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Kaneko K, Taniguchi E, Funatsu Y, Nakamura Y, Iwakura H, Ohinata K. Human milk-specific fat components enhance the secretion of ghrelin by MGN3-1 cells. Biosci Biotechnol Biochem 2024; 88:671-678. [PMID: 38453432 DOI: 10.1093/bbb/zbae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/03/2024] [Indexed: 03/09/2024]
Abstract
Triacylglycerols (TAGs) are a major fat component in human milk. Since gastric lipase produces 1,2-diacylglycerol from TAGs, we focused on the bioactivity of human milk-derived diacylglycerols in stomach cells. Ghrelin is produced in the stomach and acts as an important regulator of growth hormone secretion and energy homeostasis. In this study, we showed that 1-oleoyl-2-palmitoylglycerol (OP) increased ghrelin secretion, whereas 1,3-dioleoyl-2-palmitoylglycerol (OPO), a major component of human milk TAGs, did not increase ghrelin secretion in the ghrelin-secreting cell line, MGN3-1. Therefore, diacylglycerol OP may directly contribute to the regulation of ghrelin secretion. We also found that 2-palmitoylglycerol and 1- and 2-oleoylglycerol increased ghrelin secretion. Finally, we demonstrated that intracellular cAMP levels and preproghrelin and ghrelin O-acyl transferase expression levels were enhanced by OP treatment in MGN3-1 cells. This may represent an example of a novel mother-infant interaction mediated by fat components derived from human breast milk.
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Affiliation(s)
- Kentaro Kaneko
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki-shi, Kanagawa, Japan
| | - Eriko Taniguchi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yui Funatsu
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd., Hachiouji, Tokyo, Japan
| | - Yoshitaka Nakamura
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd., Hachiouji, Tokyo, Japan
| | - Hiroshi Iwakura
- Department of Pharmacotherapeutics, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Kousaku Ohinata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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2
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Shankar K, Varshney S, Gupta D, Mani BK, Osborne-Lawrence S, Metzger NP, Richard CP, Zigman JM. Ghrelin does not impact the blunted counterregulatory response to recurrent hypoglycemia in mice. Front Endocrinol (Lausanne) 2023; 14:1181856. [PMID: 37334290 PMCID: PMC10272800 DOI: 10.3389/fendo.2023.1181856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/23/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Recurrent episodes of insulin-induced hypoglycemia in patients with diabetes mellitus can result in hypoglycemia-associated autonomic failure (HAAF), which is characterized by a compromised response to hypoglycemia by counterregulatory hormones (counterregulatory response; CRR) and hypoglycemia unawareness. HAAF is a leading cause of morbidity in diabetes and often hinders optimal regulation of blood glucose levels. Yet, the molecular pathways underlying HAAF remain incompletely described. We previously reported that in mice, ghrelin is permissive for the usual CRR to insulin-induced hypoglycemia. Here, we tested the hypothesis that attenuated release of ghrelin both results from HAAF and contributes to HAAF. Methods C57BL/6N mice, ghrelin-knockout (KO) + control mice, and GhIRKO (ghrelin cell-selective insulin receptor knockout) + control mice were randomized to one of three treatment groups: a "Euglycemia" group was injected with saline and remained euglycemic; a 1X hypoglycemia ("1X Hypo") group underwent a single episode of insulin-induced hypoglycemia; a recurrent hypoglycemia ("Recurrent Hypo") group underwent repeated episodes of insulin-induced hypoglycemia over five successive days. Results Recurrent hypoglycemia exaggerated the reduction in blood glucose (by ~30%) and attenuated the elevations in plasma levels of the CRR hormones glucagon (by 64.5%) and epinephrine (by 52.9%) in C57BL/6N mice compared to a single hypoglycemic episode. Yet, plasma ghrelin was equivalently reduced in "1X Hypo" and "Recurrent Hypo" C57BL/6N mice. Ghrelin-KO mice exhibited neither exaggerated hypoglycemia in response to recurrent hypoglycemia, nor any additional attenuation in CRR hormone levels compared to wild-type littermates. Also, in response to recurrent hypoglycemia, GhIRKO mice exhibited nearly identical blood glucose and plasma CRR hormone levels as littermates with intact insulin receptor expression (floxed-IR mice), despite higher plasma ghrelin in GhIRKO mice. Conclusions These data suggest that the usual reduction of plasma ghrelin due to insulin-induced hypoglycemia is unaltered by recurrent hypoglycemia and that ghrelin does not impact blood glucose or the blunted CRR hormone responses during recurrent hypoglycemia.
