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Liu J, Li N, Wei C, Han F, Deng M, Ma J, Zou X, Zhou Y, Yang R, Yuan H. GHS-R1a deficiency protects against lipopolysaccharide-induced spatial memory impairment in mice. Biochem Biophys Res Commun 2024; 727:150270. [PMID: 38917617 DOI: 10.1016/j.bbrc.2024.150270] [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: 05/15/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
Neuroinflammation has been implicated in cognitive deficits of neurological and neurodegenerative diseases. There is abundant evidence that the application of ghrelin, an orexigenic hormone regulating appetite and energy balance, abrogates neuroinflammation and rescues associated memory impairment. However, the underlying mechanism is uncertain. In this study, we find that both intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of lipopolysaccharide (LPS) impairs spatial memory in mice. LPS treatment causes neuroinflammation and microglial activation in the hippocampus. Ghsr1a deletion suppresses LPS-induced microglial activation and neuroinflammation, and rescued LPS-induced memory impairment. Our findings thus suggest that GHS-R1a signaling may promote microglial immunoactivation and contribute to LPS-induced neuroinflammation. GHS-R1a may be a new therapeutic target for cognitive dysfunction associated with inflammatory conditions.
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Affiliation(s)
- Junru Liu
- Department of Neurology, Affiliated Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Medical Group)Qingdao, Shandong 266042, China; Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China
| | - Na Li
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Department of Medicine, Qingdao Binhai University, Qingdao, Shandong, 266555, China
| | - Chuang Wei
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Fubing Han
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Department of Neurosurgery, Affiliated Hospital of Qingdao University, Qingdao, Shandong, 266000, China
| | - Mingru Deng
- Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Jialin Ma
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Xueying Zou
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Yu Zhou
- Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Affiliated Qingdao Third People's Hospital, Department of Otorhinolaryngology Head and Neck, Qingdao University, Qingdao, 266021, China.
| | - Rong Yang
- Affiliated Qingdao Third People's Hospital, Department of Otorhinolaryngology Head and Neck, Qingdao University, Qingdao, 266021, China.
| | - Haicheng Yuan
- Department of Neurology, Affiliated Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Medical Group)Qingdao, Shandong 266042, China; Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China.
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2
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Fonseca PAS, Suárez-Vega A, Arranz JJ, Gutiérrez-Gil B. Integration of selective sweeps across the sheep genome: understanding the relationship between production and adaptation traits. Genet Sel Evol 2024; 56:40. [PMID: 38773423 PMCID: PMC11106937 DOI: 10.1186/s12711-024-00910-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/07/2024] [Indexed: 05/23/2024] Open
Abstract
BACKGROUND Livestock populations are under constant selective pressure for higher productivity levels for different selective purposes. This pressure results in the selection of animals with unique adaptive and production traits. The study of genomic regions associated with these unique characteristics has the potential to improve biological knowledge regarding the adaptive process and how it is connected to production levels and resilience, which is the ability of an animal to adapt to stress or an imbalance in homeostasis. Sheep is a species that has been subjected to several natural and artificial selective pressures during its history, resulting in a highly specialized species for production and adaptation to challenging environments. Here, the data from multiple studies that aim at mapping selective sweeps across the sheep genome associated with production and adaptation traits were integrated to identify confirmed selective sweeps (CSS). RESULTS In total, 37 studies were used to identify 518 CSS across the sheep genome, which were classified as production (147 prodCSS) and adaptation (219 adapCSS) CSS based on the frequency of each type of associated study. The genes within the CSS were associated with relevant biological processes for adaptation and production. For example, for adapCSS, the associated genes were related to the control of seasonality, circadian rhythm, and thermoregulation. On the other hand, genes associated with prodCSS were related to the control of feeding behaviour, reproduction, and cellular differentiation. In addition, genes harbouring both prodCSS and adapCSS showed an interesting association with lipid metabolism, suggesting a potential role of this process in the regulation of pleiotropic effects between these classes of traits. CONCLUSIONS The findings of this study contribute to a deeper understanding of the genetic link between productivity and adaptability in sheep breeds. This information may provide insights into the genetic mechanisms that underlie undesirable genetic correlations between these two groups of traits and pave the way for a better understanding of resilience as a positive ability to respond to environmental stressors, where the negative effects on production level are minimized.
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Affiliation(s)
- Pablo A S Fonseca
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Aroa Suárez-Vega
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Juan J Arranz
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Beatriz Gutiérrez-Gil
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain.
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Zhao Y, Liu Y, Tao T, Zhang J, Guo W, Deng H, Han M, Mo H, Tong X, Lin S, Yang J, Zhai H, Wang Q, Hu Z, Zhang W, Chen H, Xu G. Gastric mechanosensitive channel Piezo1 regulates ghrelin production and food intake. Nat Metab 2024; 6:458-472. [PMID: 38467889 DOI: 10.1038/s42255-024-00995-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 01/24/2024] [Indexed: 03/13/2024]
Abstract
Ghrelin, produced mainly by gastric X/A-like cells, triggers a hunger signal to the central nervous system to stimulate appetite. It remains unclear whether X/A-like cells sense gastric distention and thus regulate ghrelin production. Here we show that PIEZO1 expression in X/A-like cells decreases in patients with obesity when compared to controls, whereas it increases after sleeve gastrectomy. Male and female mice with specific loss of Piezo1 in X/A-like cells exhibit hyperghrelinaemia and hyperphagia and are more susceptible to overweight. These phenotypes are associated with impairment of the gastric CaMKKII/CaMKIV-mTOR signalling pathway. Activation of PIEZO1 by Yoda1 or gastric bead implantation inhibits ghrelin production, decreases energy intake and induces weight loss in mice. Inhibition of ghrelin production by Piezo1 through the CaMKKII/CaMKIV-mTOR pathway can be recapitulated in a ghrelin-producing cell line mHypoE-42. Our study reveals a mechanical regulation of ghrelin production and appetite by PIEZO1 of X/A-like cells, which suggests a promising target for anti-obesity therapy.
