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Yilmaz N, Yasi N RZI, Yildiz A. Intracerebroventricular injection of spexin stimulates the hypothalamic-pituitary-testicular axis and increases the secretion of male reproductive hormones in rats. Ann Anat 2024; 255:152300. [PMID: 38971451 DOI: 10.1016/j.aanat.2024.152300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 07/03/2024] [Indexed: 07/08/2024]
Abstract
BACKGROUND Male reproductive functions are regulated in the hypothalamic-pituitary-gonadal (HPG) axis. Any problem in this axis would lead to the deterioration of reproductive functions. The present study aimed to investigate the effects of intracerebroventricular (icv) Spexin (SPX) infusion on the HPG axis in detail. METHODS 40 Wistar albino rats were divided into four groups: control, sham, SPX 30 nmol and SPX 100 nmol (n=10). 30 nmol/1 µl/hour SPX was administered icv to the rats in the SPX 30 nmol group for 7 days, while rats in the SPX 100 nmol group were administered 100 nmol/1 µl/hour SPX. On the 7th day, the rats were decapitated, blood and tissue samples were collected. Serum LH, FSH and testosterone levels were determined with the ELISA method, GnRH mRNA expression level was determined in hypothalamus with the RT-PCR method. Seminiferous tubule diameter and epithelial thickness were determined with the hematoxylin-eosin staining method. RESULTS SPX infusion was increased GnRH mRNA expression in the hypothalamus tissue independent of the dose (p<0.05). Serum LH, FSH and testosterone levels in the SPX groups were increased when compared to the control and sham groups independent of the dose (p <0.05). Histological analysis revealed that SPX infusion did not lead to any changes in seminiferous epithelial thickness, while the tubule diameter increased in the SPX groups (p<0.05). CONCLUSION The study findings demonstrated that icv SPX infusion stimulated the HPG axis and increased the secretion of male reproductive hormones.
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Affiliation(s)
- Nesibe Yilmaz
- Karabük University, Faculty of Medicine, Department of Anatomy, Karabük, Turkey.
| | | | - Azibe Yildiz
- İnönü University, Faculty of Medicine, Department of Histology and Embriyology, Malatya, Turkey
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Patel K, Smith NJ. Primary cilia, A-kinase anchoring proteins and constitutive activity at the orphan G protein-coupled receptor GPR161: A tale about a tail. Br J Pharmacol 2024; 181:2182-2196. [PMID: 36772847 DOI: 10.1111/bph.16053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/22/2022] [Accepted: 02/04/2023] [Indexed: 02/12/2023] Open
Abstract
Primary cilia are non-motile antennae-like structures responsible for sensing environmental changes in most mammalian cells. Ciliary signalling is largely mediated by the Sonic Hedgehog (Shh) pathway, which acts as a master regulator of ciliary protein transit and is essential for normal embryonic development. One particularly important player in primary cilia is the orphan G protein-coupled receptor, GPR161. In this review, we introduce GPR161 in the context of Shh signalling and describe the unique features on its C-terminus such as PKA phosphorylation sites and an A-kinase anchoring protein motif, which may influence the function of the receptor, cAMP compartmentalisation and/or trafficking within primary cilia. We discuss the recent putative pairing of GPR161 and spexin-1, highlighting the additional steps needed before GPR161 could be considered 'deorphanised'. Finally, we speculate that the marked constitutive activity and unconventional regulation of GPR161 may indicate that the receptor may not require an endogenous ligand. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Kinjal Patel
- Orphan Receptor Laboratory, School of Biomedical Sciences, Faculty of Medicine & Health, UNSW Sydney, Kensington, New South Wales, Australia
| | - Nicola J Smith
- Orphan Receptor Laboratory, School of Biomedical Sciences, Faculty of Medicine & Health, UNSW Sydney, Kensington, New South Wales, Australia
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Liu Y, Wu D, Zheng H, Ni Y, Zhu L, Jiang Y, Dai J, Sun Q, Zhao Y, Zhang Q, Yang Y, Liu R. Serum Spexin Level Is Negatively Associated With Peripheral Neuropathy and Sensory Pain in Type 2 Diabetes. J Diabetes Res 2024; 2024:4538199. [PMID: 38919263 PMCID: PMC11199070 DOI: 10.1155/2024/4538199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 06/27/2024] Open
Abstract
Background: Spexin is a novel peptide hormone and has shown antinociceptive effects in experimental mice. This study is aimed at evaluating the association of serum spexin level with diabetic peripheral neuropathy (DPN) and related pain in a Chinese population. Methods: We enrolled 167 type 2 diabetes mellitus (T2DM) including 56 patients without DPN (non-DPN), 67 painless DPN, and 44 painful DPN. Serum spexin was measured using ELISA. Logistic regression models were performed to analyze the independent effects of spexin on prevalence of DPN and painful DPN. In streptozotocin (STZ)-induced diabetic mice, mechanical pain threshold was measured using electronic von Frey aesthesiometer. Human peripheral blood mononuclear cells (PBMCs) were isolated and further stimulated with lipopolysaccharide without or with spexin. The gene expression was assayed by qPCR. Results: Compared with non-DPN, serum spexin level decreased in painless DPN and further decreased in painful DPN. The odds of DPN was associated with low spexin level in T2DM, which was similar by age, sex, BMI, and diabetes duration, but attenuated in smokers. The odds of having pain was associated with decreased spexin level in DPN, which was similar by age, sex, smoking status, and diabetes duration, but attenuated in normal weight. Furthermore, we observed that mechanical pain threshold increased in spexin-treated diabetic mice. We also found that lipopolysaccharide treatment increased the mRNA level of TNF-α, IL-6, and MCP-1 in human PBMCs, while spexin treatment prevented this increase. Conclusions: These results suggested that spexin might serve as a protective factor for diabetes against neuropathology and pain-related pathogenesis.
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Affiliation(s)
- Ying Liu
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Di Wu
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Hangping Zheng
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Yunzhi Ni
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Lu Zhu
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Yaojing Jiang
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Jiarong Dai
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Quanya Sun
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Ying Zhao
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Qi Zhang
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Yehong Yang
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
| | - Rui Liu
- Department of Endocrinology and MetabolismHuashan HospitalFudan University, Shanghai 200040, China
- Institute of Endocrinology and DiabetesFudan University, Shanghai 200040, China
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Lipiec-Borowicz A, Pałasz A, Suszka-Świtek A, Filipczyk Ł, Della Vecchia A, Worthington JJ, Piwowarczyk-Nowak A. Neuropeptides in the rat claustrum - An immunohistochemical detection. Acta Histochem 2024; 126:152156. [PMID: 38518508 DOI: 10.1016/j.acthis.2024.152156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 03/24/2024]
Abstract
Neuropeptides are involved in numerous brain activities and are responsible for a wide spectrum of higher mental functions. The main purpose of this outline structural qualitative study was to identify the possible immunoreactivity of classical neuropeptides, as well as novel ones such as nesfatin-1, phoenixin (PNX), spexin (SPX), neuromedin U (NMU) and respective receptors within the rat claustrum for the first time. The study shows the novel identification of peptidergic neurotransmission in the rat claustrum which potentially implicates a contribution of this neuropeptide to numerous central neurosecretory mechanisms.
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Affiliation(s)
- Anna Lipiec-Borowicz
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, Katowice 40-752, Poland.
| | - Artur Pałasz
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, Katowice 40-752, Poland.
| | - Aleksandra Suszka-Świtek
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, Katowice 40-752, Poland
| | - Łukasz Filipczyk
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, Katowice 40-752, Poland
| | - Alessandra Della Vecchia
- Department of Clinical and Experimental Medicine, Section of Psychiatry, University of Pisa, 67, Via Roma, Pisa 56100, Italy
| | - John J Worthington
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Aneta Piwowarczyk-Nowak
- Department of Anatomy, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, Katowice 40-752, Poland
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Pałasz A, Lipiec-Borowicz A, Suszka-Świtek A, Kistowska J, Horká P, Kaśkosz A, Piwowarczyk-Nowak A, Worthington JJ, Mordecka-Chamera K. Spexin and nesfatin-1-expressing neurons in the male human claustrum. J Chem Neuroanat 2024; 136:102400. [PMID: 38342331 DOI: 10.1016/j.jchemneu.2024.102400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/07/2024] [Accepted: 02/07/2024] [Indexed: 02/13/2024]
Abstract
Neuropeptides are involved in numerous brain activities being responsible for a wide spectrum of higher mental functions. The purpose of this concise, structural and qualitative investigation was to map the possible immunoreactivity of the novel regulatory peptides: spexin (SPX) and nesfatin-1 within the human claustrum. SPX is a newly identified peptide, a natural ligand for the galanin receptors (GALR) 2/3, with no molecular structure similarities to currently known regulatory factors. SPX seems to have multiple physiological functions, with an involvement in reproduction and food-intake regulation recently revealed in animal studies. Nesfatin-1, a second pleiotropic neuropeptide, which is a derivative of the nucleobindin-2 (NUCB-2) protein, is characterized by a wide distribution in the brain. Nesfatin-1 is a substance with a strong anorexigenic effect, playing an important role in the neuronal circuits of the hypothalamus that regulate food intake and energy homeostasis. On the other hand, nesfatin-1 may be involved in several important brain functions such as sleep, reproductive behaviour, cognitive processes, stress responses and anxiety. For the first time we detected and described a population of nesfatin-1 and SPX expressing neurons in the human claustrum using immunohistochemical and fluorescent methods. The study presents the novel identification of SPX and nesfatin-1 immunopositive neurons in the human claustrum and their assemblies show similar patterns of distribution in the whole structure.
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Affiliation(s)
- Artur Pałasz
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland.
| | - Anna Lipiec-Borowicz
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Aleksandra Suszka-Świtek
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Julia Kistowska
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Petra Horká
- Institute for Environmental Studies, Faculty of Science, Charles University, Benatska 2, 12801 Prague, Czechia
| | - Andrzej Kaśkosz
- Department of Anatomy, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752 Katowice, Poland
| | - Aneta Piwowarczyk-Nowak
- Department of Anatomy, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752 Katowice, Poland
| | - John J Worthington
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Kinga Mordecka-Chamera
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
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Yalçin T, Kuloğlu T, Tektemur NK, Tektemur A, Ozan İE. Effects of N-acetylcysteine on spexin immunoreactivity in kidney tissues of rats treated with adriamycin. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2024; 27:233-240. [PMID: 38234666 PMCID: PMC10790286 DOI: 10.22038/ijbms.2023.71942.15635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 07/02/2023] [Indexed: 01/19/2024]
Abstract
Objectives Due to its negative side effects, mainly nephrotoxicity, adriamycin (ADR) is used fairly infrequently. The purpose of this study is to investigate the effects of N-acetyl cysteine (NAC) on the immunoreactivity of spexin (SPX) in the kidney tissues of rats given ADR. Materials and Methods A total of 28 male Sprague-Dawley rats were randomly assigned to four groups (n=7): control (no intervention), NAC (150 mg/kg/day, administered intraperitoneally), ADR (single dose of 15 mg/kg, administered intraperitoneally), and ADR+NAC (single dose of 15 mg/kg ADR + 150 mg/kg/day NAC, both administered intraperitoneally). The experiment was concluded on the 15th day. Results The administration of ADR resulted in biochemical and histopathological alterations in the kidney. It was found that ADR treatment led to elevated levels of TOS (total oxidative stress), apoptosis, and SPX. Conversely, when NAC was administered as a treatment, it effectively reduced TOS, apoptosis, and SPX levels. These findings suggest that SPX may contribute to the development of ADR-induced kidney damage. Conclusion Further investigations are warranted to gain a comprehensive understanding of kidney damage, and specifically to elucidate the role of SPX in this context. Additionally, these studies can pave the way for exploring novel therapeutic strategies targeting SPX to prevent and/or treat the development of kidney damage.