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Affiliation(s)
- Kripa Shankar
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Salil Varshney
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Deepali Gupta
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Bharath K. Mani
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Nathan P. Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Corine P. Richard
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jeffrey M. Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
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3
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Kaneko K, Tokuyama Y, Taniguchi E, Abe S, Nakato J, Iwakura H, Sato M, Kurabayashi A, Suzuki H, Ito A, Higuchi Y, Nakayama R, Uchiyama K, Takahashi H, Ohinata K. Rice Endoplasmic Protein-Derived Peptides, Rice-Ghretropins A and B, Stimulate Ghrelin Release in MGN3-1 Cells and Increase Plasma Acylated Ghrelin and Food Intake in Mice. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:421-429. [PMID: 36580688 DOI: 10.1021/acs.jafc.2c05965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In this study, we demonstrated that novel rice-derived bioactive peptides promote the secretion of ghrelin, an endogenous orexigenic hormone secreted from the stomach. The enzymatic digest of rice endosperm protein with subtilisin, a microorganism-derived enzyme, stimulated acylated ghrelin secretion in the ghrelin-releasing cell line MGN3-1 and increased food intake after oral administration in mice. By performing a comprehensive analysis based on structure-activity relationships, we selected candidate peptides from over 30,000 peptides in the rice digest. Among them, we found that QAFEPIRSV and TNPWHSPRQGSF, corresponding to the amino acid sequence of the rice endoplasmic proteins glutelin A1 or A2(52-60) and B1 or B2(31-42), respectively, stimulated acylated ghrelin release in MGN3-1 cells. We named them rice-ghretropins A and B. Pyroglutamate formation of rice-ghretropin A, [pyr1]-rice-ghretropin A, also promoted ghrelin secretion. Furthermore, oral administration of rice-ghretropins increased food intake, plasma ghrelin concentration, and small intestinal transit in mice. In addition, the subtilisin digest of the rice protein significantly increased food intake for 4 h in 9 month-old (control: 0.61 ± 0.049 g; digest: 0.83 ± 0.059 g) and 24 month-old mice (control: 0.52 ± 0.067 g; digest: 1.01 ± 0.064 g). In summary, we found that novel bioactive peptides, namely, rice-ghretropins, from the enzymatic digest of rice endosperm stimulated acylated ghrelin secretion and increased food intake. This is the first report of rice-derived exogenous bioactive peptides that increase acylated ghrelin secretion.
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Affiliation(s)
- Kentaro Kaneko
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Yuki Tokuyama
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Eriko Taniguchi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Shimon Abe
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Junya Nakato
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Hiroshi Iwakura
- The First Department of Medicine, Wakayama Medical University, Wakayama 841-8509, Japan
| | - Masaru Sato
- Department of Applied Genomics, Kazusa DNA Research Institute, 2-6-7 Kazusakamatari, Kisarazu, Chiba 292-0818, Japan
| | - Atsushi Kurabayashi
- Department of Applied Genomics, Kazusa DNA Research Institute, 2-6-7 Kazusakamatari, Kisarazu, Chiba 292-0818, Japan
| | - Hideyuki Suzuki
- Department of Applied Genomics, Kazusa DNA Research Institute, 2-6-7 Kazusakamatari, Kisarazu, Chiba 292-0818, Japan
| | - Akira Ito
- Rice Research Institute, Kameda Seika CO., LTD. 3-1-1Kameda-kogyodanchi, Konan, Niigata, Niigata 950-0198, Japan
| | - Yuki Higuchi
- Rice Research Institute, Kameda Seika CO., LTD. 3-1-1Kameda-kogyodanchi, Konan, Niigata, Niigata 950-0198, Japan
| | - Ryoko Nakayama
- Rice Research Institute, Kameda Seika CO., LTD. 3-1-1Kameda-kogyodanchi, Konan, Niigata, Niigata 950-0198, Japan
| | - Kimiko Uchiyama
- Rice Research Institute, Kameda Seika CO., LTD. 3-1-1Kameda-kogyodanchi, Konan, Niigata, Niigata 950-0198, Japan
| | - Hajime Takahashi
- Rice Research Institute, Kameda Seika CO., LTD. 3-1-1Kameda-kogyodanchi, Konan, Niigata, Niigata 950-0198, Japan
| | - Kousaku Ohinata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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Cornejo MP, Mustafá ER, Cassano D, Banères JL, Raingo J, Perello M. The ups and downs of growth hormone secretagogue receptor signaling. FEBS J 2021; 288:7213-7229. [PMID: 33460513 DOI: 10.1111/febs.15718] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/05/2021] [Accepted: 01/14/2021] [Indexed: 12/14/2022]
Abstract
The growth hormone secretagogue receptor (GHSR) has emerged as one of the most fascinating molecules from the perspective of neuroendocrine control. GHSR is mainly expressed in the pituitary and the brain, and plays key roles regulating not only growth hormone secretion but also food intake, adiposity, body weight, glucose homeostasis and other complex functions. Quite atypically, GHSR signaling displays a basal constitutive activity that can be up- or downregulated by two digestive system-derived hormones: the octanoylated-peptide ghrelin and the liver-expressed antimicrobial peptide 2 (LEAP2), which was recently recognized as an endogenous GHSR ligand. The existence of two ligands with contrary actions indicates that GHSR activity can be tightly regulated and that the receptor displays the capability to integrate such opposing inputs in order to provide a balanced intracellular signal. This article provides a summary of the current understanding of the biology of ghrelin, LEAP2 and GHSR and discusses the reconceptualization of the cellular and physiological implications of the ligand-regulated GHSR signaling, based on the latest findings.
