced in the porcine uterus and that their release is dependent on the hormonal status of animals.
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Affiliation(s)
- Anna Nitkiewicz
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Poland
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39
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Liguori G, Assisi L, Squillacioti C, Paino S, Mirabella N, Vittoria A. Presence, distribution and steroidogenic effect of the peptides orexin A and receptor 1 for orexins in the testis of the South American camelid alpaca (Vicugna pacos). Gen Comp Endocrinol 2012; 179:137-42. [PMID: 22909972 DOI: 10.1016/j.ygcen.2012.07.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 07/19/2012] [Accepted: 07/25/2012] [Indexed: 11/27/2022]
Abstract
The orexins A (oxA) and B are peptides discovered in the rat hypothalamus and successively found in some peripheral organs of the mammalian body. They binds two protein G-coupled receptors defined receptor 1 (ox1r) and 2 for orexins, the first of which is highly specific for oxA while the second binds both the peptides with equal affinity. This work aimed to detect the presence of oxA and ox1r in the testis of the South American camelid alpaca (Vicugna pacos) and investigate the role played by them on Leydig cell steroidogenesis. The species alpaca acquired, in the last years, increasing zootechnical interest for the quality of the wool produced and its breeding spread from the country of origin to USA, Australia and Europe. Immunohistochemistry allowed us to detect oxA in Leydig and Sertoli cells, spermatogonia, resting spermatocytes, round and oval spermatids. Ox1r-immunoreactivity was found in Leydig cells and round, oval and elongated spermatids. The expression of the two peptides in tissue extracts was established by using Western blotting technique. Such results demonstrated that in the alpaca testis exists in a cellular complex able to produce and/or internalize oxA. Finally, the effect of oxA on steroidogenesis was investigated by means of in vitro cultured thin testis slices which were added with oxA or/and Müllerian Inhibiting Substance (MIS), a steroidolitic agent basally produced by the Sertoli cell. OxA evoked increase of testosterone production while MIS a decrease. The consecutive addition of oxA and MIS, or vice versa, highlighted an antagonistic interplay between the two substances which has been thought to be the main molecular event at the basis of the oxA-stimulated steroidogenesis mechanism.
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Affiliation(s)
- Giovanna Liguori
- Department of Structures, Functions and Biological Technologies, University of Naples Federico II, Via Veterinaria 1, I-80137 Naples, Italy
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Gaskins GT, Moenter SM. Orexin a suppresses gonadotropin-releasing hormone (GnRH) neuron activity in the mouse. Endocrinology 2012; 153:3850-60. [PMID: 22673226 PMCID: PMC3404355 DOI: 10.1210/en.2012-1300] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GnRH neurons are critical for the central regulation of fertility, integrating steroidal, metabolic and other cues. GnRH neurons appear to lack receptors for many of these cues, suggesting involvement of afferent systems to convey information. Orexin A (orexin) is of interest in this regard as a neuromodulator that up-regulates metabolic activity, increases wakefulness, and affects GnRH/LH release. We examined the electrophysiological response of GnRH neurons to orexin application and how this response changes with estradiol and time of day in a defined animal model. Mice were either ovariectomized (OVX) or OVX and implanted with estradiol capsules (OVX+E). GnRH neurons from OVX+E mice exhibit low firing rates in the morning, due to estradiol-negative feedback, and high firing rates in the evening, due to positive feedback. Orexin inhibited activity of GnRH neurons from OVX mice independent of time of day. In GnRH neurons from OVX+E mice, orexin was inhibitory during the evening, suggesting orexin inhibition is not altered by estradiol. No effect of orexin was observed in OVX+E morning recordings, due to low basal GnRH activity. Inhibitory effects of orexin were mediated by the type 1 orexin receptor, but antagonism of this receptor did not increase GnRH neuron activity during estradiol-negative feedback. Spike pattern analysis revealed orexin increases interevent interval by reducing the number of single spikes and bursts. Orexin reduced spikes/burst and burst duration but did not affect intraburst interval. This suggests orexin may reduce overall firing rate by suppressing spike initiation and burst maintenance in GnRH neurons.