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Affiliation(s)
- Tuba Yalçin
- Batman University, Health Services Vocational School, First and Emergency Program, Batman, Turkey
| | - Tuncay Kuloğlu
- Firat University, Medicine Faculty, Department of Histology and Embryology, Elazığ, Turkey
| | - Nalan Kaya Tektemur
- Firat University, Medicine Faculty, Department of Histology and Embryology, Elazığ, Turkey
| | - Ahmet Tektemur
- Firat University, Medicine Faculty, Department of Medical Biology, Elazığ, Turkey
| | - İbrahim Enver Ozan
- Firat University, Medicine Faculty, Department of Histology and Embryology, Elazığ, Turkey
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Yilmaz U, Tanbek K. Spexin may induce mitochondrial biogenesis in white and brown adipocytes via the hypothalamus-pituitary-thyroid (HPT) axis. Physiol Behav 2024; 273:114401. [PMID: 37939828 DOI: 10.1016/j.physbeh.2023.114401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
AIM The present study aimed to investigate the effect of the intracerebroventricular (icv) administration of spexin on the hypothalamus-pituitary-thyroid (HPT) axis (TRH, TSH, T4 and T3 hormones) and energy expenditure (PGC-1α and UCP1 genes) in white adipose (WAT) and brown adipose tissues (BAT) in rats. Furthermore, the study aimed to determine the effects of spexin on food-water consumption and body weight of rats. MATERIAL AND METHOD The study was conducted with 40 male rats that were divided into 4 groups: Control, Sham, Spexin 30 and Spexin 100 (n = 10). Spexin (1 μl/hour) was administered to rats other than those in the control group for 7 days with osmotic minipumps intracerebroventricularly, artificial cerebrospinal fluid (vehicle) was administered to the Sham group, and 30 nMol and 100 nMol spexin was infused to the Spexin 30 and Spexin 100 groups, respectively. Food-water consumption and body weight of the rats were monitored during the experiments. After the seven-day infusion, the rats were decapitated and serum TSH, fT4 and fT3 levels were determined with ELISA on rat blood samples. Also, TRH gene expression levels from the hypothalamus tissues and PGC-1α and UCP1 expression levels from WAT and BAT were determined by real-time PCR. FINDINGS It was determined that icv spexin infusion reduced daily food consumption and body weight without leading to a significant change in water consumption (p < 0.05). Icv spexin infusion significantly decreased serum TSH, and increased fT4 and fT3 levels when compared to control and sham groups (p < 0.05). Moreover, icv spexin infusion increased the TRH expressions in the hypothalamus tissues and PGC-1α UCP1 in the WAT and BAT (p < 0.05). CONCLUSION Icv Spexin infusion may have effects on food consumption and body weight as well as, thyroid hormones and energy metabolism.
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Affiliation(s)
- Umit Yilmaz
- Department of Physiology, Faculty of Medicine, Karabuk University, Karabuk, Turkey.
| | - Kevser Tanbek
- Department of Physiology, Faculty of Medicine, Inonu University, Malatya, Turkey
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Onat E, Kocaman N, Hancer S. The protective effects of humanin in rats with experimental myocardial infarction: The role of asprosin and spexin. Heliyon 2023; 9:e18739. [PMID: 37576267 PMCID: PMC10412837 DOI: 10.1016/j.heliyon.2023.e18739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 07/09/2023] [Accepted: 07/26/2023] [Indexed: 08/15/2023] Open
Abstract
Objective In this study, by applying humanin (HN) before myocardial infarction (MI) in rats, its protection in MI and the possible roles in asprosin and spexin were investigated. Materials and methods The rats were divided into 7 groups each with 6 rats (group I (control), group II (HN 48th hour), group III (HN 7th day), group IV (MI 48th hour), group V (MI 7th day), group VI (MI + HN 48th hour), group VII (MI + HN 7th day). To create MI, 200 mg/kg isoproterenol (ISO) was administered subcutaneously to the rats. 2 mg/kg HN was given intraperitoneally (ip) to rats alone and before MI. Molecular parameters asprosin and spexin were examined by immunohistochemical in heart tissue. Biochemical parameters (aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), Troponin I) were studied in serum by enzyme-linked immunosorbent assay (ELISA) method. Results It was found in the study that the levels of spexin elevated especially towards the 7th day after MI and decreased more significantly towards the 7th day, after HN application before MI. Asprosin elevated significantly towards the 7th day after MI and decreased especially on the 7th day after HN application before MI. Also, serum AST, LDH, CK-MB, and Troponin I levels tended to decrease and a significant decrease was detected in congested veins in the heart tissue at the 48th hour of MI and erythrocyte extravasation, congested veins and necrotic muscle fibers at the 7th day of MI in rats given HN before MI. Conclusion It was concluded that HN has a cardioprotective effect in MI and asprosin and spexin might mediate this effect.
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Affiliation(s)
- Elif Onat
- Department of Medical Pharmacology, Faculty of Medicine, Adiyaman University, Adiyaman, 02040, Turkey
| | - Nevin Kocaman
- Department of Histology and Embryology, Faculty of Medicine, Firat University, Elazig, 23119, Turkey
| | - Serhat Hancer
- Department of Histology and Embryology, Faculty of Medicine, Firat University, Elazig, 23119, Turkey
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Sun X, Yu Z, Xu Y, Pu S, Gao X. The role of spexin in energy metabolism. Peptides 2023; 164:170991. [PMID: 36914115 DOI: 10.1016/j.peptides.2023.170991] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/15/2023]
Abstract
Spexin, also identified as neuropeptide Q (NPQ), is a 14 amino acid peptide discovered by bioinformatic methods. It has a conserved structure in many species and is widely expressed in the central nervous system and peripheral tissues. It has an associated receptor, galanin receptor 2/3 (GALR2/3). Mature spexin peptides can exert various functions by activating GALR2/3, such as inhibiting food intake, inhibiting lipid absorption, reducing body weight, and improving insulin resistance. Spexin is expressed in the adrenal gland, pancreas, visceral fat, and thyroid, with the highest expression in the adrenal gland, followed by the pancreas. Physiologically, spexin and insulin interact in pancreatic islets. Spexin may be one of the regulators of endocrine function in the pancreas. Spexin is a possible indicator of insulin resistance and it has a variety of functional properties, here we review its role in energy metabolism.
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Affiliation(s)
- Xiaotong Sun
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China.
| | - Ziwei Yu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Yuxin Xu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Shengdan Pu
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
| | - Xinyuan Gao
- The First Affiliated Hospital of Harbin Medical University, People's Republic of China
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Meng F, Yu Y, Li J, Han X, Du X, Cao X, Liang Q, Huang A, Kong F, Huang L, Zeng X, Bu G. Characterization of spexin (SPX) in chickens: molecular cloning, functional analysis, tissue expression and its involvement in appetite regulation. Poult Sci 2022; 102:102279. [PMID: 36402041 PMCID: PMC9673105 DOI: 10.1016/j.psj.2022.102279] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/05/2022] Open
Abstract
Spexin (SPX) is a conservative tetradecapeptide which has been proven to participate in multiple physiological processes, including anxiety, feed intake, and energy metabolism in fish and mammals. However, whether SPX exists and functions in birds remain largely unknown. Using chicken (c-) as a model, the full-length cDNA encoding cSPX precursor was cloned, and it was predicted to generate a mature peptide with 14 amino acids conserved across vertebrates. The pGL4-SRE-luciferase reporter system-based functional analysis demonstrated that cSPX was effective in activating chicken galanin type Ⅱ receptor (cGALR2), cGALR2-like receptor (cGALR2L) and galanin type Ⅲ receptor (cGALR3), thus to stimulate intracellular MAPK/ERK signaling pathway. Quantitative real-time PCR revealed that SPX was widely expressed in chicken tissues, especially abundant in the central nervous system, pituitary, testes, and pancreas. Interestingly, it was noted that chicken hypothalamic SPX mRNA could be up-regulated by 24-h and 36-h fasting, heralding its latent capacity in appetite regulation. In accordance with this speculation, peripheral injection of cSPX was proved to be functional in reducing feed intake of 3-wk-old chicks. Furthermore, we found that cSPX could reduce the expression of AgRP and MCH, with a concurrent rise in CART1 mRNA level in the hypothalamic of chicks. Collectively, our findings not only provide the evidences that SPX can act as a satiety factor by orchestrating the expression of key feeding regulators in the chicken hypothalamus but also help to facilitate a better understanding of its functional evolution across vertebrates.
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Türkel İ, Memi G, Yazgan B. Impact of spexin on metabolic diseases and inflammation: An updated minireview. Exp Biol Med (Maywood) 2022; 247:567-573. [PMID: 35068225 PMCID: PMC9014522 DOI: 10.1177/15353702211072443] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023] Open
Abstract
Spexin (SPX) is a 14 amino acid length peptide hormone which was discovered using bioinformatic tools. It is extensively expressed in central and peripheral tissues and secreted into circulation in response to metabolic stress. Recent studies revealed that SPX acts as a multifunctional peptide in various metabolic processes such as body weight, food intake, energy balance, glucose and lipid metabolism, lipid storage, salt-water balance, and arterial blood pressure. Endogenous SPX is sensitive to metabolic changes, and circulating levels of SPX have been shown to be reduced in chronic diseases such as obesity, diabetes, and insulin resistance. Moreover, in fish and rodent models, systemic SPX treatment has positive effects on metabolism including reduced food intake, fat mass, lipid accumulation, and inflammation, improved insulin sensitivity, energy expenditure, and organ functions which are underlying mechanisms in diseases. Taken together, these findings suggest that SPX is a potential drug target for the development of new pharmacological strategies to cure metabolic diseases. This review focuses on metabolo-protective properties of SPX and discusses novel insights into the biology and mechanism of SPX in the pathogenesis of diabetes, obesity, non-alcoholic fatty liver disease, metabolic syndrome, polycystic ovary syndrome, cardiovascular diseases, and kidney diseases, which are considerable global health problems.
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Affiliation(s)
- İbrahim Türkel
- Division of Exercise and Sport
Physiology, Faculty of Sport Sciences, Hacettepe University, Ankara 06800,
Turkey
| | - Gülsün Memi
- Department of Physiology, Faculty of
Medicine, Adıyaman University, Adıyaman 02040, Turkey
| | - Burak Yazgan
- Department of Medical Services and
Techniques, Sabuncuoğlu Serefeddin Health Services Vocational School, Amasya
University, Amasya 05100, Turkey
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Zhao T, Ye Z, Liu Y, Lin H, Li S, Zhang Y. Mutation of spexin2 promotes feeding, somatic growth, adiposity and insulin resistance in zebrafish. Am J Physiol Regul Integr Comp Physiol 2022; 322:R454-R465. [PMID: 35293264 DOI: 10.1152/ajpregu.00307.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Spexin2 (spx2) is a newly identified gene in vertebrates, but its biological functions remain unclear. In this study, we cloned the full-length cDNA of spx2 in zebrafish. The 288 bp open reading frame encodes a protein of 95 amino acids (aa) that contains a 14 aa mature peptide. Spx2 is highly expressed in brain and testis. Its expression was significantly down-regulated in the hypothalamus after a 1 h feeding treatment and 7 days of food deprivation. Using a zebrafish spx2-/- mutant line, we observed a greater amount of food intake and changes in mRNA levels of feeding factors. We found that, SPX2 acts as a satiety factor that inhibits food intake by downregulating the expression of agouti related neuropeptide (agrp). Moreover, spx2 mutant fish exhibited a larger body size, excessive lipid accumulation, and insulin resistance. Taken together, our results revealed that SPX2 functions as a satiety factor involved in energy metabolic regulation in zebrafish.