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Affiliation(s)
- María P Cornejo
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Emilio R Mustafá
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Montpellier cedex 5, France
| | - Jesica Raingo
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
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5
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Mani BK, Osborne-Lawrence S, Metzger N, Zigman JM. Lowering oxidative stress in ghrelin cells stimulates ghrelin secretion. Am J Physiol Endocrinol Metab 2020; 319:E330-E337. [PMID: 32543942 PMCID: PMC7473909 DOI: 10.1152/ajpendo.00119.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin is a predominantly stomach-derived peptide hormone with many actions including regulation of food intake, body weight, and blood glucose. Plasma ghrelin levels are robustly regulated by feeding status, with its levels increasing upon caloric restriction and decreasing after food intake. At least some of this regulation might be due to direct responsiveness of ghrelin cells to changes in circulating nutrients, including glucose. Indeed, oral and parental glucose administration to humans and mice lower plasma ghrelin. Also, dissociated mouse gastric mucosal cell preparations, which contain ghrelin cells, decrease ghrelin secretion when cultured in high ambient glucose. Here, we used primary cultures of mouse gastric mucosal cells in combination with an array of pharmacological tools to examine the potential role of changed intracellular oxidative stress in glucose-restricted ghrelin secretion. The antioxidants resveratrol, SRT1720, and curcumin all markedly increased ghrelin secretion. Furthermore, three different selective activators of Nuclear factor erythroid-derived-2-like 2 (Nrf2), a master regulator of the antioxidative cellular response to oxidative stress, increased ghrelin secretion. These antioxidant compounds blocked the inhibitory effects of glucose on ghrelin secretion. Therefore, we conclude that lowering oxidative stress within ghrelin cells stimulates ghrelin secretion and blocks the direct effects of glucose on ghrelin cells to inhibit ghrelin secretion.
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Affiliation(s)
- Bharath K Mani
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Nathan Metzger
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jeffrey M Zigman
- Center for Hypothalamic Research and Division of Endocrinology, Department of Internal Medicine and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
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6
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Saito H, Nakakita Y, Segawa S, Tsuchiya Y. Oral administration of heat-killed Lactobacillus brevis SBC8803 elevates the ratio of acyl/des-acyl ghrelin in blood and increases short-term food intake. Benef Microbes 2019; 10:671-677. [DOI: 10.3920/bm2018.0091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
It is known that gastrointestinal microbiota, probiotics and heat-killed microbes can regulate intestinal immunity; however, their effect on the secretion of gastrointestinal hormones is unclear. The secretion of gastrointestinal hormones can be mediated by the elevation of intracellular Ca2+ concentration, suggesting that these hormones may act through common mechanisms. We have previously shown that heat-killed Lactobacillus brevis SBC8803 (hk-SBC8803) induced the secretion of serotonin and elevated intracellular Ca2+ concentration in serotonin-producing RIN-14B cells, suggesting that hk-SBC8803 could potentially cause the same effect on other gastrointestinal hormones, including hunger hormone ghrelin. Here, we tested this hypothesis by treating cultured cells and experimental animals with hk-SBC8803 and assessing ghrelin secretion, expression of ghrelin-related genes, and food intake. The results indicated that hk-SBC8803 treatment for 30 min significantly upregulated the secretion of acyl ghrelin (active form) (P=0.046) and mRNA expression of the Syt3 (synaptotagmin 3) gene related to ghrelin exocytosis (P<0.05) in primary mouse stomach cells. In addition, oral administration of 500 mg/kg hk-SBC8803 to rats tended to upregulate acyl ghrelin concentration (P=0.10) and significantly increased the ratio of acyl to des-acyl (inactive) ghrelin (P=0.027) in blood, which corresponded to a tendency of stimulating food intake (P=0.087) at 30 min post-treatment. However, when in order to minimise individual differences we normalised the data on food intake to those on one-day food intake prior to food deprivation, the resultant food intake ratio showed a significant increase (by 5% compared to control; P=0.032) at 30 min after hk-SBC8803 treatment, indicating that hk-SBC8803 administration stimulated rats to take more food during the first meal after fasting. These results suggest that hk-SBC8803 induces short-term ghrelin secretion and transiently increases appetite, which is an important effect for individuals with low energy intake.