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Affiliation(s)
- Yawen Zhao
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Yang Liu
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Tian Tao
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Jinshan Zhang
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Wenying Guo
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Handan Deng
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Mengxue Han
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Haocong Mo
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Xiaohan Tong
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Song Lin
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Jie Yang
- Department of Pathology, School of Basic Medicine, Guangzhou Medical University, Guangzhou, China
| | - Hening Zhai
- Endoscopy Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Qimeng Wang
- Biotherapy Center; Cell-gene Therapy Translational Medicine Research Center, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Zhengfang Hu
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, China
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Hui Chen
- Biotherapy Center; Cell-gene Therapy Translational Medicine Research Center, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
| | - Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China.
- Key Laboratory of Viral Pathogenesis & Infection Prevention and Control (Jinan University), Ministry of Education, Guangzhou, China.
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4
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Li N, Li N, Yang L, Gu H, Ji J, Zhou H, Zhu Q, Yu M, Sun Y, Zhou Y. GHSR1a deficiency suppresses inhibitory drive on dCA1 pyramidal neurons and contributes to memory reinforcement. Cereb Cortex 2023; 33:2612-2625. [PMID: 35797708 DOI: 10.1093/cercor/bhac230] [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: 04/08/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 11/12/2022] Open
Abstract
Growth hormone secretagogue receptor 1a (GHSR1a)-the receptor for orexigenic hormone ghrelin-is a G protein-coupled receptor that is widely distributed in the brain, including the hippocampus. Studies have demonstrated that genetic deletion of GHSR1a affects memory, suggesting the importance of ghrelin/GHSR1a signaling in cognitive control. However, current reports are controversial, and the mechanism underlying GHSR1a modulation of memory is uncertain. Here, we first report that global GHSR1a knockout enhances hippocampus-dependent memory, facilitates initial LTP in dorsal hippocampal Schaffer Collateral-CA1 synapses, and downregulates Akt activity in the hippocampus. Moreover, we show that the intrinsic excitability of GAD67+ interneurons-rather than neighboring pyramidal neurons in the dCA1-is suppressed by GHSR1a deletion, an effect that is antagonized by acute application of the Akt activator SC79. In addition, the inhibitory postsynaptic currents (IPSCs) on dCA1 pyramidal neurons are selectively reduced in mice with a GHSR1a deficiency. Finally, we demonstrate that selectively increasing the excitability of parvalbumin-expressing interneurons by hM3Dq-DREADDs increases IPSCs on dCA1 pyramidal neurons and normalizes memory in Ghsr1a KO mice. Our findings thus reveal a novel mechanism underlying memory enhancement of GHSR1a deficiency and herein support an adverse effect of GHSR1a signaling in hippocampus-dependent memory processes.
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Affiliation(s)
- Na Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Medicine, Qingdao Binhai University, 425 West Jialing River Rd, Qingdao, Shandong, 266555, China
| | - Nan Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
| | - Liu Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Huating Gu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Junjie Ji
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Hao Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Qianqian Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Ming Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M University, 750 Agronomy Rd, College Station, TX, 77843, United States
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
- Department of Physiology, Institute of Brain Sciences and Related Disorders, Qingdao University, 308 Ningxia Rd., Qingdao, Shandong, 266071, China
- Department of rehabilitation medicine, Affiliated Hospital of Qingdao University, 16 Jiangsu Rd., Qingdao, Shandong, 266000, China
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5
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Peris-Sampedro F, Le May MV, Stoltenborg I, Schéle E, Dickson SL. A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? J Neuroendocrinol 2021; 33:e13025. [PMID: 34427011 DOI: 10.1111/jne.13025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/09/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
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Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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6
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Kimura R, Kondo D, Takemi S, Fujishiro M, Tsukahara S, Sakai T, Sakata I. The role of central corticotrophin-releasing factor receptor signalling in plasma glucose maintenance through ghrelin secretion in calorie-restricted mice. J Neuroendocrinol 2021; 33:e12961. [PMID: 33675127 DOI: 10.1111/jne.12961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 11/27/2022]
Abstract
Under severe calorie restriction (CR), the ghrelin-growth hormone axis in mice is involved in the maintenance of plasma glucose levels. Ghrelin, a stomach-derived acylated peptide, is up-regulated by the sympathetic nerve in the negative energy status. Central corticotrophin-releasing factor receptor (CRF-R) signalling stimulates the sympathetic tone. The present study aimed to examine the effect of central CRF-R signalling on the maintenance of plasma glucose concentrations in severe calorie-restricted mice with the involvement of ghrelin. Intracerebroventricular injections of urocorin-1 and urocorin-2, which are natural ligands for CRF-R1 and CRF-R2, elevated plasma ghrelin concentrations and ghrelin elevation with an i.c.v. injection of urocorin-1 was cancelled by atenolol (β1 adrenergic receptor antagonist) administration. We then established a mice model of 60% CR and found that the administration of [d-Lys3]-GHRP-6 (a ghrelin receptor antagonist) in mice under 60% CR reduced the plasma glucose concentration more compared to the vehicle mice. Similarly, the atenolol injection in mice under 60% CR significantly reduced the plasma glucose concentration, which was rescued by the co-administration of ghrelin. An i.c.v. injection of the alpha helical CRH, a non-selective corticotrophin-releasing factor receptor antagonist, in mice under 60% CR significantly reduced the plasma glucose concentration, although the co-administration of α-helical CRH with ghrelin maintained plasma glucose levels. These results suggest that central CRF-R signalling is involved in the maintenance of plasma glucose levels in mice under severe CR via the sympathetic-ghrelin pathway.