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Affiliation(s)
- Tingting Zhao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Zhifeng Ye
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yun Liu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Haoran Lin
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shuisheng Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yong Zhang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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13
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Gołyszny M, Obuchowicz E, Zieliński M. Neuropeptides as regulators of the hypothalamus-pituitary-gonadal (HPG) axis activity and their putative roles in stress-induced fertility disorders. Neuropeptides 2022; 91:102216. [PMID: 34974357 DOI: 10.1016/j.npep.2021.102216] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/21/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022]
Abstract
Neuropeptides being regulators of the hypothalamus-pituitary-adrenal (HPA) axis activity, also affect the function of the hypothalamus-pituitary-gonadal (HPG) axis by regulating gonadotrophin-releasing hormone (GnRH) secretion from hypothalamic neurons. Here, we review the available data on how neuropeptides affect HPG axis activity directly or indirectly via their influence on the HPA axis. The putative role of neuropeptides in stress-induced infertility, such as polycystic ovary syndrome, is also described. This review discusses both well-known neuropeptides (i.e., kisspeptin, Kp; oxytocin, OT; arginine-vasopressin, AVP) and more recently discovered peptides (i.e., relaxin-3, RLN-3; nesfatin-1, NEFA; phoenixin, PNX; spexin, SPX). For the first time, we present an up-to-date review of all published data regarding interactions between the aforementioned neuropeptide systems. The reviewed literature suggest new pathophysiological mechanisms leading to fertility disturbances that are induced by stress.
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Affiliation(s)
- Miłosz Gołyszny
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
| | - Ewa Obuchowicz
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
| | - Michał Zieliński
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
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14
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Jeong B, Kim KK, Lee TH, Kim HR, Park BS, Park JW, Jeong JK, Seong JY, Lee BJ. Spexin Regulates Hypothalamic Leptin Action on Feeding Behavior. Biomolecules 2022; 12:biom12020236. [PMID: 35204737 PMCID: PMC8961618 DOI: 10.3390/biom12020236] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023] Open
Abstract
Spexin (SPX) is a recently identified neuropeptide that is believed to play an important role in the regulation of energy homeostasis. Here, we describe a mediating function of SPX in hypothalamic leptin action. Intracerebroventricular (icv) SPX administration induced a decrease in food intake and body weight gain. SPX was found to be expressed in cells expressing leptin receptor ObRb in the mouse hypothalamus. In line with this finding, icv leptin injection increased SPX mRNA in the ObRb-positive cells of the hypothalamus, which was blocked by treatment with a STAT3 inhibitor. Leptin also increased STAT3 binding to the SPX promoter, as measured by chromatin immunoprecipitation assays. In vivo blockade of hypothalamic SPX biosynthesis with an antisense oligodeoxynucleotide (AS ODN) resulted in a diminished leptin effect on food intake and body weight. AS ODN reversed leptin’s effect on the proopiomelanocortin (POMC) mRNA expression and, moreover, decreased leptin-induced STAT3 binding to the POMC promoter sequence. These results suggest that SPX is involved in leptin’s action on POMC gene expression in the hypothalamus and impacts the anorexigenic effects of leptin.
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Affiliation(s)
- Bora Jeong
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
| | - Kwang-Kon Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
| | - Tae-Hwan Lee
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
| | - Han-Rae Kim
- Department of Pharmacology and Physiology, School of Medicine & Health Sciences, The George Washington University, Washington, DC 22037, USA; (H.-R.K.); (J.-K.J.)
| | - Byong-Seo Park
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
| | - Jeong-Woo Park
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
| | - Jin-Kwon Jeong
- Department of Pharmacology and Physiology, School of Medicine & Health Sciences, The George Washington University, Washington, DC 22037, USA; (H.-R.K.); (J.-K.J.)
| | - Jae-Young Seong
- Graduate School of Medicine, Korea University, Seoul 02841, Korea
- Correspondence: (J.-Y.S.); (B.-J.L.)
| | - Byung-Ju Lee
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 44610, Korea; (B.J.); (K.-K.K.); (T.-H.L.); (B.-S.P.); (J.-W.P.)
- Correspondence: (J.-Y.S.); (B.-J.L.)
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Assefa F, Kim JA, Lim J, Nam SH, Shin HI, Park EK. The Neuropeptide Spexin Promotes the Osteoblast Differentiation of MC3T3-E1 Cells via the MEK/ERK Pathway and Bone Regeneration in a Mouse Calvarial Defect Model. Tissue Eng Regen Med 2021; 19:189-202. [PMID: 34951679 PMCID: PMC8782952 DOI: 10.1007/s13770-021-00408-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/20/2021] [Accepted: 10/24/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The neural regulation of bone regeneration has emerged recently. Spexin (SPX) is a novel neuropeptide and regulates multiple biological functions. However, the effects of SPX on osteogenic differentiation need to be further investigated. Therefore, the aim of this study is to investigate the effects of SPX on osteogenic differentiation, possible underlying mechanisms, and bone regeneration. METHODS In this study, MC3T3-E1 cells were treated with various concentrations of SPX. Cell proliferation, osteogenic differentiation marker expressions, alkaline phosphatase (ALP) activity, and mineralization were evaluated using the CCK-8 assay, reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), ALP staining, and alizarin red S staining, respectively. To determine the underlying molecular mechanism of SPX, the phosphorylation levels of signaling molecules were examined via western blot analysis. Moreover, in vivo bone regeneration by SPX (0.5 and 1 µg/µl) was evaluated in a calvarial defect model. New bone formation was analyzed using micro-computed tomography (micro-CT) and histology. RESULTS The results indicated that cell proliferation was not affected by SPX. However, SPX significantly increased ALP activity, mineralization, and the expression of genes for osteogenic differentiation markers, including runt-related transcription factor 2 (Runx2), Alp, collagen alpha-1(I) chain (Col1a1), osteocalcin (Oc), and bone sialoprotein (Bsp). In contrast, SPX downregulated the expression of ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1). Moreover, SPX upregulated phosphorylated mitogen-activated protein kinase kinase (MEK1/2) and extracellular signal-regulated kinase (ERK1/2). In vivo studies, micro-CT and histologic analysis revealed that SPX markedly increased a new bone formation. CONCLUSION Overall, these results demonstrated that SPX stimulated osteogenic differentiation in vitro and increased in vivo bone regeneration via the MEK/ERK pathway.
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Affiliation(s)
- Freshet Assefa
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea
| | - Ju Ang Kim
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea
| | - Jiwon Lim
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea
| | - Sang-Hyeon Nam
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea
| | - Hong-In Shin
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea
| | - Eui Kyun Park
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Jung-gu, Daegu, 41940, Korea.
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16
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Spexin: Its role, regulation, and therapeutic potential in the hypothalamus. Pharmacol Ther 2021; 233:108033. [PMID: 34763011 DOI: 10.1016/j.pharmthera.2021.108033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 12/14/2022]
Abstract
Spexin is the most recently discovered member of the galanin/kisspeptin/spexin family of peptides. This 14-amino acid peptide is highly conserved and is implicated in homeostatic functions including, but not limited to, metabolism, energy homeostasis, and reproduction. Spexin is expressed by neurons in the hypothalamus, which coordinate energy homeostasis and reproduction. Critically, levels of spexin appear to be altered in disorders related to energy homeostasis and reproduction, such as obesity, diabetes, and polycystic ovarian syndrome. In this review, we discuss the evidence for the involvement of spexin in the hypothalamic control of energy homeostasis and reproduction. The anorexigenic properties of spexin have been attributed to its effects on the energy-regulating neuropeptide Y/agouti-related peptide neurons and proopiomelanocortin neurons. While the role of spexin in reproduction remains unclear, there is evidence that gonadotropin-releasing hormone expressing neurons may produce and respond to spexin. Furthermore, we discuss the disorders and concomitant treatments, which have been reported to alter spexin expression, as well as the underlying signaling mechanisms that may be involved. Finally, we discuss the biochemical basis of spexin, its interaction with its cognate receptors, and how this information can be adapted to develop therapeutics for disorders related to the alteration of energy homeostasis and reproduction.
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Tejaswi G, Dayanand CD, Prabhakar K. Insulin resistance and decreased spexin in Indian Patients with Type 2 Diabetes Mellitus. Bioinformation 2021; 17:790-797. [PMID: 35539887 PMCID: PMC9049087 DOI: 10.6026/97320630017790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 01/11/2023] Open
Abstract
Spexin is novel biomarker, which plays a potential role in glucose and lipid metabolisms. However, there was paucity of serum spexin levels in obesity and diabetes mellitus subjects. Hence the current study was aimed to find the relationship between the serum spexin levels in type 2 Diabetes mellitus (type 2 DM) with extrapolation of cardiovascular disease (CVD) risk. A cross-sectional study included 330 participants, subdivided as control (n=110), type 2 DM (n=110) and type 2 DM with CVD groups (n=110). HbA1c, insulin, lipid profile, spexin & leptin including blood pressure and body mass index were analyzed from all the participants. The serum spexin levels (ng/ml) were significantly decreased in type 2 DM (mean ± sd: 0.65 ± 0.03) and type 2 DM with CVD (0.48 ± 0.02) groups compared to the control (0.79 ± 0.03) group (p<0.001). The decreased spexin levels were observed in type 2 DM, and further more decreased in type 2 DM with CVD patients compared to controls indicating that spexin levels could be served as an early prediction of obesity-induced T2DM with CVD risk.
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Affiliation(s)
- G Tejaswi
- Department of Biochemistry, Sri Devaraj Urs Academy of Higher Education & Research, Kolar, Karnataka, India
| | - CD Dayanand
- Department of Biochemistry, Sri Devaraj Urs Academy of Higher Education & Research, Kolar, Karnataka, India
| | - K Prabhakar
- Department of General Medicine, Sri Devaraj Urs Academy of Higher Education & Research, Kolar, Karnataka, India
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18
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Memi G, Yazgan B. Adropin and spexin hormones regulate the systemic inflammation in adenine-induced chronic kidney failure in rat. CHINESE J PHYSIOL 2021; 64:194-201. [PMID: 34472450 DOI: 10.4103/cjp.cjp_13_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Chronic kidney disease is one of the major global health problems. Chronic renal failure is stimulated by many cytokines and chemokines. Adropin and spexin (SPX) are peptides hormones. These peptides could affect inflammatory conditions, but this is unclear. Due to the limited information, we planned to investigate the impact of adropin and SPX hormones on systemic inflammation in adenine induced chronic kidney failure rat model. Chronic kidney failure was induced by administering adenine hemisulfate. Renal functions were measured by an autoanalyzer. Granulocyte colony-stimulating factor (G-CSF), interferon-gamma (IFN-γ), interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17A, tumor necrosis factor-alpha, Eotaxin, growth-regulated oncogene-alpha, IP-10, monocyte chemoattractant protein (MCP)-1, MCP-3, macrophage inflammatory protein (MIP)-1α, MIP-2, and RANTES levels were determined by Luminex. We observed an increase in 24-h urine volume and serum creatinine. Blood urea nitrogen (BUN) and urine protein levels were also significantly higher in the chronic kidney failure (CKF) group. Urine protein and 24-h urine volume were reduced with adropin and SPX treatments. Furthermore, G-CSF, IFN-γ, IL-4, IL-5, IL-10, IL-12, IL-17A, and GRO-α significantly increased by CKF induction; however, these cytokines and chemokines significantly decreased by adropin treatment in the CKF group. Furthermore, adropin increased IP-10, MCP-1, MIP-1α, and MIP-2 levels. In addition, SPX treatment had a more limited effect, decreasing only G-CSF, IFN-γ, and IL-5 levels. The combined adropin + SPX treatment significantly reduced G-CSF, IFN-γ, IL-4, IL-5, IL-12, and IL-17A. Furthermore, IP-10, MCP-1, MCP-3, and MIP-2 were significantly increased by these combined treatments. Our findings indicate that renal functions and inflammatory response were modulated by adropin and SPX peptides. These peptides may have protective effects on systemic inflammation and renal failure progression.