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Affiliation(s)
- Garrett T Gaskins
- Department of Molecular and Integrative Physiology, University of Michigan, 7725 Medical Science II, 1137 East Catherine Street, Ann Arbor Michigan 48109-5622, USA
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Kaminski T, Smolinska N. Expression of orexin receptors in the pituitary. VITAMINS AND HORMONES 2012; 89:61-73. [PMID: 22640608 DOI: 10.1016/b978-0-12-394623-2.00004-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Orexin receptors type 1 (OX1R) and type 2 (OX2R) are G protein-coupled receptors whose structure is highly conserved in mammals. OX1R is selective for orexin A, and OX2R binds orexin A and orexin B with similar affinity. Orexin receptor expression was observed in human, rat, porcine, sheep as well as Xenopus laevis pituitaries, both in the adenohypophysis and in the neurohypophysis. The expression level is regulated by gonadal steroid hormones and GnRH. The majority of orexins reaching the pituitary originate from the lateral hypothalamus, but due to the presence of the receptors and the local production of orexins in the pituitary, orexins could deliver an auto/paracrine effect within the gland. Cumulative data indicate that orexins are involved in the regulation of LH, GH, PRL, ACTH, and TSH secretion by pituitary cells, pointing to orexins' effect on the functioning of the endocrine axes. Those hormones may also serve as a signal linking metabolic status with endocrine control of sleep, arousal, and reproduction processes.
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Affiliation(s)
- Tadeusz Kaminski
- Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Olsztyn-Kortowo, Poland
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Acosta-Martínez M. PI3K: An Attractive Candidate for the Central Integration of Metabolism and Reproduction. Front Endocrinol (Lausanne) 2011; 2:110. [PMID: 22654843 PMCID: PMC3356143 DOI: 10.3389/fendo.2011.00110] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 12/13/2011] [Indexed: 12/19/2022] Open
Abstract
In neurons, as in a variety of other cell types, the enzyme phosphatidylinositol-3-kinase (PI3K) is a key intermediate that is common to the signaling pathways of a number of peripheral metabolic cues, including insulin and leptin, which are well known to regulate both metabolic and reproductive functions. This review article will explore the possibility that PI3K is a key integrator of metabolic and neural signals regulating gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) release and explore the hypothesis that this enzyme is pivotal in many disorders where gonadotropin release is at risk. Although the mechanisms mediating the influence of metabolism and nutrition on fertility are currently unclear, the strong association between metabolic disorders and infertility is undeniable. For example, women suffering from anorectic disorders experience amenorrhea as a consequence of malnutrition-induced impairment of LH release, and at the other extreme, obesity is also commonly co-morbid with menstrual dysfunction and infertility. Impaired hypothalamic insulin and leptin receptor signaling is thought to be at the core of reproductive disorders associated with metabolic dysfunction. While low levels of leptin and insulin characterize states of negative energy balance, prolonged nutrient excess is associated with insulin and leptin resistance. Metabolic models known to alter GnRH/LH release such as diabetes, diet-induced obesity, and caloric restriction are also accompanied by impairment of PI3K signaling in insulin and leptin sensitive tissues including the hypothalamus. However, a clear link between this signaling pathway and the control of GnRH release by peripheral metabolic cues has not been established. Investigating the role of the signaling pathways shared by metabolic cues that are critical for a normal reproductive state can help identify possible targets in the treatment of metabolic and reproductive disorders such as polycystic ovarian syndrome.
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Affiliation(s)
- Maricedes Acosta-Martínez
- Department of Physiology and Biophysics, Medical Center, Stony Brook UniversityStony Brook, NY, USA
- *Correspondence: Maricedes Acosta-Martínez, Department of Physiology and Biophysics, Medical Center, Stony Brook University, Stony Brook, NY 11794-8661, USA. e-mail:
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True C, Grove KL, Smith MS. Beyond Leptin: Emerging Candidates for the Integration of Metabolic and Reproductive Function during Negative Energy Balance. Front Endocrinol (Lausanne) 2011; 2:53. [PMID: 22645510 PMCID: PMC3355832 DOI: 10.3389/fendo.2011.00053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 09/29/2011] [Indexed: 12/19/2022] Open
Abstract
Reproductive status is tightly coupled to metabolic state in females, and ovarian cycling in mammals is halted when energy output exceeds energy input, a metabolic condition known as negative energy balance. This inhibition of reproductive function during negative energy balance occurs due to suppression of gonadotropin-releasing hormone (GnRH) release in the hypothalamus. The GnRH secretagogue kisspeptin is also inhibited during negative energy balance, indicating that inhibition of reproductive neuroendocrine circuits may occur upstream of GnRH itself. Understanding the metabolic signals responsible for the inhibition of reproductive pathways has been a compelling research focus for many years. A predominant theory in the field is that the status of energy balance is conveyed to reproductive neuroendocrine circuits via the adipocyte hormone leptin. Leptin is stimulatory for GnRH release and lower levels of leptin during negative energy balance are believed to result in decreased stimulatory drive for GnRH cells. However, recent evidence found that restoring leptin to physiological levels did not restore GnRH function in three different models of negative energy balance. This suggests that although leptin may be an important permissive signal for reproductive function as indicated by many years of research, factors other than leptin must critically contribute to negative energy balance-induced reproductive inhibition. This review will focus on emerging candidates for the integration of metabolic status and reproductive function during negative energy balance.