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Affiliation(s)
- H. Saito
- Frontier Laboratories for Value Creation, Sapporo Holdings Ltd., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
| | - Y. Nakakita
- Frontier Laboratories for Value Creation, Sapporo Holdings Ltd., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
| | - S. Segawa
- Frontier Laboratories for Value Creation, Sapporo Holdings Ltd., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
| | - Y. Tsuchiya
- Frontier Laboratories for Value Creation, Sapporo Holdings Ltd., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
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Gupta D, Chuang JC, Mani BK, Shankar K, Rodriguez JA, Osborne-Lawrence S, Metzger NP, Zigman JM. β1-adrenergic receptors mediate plasma acyl-ghrelin elevation and depressive-like behavior induced by chronic psychosocial stress. Neuropsychopharmacology 2019; 44:1319-1327. [PMID: 30758330 PMCID: PMC6785135 DOI: 10.1038/s41386-019-0334-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/06/2018] [Accepted: 02/04/2019] [Indexed: 12/19/2022]
Abstract
The ghrelin system is a key component of the mood and metabolic responses to chronic psychosocial stress. For example, circulating acyl-ghrelin rises in several rodent and human stress models, administered acyl-ghrelin induces antidepressant-like behavioral responses in mice, and mice with deleted ghrelin receptors (GHSRs) exhibit exaggerated depressive-like behaviors, changed eating behaviors, and altered metabolism in response to chronic stress. However, the mechanisms mediating stress-induced rises in ghrelin are unknown and ghrelin's antidepressant-like efficacy in the setting of chronic stress is incompletely characterized. Here, we used a pharmacological approach in combination with a 10-day chronic social defeat stress (CSDS) model in male mice to investigate whether the sympathoadrenal system is involved in the ghrelin response to stress. We also examined the antidepressant-like efficacy of administered ghrelin and the synthetic GHSR agonist GHRP-2 during and/or after CSDS. We found that administration of the β1-adrenergic receptor (β1AR) blocker atenolol during CSDS blunts the elevation of plasma acyl-ghrelin and exaggerates depressive-like behavior. Neither acute injection of acyl-ghrelin directly following CSDS nor its chronic administration during or after CSDS nor chronic delivery of GHRP-2 during and after CSDS improved stress-induced depressive-like behavior. Thus, β1ARs drive the acyl-ghrelin response to CSDS, but supplementing the natural increases in acyl-ghrelin with exogenous acyl-ghrelin or GHSR agonist does not further enhance the antidepressant-like actions of the endogenous ghrelin system in the setting of CSDS.
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Affiliation(s)
- Deepali Gupta
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Jen-Chieh Chuang
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Bharath K. Mani
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Kripa Shankar
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Juan A. Rodriguez
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Sherri Osborne-Lawrence
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Nathan P. Metzger
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA
| | - Jeffrey M. Zigman
- 0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Hypothalamic Research, UT Southwestern Medical Center, 5323 Harry Hines Blvd., MC9077, Dallas, TX 75390-9077 USA ,0000 0000 9482 7121grid.267313.2Department of Internal Medicine, Division of Endocrinology, UT Southwestern Medical Center, Dallas, TX USA ,0000 0000 9482 7121grid.267313.2Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX USA
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Mani BK, Shankar K, Zigman JM. Ghrelin's Relationship to Blood Glucose. Endocrinology 2019; 160:1247-1261. [PMID: 30874792 PMCID: PMC6482034 DOI: 10.1210/en.2019-00074] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/09/2019] [Indexed: 12/16/2022]
Abstract
Much effort has been directed at studying the orexigenic actions of administered ghrelin and the potential effects of the endogenous ghrelin system on food intake, food reward, body weight, adiposity, and energy expenditure. Although endogenous ghrelin's actions on some of these processes remain ambiguous, its glucoregulatory actions have emerged as well-recognized features during extreme metabolic conditions. The blood glucose-raising actions of ghrelin are beneficial during starvation-like conditions, defending against life-threatening falls in blood glucose, but they are seemingly detrimental in obese states and in certain monogenic forms of diabetes, contributing to hyperglycemia. Also of interest, blood glucose negatively regulates ghrelin secretion. This article reviews the literature suggesting the existence of a blood glucose-ghrelin axis and highlights the factors that mediate the glucoregulatory actions of ghrelin, especially during metabolic extremes such as starvation and diabetes.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kripa Shankar
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
- Correspondence: Jeffrey M. Zigman, MD, PhD, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390. E-mail:
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Kjalarsdottir L, Tersey SA, Vishwanath M, Chuang JC, Posner BA, Mirmira RG, Repa JJ. 1,25-Dihydroxyvitamin D 3 enhances glucose-stimulated insulin secretion in mouse and human islets: a role for transcriptional regulation of voltage-gated calcium channels by the vitamin D receptor. J Steroid Biochem Mol Biol 2019; 185:17-26. [PMID: 30071248 DOI: 10.1016/j.jsbmb.2018.07.004] [Citation(s) in RCA: 30] [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: 12/30/2017] [Revised: 06/26/2018] [Accepted: 07/06/2018] [Indexed: 12/12/2022]
Abstract
AIM Vitamin D deficiency in rodents negatively affects glucose-stimulated insulin secretion (GSIS) and human epidemiological studies connect poor vitamin D status with type 2 diabetes. Previous studies performed primarily in rat islets have shown that vitamin D can enhance GSIS. However the molecular pathways linking vitamin D and insulin secretion are currently unknown. Therefore, experiments were undertaken to elucidate the transcriptional role(s) of the vitamin D receptor (VDR) in islet function. METHODS Human and mouse islets were cultured with vehicle or 1,25-dihydroxyvitamin-D3 (1,25D3) and then subjected to GSIS assays. Insulin expression, insulin content, glucose uptake and glucose-stimulated calcium influx were tested. Microarray analysis was performed. In silico analysis was used to identify VDR response elements (VDRE) within target genes and their activity was tested using reporter assays. RESULTS Vdr mRNA is abundant in islets and Vdr expression is glucose-responsive. Preincubation of mouse and human islets with 1,25D3 enhances GSIS and increases glucose-stimulated calcium influx. Microarray analysis identified the R-type voltage-gated calcium channel (VGCC) gene, Cacna1e, which is highly upregulated by 1,25D3 in human and mouse islets and contains a conserved VDRE in intron 7. Results from GSIS assays suggest that 1,25D3 might upregulate a variant of R-type VGCC that is resistant to chemical inhibition. CONCLUSION These results suggest that the role of 1,25D3 in regulating calcium influx acts through the R-Type VGCC during GSIS, thereby modulating the capacity of beta cells to secrete insulin.