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Affiliation(s)
- Gulsun Memi
- Department of Physiology, School of Medicine, Adıyaman University, Adıyaman, Turkey
| | - Burak Yazgan
- Department of Medical Services and Techniques, Sabuncuoglu Serefeddin Health Services Vocational School; Department of Molecular Medicine, Institute of Health Sciences, Amasya University, Amasya, Turkey
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Yazgan B, Avcı F, Memi G, Tastekin E. Inflammatory response and matrix metalloproteinases in chronic kidney failure: Modulation by adropin and spexin. Exp Biol Med (Maywood) 2021; 246:1917-1927. [PMID: 34024143 PMCID: PMC8424640 DOI: 10.1177/15353702211012417] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
Chronic kidney disease is a major global public health problem. The peptide hormones adropin and spexin modulate many physiological functions such as energy balance and glucose, lipid and protein metabolism. However, it is unclear whether these peptides may exert effects on renal damage, tissue remodeling, and inflammatory conditions. In view of the limited information, we aimed to investigate the effect of adropin and spexin on matrix metalloproteinase and inflammatory response genes a rat model of adenine-induced chronic kidney failure. Chronic kidney failure was induced in rats by administering adenine hemisulfate. Renal function was determined in an autoanalyzer. Histopathological modifications were assessed by H&E staining. mRNA expression levels of ALOX 15, COX 1, COX 2, IL-1β, IL-10, IL-17A, IL-18 IL-21, IL-33, KIM-1, MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-13, NGAL, TGFβ1, TIMP-1, and TNFα in kidney tissue were measured by qPCR. Our results showed an increase of 24-h urine volume, serum creatinine, BUN, and urine protein levels in group with adenine-induced CKF. Adropin and spexin treatments decreased urine protein and 24-h urine volume. Renal damage, TIMP-1, IL-33, and MMP-2 increased after CKF induction, while COX 1, MMP-9, and MMP-13 levels were significantly reduced. Furthermore, KIM-1, TIMP-1, IL-33, and MMP-2 were downregulated by spexin treatment. Renal damage, NGAL, TIMP-1 IL-17A, IL-33, MMP-2, and MMP-3 decreased after adropin treatment, while MMP-13 levels were upregulated. Treatment with adropin+spexin decreased KIM-1, NGAL, TIMP-1, IL-1β, IL-17A, IL-18, IL-33, ALOX 15, COX 1, COX 2, TGFβ1, TNFα, MMP-2, MMP-3, and MMP-7, but increased MMP-13 levels. Our findings revealed that inflammatory response and MMP genes were modulated by adropin and spexin. These peptides may have protective effects on inflammation and chronic kidney damage progression.
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Affiliation(s)
- Burak Yazgan
- Department of Medical Services and Techniques, Sabuncuoğlu Serefeddin Health Services Vocational School, Amasya University, Amasya 05100, Turkey
- Department of Molecular Medicine, Institute of Health Sciences, Amasya University, Amasya 05100, Turkey
| | - Filiz Avcı
- Department of Molecular Medicine, Institute of Health Sciences, Amasya University, Amasya 05100, Turkey
| | - Gülsün Memi
- Department of Nursing, Hakkı Yoruk Health School, Trakya University, Edirne 22030, Turkey
- Department of Physiology, Institute of Health Sciences, Trakya University, Edirne 22030, Turkey
| | - Ebru Tastekin
- Department of Pathology, Faculty of Medicine, Trakya University, Edirne 22030, Turkey
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Chen Y, He M, Lei MML, Ko WKW, Lin C, Bian Z, Wong AOL. Mouse Spexin: (III) Differential Regulation by Glucose and Insulin in Glandular Stomach and Functional Implication in Feeding Control. Front Endocrinol (Lausanne) 2021; 12:681648. [PMID: 34025589 PMCID: PMC8138665 DOI: 10.3389/fendo.2021.681648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
Spexin (SPX), a neuropeptide with diverse functions, is a novel satiety factor in fish models and its role in feeding control has been recently confirmed in mammals. In mouse, food intake was shown to trigger SPX expression in glandular stomach with parallel rise in serum SPX and these SPX signals could inhibit feeding via central actions within the hypothalamus. However, the mechanisms for SPX regulation by food intake are still unclear. To examine the role of insulin signal caused by glucose uptake in SPX regulation, the mice were IP injected with glucose and insulin, respectively. In this case, serum SPX was elevated by glucose but not altered by insulin. Meanwhile, SPX transcript expression in the glandular stomach was up-regulated by glucose but the opposite was true for insulin treatment. Using in situ hybridization, the differential effects on SPX gene expression were located in the gastric mucosa of glandular stomach. Co-injection experiments also revealed that glucose stimulation on serum SPX and SPX mRNA expressed in glandular stomach could be blocked by insulin. In gastric mucosal cells prepared from glandular stomach, the opposite effects on SPX transcript expression by glucose and insulin could still be noted with similar blockade of the stimulatory effects of glucose by insulin. In this cell model, SPX gene expression induced by glucose was mediated by glucose uptake via GLUT, ATP synthesis by glycolysis/respiratory chain, and subsequent modulation of KATP channel activity, but the voltage-sensitive Ca2+ channels were not involved. The corresponding inhibition by insulin, however, was mediated by PI3K/Akt, MEK1/2/ERK1/2, and P38MAPK cascades coupled to insulin receptor but not IGF-1 receptor. Apparently, glucose uptake in mice can induce SPX expression in the glandular stomach through ATP synthesis via glucose metabolism and subsequent modification of KATP channel activity, which may contribute to SPX release into circulation to act as the satiety signal after food intake. The insulin rise caused by glucose uptake, presumably originated from the pancreas, may serve as a negative feedback to inhibit the SPX response by activating MAPK and PI3K/Akt pathways in the stomach.
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Affiliation(s)
- Yuan Chen
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Mulan He
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Martina M. L. Lei
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Wendy K. W. Ko
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Chengyuan Lin
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Zhaoxiang Bian
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Anderson O. L. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
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21
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Pałasz A, Żarczyński P, Bogus K, Mordecka-Chamera K, Della Vecchia A, Skałbania J, Worthington JJ, Krzystanek M, Żarczyńska M. Modulatory effect of olanzapine on SMIM20/phoenixin, NPQ/spexin and NUCB2/nesfatin-1 gene expressions in the rat brainstem. Pharmacol Rep 2021; 73:1188-1194. [PMID: 33928538 PMCID: PMC8413215 DOI: 10.1007/s43440-021-00267-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/22/2022]
Abstract
Background Phoenixin, spexin and nesfatin-1 belong to a family of newly discovered multifunctional neuropeptides that play regulatory roles in several brain structures and modulate the activity of important neural networks. However, little is known about their expression and action at the level of brainstem. The present work was, therefore, focused on gene expression of the aforementioned peptides in the brainstem of rats chronically treated with olanzapine, a second generation antipsychotic drug. Methods Studies were carried out on adult, male Sprague–Dawley rats that were divided into 2 groups: control and experimental animals treated with olanzapine (28-day-long intraperitoneal injection, at dose 5 mg/kg daily). All individuals were killed under anesthesia and the brainstem excised. Total mRNA was isolated from homogenized samples of both structures and the RT-PCR method was used for estimation of related SMIM20/phoenixin, NPQ/spexin and NUCB2/nesfatin-1 gene expression. Results Long-term treatment with olanzapine is reflected in qualitatively different changes in expression of examined neuropeptides mRNA in the rat brainstem. Olanzapine significantly decreased NPQ/spexin mRNA expression, but increased SMIM20/phoenixin mRNA level in the rat brainstem; while NUCB2/nesfatin-1 mRNA expression remained unchanged. Conclusions Olanzapine can affect novel peptidergic signaling in the rat brainstem. This may cautiously suggest the presence of an alternative mode of its action.
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Affiliation(s)
- Artur Pałasz
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland.
| | - Piotr Żarczyński
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland
| | - Katarzyna Bogus
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland
| | - Kinga Mordecka-Chamera
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland
| | - Alessandra Della Vecchia
- Department of Clinical and Experimental Medicine, Section of Psychiatry, University of Pisa, 67, Via Roma, 56100, Pisa, Italy
| | - Jakub Skałbania
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland
| | - John J Worthington
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Marek Krzystanek
- Clinic of Psychiatric Rehabilitation, Department of Psychiatry and Psychotherapy, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Ziolowa 45/47, 40-635, Katowice, Poland
| | - Małgorzata Żarczyńska
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków Street 18, 40-752, Katowice, Poland
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Ferris CF. Rethinking the Conditions and Mechanism for Glymphatic Clearance. Front Neurosci 2021; 15:624690. [PMID: 33897347 PMCID: PMC8060639 DOI: 10.3389/fnins.2021.624690] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/10/2021] [Indexed: 11/13/2022] Open
Abstract
Critical studies that form the foundation of the glymphatic system and the clearance of metabolic by-products of unwanted proteins from the brain are reviewed. Concerns are raised about studying glymphatic flow in anesthetized animals and making assumptions about the whole brain based upon data collected from a cranial window on the cortex. A new model is proposed arguing that the flow of cerebral spinal fluid and parenchymal clearance in the perivascular system of unwanted proteins is regulated by circadian changes in brain temperature and blood flow at the level of the microvasculature.
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Affiliation(s)
- Craig F Ferris
- Department Psychology and Pharmaceutical Sciences, Center for Translational Neuroimaging, Northeastern University, Boston, MA, United States
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El-Saka MH, Abo El Gheit RE, El Saadany A, Alghazaly GM, Marea KE, Madi NM. Effect of spexin on renal dysfunction in experimentally obese rats: potential mitigating mechanisms via galanin receptor-2. Arch Physiol Biochem 2021:1-10. [PMID: 33632048 DOI: 10.1080/13813455.2021.1887265] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This study declared effect of spexin (SPX) on renal dysfunction in obese rats and its potential mitigating mechanisms which could mediated via galanin receptor-2 (GALR-2). Thirty two 32 Wistar male rats were arranged into four groups: control, high fat/fructose diet (HFFD), HFFD + SPX and HFFD + M871 (galanin receptor 2 antagonist)+SPX. At the termination of the experiment, urine volume, body mass index, Lee index and mean arterial blood pressure were assessed. Renal function was evaluated. Lipid profile, fasting glucose, insulin, insulin resistance and SPX levels were estimated. Also, renal histopathological, immunohistochemical and relative gene expression of renal tissue were done. Also, renal protein carbonyl, reduced glutathione, interferon gamma, monocyte chemoattractant protein-1, interleukin-10 and hydroxyproline were determined.Our results explored that SPX treatment prominently mitigated the metabolic changes and renal dysfunction induced by HFFD via GALR-2. SPX improved insulin resistance, dyslipidemia, renal oxidative stress, inflammation, apoptosis, and fibrosis. So, SPX can be considered as prospective therapeutic agent for treating renal dysfunction.