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Affiliation(s)
- Risa Kimura
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Daisuke Kondo
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Miyuki Fujishiro
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Nikkol Group Cosmos Technical Center Co., Ltd, Tokyo, Japan
| | - Shinji Tsukahara
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Division of Strategy Research, Graduate School of Science and Engineering, Area of Life-NanoBio, Saitama University, Saitama, Japan
| | | | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
- Division of Strategy Research, Graduate School of Science and Engineering, Area of Life-NanoBio, Saitama University, Saitama, Japan
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7
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Liang Y, Yin W, Yin Y, Zhang W. Ghrelin Based Therapy of Metabolic Diseases. Curr Med Chem 2021; 28:2565-2576. [PMID: 32538716 PMCID: PMC11213490 DOI: 10.2174/0929867327666200615152804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/04/2020] [Accepted: 05/18/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Ghrelin, a unique 28 amino acid peptide hormone secreted by the gastric X/A like cells, is an endogenous ligand of the growth hormone secretagogue receptor (GHSR). Ghrelin-GHSR signaling has been found to exert various physiological functions, including stimulation of appetite, regulation of body weight, lipid and glucose metabolism, and increase of gut motility and secretion. This system is thus critical for energy homeostasis. OBJECTIVE The objective of this review is to highlight the strategies of ghrelin-GHSR based intervention for therapy of obesity and its related metabolic diseases. RESULTS Therapeutic strategies of metabolic disorders targeting the ghrelin-GHSR pathway involve neutralization of circulating ghrelin by antibodies and RNA spiegelmers, antagonism of ghrelin receptor by its antagonists and inverse agonists, inhibition of ghrelin O-acyltransferase (GOAT), as well as potential pharmacological approach to decrease ghrelin synthesis and secretion. CONCLUSION Various compounds targeting the ghrelin-GHSR system have shown promising efficacy for the intervention of obesity and relevant metabolic disorders in animals and in vitro. Further clinical trials to validate their efficacy in human beings are urgently needed.
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Affiliation(s)
- Yuan Liang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wenzhen Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yue Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA
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Tian W, Yuan X, Song Y, Zhai J, Wei H, Wang L, Li D, Chen Q. miR-218 inhibits glucose metabolism in non-small cell lung cancer via the NF-κB signaling pathway. Exp Ther Med 2020; 21:106. [PMID: 33335569 DOI: 10.3892/etm.2020.9538] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 03/03/2020] [Indexed: 12/13/2022] Open
Abstract
High glucose metabolism is recognized as one of the hallmarks of cancer and increased expression levels of several key factors involved in glucose metabolism have been reported in non-small cell lung cancer (NSCLC). Previous studies showed that microRNA (miR)-218 is reduced in NSCLC, but its function in glucose metabolism in NSCLC is not fully understood. The present study aimed to investigate the effect of miR-218 on glucose metabolism in NSCLC cell lines and the underlying molecular mechanism. The present results suggested that miR-218 reduced glucose consumption, the mechanism of glycolysis and activity in the pentose phosphate pathway. In addition, glucose transporter 1 (GLUT1) was identified to be a direct target of miR-218, while overexpression of GLUT1 did not abolish the effect of miR-218 on glucose metabolism. The present results indicated that phosphorylation of NF-κB p65 was significantly decreased by miR-218 in NSCLC cells and that activation of NF-κB led to the inhibition of miR-218 regulation of glucose metabolism. In conclusion, the present results suggested that miR-218 downregulated glucose metabolism in NSCLC not only by directly targeting GLUT1, but also via the NF-κB signaling pathway.
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Affiliation(s)
- Wenxian Tian
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Xiangfei Yuan
- Tianjin Key Laboratory of Acute Abdomen Disease Associated Organ Injury and Institute of Traditional Chinese and Western Medicine, Institute of Acute Abdominal Diseases, Tianjin Nankai Hospital, Tianjin 300100, P.R. China
| | - Yongna Song
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Jianxia Zhai
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Haixia Wei
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Linna Wang
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Dan Li
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
| | - Qiusheng Chen
- Department of Pulmonary and Critical Care Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
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9
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Zhang F, Xu F, Mi X, Dong L, Xiao Y, Jiang S, Li GD, Zhou Y. Ghrelin/GHS-R1a signaling plays different roles in anxiety-related behaviors after acute and chronic caloric restriction. Biochem Biophys Res Commun 2020; 529:1131-1136. [PMID: 32819576 DOI: 10.1016/j.bbrc.2020.05.227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 05/31/2020] [Indexed: 12/31/2022]
Abstract
The brain-gut hormone ghrelin and its receptor GHS-R1a, the growth hormone secretagogue receptor 1a, regulates diverse functions of central nervous system including stress response and mood. Both acute and chronic caloric restrictions (CR) were reported to increase endogenous ghrelin level meanwhile regulate anxiety-related behaviors; however, the causal relationship between CR-induced ghrelin elevation and anxiety are not fully established. Here, we introduced an acute (24 h) and a chronic (10wks) CR procedure to both GHS-R1a KO (Ghsr-/-) mice and WT (Ghsr+/+) littermates, and compared their anxiety-related behaviors. We found that acute CR induced anxiolytic and anti-despairing behaviors in Ghsr+/+ mice but not in Ghsr-/- mice. Ad-libitum refeeding abolished the effect of acute CR on anxiety-related behaviors. In contrast, chronic CR for 10wks facilitated despair-like behavior meanwhile inhibited anxiety-like behavior in Ghsr+/+ mice. GHS-R1a deficiency rescued despair-like behavior while did not affect anxiolytic response induced by chronic CR. In addition, we found elevated interleukin-6 (IL-6) in serum of Ghsr+/+ mice after chronic CR, but not in Ghsr-/- mice. Altogether, our findings indicated that acute CR and chronic CR have different impacts on anxiety-related behaviors, and the former is dependent on ghrelin/GHS-R1a signaling while the latter may not always be. In addition, our findings suggested that GHS-R1a-dependent elevation in serum IL-6 might contribute to increased despair-like behavior in chronic CR state.
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Affiliation(s)
- Fengyi Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Fenghua Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Xue Mi
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Linfei Dong
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Yuhao Xiao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Shibang Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Guo-Dong Li
- GUODONG LI MD Practice, Beverly Hills, California, 90211, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China.
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10
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Gong B, Jiao L, Du X, Li Y, Bi M, Jiao Q, Jiang H. Ghrelin promotes midbrain neural stem cells differentiation to dopaminergic neurons through Wnt/β-catenin pathway. J Cell Physiol 2020; 235:8558-8570. [PMID: 32329059 DOI: 10.1002/jcp.29699] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/05/2020] [Accepted: 03/30/2020] [Indexed: 12/19/2022]
Abstract
Ghrelin plays a neuroprotective role in the process of dopaminergic (DAergic) neurons degeneration in Parkinson's disease (PD). However, it still largely unknown whether ghrelin could affect the midbrain neural stem cells (mbNSCs) from which DAergic neurons are originated. In the present study, we observed that ghrelin enhanced mbNSCs proliferation, and promoted neuronal differentiation especially DAergic neuron differentiation both in vitro and ex vivo. The messenger RNA levels of Wnt1, Wnt3a, and glial cell line-derived neurotrophic factor were increased in response to the ghrelin treatment. Results showed that Wnt/β-catenin pathway was relevant to this DAergic neuron differentiation induced by ghrelin. Our finding gave a new evidence that ghrelin may enable clinical therapies for PD by its neurogenesis role.