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Affiliation(s)
- Cadence True
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
| | - Kevin L. Grove
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
| | - M. Susan Smith
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
- *Correspondence: M. Susan Smith, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA. e-mail:
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Nitkiewicz A, Smolinska N, Przala J, Kaminski T. Expression of orexin receptors 1 (OX1R) and 2 (OX2R) in the porcine ovary during the oestrous cycle. ACTA ACUST UNITED AC 2010; 165:186-90. [DOI: 10.1016/j.regpep.2010.07.166] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 07/16/2010] [Accepted: 07/26/2010] [Indexed: 01/09/2023]
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NING HM, GE YM, SU J, ZHANG WL, YAO Y, YANG GH, LEI ZH. Effects of Orexin A on mRNA Expression of Various Neuropeptides in the Hypothalamus and Pituitary, and on Serum LH Levels in Ovariectomized Gilts. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/s1671-2927(09)60227-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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The neuroendocrine basis of lactation-induced suppression of GnRH: role of kisspeptin and leptin. Brain Res 2010; 1364:139-52. [PMID: 20727862 DOI: 10.1016/j.brainres.2010.08.038] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/11/2010] [Accepted: 08/12/2010] [Indexed: 11/22/2022]
Abstract
Lactation is an important physiological model of the integration of energy balance and reproduction, as it involves activation of potent appetitive neuropeptide systems coupled to a profound inhibition of pulsatile GnRH/LH secretion. There are multiple systems that contribute to the chronic hyperphagia of lactation: 1) suppression of the metabolic hormones, leptin and insulin, 2) activation of hypothalamic orexigenic neuropeptide systems NPY, AGRP, orexin (OX) and melanin concentrating hormone (MCH), 3) special induction of NPY expression in the dorsomedial hypothalamus, and 4) suppression of anorexigenic systems POMC and CART. These changes ensure adequate energy intake to meet the metabolic needs of milk production. There is significant overlap in all of the systems that regulate food intake with the regulation of GnRH, suggesting there could be several redundant factors acting to suppress GnRH/LH during lactation. In addition to an overall increase in inhibitory tone acting directly on GnRH cell bodies that is brought about by increases in orexigenic systems, there are also effects at the ARH to disrupt Kiss1/neurokinin B/dynorphin neuronal function through inhibition of Kiss1 and NKB. These changes could lead to an increase in inhibitory auto-regulation of the Kiss1 neurons and a possible disruption of pulsatile GnRH release. While the low levels of leptin and insulin contribute to the changes in ARH appetitive systems, they do not appear to contribute to the suppression of ARH Kiss1 or NKB. The inhibition of Kiss1 may be the key factor in the suppression of GnRH during lactation, although the mechanisms responsible for its inhibition are unknown.
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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: 55] [Impact Index Per Article: 3.9] [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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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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Silveyra P, Cataldi NI, Lux-Lantos VA, Libertun C. Role of orexins in the hypothalamic-pituitary-ovarian relationships. Acta Physiol (Oxf) 2010; 198:355-60. [PMID: 19796256 DOI: 10.1111/j.1748-1716.2009.02049.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Appropriate nutritional and vigilance states are needed for reproduction. In previous works, we described the influence of the hormonal milieu of proestrus on the orexinergic system and we found that orexin receptor 1 expression in the hypothalamus, but not other neural areas, and the adenohypophysis was under the influence of oestradiol and the time of the day. Information from the sexual hormonal milieu of proestrous afternoon impacts on various components of the orexinergic system and alertness on this particular night of proestrus would be of importance for successful reproduction. In this review, we summarize the available experimental data supporting the participation of orexins in the hypothalamic-pituitary-ovarian relationships. All together, these results suggest a role of the orexinergic system as an integrative link among vital functions such as reproduction, food intake, alertness and the inner biological clock.
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Affiliation(s)
- P Silveyra
- Instituto de Biología y Medicina Experimental-CONICET, Buenos Aires, Argentina
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