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Affiliation(s)
| | | | | | | | - Karima E Marea
- Department of Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Nermin M Madi
- Department of Physiology, Tanta University, Tanta, Egypt
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24
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Mills EG, Izzi-Engbeaya C, Abbara A, Comninos AN, Dhillo WS. Functions of galanin, spexin and kisspeptin in metabolism, mood and behaviour. Nat Rev Endocrinol 2021; 17:97-113. [PMID: 33273729 DOI: 10.1038/s41574-020-00438-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
The bioactive peptides galanin, spexin and kisspeptin have a common ancestral origin and their pathophysiological roles are increasingly the subject of investigation. Evidence suggests that these bioactive peptides play a role in the regulation of metabolism, pancreatic β-cell function, energy homeostasis, mood and behaviour in several species, including zebrafish, rodents and humans. Galanin signalling suppresses insulin secretion in animal models (but not in humans), is potently obesogenic and plays putative roles governing certain evolutionary behaviours and mood modulation. Spexin decreases insulin secretion and has potent anorectic, analgesic, anxiolytic and antidepressive-like effects in animal models. Kisspeptin modulates glucose-stimulated insulin secretion, food intake and/or energy expenditure in animal models and humans. Furthermore, kisspeptin is implicated in the control of reproductive behaviour in animals, modulation of human sexual and emotional brain processing, and has antidepressive and fear-suppressing effects. In addition, galanin-like peptide is a further member of the galaninergic family that plays emerging key roles in metabolism and behaviour. Therapeutic interventions targeting galanin, spexin and/or kisspeptin signalling pathways could therefore contribute to the treatment of conditions ranging from obesity to mood disorders. However, many gaps and controversies exist, which must be addressed before the therapeutic potential of these bioactive peptides can be established.
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Affiliation(s)
- Edouard G Mills
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - Chioma Izzi-Engbeaya
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Ali Abbara
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Alexander N Comninos
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK
| | - Waljit S Dhillo
- Section of Endocrinology and Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK.
- Department of Endocrinology, Imperial College Healthcare NHS Trust, London, UK.
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25
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Behrooz M, Vaghef-Mehrabany E, Moludi J, Ostadrahimi A. Are spexin levels associated with metabolic syndrome, dietary intakes and body composition in children? Diabetes Res Clin Pract 2021; 172:108634. [PMID: 33347897 DOI: 10.1016/j.diabres.2020.108634] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 11/23/2020] [Accepted: 12/15/2020] [Indexed: 12/21/2022]
Abstract
AIMS The aim of the present study was to investigate whether circulating levels of spexin is related to metabolic syndrome, some dietary intakes (Total energyintake, Macronutrient intakes) and body composition in children. METHODS 90 children were recruited in the present cross sectional study. Anthropometric measures, body composition, blood pressure, dietary intakes, resting metabolic rate, physical activity level, appetite status, pubertal stage, serum spexin, fasting blood glucose, high-sensitivity C-reactive protein, insulin and lipid profile were measured using standard techniques. RESULTS 14 children met the criteria for metabolic syndrome. Median (IQR) of spexin levels were significantly lower in children with high fat mass and children with higher systolic blood pressure (SBP), compared to children with normal fat mass and normal SBP: (P < 0.05). A protective independent effect was detected for the highest tertile of serum spexin on metabolic syndrome in adjusted models; Crude OR (CI): 0.23 (0.04-1.2), P-trend = 0.08; Model 1: OR (CI): 0.15(0.02-1.01), P-trend = 0.05; Model 2: OR (CI): 0.10 (0.01-0.90), P-trend = 0.03. There was a significant negative association between spexin and total dietary fat intake (r= - 0.21; P < 0.04). CONCLUSION This findings can further highlight the importance of the relationship between spexin, adipose tissue and adipose tissue metabolism.
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Affiliation(s)
- Maryam Behrooz
- Student Research Committee, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran; Maraghe University of Medical Sciences, Department of Nutrition and Food Sciences, Department of Nutrition and Food Sciences, Iran
| | | | - Jalal Moludi
- School of Nutrition Sciences and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Alireza Ostadrahimi
- Nutrition Research Center, Department of Clinical Nutrition, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
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Wong MKH, Chen Y, He M, Lin C, Bian Z, Wong AOL. Mouse Spexin: (II) Functional Role as a Satiety Factor inhibiting Food Intake by Regulatory Actions Within the Hypothalamus. Front Endocrinol (Lausanne) 2021; 12:681647. [PMID: 34276562 PMCID: PMC8283969 DOI: 10.3389/fendo.2021.681647] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/13/2021] [Indexed: 11/17/2022] Open
Abstract
Spexin (SPX) is a pleiotropic peptide with highly conserved protein sequence from fish to mammals and its biological actions are mediated by GalR2/GalR3 receptors expressed in target tissues. Recently, SPX has been confirmed to be a novel satiety factor in fish species but whether the peptide has a similar function in mammals is still unclear. Using the mouse as a model, the functional role of SPX in feeding control and the mechanisms involved were investigated. After food intake, serum SPX in mice could be up-regulated with elevations of transcript expression and tissue content of SPX in the glandular stomach but not in other tissues examined. As revealed by immunohistochemical staining, food intake also intensified SPX signals in the major cell types forming the gastric glands (including the foveolar cells, parietal cells, and chief cells) within the gastric mucosa of glandular stomach. Furthermore, IP injection of SPX was effective in reducing food intake with parallel attenuation in transcript expression of NPY, AgRP, NPY type 5 receptor (NPY5R), and ghrelin receptor (GHSR) in the hypothalamus, and these inhibitory effects could be blocked by GalR3 but not GalR2 antagonism. In agreement with the central actions of SPX, similar inhibition on feeding and hypothalamic expression of NPY, AgRP, NPY5R, and GHSR could also be noted with ICV injection of SPX. In the same study, in contrast to the drop in NPY5R and GHSR, SPX treatment could induce parallel rises of transcript expression of leptin receptor (LepR) and melanocortin 4 receptor (MC4R) in the hypothalamus. These findings, as a whole, suggest that the role of SPX as a satiety factor is well conserved in the mouse. Apparently, food intake can induce SPX production in glandular stomach and contribute to the postprandial rise of SPX in circulation. Through GalR3 activation, this SPX signal can act within the hypothalamus to trigger feedback inhibition on feeding by differential modulation of feeding regulators (NPY and AgRP) and their receptors (NPY5R, GHSR, LepR, and MC4R) involved in the feeding circuitry within the CNS.
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Affiliation(s)
- Matthew K. H. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Yuan Chen
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Mulan He
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Chengyuan Lin
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Zhaoxiang Bian
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Anderson O. L. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
- *Correspondence: Anderson O. L. Wong,
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Wong MKH, He M, Sze KH, Huang T, Ko WKW, Bian ZX, Wong AOL. Mouse Spexin: (I) NMR Solution Structure, Docking Models for Receptor Binding, and Histological Expression at Tissue Level. Front Endocrinol (Lausanne) 2021; 12:681646. [PMID: 34276561 PMCID: PMC8285161 DOI: 10.3389/fendo.2021.681646] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/27/2021] [Indexed: 01/10/2023] Open
Abstract
Spexin (SPX), a highly conserved neuropeptide, is known to have diverse functions and has been implicated/associated with pathological conditions, including obesity, diabetes, anorexia nervosa, and anxiety/mood disorders. Although most of the studies on SPX involved the mouse model, the solution structure of mouse SPX, structural aspects for SPX binding with its receptors GalR2/3, and its cellular expression/distribution in mouse tissues are largely unknown. Using CD and NMR spectroscopies, the solution structure of mouse SPX was shown to be in the form of a helical peptide with a random coil from Asn1 to Pro4 in the N-terminal followed by an α-helix from Gln5 to Gln14 in the C-terminus. The molecular surface of mouse SPX is largely hydrophobic with Lys11 as the only charged residue in the α-helix. Based on the NMR structure obtained, docking models of SPX binding with mouse GalR2 and GalR3 were constructed by homology modeling and MD simulation. The models deduced reveal that the amino acids in SPX, especially Asn1, Leu8, and Leu10, could interact with specific residues in ECL1&2 and TMD2&7 of GalR2 and GalR3 by H-bonding/hydrophobic interactions, which provides the structural evidence to support the idea that the two receptors can act as the cognate receptors for SPX. For tissue distribution of SPX, RT-PCR based on 28 tissues/organs harvested from the mouse demonstrated that SPX was ubiquitously expressed at the tissue level with notable signals detected in the brain, GI tract, liver, gonad, and adrenal gland. Using immunohistochemical staining, protein signals of SPX could be located in the liver, pancreas, white adipose tissue, muscle, stomach, kidney, spleen, gonad, adrenal, and hypothalamo-pituitary axis in a cell type-specific manner. Our results, as a whole, not only can provide the structural information for ligand/receptor interaction for SPX but also establish the anatomical basis for our on-going studies to examine the physiological functions of SPX in the mouse model.
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Affiliation(s)
- Matthew K. H. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Mulan He
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kong Hung Sze
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong, Hong Kong
| | - Tao Huang
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Wendy K. W. Ko
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Zhao-Xiang Bian
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, Hong Kong
| | - Anderson O. L. Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
- *Correspondence: Anderson O. L. Wong,
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28
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Wang L, Tran A, Lee J, Belsham DD. Palmitate differentially regulates Spexin, and its receptors Galr2 and Galr3, in GnRH neurons through mechanisms involving PKC, MAPKs, and TLR4. Mol Cell Endocrinol 2020; 518:110991. [PMID: 32841709 DOI: 10.1016/j.mce.2020.110991] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/03/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023]
Abstract
The function of the gonadotropin-releasing hormone (GnRH) neuron is critical to maintain reproductive function and a significant decrease in GnRH can lead to disorders affecting fertility, including hypogonadotropic hypogonadism. Spexin (SPX) is a novel hypothalamic neuropeptide that exerts inhibitory effects on reproduction and feeding by acting through galanin receptor 2 (GALR2) and galanin receptor 3 (GALR3). Fatty acids can act as nutritional signals that regulate the hypothalamic-pituitary-gonadal (HPG) axis, and elevated levels of circulating saturated fatty acids associated with high fat diet (HFD)-feeding have been shown to induce neuroinflammation, endoplasmic reticulum stress and hormonal resistance in the hypothalamus, as well as alter neuropeptide expression. We previously demonstrated that palmitate, the most common saturated fatty acid in a HFD, elevates the expression of Spx, Galr2 and Galr3 mRNA in a model of appetite-regulating neuropeptide Y hypothalamic neurons. Here, we found that Spx, Galr2 and Galr3 mRNA were also significantly induced by palmitate in a model of reproductive GnRH neurons, mHypoA-GnRH/GFP. As a follow-up to our previous report, we examined the molecular pathways by which Spx and galanin receptor mRNA was regulated in this cell line. Furthermore, we performed inhibitor studies, which revealed that the effect of palmitate on Spx and Galr3 mRNA involved activation of the innate immune receptor TLR4, and we detected differential regulation of the three genes by the protein kinases PKC, JNK, ERK, and p38. However, the intracellular metabolism of palmitate to ceramide did not appear to be involved in the palmitate-mediated gene regulation. Overall, this suggests that SPX may play a role in reproduction at the level of the hypothalamus and the pathways by which Spx, Galr2 and Galr3 are altered by fatty acids could provide insight into the mechanisms underlying reproductive dysfunction in obesity.