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Affiliation(s)
- Bing Gong
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lingling Jiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xixun Du
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yong Li
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Mingxia Bi
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Jiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Hong Jiang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
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11
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Martin AM, Sun EW, Keating DJ. Mechanisms controlling hormone secretion in human gut and its relevance to metabolism. J Endocrinol 2019; 244:R1-R15. [PMID: 31751295 PMCID: PMC6892457 DOI: 10.1530/joe-19-0399] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/18/2019] [Indexed: 12/16/2022]
Abstract
The homoeostatic regulation of metabolism is highly complex and involves multiple inputs from both the nervous and endocrine systems. The gut is the largest endocrine organ in our body and synthesises and secretes over 20 different hormones from enteroendocrine cells that are dispersed throughout the gut epithelium. These hormones include GLP-1, PYY, GIP, serotonin, and CCK, each of whom play pivotal roles in maintaining energy balance and glucose homeostasis. Some are now the basis of several clinically used glucose-lowering and weight loss therapies. The environment in which these enteroendocrine cells exist is also complex, as they are exposed to numerous physiological inputs including ingested nutrients, circulating factors and metabolites produced from neighbouring gut microbiome. In this review, we examine the diverse means by which gut-derived hormones carry out their metabolic functions through their interactions with different metabolically important organs including the liver, pancreas, adipose tissue and brain. Furthermore, we discuss how nutrients and microbial metabolites affect gut hormone secretion and the mechanisms underlying these interactions.
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Affiliation(s)
- Alyce M Martin
- College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Emily W Sun
- College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Damien J Keating
- College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- Correspondence should be addressed to D J Keating:
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12
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Acute But Not Chronic Calorie Restriction Defends against Stress-Related Anxiety and Despair in a GHS-R1a-Dependent Manner. Neuroscience 2019; 412:94-104. [DOI: 10.1016/j.neuroscience.2019.05.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 12/27/2022]
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13
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Maugham ML, Seim I, Thomas PB, Crisp GJ, Shah ET, Herington AC, Gregory LS, Nelson CC, Jeffery PL, Chopin LK. Limited short-term effects on human prostate cancer xenograft growth and epidermal growth factor receptor gene expression by the ghrelin receptor antagonist [D-Lys 3]-GHRP-6. Endocrine 2019; 64:393-405. [PMID: 30390209 DOI: 10.1007/s12020-018-1796-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 10/17/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE The ghrelin axis regulates many physiological functions (including appetite, metabolism, and energy balance) and plays a role in disease processes. As ghrelin stimulates prostate cancer proliferation, the ghrelin receptor antagonist [D-Lys3]-GHRP-6 is a potential treatment for castrate-resistant prostate cancer and for preventing the metabolic consequences of androgen-targeted therapies. We therefore explored the effect of [D-Lys3]-GHRP-6 on PC3 prostate cancer xenograft growth. METHODS NOD/SCID mice with PC3 prostate cancer xenografts were administered 20 nmoles/mouse [D-Lys3]-GHRP-6 daily by intraperitoneal injection for 14 days and tumour volume and weight were measured. RNA sequencing of tumours was conducted to investigate expression changes following [D-Lys3]-GHRP-6 treatment. A second experiment, extending treatment time to 18 days and including a higher dose of [D-Lys3]-GHRP-6 (200 nmoles/mouse/day), was undertaken to ensure repeatability. RESULTS We demonstrate here that daily intraperitoneal injection of 20 nmoles/mouse [D-Lys3]-GHRP-6 reduces PC3 prostate cancer xenograft tumour volume and weight in NOD/SCID mice at two weeks post treatment initiation. RNA-sequencing revealed reduced expression of epidermal growth factor receptor (EGFR) in these tumours. Further experiments demonstrated that the effects of [D-Lys3]-GHRP-6 are transitory and lost after 18 days of treatment. CONCLUSIONS We show that [D-Lys3]-GHRP-6 has transitory effects on prostate xenograft tumours in mice, which rapidly develop an apparent resistance to the antagonist. Although further studies on [D-Lys3]-GHRP-6 are warranted, we suggest that daily treatment with the antagonist is not a suitable treatment for advanced prostate cancer.
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Affiliation(s)
- Michelle L Maugham
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Skeletal Biology and Forensic Anthropology Research Laboratory, Cancer Program, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Inge Seim
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Patrick B Thomas
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Gabrielle J Crisp
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Esha T Shah
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Adrian C Herington
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Laura S Gregory
- Skeletal Biology and Forensic Anthropology Research Laboratory, Cancer Program, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Colleen C Nelson
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Penny L Jeffery
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Lisa K Chopin
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
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14
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Guo L, Niu M, Yang J, Li L, Liu S, Sun Y, Zhou Z, Zhou Y. GHS-R1a Deficiency Alleviates Depression-Related Behaviors After Chronic Social Defeat Stress. Front Neurosci 2019; 13:364. [PMID: 31057357 PMCID: PMC6478702 DOI: 10.3389/fnins.2019.00364] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 03/29/2019] [Indexed: 12/13/2022] Open
Abstract
Ghrelin is an important orexigenic hormone that regulates feeding, metabolism and glucose homeostasis in human and rodents. Ghrelin functions by binding to its receptor, the growth hormone secretagogue receptor 1a (GHS-R1a), which is widely expressed inside and outside of the brain. Recent studies suggested that acyl-ghrelin, the active form of ghrelin, is a persistent biomarker for chronic stress exposure. However, how ghrelin/GHS-R1a signaling contributes to stress responses and mood regulation remains uncertain. In this study, we applied the chronic social defeat stress (CSDS) paradigm to both GHS-R1a knock-out (Ghsr-/-) mice and littermate control (Ghsr+/+) mice, and then measured their depression- and anxiety-related behaviors. We found that Ghsr+/+ mice, but not Ghsr-/- mice, displayed apparent anxiety and depression after CSDS, while two groups mice showed identical behaviors at baseline, non-stress state. By screening the central and peripheral responses of Ghsr-/- mice and Ghsr+/+ mice to chronic stress, we found similar elevations of total ghrelin and adrenocorticotropic hormone (ACTH) in the serum of Ghsr-/- mice and Ghsr+/+ mice after CSDS, but decreased interleukin-6 (IL-6) in the serum of defeated Ghsr-/- mice compared to defeated Ghsr+/+ mice. We also found increased concentration of brain derived neurotropic factor (BDNF) in the hippocampus of Ghsr-/- mice compared to Ghsr+/+ mice after CSDS. The basal levels of ghrelin, ACTH, IL-6, and BDNF were not different between Ghsr-/- mice and Ghsr+/+ mice. Our findings thus suggested that the differential expressions of BDNF and IL-6 after CSDS may contribute to less anxiety and less despair observed in GHS-R1a-deficient mice than in WT control mice. Therefore, ghrelin/GHS-R1a signaling may play a pro-anxiety and pro-depression effect in response to chronic stress, while GHS-R1a deficiency may provide resistance to depressive symptoms of CSDS.
