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Jing M, Wang S, Li D, Wang Z, Li Z, Lu Y, Sun T, Qiu C, Chen F, Yu H, Zhang W. Lorcaserin Inhibit Glucose-Stimulated Insulin Secretion and Calcium Influx in Murine Pancreatic Islets. Front Pharmacol 2021; 12:761966. [PMID: 34803706 PMCID: PMC8602196 DOI: 10.3389/fphar.2021.761966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
Lorcaserin is a serotonergic agonist specific to the 5-hydroxytryptamine 2c receptor (5-HT2CR) that is FDA approved for the long-term management of obesity with or without at least one weight-related comorbidity. Lorcaserin can restrain patients' appetite and improve insulin sensitivity and hyperinsulinemia mainly through activating 5-HT2CR in the hypothalamus. It is known that the mCPP, a kind of 5-HT2CR agonist, decreases plasma insulin concentration in mice and previous research in our laboratory found that mCPP inhibited glucose-stimulated insulin secretion (GSIS) by activating 5-HT2CR on the β cells. However, the effect of lorcaserin on GSIS of pancreatic β cell has not been studied so far. The present study found that 5-HT2CR was expressed in both mouse pancreatic β cells and β-cell-derived MIN6 cells. Dose-dependent activation of 5-HT2CR by lorcaserin suppressed GSIS and SB242084 or knockdown of 5-HT2CR abolished lorcaserin's effect in vitro. Additionally, lorcaserin also suppressed GSIS in high-fat diet (HFD)-fed mice in dose-dependent manner. Lorcaserin did not change insulin synthesis ATP content, but lorcaserin decrease cytosolic free calcium level [(Ca2+)i] in MIN6 cells stimulated with glucose and also inhibit insulin secretion and (Ca2+)i in MIN6 treated with potassium chloride. Furthermore, stimulation with the L-type channel agonist, Bay K8644 did not restore GSIS in MIN6 exposed to lorcaserin. Lorcaserin inhibits the cAMP generation of MIN6 cells and pretreatment with the Gα i/o inhibitor pertussis toxin (PTX), abolished lorcaserin-induced suppression of GSIS in β cells, while membrane-permeable cAMP analogue db-cAMP had same effect as PTX. These date indicated lorcaserin coupled to PTX-sensitive Gα i/o proteins in β cells reduced intracellular cAMP level and Ca2+ influx, thereby causing GSIS dysfunction of β cell. These results highlight a novel signaling mechanism of lorcaserin and provide valuable insights into the further investigation of 5-HT2CR functions in β-cell biology and it also provides guidance for the clinical application of lorcaserin.
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Affiliation(s)
- Muhan Jing
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Shanshan Wang
- Laboratory Animal Center, Department of Science and Technology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ding Li
- Department of Forensic Medicine, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Zeyu Wang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Ziwen Li
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Yichen Lu
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Tong Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Chen Qiu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Fang Chen
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Haijuan Yu
- Department of Obstetrics, Traditional Chinese Medicine Hospital of Jingning, Nanjing, China
| | - Wei Zhang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
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Wu CH, Chang CS, Yang YK, Shen LH, Yao WJ. Comparison of brain serotonin transporter using [I-123]-ADAM between obese and non-obese young adults without an eating disorder. PLoS One 2017; 12:e0170886. [PMID: 28182708 PMCID: PMC5300236 DOI: 10.1371/journal.pone.0170886] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 01/12/2017] [Indexed: 11/25/2022] Open
Abstract
Cerebral serotonin metabolism has an important but controversial role in obesity. However, it is not given enough attention in morbidly obese young adults. We used single photon emission computed tomography (SPECT) with [I-123]-labeled 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine (ADAM) to investigate changes in serotonin transporter (SERT) availability in 10 morbidly obese young adults without an eating disorder (M/F = 5/5, body mass index (BMI): 40.3 ± 4.1 kg/m2, percentage of body fat (BF%): 46.0 ± 3.9%) and 10 age- and sex-matched non-obese controls (BMI: 20.3 ± 1.2 kg/m2, BF%: 20.6 ± 8.9%). All participants underwent SPECT at 10 min and 6 h after an injection of 200 MBq of [I-123]-ADAM. The SERT binding site (midbrain) was drawn with cerebellum normalization. The BF% and fat distribution were measured using dual-energy X-ray absorptiometry. The midbrain/cerebellum SERT binding ratios (2.49 ± 0.46 vs. 2.47 ± 0.47; p = 0.912) at 6 h were not significantly different between groups, nor was the distribution of the summed images at 10 min (1.36 ± 0.14 vs. 1.35 ± 0.11; p = 0.853). There were no significant correlations between midbrain/cerebellum SERT binding ratio and age, BMI, BF%, or fat distribution. No significant difference in SERT availability in the midbrain between morbidly obese and non-obese young adults without an eating disorder indicates an unmet need for investigating the role of cerebral serotonin in obesity.
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Affiliation(s)
- Chih-Hsing Wu
- Departments of Family Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
- Institutes of Behavioral Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
- Institutes of Gerontology, National Cheng Kung University College of Medicine, Tainan, Taiwan
| | - Chin-Sung Chang
- Departments of Family Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
- Institutes of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
| | - Yen Kuang Yang
- Institutes of Behavioral Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
- Departments of Psychiatry, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
| | - Lie-Hang Shen
- Institute of Nuclear Energy Research, Longtan Township, Taoyuan County, Taiwan
| | - Wei-Jen Yao
- Departments of Nuclear Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
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Gonzales GF. Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes. Asian J Androl 2013; 15:368-74. [PMID: 23524530 DOI: 10.1038/aja.2012.170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl(-1)<haemoglobin (Hb)≤21 g dl(-1)) and others with excessive erythrocytosis (EE) (Hb>21 g dl(-1)). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.
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Affiliation(s)
- Gustavo F Gonzales
- High Altitude Research Institute and Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima 31, Peru.
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