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Affiliation(s)
- Lu Wang
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Andy Tran
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Juliette Lee
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
| | - Denise D Belsham
- Departments of Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada; Medicine, Faculty of Medicine, University of Toronto, Ontario, Canada; Obstetrics and Gynecology, Faculty of Medicine, University of Toronto, Ontario, Canada.
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Pałasz A, Suszka-Świtek A, Kaśkosz A, Plewka D, Bogus K, Filipczyk Ł, Błaszczyk I, Bacopoulou F, Worthington JJ, Piwowarczyk-Nowak A, Tyszkiewicz-Nwafor M, Wiaderkiewicz R. Spexin-expressing neurons in the magnocellular nuclei of the human hypothalamus. J Chem Neuroanat 2020; 111:101883. [PMID: 33161073 DOI: 10.1016/j.jchemneu.2020.101883] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 12/19/2022]
Abstract
Neuropeptides are involved in numerous brain activities being responsible for a wide spectrum of higher mental functions. The purpose of this concise, structural and qualitative investigation was to map the possible immunoreactivity of the novel neuropeptide spexin (SPX) within the human magnocellular hypothalamus. SPX is a newly identified peptide, a natural ligand for the galanin receptors (GALR) 2/3, with no molecular structure similarities to currently known regulatory factors. SPX seems to have multiple physiological functions, with an involvement in reproduction and food-intake regulation recently revealed in animal studies. For the first time we describe SPX expressing neurons in the supraoptic (SON) and paraventricular (PVN) nuclei of the human hypothalamus using immunohistochemical and fluorescent methods, key regions involved in the mechanisms of osmotic homeostasis, energy expenditure, consummatory behaviour, reproductive processes, social recognition and stress responses. The vast majority of neurons located in both examined neurosecretory nuclei show abundant SPX expression and this may indirectly implicate a potential contribution of SPX signalling to the hypothalamic physiology in the human brain.
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Affiliation(s)
- Artur Pałasz
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland.
| | - Aleksandra Suszka-Świtek
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Andrzej Kaśkosz
- Department of Anatomy, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Danuta Plewka
- Department of Cytophysiology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Katarzyna Bogus
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Łukasz Filipczyk
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Iwona Błaszczyk
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Flora Bacopoulou
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, 'Aghia Sophia' Children's Hospital, Athens, Greece
| | - John J Worthington
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Aneta Piwowarczyk-Nowak
- Department of Anatomy, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
| | - Marta Tyszkiewicz-Nwafor
- Department of Child and Adolescent Psychiatry, Poznan University of Medical Sciences, ul. Szpitalna 27/33, 60-572, Poznań, Poland
| | - Ryszard Wiaderkiewicz
- Department of Histology, School of Medical Sciences in Katowice, Medical University of Silesia, ul. Medyków 18, 40-752, Katowice, Poland
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30
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Tran A, Loganathan N, McIlwraith EK, Belsham DD. Palmitate and Nitric Oxide Regulate the Expression of Spexin and Galanin Receptors 2 and 3 in Hypothalamic Neurons. Neuroscience 2020; 447:41-52. [DOI: 10.1016/j.neuroscience.2019.10.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/14/2019] [Accepted: 10/16/2019] [Indexed: 12/13/2022]
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Lomet D, Robert V, Poissenot K, Beltramo M, Dardente H. No evidence that Spexin impacts LH release and seasonal breeding in the ewe. Theriogenology 2020; 158:1-7. [PMID: 32916519 DOI: 10.1016/j.theriogenology.2020.08.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 01/11/2023]
Abstract
Spexin (SPX) is a recently identified peptide hormone of 14 amino acids. Interestingly, Spx and Kiss1 genes share a common ancestor gene. Considering that KISS1 peptides are key controllers of breeding in mammals and circumstantial evidence that SPX regulates gonadotropins in some fish species, we hypothesized that SPX may play a KISS1-related role in sheep. Here, we cloned the ovine Spx cDNA, performed in vivo injection and infusion of SPX (i.c.v. route, with or without concomittant KISS1 presence) and assessed a potential regulation of Spx expression by season, thyroid hormone and estradiol in the medio-basal hypothalamus of the ewe. Our data do not provide support for a role of SPX in the control of the gonadotropic axis in the ewe.
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Affiliation(s)
- Didier Lomet
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Vincent Robert
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Kevin Poissenot
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | | | - Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France.
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Khadir A, Kavalakatt S, Madhu D, Devarajan S, Abubaker J, Al-Mulla F, Tiss A. Spexin as an indicator of beneficial effects of exercise in human obesity and diabetes. Sci Rep 2020; 10:10635. [PMID: 32606431 PMCID: PMC7327065 DOI: 10.1038/s41598-020-67624-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 05/07/2020] [Indexed: 12/20/2022] Open
Abstract
Spexin is a novel neuropeptide playing an emerging role in metabolic diseases such as obesity and diabetes via involvement in energy homeostasis and food intake. The present study investigated the effects of obesity and type 2 diabetes (T2D) on circulating levels of spexin and its modulation by physical exercise. Normal-weight (n = 50) and obese adults with and without T2D (n = 69 and n = 66, respectively) were enrolled in the study. A subgroup of obese participants (n = 47) underwent a supervised 3-month exercise programme. Plasma spexin levels were measured by ELISA and correlated with various markers. Plasma spexin levels decreased in obese participants with or without T2D compared with those of normal-weight participants (0.43 ± 0.11, 0.44 ± 0.12 and 0.61 ± 0.23 ng/ml, respectively; P < 0.001). Spexin levels negatively correlated with adiposity markers and blood pressure in the whole study population (P < 0.05). Multiple regression analysis revealed blood pressure was the greatest predictive determinant of plasma spexin levels, which significantly increased in response to physical exercise in obese participants without and with T2D (P < 0.05). Spexin levels significantly increased only in responders to exercise (those with increased oxygen consumption, VO2 max) with a concomitant improvement in metabolic profile. In conclusion, plasma spexin levels may be an indicator of response to physical exercise.
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Affiliation(s)
- Abdelkrim Khadir
- Biochemistry and Molecular Biology Department, Research Division, Dasman Diabetes Institute, P.O. Box1180, 15462, Dasman, Kuwait
| | - Sina Kavalakatt
- Biochemistry and Molecular Biology Department, Research Division, Dasman Diabetes Institute, P.O. Box1180, 15462, Dasman, Kuwait
| | - Dhanya Madhu
- Biochemistry and Molecular Biology Department, Research Division, Dasman Diabetes Institute, P.O. Box1180, 15462, Dasman, Kuwait
| | | | - Jehad Abubaker
- Biochemistry and Molecular Biology Department, Research Division, Dasman Diabetes Institute, P.O. Box1180, 15462, Dasman, Kuwait
| | - Fahd Al-Mulla
- Research Division, Dasman Diabetes Institute, Dasman, Kuwait
| | - Ali Tiss
- Biochemistry and Molecular Biology Department, Research Division, Dasman Diabetes Institute, P.O. Box1180, 15462, Dasman, Kuwait.
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Spexin as an anxiety regulator in mouse hippocampus: Mechanisms for transcriptional regulation of spexin gene expression by corticotropin releasing factor. Biochem Biophys Res Commun 2020; 525:326-333. [PMID: 32093887 DOI: 10.1016/j.bbrc.2020.02.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 02/05/2020] [Indexed: 11/23/2022]
Abstract
Spexin (SPX) acts as a neuropeptide with pleiotropic functions that can participate in anxiety regulation. Corticotropin releasing factor (CRF) is widely expressed in brain tissues and associated with depression and anxiety and addiction. With the anxious mice under chronic unpredictable stress, we found SPX mRNA expression level in the hippocampus of the brain was significantly reduced, while local CRF mRNA expression level was increased. Furthermore, CRF injection in the hippocampus could also decrease SPX mRNA expression levels in hippocampus and other brain tissues, including pituitary and hypothalamus. With the primary mouse hippocampal cell model, CRF treatment could decrease SPX mRNA expression at hippocampal cell level and this inhibitory effect was mediated only by corticotropin releasing factor receptor 2 (CRFR2) but not corticotropin releasing factor receptor 1 (CRFR1). In HEK293 cells with CRFR2 over-expression, CRF could also inhibit SPX promoter activity coupling with AC/cAMP/PKA and MEK1/2/Erk1/2 cascades. In addition, Epac was also involved with the CRF-repressed SPX promoter activity and cross-talked with MEK1/2/Erk1/2 pathway. CRF could inhibit SPX gene expression in mouse hippocampus via transcriptional activation at the promoter level with coupling of AC/cAMP and MEK1/2/Erk1/2 signaling, which will be relevant to the anxiety response mediated by SPX in central nervous system.
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Lv S, Zhou Y, Feng Y, Zhang X, Wang X, Yang Y, Wang X. Peripheral Spexin Inhibited Food Intake in Mice. Int J Endocrinol 2020; 2020:4913785. [PMID: 32831833 PMCID: PMC7426757 DOI: 10.1155/2020/4913785] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/31/2020] [Accepted: 06/15/2020] [Indexed: 11/17/2022] Open
Abstract
Spexin (SPX, NPQ), a novel endogenous neuropeptide, was firstly identified by bioinformatics. Spexin gene and protein widely distributed in the central nervous system and peripheral tissues, such as the hypothalamus and digestive tract. The role of spexin in appetite regulation in mammalian is still unclear. The present study was designed to investigate the mechanism and effect of peripheral spexin on food intake in mice. During the light period, an intraperitoneal (i.p.) injection of spexin (10 nmol/mouse) significantly inhibited cumulative food intake at 2, 4, and 6 h after treatment in fasted mice. During the dark period, spexin (1 and 10 nmol/mouse, i.p.) significantly suppressed cumulative food intake at 4 and 6 h after treatment in freely feeding mice. The GALR3 antagonist SNAP37889, not GALR2 antagonist, significantly antagonized the inhibitory effect on cumulative food intake (0-6 h) induced by spexin. Spexin significantly reduced the mRNA level of Npy mRNA, not Agrp, Pomc, Cart, Crh, Orexin, or Mch, in the hypothalamus. Spexin (10 nmol/mouse, i.p.) increased the number of c-Fos positive neurons in hypothalamic AHA and SCN, but not in ARC, DMN, LHA, PVN, SON, or VMH. The hypothalamic p-CaMK2 protein expression was upregulated by spexin. This study indicated that acute peripheral injection of spexin inhibited mouse food intake. The anorectic effect may be mediated by GALR3, and inhibiting neuropeptide Y (NPY) via p-CaMK2 and c-Fos in the hypothalamus.