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Affiliation(s)
- Li Guo
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China.,Department of Physiology, Binzhou Medical University, Yantai, China
| | - Minglu Niu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China.,Department of Clinic Laboratory, PKU Care Luzhong Hospital, Zibo, China
| | - Jie Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China.,Dongying No.1 Middle School, Dongying, China
| | - Li Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China
| | - Shuhan Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China
| | - Yuxiang Sun
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, United States
| | - Zhishang Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China.,Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, China
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, China.,Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, China
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15
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Waise TMZ, Rasti M, Duca FA, Zhang SY, Bauer PV, Rhodes CJ, Lam TKT. Inhibition of upper small intestinal mTOR lowers plasma glucose levels by inhibiting glucose production. Nat Commun 2019; 10:714. [PMID: 30755615 PMCID: PMC6372624 DOI: 10.1038/s41467-019-08582-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/16/2019] [Indexed: 12/11/2022] Open
Abstract
Glucose homeostasis is partly controlled by the energy sensor mechanistic target of rapamycin (mTOR) in the muscle and liver. However, whether mTOR in the small intestine affects glucose homeostasis in vivo remains unknown. Here, we first report that delivery of rapamycin or an adenovirus encoding the dominant negative acting mTOR-mutated protein into the upper small intestine is sufficient to inhibit small intestinal mTOR signaling and lower glucose production in rodents with high fat diet-induced insulin resistance. Second, we found that molecular activation of small intestinal mTOR blunts the glucose-lowering effect of the oral anti-diabetic agent metformin, while inhibiting small intestinal mTOR alone lowers plasma glucose levels by inhibiting glucose production in rodents with diabetes as well. Thus, these findings illustrate that inhibiting upper small intestinal mTOR is sufficient and necessary to lower glucose production and enhance glucose homeostasis, and thereby unveil a previously unappreciated glucose-lowering effect of small intestinal mTOR. The mechanistic target of rapamycin (TOR) functions as an energy sensor and contributes to the control of glucose homeostasis. Here, the authors show that mTOR in the upper small intestine regulates hepatic glucose production and is required for the glucose lowering effect of metformin.
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Affiliation(s)
- T M Zaved Waise
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Mozhgan Rasti
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Frank A Duca
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada.,School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Song-Yang Zhang
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Paige V Bauer
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada.,Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Christopher J Rhodes
- Kovler Diabetes Center, Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, 60637, USA.,MedImmune LLC, Gaithersburg, MD, 20878, USA
| | - Tony K T Lam
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada. .,Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Department of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, M5G 2C4, Canada.
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16
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Li Z, Yu R, Yin W, Qin Y, Ma L, Mulholland M, Zhang W. mTOR Signaling in X/A-Like Cells Contributes to Lipid Homeostasis in Mice. Hepatology 2019; 69:860-875. [PMID: 30141265 PMCID: PMC6351211 DOI: 10.1002/hep.30229] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/19/2018] [Indexed: 01/02/2023]
Abstract
Gastric mechanistic target of rapamycin (mTOR) signaling is inversely associated with the expression and secretion of ghrelin, a 28-aa peptide hormone produced by gastric X/A-like cells. Ghrelin contributes to obesity and hepatic steatosis. We sought to control global lipid metabolism via the manipulation of gastric mTOR signaling in X/A-like cells. We established a ghrl-cre transgene in which the Cre enzyme is expressed in X/A-like cells under the control of the ghrelin-promoter. mTORflox/flox and tuberous sclerosis 1 (TSC1)flox/flox mice were separately bred with ghrl-cre mice to generate mTOR-ghrl-cre or TSC1-ghrl-cre mice, within which mTOR signaling was suppressed or activated, respectively. Lipid metabolism in liver and adipose depots was analyzed. Under the control of the ghrelin-promoter, the Cre enzyme was exclusively expressed in stomach X/A-like cells in adult animals. Knockout of mTOR in X/A-like cells increased circulating acyl-ghrelin and promoted hepatic lipogenesis with effects on adipose depots. Activation of mTOR signaling by deletion of its upstream inhibitor, TSC1, decreased ghrelin expression and secretion, altering lipid metabolism as evidenced by resistance to high-fat diet-induced obesity and hepatic steatosis. Both ghrelin administration and injection of rapamycin, an inhibitor of mTOR, altered the phenotypes of TSC1-ghrl-cre mice. Conclusion: Gastric mTOR signaling in X/A-like cells contributes to organism lipid homeostasis by regulating hepatic and adipose lipid metabolism. Gastric mTOR signaling may provide an alternative strategy for intervention in lipid disorders.