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Affiliation(s)
- Lilja Kjalarsdottir
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States.
| | - Sarah A Tersey
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Mridula Vishwanath
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States
| | - Jen-Chieh Chuang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States
| | - Bruce A Posner
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States
| | - Raghavendra G Mirmira
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Joyce J Repa
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, United States.
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10
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Dominguez Gutierrez G, Kim J, Lee AH, Tong J, Niu J, Gray SM, Wei Y, Ding Y, Ni M, Adler C, Murphy AJ, Gromada J, Xin Y. Gene Signature of the Human Pancreatic ε Cell. Endocrinology 2018; 159:4023-4032. [PMID: 30380031 PMCID: PMC6963699 DOI: 10.1210/en.2018-00833] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/17/2018] [Indexed: 12/31/2022]
Abstract
The ghrelin-producing ε cell represents the fifth endocrine cell type in human pancreatic islets. The abundance of ε cells in adult pancreas is extremely low, which has hampered the investigation on the molecular pathways regulating the development and the function of this cell type. In this study, we explored the molecular features defining the function of pancreatic ε cells isolated from adult nondiabetic donors using single-cell RNA sequencing technology. We focus on transcription factors, cell surface receptors, and genes involved in metabolic pathways that contribute to regulation of cellular function. Furthermore, the genes that separate ε cells from the other islet endocrine cell types are presented. This study expands prior knowledge about the genes important for ε cell functioning during development and provides a resource to interrogate the transcriptome of this rare human islet cell type.
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Affiliation(s)
| | - Jinrang Kim
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
| | - Ann-Hwee Lee
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
| | - Jenny Tong
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - JingJing Niu
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - Sarah M Gray
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - Yi Wei
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
| | - Yueming Ding
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
| | - Min Ni
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
| | | | | | | | - Yurong Xin
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York
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11
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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12
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Insights into exchange factor directly activated by cAMP (EPAC) as potential target for cancer treatment. Mol Cell Biochem 2018; 447:77-92. [PMID: 29417338 DOI: 10.1007/s11010-018-3294-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 01/19/2018] [Indexed: 01/02/2023]
Abstract
Cancer remains a global health problem and approximately 1.7 million new cancer cases are diagnosed every year worldwide. Although diverse molecules are currently being explored as targets for cancer therapy the tumor treatment and therapy is highly tricky. Secondary messengers are important for hormone-mediated signaling pathway. Cyclic AMP (cAMP), a secondary messenger responsible for various physiological processes regulates cell metabolism by activating Protein kinase A (PKA) and by targeting exchange protein directly activated by cAMP (EPAC). EPAC is present in two isoforms EPAC1 and EPAC2, which exhibit different tissue distribution and is involved in GDP/GTP exchange along with activating Rap1- and Rap2-mediated signaling pathways. EPAC is also known for its dual role in cancer as pro- and anti-proliferative in addition to metastasis. Results after perturbing EPAC activity suggests its involvement in cancer cell migration, proliferation, and cytoskeleton remodeling which makes it a potential therapeutic target for cancer treatments.
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13
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Mani BK, Castorena CM, Osborne-Lawrence S, Vijayaraghavan P, Metzger NP, Elmquist JK, Zigman JM. Ghrelin mediates exercise endurance and the feeding response post-exercise. Mol Metab 2018; 9:114-130. [PMID: 29396372 PMCID: PMC5870098 DOI: 10.1016/j.molmet.2018.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/09/2018] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
Objective Exercise training has several well-established health benefits, including many related to body weight, appetite control, and blood glucose homeostasis. However, the molecular mechanisms and, in particular, the hormonal systems that mediate and integrate these beneficial effects are poorly understood. In the current study, we aimed to investigate the role of the hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR; ghrelin receptor), in mediating the effects of exercise on food intake and blood glucose following exercise as well as in regulating exercise endurance capacity. Methods We used two mouse models of treadmill running to characterize the changes in plasma ghrelin with exercise. We also assessed the role of the ghrelin system to influence food intake and blood glucose after exercise, exercise endurance, and parameters potentially linked to responses to exercise. Mice lacking GHSRs (GHSR-null mice) and wild-type littermates were studied. Results An acute bout of exercise transiently elevated plasma acyl-ghrelin. Without the action of this increased ghrelin on GHSRs (as in GHSR-null mice), high intensity interval exercise markedly reduced food intake compared to control mice. The effect of exercise to acutely raise blood glucose remained unmodified in GHSR-null mice. Exercise-induced increases in plasma ghrelin positively correlated with endurance capacity, and time to exhaustion was reduced in GHSR-null mice as compared to wild-type littermates. In an effort to mechanistically explain their reduced exercise endurance, exercised GHSR-null mice exhibited an abrogated sympathoadrenal response, lower overall insulin-like growth factor-1 levels, and altered glycogen utilization. Conclusions Exercise transiently increases plasma ghrelin. GHSR-null mice exhibit decreased food intake following high intensity interval exercise and decreased endurance when submitted to an exercise endurance protocol. These data suggest that an intact ghrelin system limits the capacity of exercise to restrict food intake following exercise, although it enhances exercise endurance. High intensity exercise transiently increases plasma ghrelin. Without ghrelin action on its receptors (growth hormone secretagogue receptors), exercise markedly reduces food intake. An intact ghrelin system enhances exercise endurance.