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Affiliation(s)
- Shuangyu Lv
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Yuchen Zhou
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Yu Feng
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Xiaomei Zhang
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Xinyue Wang
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Yanjie Yang
- Institute of Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Xinchun Wang
- The First Affiliated Hospital of Henan University, Kaifeng 475001, China
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Cohen Y, Hausken K, Bonfil Y, Gutnick M, Levavi-Sivan B. Spexin and a Novel Cichlid-Specific Spexin Paralog Both Inhibit FSH and LH Through a Specific Galanin Receptor (Galr2b) in Tilapia. Front Endocrinol (Lausanne) 2020; 11:71. [PMID: 32153508 PMCID: PMC7044129 DOI: 10.3389/fendo.2020.00071] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/03/2020] [Indexed: 12/15/2022] Open
Abstract
Spexin (SPX) is a 14 amino acid peptide hormone that has pleiotropic functions across vertebrates, one of which is involvement in the brain-pituitary-gonad axis of fish. SPX(1) has been identified in each class of vertebrates, and a second SPX (named SPX2) has been found in some non-mammalian species. We have cloned two spexin paralogs, designated as Spx1a and Spx1b, from Nile tilapia (Oreochromis niloticus) that have varying tissue distribution patterns. Spx1b is a novel peptide only identified in cichlid fish, and is more closely related to Spx1 than Spx2 homologs as supported by phylogenetic, synteny, and functional analyses. Kisspeptin, Spx, and galanin (Gal) peptides and their corresponding kiss receptors and Gal receptors (Galrs), respectively, are evolutionarily related. Cloning of six tilapia Galrs (Galr1a, Galr1b, Galr2a, Galr2b, Galr type 1, and Galr type 2) and subsequent in vitro second-messenger reporter assays for Gαs, Gαq, and Gαi suggests that Gal and Spx activate Galr1a/Galr2a and Galr2b, respectively. A decrease in plasma follicle stimulating hormone and luteinizing hormone concentrations was observed with injections of Spx1a or Spx1b in vivo. Additionally, application of Spx1a and Spx1b to pituitary slices decreased the firing rate of LH cells, suggesting that the peptides can act directly at the level of the pituitary. These data collectively suggest an inhibitory mechanism of action against the secretion of gonadotropins for a traditional and a novel spexin paralog in cichlid species.
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Affiliation(s)
- Yaron Cohen
- Department of Animal Sciences, Hebrew University of Jerusalem, Rehovot, Israel
| | - Krist Hausken
- Department of Animal Sciences, Hebrew University of Jerusalem, Rehovot, Israel
| | - Yoav Bonfil
- Department of Animal Sciences, Hebrew University of Jerusalem, Rehovot, Israel
| | - Michael Gutnick
- The Robert H. Smith Faculty of Agriculture, Food, and Environment, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Berta Levavi-Sivan
- Department of Animal Sciences, Hebrew University of Jerusalem, Rehovot, Israel
- *Correspondence: Berta Levavi-Sivan
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Bitarafan V, Esteghamati A, Azam K, Yosaee S, Djafarian K. Comparing serum concentration of spexin among patients with metabolic syndrome, healthy overweight/obese, and normal-weight individuals. Med J Islam Repub Iran 2019; 33:93. [PMID: 31696087 PMCID: PMC6825375 DOI: 10.34171/mjiri.33.93] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Indexed: 12/02/2022] Open
Abstract
Background: There are many factors related to etiology of metabolic syndrome (MetS) including obesity. Spexin, a peptide hormone released from adipose tissue, is the most down-regulated gene in obese, compared to non-obese adipose tissue. Hence, it potentially contributes to the progression and development of metabolic diseases. This study was designed to evaluate serum concentration of spexin in patients with MetS compared to weight-matched and normal-weight controls. Methods: In this case-control study, 153 participants (51 per group) were collected from October 2014 to June 2016. The study groups were all matched for age and sex and included overweight/obese individuals with MetS and 2 control groups without MetS (including weight-matched and normal-weight participants). Body composition and serum concentration of spexin and leptin were measured. Results: Serum leptin and spexin levels were significantly higher and lower, respectively, in normal-weight compared to overweight/obese groups with/without MetS (p< 0.02). No significant difference was observed in serum leptin and spexin concentrations between the overweight/obese groups with/without MetS (p≥ 0.05). Also, spexin, with cutoff value of 4.6, had 78% sensitivity and 82% specificity for diagnosing overweight/obese from normal-weight participants. Spexin had 78% sensitivity and specificity, with cutoff value of 4.35, in diagnosing MetS participants from normal-weight group. Conclusion: This study found no correlation between the circulating level of spexin and MetS development. Higher serum concentration of spexin in normal-weight adults compared to the obese participants illustrated the potential role of this novel peptide in obesity.
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Affiliation(s)
- Vida Bitarafan
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.,Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Alireza Esteghamati
- Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Kamal Azam
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Somaye Yosaee
- Department of Nutrition Sciences, School of Health, Larestan University of Medical Sciences, Larestan, Iran.,Department of Nutrition Sciences, Emam Reza Teaching Hospital, Larestan University of Medical Sciences, Larestan, Iran
| | - Kurosh Djafarian
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
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Jeong I, Kim E, Seong JY, Park HC. Overexpression of Spexin 1 in the Dorsal Habenula Reduces Anxiety in Zebrafish. Front Neural Circuits 2019; 13:53. [PMID: 31474838 PMCID: PMC6702259 DOI: 10.3389/fncir.2019.00053] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/26/2019] [Indexed: 01/01/2023] Open
Abstract
Spexin (SPX) is an evolutionarily conserved neuropeptide that is expressed in the mammalian brain and peripheral tissue. Two orthologs are present in the teleost, SPX1 and SPX2. SPX1 is involved in reproduction and food intake. Recently, SPX1 neurons have been found to be located in the specific nuclei of dorsal habenula (dHb) and to project into the interpeduncular nucleus (IPN), in which galanin receptor 2a/2b (GALR2a/2b) expression was also observed. This indicates that habenula SPX1 neurons may interact with GALR2a/2b in the IPN; however, the function of SPX1 in the dHb-IPN neuronal circuit remains unknown. To determine the role of SPX1 in the dHb-IPN neural circuit, we generated transgenic zebrafish overexpressing SPX1 specifically in the dHb. We found that transgenic zebrafish overexpressing SPX1 in the dHb had anxiolytic behaviors compared with their wildtype siblings. Furthermore, quantitative PCR revealed that mRNA expression of galr2a and galr2b in the IPN and serotonin-related genes in the raphe was upregulated in the brains of transgenic zebrafish. Taken together, our data suggest that SPX1 function in the dHb-IPN neural circuits is implicated in the regulation of anxiety behaviors via modulation of the serotoninergic system in zebrafish.
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Affiliation(s)
- Inyoung Jeong
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, South Korea
| | - Eunmi Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, South Korea
| | - Jae Young Seong
- Department of Biomedical Sciences, Korea University, Seoul, South Korea
| | - Hae-Chul Park
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, South Korea
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Liu Y, Sun L, Zheng L, Su M, Liu H, Wei Y, Li D, Wang Y, Dai C, Gong Y, Zhao C, Li Y. Spexin protects cardiomyocytes from hypoxia-induced metabolic and mitochondrial dysfunction. Naunyn Schmiedebergs Arch Pharmacol 2019; 393:25-33. [DOI: 10.1007/s00210-019-01708-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022]
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39
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Lv SY, Zhou YC, Zhang XM, Chen WD, Wang YD. Emerging Roles of NPQ/Spexin in Physiology and Pathology. Front Pharmacol 2019; 10:457. [PMID: 31133851 PMCID: PMC6514225 DOI: 10.3389/fphar.2019.00457] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 04/11/2019] [Indexed: 01/25/2023] Open
Abstract
Spexin (SPX), also called neuropeptide Q (NPQ), is a novel endogenous neuropeptide. Spexin gene and protein are widely expressed in central nervous system and peripheral tissues in humans, rodents, goldfish, etc. A few of physiological and pathological roles of spexin are gradually emerged recently. This article summarized the roles of spexin in feeding behavior, gastrointestinal motility, obesity, diabetes, energy metabolism, endocrine, mental diseases, and cardiovascular function. Given the broad roles of spexin, this neuropeptide has attracted much interest from investigators and will be as a promising future target for novel therapeutic research and drug design.
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Affiliation(s)
- Shuang-Yu Lv
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Yu-Chen Zhou
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Xiao-Mei Zhang
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Wei-Dong Chen
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China.,Key Laboratory of Molecular Pathology, School of Basic Medical Science, Inner Mongolia Medical University, Hohhot, China
| | - Yan-Dong Wang
- State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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40
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Distribution and neuronal circuit of spexin 1/2 neurons in the zebrafish CNS. Sci Rep 2019; 9:5025. [PMID: 30903017 PMCID: PMC6430828 DOI: 10.1038/s41598-019-41431-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 03/04/2019] [Indexed: 02/06/2023] Open
Abstract
Spexin (SPX) is a highly conserved neuropeptide that is widely expressed in mammalian brain and peripheral tissue. In teleost, SPX1 is mainly expressed in the brain and ovary, and is involved in reproduction and food intake. A second form of SPX, SPX2, was recently identified in chick, Xenopus, and zebrafish. The expression pattern and roles of SPX2 are unknown. SPX (spx1) is highly expressed in the vertebrate brain, but its distribution, circuits, and interactions with its putative receptor are unknown. Here, we observed expression of spx1 in the midbrain and hindbrain, and spx2 in the hypothalamic preoptic area using in situ RNA hybridization in zebrafish. Analysis of transgenic reporter zebrafish revealed that hindbrain SPX1 neurons are PAX2+ inhibitory interneurons and project to the spinal cord, where they interact with galanin receptor 2b (GALR2b) neurons, suggesting that hindbrain SPX1 neurons are reticulospinal neurons. spx1 mRNA and SPX1 reporter expression were observed in dorsal habenula (dHb). SPX1 neurons in the dHb project to the interpeduncular nucleus (IPN), where GALR2a and GALR2b expression was also observed, suggesting that habenula SPX1 neurons may interact with GALR2a/2b in the IPN.
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41
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Sassek M, Kolodziejski PA, Szczepankiewicz D, Pruszynska-Oszmalek E. Spexin in the physiology of pancreatic islets-mutual interactions with insulin. Endocrine 2019; 63:513-519. [PMID: 30267353 DOI: 10.1007/s12020-018-1766-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 09/15/2018] [Indexed: 11/28/2022]
Abstract
Spexin is an interesting peptide, which may play an important role in the regulation of the metabolic homeostasis of an organism. Current knowledge on spexin expression, secretion, and influence on tissues and endocrine glands is very limited. We investigated spexin localization in the endocrine pancreas and measured its in vitro secretion from isolated pancreatic islets at various glucose concentrations, simultaneously monitoring insulin release. Also, gene expression for spexin and insulin was estimated. We found the presence of spexin inside beta cells and an increase in its release from islets after a short term and decrease after a long term following glucose administration. Finally, negative feedback loops between spexin and insulin were found, indicating the presence of multilateral relationships between glucose, insulin, and spexin inside pancreatic islets.
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Affiliation(s)
- Maciej Sassek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska street 35, 60-637, Poznan, Poland
| | - Pawel A Kolodziejski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska street 35, 60-637, Poznan, Poland.
| | - Dawid Szczepankiewicz
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska street 35, 60-637, Poznan, Poland
| | - Ewa Pruszynska-Oszmalek
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska street 35, 60-637, Poznan, Poland
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42
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Lv SY, Cui B, Yang Y, Du H, Zhang X, Zhou Y, Ye W, Nie X, Li Y, Wang Q, Chen WD, Wang YD. Spexin/NPQ Induces FBJ Osteosarcoma Oncogene (Fos) and Produces Antinociceptive Effect against Inflammatory Pain in the Mouse Model. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:886-899. [PMID: 30664863 DOI: 10.1016/j.ajpath.2018.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 11/05/2018] [Accepted: 12/07/2018] [Indexed: 01/12/2023]
Abstract
Spexin/NPQ is a novel highly conserved neuropeptide. It has a widespread expression in the periphery and central nervous system. However, the effects of central spexin on acute inflammatory pain are still unknown. This study explored the mechanisms and effects of supraspinal spexin on inflammatory pain. The results from the mouse formalin test show that i.c.v. administration of spexin decreased licking/biting time during the late and early phases. The nonamidated spexin had no effect on pain response. The antinociception of spexin was blocked by galanin receptor 3 antagonist SNAP 37889. The Galr3 and Adcy4 mRNA levels in the brain were increased after injection with spexin. The antinociceptive effects of spexin were completely reversed by opioid receptor antagonist naloxone and κ-opioid receptor antagonist nor-binaltorphimine dihydrochloride. Spexin up-regulated the dynorphin and κ-opioid receptor gene and protein expression. PCR array assay and real-time PCR analysis show that spexin up-regulated the mRNA level of the FBJ osteosarcoma oncogene (Fos). T-5224, the inhibitor of c FBJ osteosarcoma oncogene (c-Fos)/activator protein 1 (AP-1), blocked the increased mRNA level of Pdyn and Oprk1 induced by spexin. I.C.V. spexin (2.43 mg/kg) increased the number of c-Fos-positive neurons in most subsections of periaqueductal gray. In addition, in the acetic acid-induced writhing test, i.c.v. spexin produced an antinociceptive effect. Our results indicate that spexin might be a novel neuropeptide with an antinociceptive effect against acute inflammatory pain.