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Affiliation(s)
- Ziru Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China,Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA
| | - Ruili Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Wenzhen Yin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Yan Qin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Liangxiao Ma
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Michael Mulholland
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA,Corresponding author. Contact information: Michael W. Mulholland, Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. Tel: 1-734-936-3236; ; Or. Weizhen Zhang, NCRC 26-241N, 2800 Plymouth Rd, Ann Arbor, MI 48105, United State, Tel: 1-734-615-0360; Fax: 1-734-763-4135;
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China,Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA,Corresponding author. Contact information: Michael W. Mulholland, Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. Tel: 1-734-936-3236; ; Or. Weizhen Zhang, NCRC 26-241N, 2800 Plymouth Rd, Ann Arbor, MI 48105, United State, Tel: 1-734-615-0360; Fax: 1-734-763-4135;
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17
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Wang J, He L, Huwatibieke B, Liu L, Lan H, Zhao J, Li Y, Zhang W. Ghrelin Stimulates Endothelial Cells Angiogenesis through Extracellular Regulated Protein Kinases (ERK) Signaling Pathway. Int J Mol Sci 2018; 19:ijms19092530. [PMID: 30149681 PMCID: PMC6164813 DOI: 10.3390/ijms19092530] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/16/2018] [Accepted: 08/19/2018] [Indexed: 02/07/2023] Open
Abstract
Adipose tissue is hyper-vascularized. Vessels in adipose tissue not only supply nutrients and oxygen to nourish adipocytes, but also provide cytokines that regulate mass and function of adipose tissue. Understanding the fundamental mechanisms how vessels modulate adipocyte functions would provide new therapeutic options for treatment of metabolic disease and obesity. In recent years, researches about ghrelin are focused on glucose and lipid metabolism, but its effect on vascular function remains uncharacterized. In the present study, ghrelin receptor gene deletion mice (Ghsr-/- mice) were used to study ghrelin-regulated vascular metabolism in white adipose tissue. Ghsr-/- mice demonstrated lower food intake, lower body weight, and resistance to high-fat diet-induced obesity. The number of vessels in white adipose tissue was decreased in Ghsr-/- mice when compared with wild type mice fed with high-fat diet. To further define ghrelin effects in vitro, we used endothelial progenitor cells from wild type and Ghsr-/- mice as well as human umbilical vein endothelial cells in our experiments. We found that ghrelin stimulated endothelial cells angiogenesis and migration through the MEK-ERK signaling pathway. [d-Lys3]-GHRP-6 and PD98059 could reverse the effects of ghrelin on endothelial cells. Our study indicates that ghrelin activates its receptor on endothelial cells to promote angiogenesis and migration via a mechanism involving the extracellular regulated protein kinases (ERK) signaling pathway.
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Affiliation(s)
- Jun Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
| | - Lin He
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing 100191, China.
| | - Bahetiyaer Huwatibieke
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
| | - Lingchao Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
| | - He Lan
- Department of Clinical Laboratory, Capital Medical University, Beijing 100053, China.
| | - Jing Zhao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
| | - Yin Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.
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18
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Improvement of Adipose Macrophage Polarization in High Fat Diet-Induced Obese GHSR Knockout Mice. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4924325. [PMID: 30112394 PMCID: PMC6077514 DOI: 10.1155/2018/4924325] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/06/2018] [Accepted: 05/28/2018] [Indexed: 12/16/2022]
Abstract
Purpose Adipose tissue inflammation is the key linking obesity to insulin resistance. Over 50% of the interstitial cells in adipose tissue are macrophages, which produce inflammatory cytokines and therefore play an important role in the progression of insulin resistance. Within this classification view, macrophage biology is driven by two polarization phenotypes, M1 (proinflammatory) and M2 (anti-inflammatory). The unique functional receptor of ghrelin, growth hormone secretagogue receptor (GHSR), is a classic seven-transmembrane G protein-coupled receptor that is linked to multiple intracellular signaling pathways. Knockout of GHSR improves the obesity and glucose metabolic disorders, suggesting a crucial role of ghrelin activity in insulin resistance. Here, we discussed whether macrophage polarization phenotypes in adipose tissue were changed in GHSR knockout (GHSR-/-) mice. Methods GHSR-/- mice were fed with normal chow diet (NCD) or high fat diet (HFD). Markers of different macrophage polarization phenotypes were detected by real-time RT-PCR. Results The size of adipocytes decreased and interstitial cells, especially infiltrated macrophages, reduced in epididymal adipose tissue of GHSR-/- mice fed with HFD. Compared with wild type mice, the mRNA levels of inflammatory adipokines such as resistin, IL-6, and PAI-1 were significantly lower in epididymal adipose tissue of GHSR-/- mice, whereas anti-inflammatory adipokine, adiponectin, was significantly higher. M1 markers, MCP-1, TNF-α, and iNOS, were significantly lower in epididymal adipose tissue of GHSR-/- mice, whereas M2 markers, Arg-1, Mgl-1, were Mrc1, were significantly higher. Conclusion The GHSR-/- mice fed with HFD showed suppressed adipose inflammation, reduced macrophage infiltration, and enhanced M2 polarization of macrophages in adipose tissue, which improved insulin sensitivity.
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19
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He R, Yin Y, Li Y, Li Z, Zhao J, Zhang W. Esophagus-duodenum Gastric Bypass Surgery Improves Glucose and Lipid Metabolism in Mice. EBioMedicine 2018; 28:241-250. [PMID: 29398599 PMCID: PMC5898028 DOI: 10.1016/j.ebiom.2018.01.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/23/2018] [Accepted: 01/23/2018] [Indexed: 12/12/2022] Open
Abstract
Background Despite of its significant therapeutic effects on obesity and metabolic diseases, Roux-en-Y gastric bypass (RYGB) has limited clinical application because of considerable impacts on the gastrointestinal structure and postoperative complications. This study aims to develop a simplified surgical approach with less damage and complication but efficient metabolic benefit. Methods The effects of Esophagus-Duodenum gastric bypass (EDGB) on body weight, food intake, glucose and lipid metabolism were compared to RYGB in mice. Findings EDGB is simple, has higher survival rate and less complication. Relative to RYGB, EDGB demonstrated modest body weight control, identical improvement of glucose and lipid metabolism in obese mice. Blood glucose increased significantly 15 and 30 min after oral glucose administration, then markedly decreased in both EDGB and RYGB groups relative to the sham surgery, indicating a quicker absorption of oral glucose and improvement in glucose uptake by insulin targeted tissues. Insulin sensitivity was identically improved. EDGB significantly decreased plasma and hepatic triglyceride levels, while increased browning in visceral and subcutaneous white adipose tissue to the extent identical to RYGB. Levels of ghrelin and nesfatin-1 increased significantly after EDGB and RYGB. Interpretation EDGB is a valuable model to study the metabolic benefit of bariatric surgery in mice. Esophagus-Duodenum gastric bypass surgery is easier and safer to perform in mice. Esophagus-Duodenum gastric bypass can produce a metabolic benefit as efficient as Roux-en-Y gastric bypass. EDGB may serve as an alternative model to study the weight-loss-independent mechanisms for glycemic control.