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Affiliation(s)
- Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carlos M Castorena
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prasanna Vijayaraghavan
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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14
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Effects of Ghrelin miRNA on Inflammation and Calcium Pathway in Pancreatic Acinar Cells of Acute Pancreatitis. Pancreas 2017; 46:1305-1313. [PMID: 28984792 DOI: 10.1097/mpa.0000000000000946] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The study investigated the effects of endogenous targeted inhibition of ghrelin gene on inflammation and calcium pathway in an in vitro pancreatic acinar cell model of acute pancreatitis. METHODS Lentiviral expression vector against ghrelin gene was constructed and transfected into AR42J cells. The mRNA and protein expression of each gene were detected by reverse transcription polymerase chain reaction, Western blotting, or enzyme-linked immunosorbent assay. The concentration of intracellular calcium ([Ca]i) was determined by calcium fluorescence mark probe combined with laser scanning confocal microscopy. RESULTS Compared with the control group, cerulein could upregulate mRNA and protein expression of inflammatory factors, calcium pathway, ghrelin, and [Ca]i. mRNA and protein expression of inflammatory factors increased significantly in cells transfected with ghrelin miRNA compared with the other groups. Intracellular calcium and expression of some calcium pathway proteins decreased significantly in cells transfected with ghrelin miRNA compared with the other groups. CONCLUSIONS Targeted inhibition of ghrelin gene in pancreatic acinar cells of acute pancreatitis can upregulate the expression of the intracellular inflammatory factors and alleviate the intracellular calcium overload.
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15
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Mani BK, Osborne-Lawrence S, Vijayaraghavan P, Hepler C, Zigman JM. β1-Adrenergic receptor deficiency in ghrelin-expressing cells causes hypoglycemia in susceptible individuals. J Clin Invest 2016; 126:3467-78. [PMID: 27548523 DOI: 10.1172/jci86270] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 07/07/2016] [Indexed: 01/06/2023] Open
Abstract
Ghrelin is an orexigenic gastric peptide hormone secreted when caloric intake is limited. Ghrelin also regulates blood glucose, as emphasized by the hypoglycemia that is induced by caloric restriction in mouse models of deficient ghrelin signaling. Here, we hypothesized that activation of β1-adrenergic receptors (β1ARs) localized to ghrelin cells is required for caloric restriction-associated ghrelin release and the ensuing protective glucoregulatory response. In mice lacking the β1AR specifically in ghrelin-expressing cells, ghrelin secretion was markedly blunted, resulting in profound hypoglycemia and prevalent mortality upon severe caloric restriction. Replacement of ghrelin blocked the effects of caloric restriction in β1AR-deficient mice. We also determined that treating calorically restricted juvenile WT mice with beta blockers led to reduced plasma ghrelin and hypoglycemia, the latter of which is similar to the life-threatening, fasting-induced hypoglycemia observed in infants treated with beta blockers. These findings highlight the critical functions of ghrelin in preventing hypoglycemia and promoting survival during severe caloric restriction and the requirement for ghrelin cell-expressed β1ARs in these processes. Moreover, these results indicate a potential role for ghrelin in mediating beta blocker-associated hypoglycemia in susceptible individuals, such as young children.