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Affiliation(s)
- Shuang-Yu Lv
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Binbin Cui
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Yanjie Yang
- Laboratory of Cell Signal Transduction, School of Medicine, Henan University, Kaifeng, China
| | - Hua Du
- Department of Pathology, College of Basic Medicine, Inner Mongolia Medical University, Hohhot, China
| | - Xiaomei Zhang
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Yuchen Zhou
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Wenling Ye
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Xiaobo Nie
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Yang Li
- Department of Orthopaedics, The 969th Hospital of People's Liberation Army of China, Hohhot, China
| | - Qun Wang
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China
| | - Wei-Dong Chen
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, China; Department of Pathology, College of Basic Medicine, Inner Mongolia Medical University, Hohhot, China.
| | - Yan-Dong Wang
- State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
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Al-Daghri NM, Sabico S, Al-Hazmi H, Alenad AM, Al-Amro A, Al-Ghamdi A, Hussain SD, Chrousos G, Alokail MS. Circulating spexin levels are influenced by the presence or absence of gestational diabetes. Cytokine 2019; 113:291-295. [DOI: 10.1016/j.cyto.2018.07.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 06/28/2018] [Accepted: 07/17/2018] [Indexed: 02/06/2023]
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Lim CH, Lee MYM, Soga T, Parhar I. Evolution of Structural and Functional Diversity of Spexin in Mammalian and Non-mammalian Vertebrate Species. Front Endocrinol (Lausanne) 2019; 10:379. [PMID: 31275244 PMCID: PMC6593056 DOI: 10.3389/fendo.2019.00379] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 05/28/2019] [Indexed: 01/15/2023] Open
Abstract
Spexin (SPX) is a novel neuropeptide, which was first identified in the human genome using bioinformatics. Since then, orthologs of human SPX have been identified in mammalian and non-mammalian vertebrates. The mature sequence of SPX, NWTPQAMLYLKGAQ, is evolutionally conserved across vertebrate species, with some variations in teleost species where Ala at position 13 is substituted by Thr. In mammals, the gene structure of SPX comprises six exons and five introns, however, variation exists within non-mammalian species, goldfish and zebrafish having five exons while grouper has six exons. Phylogenetic and synteny analysis, reveal that SPX is grouped together with two neuropeptides, kisspeptin (KISS) and galanin (GAL) as a family of peptides with a common evolutionary ancestor. A paralog of SPX, termed SPX2 has been identified in non-mammalians but not in the mammalian genome. Ligand-receptor interaction study also shows that SPX acts as a ligand for GAL receptor 2 (2a and 2b in non-mammalian vertebrates) and 3. SPX acts as a neuromodulator with multiple central and peripheral physiological roles in the regulation of insulin release, fat metabolism, feeding behavior, and reproduction. Collectively, this review provides a comprehensive overview of the evolutionary diversity as well as molecular and physiological roles of SPX in mammalian and non-mammalian vertebrate species.
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45
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Spexin: A novel regulator of adipogenesis and fat tissue metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:1228-1236. [DOI: 10.1016/j.bbalip.2018.08.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 01/31/2023]
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46
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Deng SP, Chen HP, Zhai Y, Jia LY, Liu JY, Wang M, Jiang DN, Wu TL, Zhu CH, Li GL. Molecular cloning, characterization and expression analysis of spexin in spotted scat (Scatophagus argus). Gen Comp Endocrinol 2018; 266:60-66. [PMID: 29753927 DOI: 10.1016/j.ygcen.2018.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/11/2018] [Accepted: 04/14/2018] [Indexed: 12/14/2022]
Abstract
Spexin (Spx), a novel neuropeptide, composed of 14 amino acid residues, is evolutionally conserved from fish to mammals. It has been suggested that Spx has pleiotropic functions in mammals. However, reports about Spx are very limited. To clarify the roles of Spx in the regulation of reproduction and food-intake in the spotted scat, the spx (ssspx) gene was cloned and analyzed. Analysis of the tissue distribution by RT-PCR showed that ssspx expression was widespread. During ovary development, expression of ssspx was found to be highest in phase II, moderate in phase III, and at its lowest level in phase IV. Ssspx expression was significantly down-regulated in the hypothalamus after treatment with E2 both in vitro and in vivo. A significant increase of ssspx was observed after 2 and 7 days of food deprivation. However, the ssspx transcript levels in the 7 day fasting group decreased significantly after refeeding 3 h after the scheduled feeding time. This suggests that ssSpx may be involved in the regulation of reproduction and food-intake in the spotted scat.
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Affiliation(s)
- Si-Ping Deng
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China; Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Hua-Pu Chen
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Yi Zhai
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Li-Ying Jia
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jian-Ye Liu
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Mei Wang
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Dong-Neng Jiang
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Tian-Li Wu
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Chun-Hua Zhu
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Guang-Li Li
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China.
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47
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Conformational signatures in β-arrestin2 reveal natural biased agonism at a G-protein-coupled receptor. Commun Biol 2018; 1:128. [PMID: 30272007 PMCID: PMC6123711 DOI: 10.1038/s42003-018-0134-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 08/08/2018] [Indexed: 01/14/2023] Open
Abstract
Discovery of biased ligands and receptor mutants allows characterization of G-protein- and β-arrestin-mediated signaling mechanisms of G-protein-coupled receptors (GPCRs). However, the structural mechanisms underlying biased agonism remain unclear for many GPCRs. We show that while Galanin induces the activation of the galanin receptor 2 (Galr2) that leads to a robust stimulation toward Gαq-protein and β-arrestin1/2, an alternative ligand Spexin and its analog have biased agonism toward G-protein signaling relative to Galanin. We used intramolecular fluorescein arsenical hairpin bioluminescence resonance energy transfer-based biosensors of β-arrestin2 combined with NanoBit technology to measure β-arrestin2–Galr2 interactions in real-time living systems. We found that Spexin and Galanin induce specific active conformations of Galr2, which may lead to different internalization rates of the receptor as well as different signaling outputs. This work represents an additional pharmacological evidence of endogenous G-protein-biased agonism at a GPCR. Arfaxad Reyes-Alcaraz et al. report that galanin induces robust signaling mediated by β-arrestin1/2 and Gαq, whereas an alternative ligand spexin prefers the Gαq-protein signaling pathway. This study provides mechanistic insights into how endogenous ligands can generate biased signaling outputs.
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Ma A, Bai J, He M, Wong AOL. Spexin as a neuroendocrine signal with emerging functions. Gen Comp Endocrinol 2018; 265:90-96. [PMID: 29355530 DOI: 10.1016/j.ygcen.2018.01.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/13/2018] [Accepted: 01/13/2018] [Indexed: 12/19/2022]
Abstract
Spexin (SPX), a novel peptide coevolved with the galanin/kisspeptin family, was first identified by bioinformatics prior to its protein purification/functional studies. Its mature peptide is highly conserved among different vertebrate classes. Based on the studies in mammals and fish models, SPX was found to be widely distributed at tissue level, secreted into systemic circulation, identified at notable levels in central nervous system and peripheral tissues, and has been confirmed/implicated in multiple functions in different tissues/organs, suggesting that SPX may serve as a neuroendocrine signal with pleotropic functions. In this article, different isoforms of SPX and their binding with their cognate receptors GalR2 and GalR3, the biological functions of SPX reported in mammals including GI tract movement, energy balance and weight loss, fatty acid uptake, glucose homeostasis, nociception and cardiovascular/renal functions, as well as the recent findings in fish models regarding the role of SPX in reproduction and feeding control will be reviewed with interesting questions for future investigations.
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Affiliation(s)
- Ani Ma
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Jin Bai
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Mulan He
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Anderson O L Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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Abstract
OBJECTIVES Spexin is a peptide whose action is poorly understood but which is expressed in many tissues. This encouraged us to investigate the potential role of spexin in the regulation of pancreatic secretion. METHODS Cells/islets were incubated with different concentrations of glucose and spexin to measure insulin secretion. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and BrdU (5-bromo-2'-deoxyuridine) tests were performed to assess the viability and proliferation of pancreatic islets after spexin treatment. Real-time polymerase chain reaction was used to detect messenger RNA expression for insulin, insulin receptor, and Pdx (pancreatic duodenal homeobox-1). RESULTS Insulin secretion from cultured cells and isolated islets was reduced by spexin at 16 mM glucose level. In obese rats, insulin secretion was decreased after injection with spexin. Spexin treatment showed an increase in cultured cells and pancreatic islets cell viability and proliferation as well as an increase in proliferating cell nuclear antigen protein level. In contrast, a decrease in insulin and Pdx gene expression was found. CONCLUSIONS The effects of spexin on insulin secretion in vitro and in vivo and also on cells viability and proliferation confirm that this peptide may be strongly involved in the pathogenesis of diabetes or its recovery.
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Wang S, Wang B, Chen S. Spexin in the half-smooth tongue sole (Cynoglossus semilaevis): molecular cloning, expression profiles, and physiological effects. FISH PHYSIOLOGY AND BIOCHEMISTRY 2018; 44:829-839. [PMID: 29404821 DOI: 10.1007/s10695-018-0472-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Spexin (SPX), a novel neuropeptide discovered by the bioinformatics approach, has been shown to exert pleiotropic functions in mammals. However, little information regarding the physiological role of SPX is available in teleosts. As a first step, we cloned the spexin gene from a flatfish, the half-smooth tongue sole. The open reading frame (ORF) of tongue sole spexin contained 363 nucleotides encoding a 120 amino acid (aa) preprohormone with a calculated molecular mass and isoelectric point of 14.06 kDa and 5.86, respectively. The tongue sole SPX precursor contained a 27 aa signal peptide and a 14 aa mature peptide flanked by two dibasic protein cleavage sites (RR and GRR). Tissue distribution analysis showed that spexin mRNA could be detected in various tissues, notably in the brain. In addition, fasting stimulated the hypothalamic expression of spexin mRNA. Intraperitoneal injection of SPX increased gnih and gnrh3 mRNA levels in the hypothalamus; however, SPX inhibited the pituitary expression of gh, fshβ, and gthα mRNAs. Overall, our results reveal the existence of a functional SPX in the tongue sole, which could represent an important factor in the neuroendocrine control of flatfish reproduction and growth, and the spexin mRNA expression is regulated by feeding status.
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Affiliation(s)
- Shengpeng Wang
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 106 Nanjing Road, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Bin Wang
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 106 Nanjing Road, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Songlin Chen
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 106 Nanjing Road, Qingdao, 266071, China.
- Laboratory for Marine Fisheries and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
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