A valuable bariatric surgery designated as esophagus-duodenum gastric bypass surgery is easier and safer to perform. Post-operative complications are rare and survival rate is higher. The benefits to reduce bodyweight and improve blood glucose are identical to the commonly used bariatric surgery named Roux-en-Y gastric bypass surgery. In addition, esophagus-duodenum gastric bypass surgery improves lipid profile in the extent identical to Roux-en-Y gastric bypass surgery. Our study indicates that esophagus-duodenum gastric bypass surgery may provide an alternative approach for the intervention of obesity, and its associated metabolic dysfunctions such as diabetes and fatty liver.
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Affiliation(s)
- Rui He
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Key Laboratory of Reproduction and Genetic of Ningxia Hui Autonomous Region, School of Basic Medicine, Ningxia Medical University, Shengli Street No.1160, Yinchuan 750004, China
| | - Yue Yin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yin Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Ziru Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Zhao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA.
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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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Li Z, Zhang J, Mulholland M, Zhang W. mTOR activation protects liver from ischemia/reperfusion-induced injury through NF-κB pathway. FASEB J 2017; 31:3018-3026. [PMID: 28356345 DOI: 10.1096/fj.201601278r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/13/2017] [Indexed: 01/22/2023]
Abstract
Hepatic steatosis renders liver more vulnerable to ischemia/reperfusion injury (IRI), which commonly occurs in transplantation, trauma, and liver resection. The underlying mechanism is not fully characterized. We aimed to clarify the role of mechanistic target of rapamycin (mTOR) signaling in hepatic ischemia/reperfusion injury (HIRI) in normal and steatotic liver using Alb-TSC1-/- (AT) and Alb-mTOR-/- (Am) transgenic mice. Steatotic liver induced by high-fat diet was more vulnerable to IRI. Activation of hepatic mTOR in AT mice decreased lipid accumulation attenuated HIRI as measured by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, circulating levels of alanine aminotransferase and lactate dehydrogenase, and inflammatory mediators such as monocyte chemoattractant protein 1 (MCP-1), TNF-α, and IL-6 and hepatic cleaved caspase 3 in mice fed either a normal chow diet or a high-fat diet. The effects of mTOR activation on hepatic cleaved caspase 3 were reversed by rapamycin, an inhibitor of mTOR signaling. Inhibition of hepatic mTOR in Am mice increased hepatic lipid deposition and HIRI. The increment in hepatic susceptibility to IRI was significantly attenuated by pretreatment with IKKβ inhibitor. Further, suppression of mTOR facilitated nuclear translocation of NF-κB p65. In conclusion, our study suggests that mTOR activity in hepatocytes decreases hepatic vulnerability to injury through a mechanism dependent on NF-κB proinflammatory cytokine signaling pathway in both normal and steatotic liver.-Li, Z., Zhang, J., Mulholland, M., Zhang, W. mTOR activation protects liver from ischemia/reperfusion-induced injury through NF-κB pathway.
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Affiliation(s)
- Ziru Li
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Jing Zhang
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Michael Mulholland
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Weizhen Zhang
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, Michigan, USA .,Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
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Li Z, Mulholland M, Zhang W. Ghrelin O-acyltransferase (GOAT) and energy metabolism. SCIENCE CHINA-LIFE SCIENCES 2016; 59:281-91. [PMID: 26732975 DOI: 10.1007/s11427-015-4973-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/09/2015] [Indexed: 12/16/2022]
Abstract
Ghrelin O-acyltransferase (GOAT), a member of MBOATs family, is essential for octanoylation of ghrelin, which is required for active ghrelin to bind with and activate its receptor. GOAT is expressed mainly in the stomach, pancreas and hypothalamus. Levels of GOAT are altered by energy status. GOAT contains 11 transmembrane helices and one reentrant loop. Its invariant residue His-338 and conserved Asn-307 are located in the endoplasmic reticulum lumen and cytosol respectively. GOAT contributes to the regulation of food intake and energy expenditure, as well as glucose and lipids homeostasis. Deletion of GOAT blocks the acylation of ghrelin leading to subsequent impairment in energy homeostasis and survival when mice are challenged with high energy diet or severe caloric restriction. GO-CoA-Tat, a peptide GOAT inhibitor, attenuates acyl-ghrelin production and prevents weight gain induced by a medium-chain triglycerides-rich high fat diet. Further, GO-CoA-Tat increases glucose- induced insulin secretion. Overall, inhibition of GOAT is a novel strategy for treatment of obesity and related metabolic disorders.
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Affiliation(s)
- Ziru Li
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA
| | - Michael Mulholland
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA.
| | - Weizhen Zhang
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA. .,Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, 100191, China.
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Yin Y, Li Z, Gao L, Li Y, Zhao J, Zhang W. AMPK-dependent modulation of hepatic lipid metabolism by nesfatin-1. Mol Cell Endocrinol 2015; 417:20-6. [PMID: 26363221 DOI: 10.1016/j.mce.2015.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/06/2015] [Accepted: 09/07/2015] [Indexed: 01/20/2023]
Abstract
The aim of this study was to characterize the mechanism by which peripheral nesfatin-1 regulates hepatic lipid metabolism. Continuous peripheral infusion of nesfatin-1 reduced adiposity and plasma levels of triglyceride and cholesterol. In mice fed high fat diet, peripheral nesfatin-1 significantly decreased hepatic steatosis measured by triglyceride content and oil red staining area and diameter. These alterations were associated with a significant reduction in lipogenesis-related transcriptional factors PPARγ and SREBP1, as well as rate-limited enzyme genes such as acaca, fasn, gpam, dgat1 and dgat2. In primary hepatocytes, nesfatin-1 inhibited both basal and oleic acid stimulated triglyceride accumulation, which was accompanied by a decrement in lipogenesis-related genes and an increase in β-oxidation-related genes. In cultured hepatocytes, nesfatin-1 increased levels of AMPK phosphorylation. Inhibition of AMPK by compound C blocked the reduction of triglyceride content elicited by nesfatin-1. Our studies demonstrate that nesfatin-1 attenuates lipid accumulation in hepatocytes by an AMPK-dependent mechanism.