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16
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Koyama H, Iwakura H, Dote K, Bando M, Hosoda H, Ariyasu H, Kusakabe T, Son C, Hosoda K, Akamizu T, Kangawa K, Nakao K. Comprehensive Profiling of GPCR Expression in Ghrelin-Producing Cells. Endocrinology 2016; 157:692-704. [PMID: 26671185 DOI: 10.1210/en.2015-1784] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To determine the comprehensive G protein-coupled receptor (GPCR) expression profile in ghrelin-producing cells and to elucidate the role of GPCR-mediated signaling in the regulation of ghrelin secretion, we determined GPCR expression profiles by RNA sequencing in the ghrelin-producing cell line MGN3-1 and analyzed the effects of ligands for highly expressed receptors on intracellular signaling and ghrelin secretion. Expression of selected GPCRs was confirmed in fluorescence-activated cell-sorted fluorescently tagged ghrelin-producing cells from ghrelin-promoter CreERT2/Rosa-CAG-LSL-ZsGreen1 mice. Expression levels of GPCRs previously suggested to regulate ghrelin secretion including adrenergic-β1 receptor, GPR81, oxytocin receptor, GPR120, and somatostatin receptor 2 were high in MGN3-1 cells. Consistent with previous reports, isoproterenol and oxytocin stimulated the Gs and Gq pathways, respectively, whereas lactate, palmitate, and somatostatin stimulated the Gi pathway, confirming the reliability of current assays. Among other highly expressed GPCRs, prostaglandin E receptor 4 agonist prostaglandin E2 significantly stimulated the Gs pathway and ghrelin secretion. Muscarine, the canonical agonist of cholinergic receptor muscarinic 4, stimulated both the Gq and Gi pathways. Although muscarine treatment alone did not affect ghrelin secretion, it did suppress forskolin-induced ghrelin secretion, suggesting that the cholinergic pathway may play a role in counterbalancing the stimulation of ghrelin by Gs (eg, by adrenaline). In addition, GPR142 ligand tryptophan stimulated ghrelin secretion. In conclusion, we determined the comprehensive expression profile of GPCRs in ghrelin-producing cells and identified two novel ghrelin regulators, prostaglandin E2 and tryptophan. These results will lead to a greater understanding of the physiology of ghrelin and facilitate the development of ghrelin-modulating drugs.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cell Line, Tumor
- Colforsin/pharmacology
- Dinoprostone/pharmacology
- Gastric Mucosa/cytology
- Gastric Mucosa/drug effects
- Gastric Mucosa/metabolism
- Gene Expression Profiling
- Ghrelin/drug effects
- Ghrelin/metabolism
- Hormones/pharmacology
- Immunohistochemistry
- Isoproterenol/pharmacology
- Lactic Acid/pharmacology
- Mice
- Mice, Transgenic
- Muscarine/pharmacology
- Muscarinic Agonists/pharmacology
- Oxytocics/pharmacology
- Oxytocin/pharmacology
- Palmitates/pharmacology
- RNA, Messenger/metabolism
- Receptor, Muscarinic M4/agonists
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Oxytocin/drug effects
- Receptors, Oxytocin/genetics
- Receptors, Oxytocin/metabolism
- Receptors, Prostaglandin E, EP4 Subtype/agonists
- Receptors, Somatostatin/drug effects
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
- Sequence Analysis, RNA
- Somatostatin/pharmacology
- Tryptophan/pharmacology
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Affiliation(s)
- Hiroyuki Koyama
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroshi Iwakura
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Katsuko Dote
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Mika Bando
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroshi Hosoda
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Hiroyuki Ariyasu
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Toru Kusakabe
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Choel Son
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kiminori Hosoda
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Takashi Akamizu
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kenji Kangawa
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
| | - Kazuwa Nakao
- Medical Innovation Center (H.I., K.D., M.B., T.K., C.S., K.H., K.K., K.N.) and Departments of Diabetes, Endocrinology, and Nutrition (H.K.) and Human Health Sciences (K.H.), Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; National Cerebral and Cardiovascular Center Research Institute (H.H., K.K.), Osaka 565-8565; Japan; and The First Department of Medicine (H.A., T.A.), Wakayama Medical University, Wakayama 641-8509, Japan
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17
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Grimes MT, Powell M, Gutierrez SM, Darby-King A, Harley CW, McLean JH. Epac activation initiates associative odor preference memories in the rat pup. ACTA ACUST UNITED AC 2015; 22:74-82. [PMID: 25593293 PMCID: PMC4341366 DOI: 10.1101/lm.037101.114] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Here we examine the role of the exchange protein directly activated by cAMP (Epac) in β-adrenergic-dependent associative odor preference learning in rat pups. Bulbar Epac agonist (8-pCPT-2-O-Me-cAMP, or 8-pCPT) infusions, paired with odor, initiated preference learning, which was selective for the paired odor. Interestingly, pairing odor with Epac activation produced both short-term (STM) and long-term (LTM) odor preference memories. Training using β-adrenergic-activation paired with odor recruited rapid and transient ERK phosphorylation consistent with a role for Epac activation in normal learning. An ERK antagonist prevented intermediate-term memory (ITM) and LTM, but not STM. Epac agonist infusions induced ERK phosphorylation in the mitral cell layer, in the inner half of the dendritic external plexiform layer, in the glomeruli and, patchily, among granule cells. Increased CREB phosphorylation in the mitral and granule cell layers was also seen. Simultaneous blockade of both ERK and CREB pathways prevented any long-term β-adrenergic activated odor preference memory, while LTM deficits associated with blocking only one pathway were prevented by stronger β-adrenergic activation. These results suggest that Epac and PKA play parallel and independent, as well as likely synergistic, roles in creating cAMP-dependent associative memory in rat pups. They further implicate a novel ERK-independent pathway in the mediation of STM by Epac.
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Affiliation(s)
- Matthew T Grimes
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
| | - Maria Powell
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
| | - Sandra Mohammed Gutierrez
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
| | - Andrea Darby-King
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
| | - Carolyn W Harley
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
| | - John H McLean
- Division of BioMedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3V6 Canada
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18
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Wellman MK, Patterson ZR, MacKay H, Darling JE, Mani BK, Zigman JM, Hougland JL, Abizaid A. Novel Regulator of Acylated Ghrelin, CF801, Reduces Weight Gain, Rebound Feeding after a Fast, and Adiposity in Mice. Front Endocrinol (Lausanne) 2015; 6:144. [PMID: 26441834 PMCID: PMC4585333 DOI: 10.3389/fendo.2015.00144] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/01/2015] [Indexed: 01/04/2023] Open
Abstract
Ghrelin is a 28 amino acid hormonal peptide that is intimately related to the regulation of food intake and body weight. Once secreted, ghrelin binds to the growth hormone secretagogue receptor-1a, the only known receptor for ghrelin and is capable of activating a number of signaling cascades, ultimately resulting in an increase in food intake and adiposity. Because ghrelin has been linked to overeating and the development of obesity, a number of pharmacological interventions have been generated in order to interfere with either the activation of ghrelin or interrupting ghrelin signaling as a means to reducing appetite and decrease weight gain. Here, we present a novel peptide, CF801, capable of reducing circulating acylated ghrelin levels and subsequent body weight gain and adiposity. To this end, we show that IP administration of CF801 is sufficient to reduce circulating plasma acylated ghrelin levels. Acutely, intraperitoneal injections of CF801 resulted in decreased rebound feeding after an overnight fast. When delivered chronically, they decreased weight gain and adiposity without affecting caloric intake. CF801, however, did cause a change in diet preference, decreasing preference for a high-fat diet and increasing preference for regular chow diet. Given the complexity of ghrelin receptor function, we propose that CF801, along with other compounds that regulate ghrelin secretion, may prove to be a beneficial tool in the study of the ghrelin system, and potential targets for ghrelin-based obesity treatments without altering the function of ghrelin receptors.
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Affiliation(s)
| | | | - Harry MacKay
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | | | - Bharath K. Mani
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Internal Medicine, Division of Endocrinology and Metabolism, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M. Zigman
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Internal Medicine, Division of Endocrinology and Metabolism, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- *Correspondence: Alfonso Abizaid, Department of Neuroscience, Carleton University, 1125 Colonel By Drive, 329 Life Science Research Building, Ottawa, ON K1S 5B6, Canada,
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Iwakura H, Kangawa K, Nakao K. The regulation of circulating ghrelin - with recent updates from cell-based assays. Endocr J 2015; 62:107-22. [PMID: 25273611 DOI: 10.1507/endocrj.ej14-0419] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Ghrelin is a stomach-derived orexigenic hormone with a wide range of physiological functions. Elucidation of the regulation of the circulating ghrelin level would lead to a better understanding of appetite control in body energy homeostasis. Earlier studies revealed that circulating ghrelin levels are under the control of both acute and chronic energy status: at the acute scale, ghrelin levels are increased by fasting and decreased by feeding, whereas at the chronic scale, they are high in obese subjects and low in lean subjects. Subsequent studies revealed that nutrients, hormones, or neural activities can influence circulating ghrelin levels in vivo. Recently developed in vitro assay systems for ghrelin secretion can assess whether and how individual factors affect ghrelin secretion from cells. In this review, on the basis of numerous human, animal, and cell-based studies, we summarize current knowledge on the regulation of circulating ghrelin levels and enumerate the factors that influence ghrelin levels.
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Affiliation(s)
- Hiroshi Iwakura
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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Uchida A, Zechner JF, Mani BK, Park WM, Aguirre V, Zigman JM. Altered ghrelin secretion in mice in response to diet-induced obesity and Roux-en-Y gastric bypass. Mol Metab 2014; 3:717-30. [PMID: 25353000 PMCID: PMC4209356 DOI: 10.1016/j.molmet.2014.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/22/2014] [Accepted: 07/25/2014] [Indexed: 01/06/2023] Open
Abstract
The current study examined potential mechanisms for altered circulating ghrelin levels observed in diet-induced obesity (DIO) and following weight loss resulting from Roux-en-Y gastric bypass (RYGB). We hypothesized that circulating ghrelin levels were altered in obesity and after weight loss through changes in ghrelin cell responsiveness to physiological cues. We confirmed lower ghrelin levels in DIO mice and demonstrated elevated ghrelin levels in mice 6 weeks post-RYGB. In both DIO and RYGB settings, these changes in ghrelin levels were associated with altered ghrelin cell responsiveness to two key physiological modulators of ghrelin secretion - glucose and norepinephrine. In DIO mice, increases in ghrelin cell density within both the stomach and duodenum and in somatostatin-immunoreactive D cell density in the duodenum were observed. Our findings provide new insights into the regulation of ghrelin secretion and its relation to circulating ghrelin within the contexts of obesity and weight loss.
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Affiliation(s)
- Aki Uchida
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Juliet F Zechner
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Digestive and Liver Diseases, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Won-Mee Park
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vincent Aguirre
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Digestive and Liver Diseases, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Division of Endocrinology & Metabolism, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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