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Affiliation(s)
- Yue Yin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Ziru Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Ling Gao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yin Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Zhao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA.
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Xu G, Hong X, Tang H, Jiang S, Liu F, Shen Z, Li Z, Zhang W. Ghrelin regulates GLP-1 production through mTOR signaling in L cells. Mol Cell Endocrinol 2015; 416:9-18. [PMID: 26279396 DOI: 10.1016/j.mce.2015.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/08/2015] [Accepted: 08/11/2015] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide (GLP-1), an intestinal incretin produced in L-cells and released in response to meal intake, functions to promote insulin secretion and to decrease plasma glucose. Ghrelin is an orexigenic hormone critical for glucose homeostasis. The molecular mechanism by which ghrelin alters GLP-1 production remains largely unknown. Here we showed that ghrelin attenuates GLP-1 production through mTOR signaling. In GHSR1a null mice, ileal mTOR signaling, proglucagon and circulating GLP-1 were significantly increased. Antagonism of the GHSR1a by D-Lys-3-GHRP-6 increased GLP-1 synthesis and release in STC-1 cells. Treatment of STC-1 cells with ghrelin decreased the production of GLP-1. This effect was associated with a significant inhibition of mTOR signaling. Overexpression of ghrelin inhibited proglucagon promoter activity and GLP-1 production. Inhibition of mTOR activity by mTOR siRNA blocked D-Lys-3-GHRP-6 induced GLP-1 production in STC-1 cells. Our results suggest that mTOR signaling mediates the inhibitory effect of ghrelin on GLP-1 production.
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Affiliation(s)
- Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China.
| | - Xiaosi Hong
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Hong Tang
- Shenzhen University Diabetes Center, Shenzhen University Health Science Center, 3688 Nanhai Avenue, Nanshan District, Shenzhen, Guangdong, 518060, China
| | - Sushi Jiang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Fenting Liu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Zhemin Shen
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Ziru Li
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA
| | - Weizhen Zhang
- Shenzhen University Diabetes Center, Shenzhen University Health Science Center, 3688 Nanhai Avenue, Nanshan District, Shenzhen, Guangdong, 518060, China; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA.
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Xu G, Li Z, Ding L, Tang H, Guo S, Liang H, Wang H, Zhang W. Intestinal mTOR regulates GLP-1 production in mouse L cells. Diabetologia 2015; 58:1887-97. [PMID: 26037201 DOI: 10.1007/s00125-015-3632-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/20/2015] [Indexed: 02/08/2023]
Abstract
AIMS/HYPOTHESIS Glucagon-like peptide (GLP-1), an intestinal incretin produced in L cells through proglucagon processing, is released in response to meal intake. The intracellular mechanism by which L cells sense the organism energy level to coordinate the production of GLP-1 remains unclear. Mechanistic target of rapamycin (mTOR) is an intracellular fuel sensor critical for energy homeostasis. In this study, we investigated whether intestinal mTOR regulates GLP-1 production in L cells. METHODS The effects of mTOR on GLP-1 production were examined in lean- or high-fat diet (HFD) induced diabetic C57/BL6, db/db, Neurog3-Tsc1(-/-) mice, and STC-1 cells. GLP-1 expression was investigated by real-time PCR and western blotting. Plasma GLP-1 and insulin were detected by enzyme immunoassay and radioimmunoassay, respectively. RESULTS Fasting downregulated mTOR activity, which was associated with a decrement of intestinal proglucagon and circulating GLP-1. Upon re-feeding, these alterations returned to the levels of fed animals. In HFD induced diabetic mice, ileal mTOR signalling, proglucagon and circulating GLP-1 were significantly decreased. Inhibition of mTOR signalling by rapamycin decreased levels of intestinal and plasma GLP-1 in both normal and diabetic mice. Activation of the intestinal mTOR signalling by L-leucine or Tsc1 gene deletion increased levels of intestinal proglucagon and plasma GLP-1. Overexpression of mTOR stimulated proglucagon promoter activity and GLP-1 production, whereas inhibition of mTOR activity by overexpression of tuberous sclerosis 1 (TSC1) or TSC2 decreased proglucagon promoter activity and GLP-1 production in STC-1 cells. CONCLUSIONS/INTERPRETATION mTOR may link energy supply with the production of GLP-1 in L cells.
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Affiliation(s)
- Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, Guangdong, China
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Kitahara A, Takahashi K, Moriya R, Onuma H, Handa K, Sumitani Y, Tanaka T, Katsuta H, Nishida S, Sakurai T, Inukai K, Ohno H, Ishida H. Ghrelin augments the expressions and secretions of proinflammatory adipokines, VEGF120 and MCP-1, in differentiated 3T3-L1 adipocytes. J Cell Physiol 2015; 230:199-209. [PMID: 24958127 DOI: 10.1002/jcp.24699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 06/11/2014] [Accepted: 06/18/2014] [Indexed: 01/26/2023]
Abstract
Ghrelin is a physiological-active peptide with growth hormone-releasing activity, orexigenic activity, etc. In addition, the recent study has also suggested that ghrelin possesses the pathophysiological abilities related with type 2 diabetes. However, the ghrelin-direct-effects implicated in type 2 diabetes on peripheral tissues have been still unclear, whereas its actions on the central nervous system (CNS) appear to induce the development of diabetes. Thus, to assess its peripheral effects correlated with diabetes, we investigated the regulatory mechanisms about adipokines, which play a central role in inducing peripheral insulin resistance, secreted from mature 3T3-L1 adipocytes stimulated with ghrelin in vitro . The stimulation with 50 nmol/L ghrelin for 24 h resulted in the significant 1.9-fold increase on vascular endothelial growth factor-120 (VEGF(120)) releases (p < 0.01) and the 1.7-fold on monocyte chemoattractant protein-1 (MCP-1) (p < 0.01) from 3T3-L1 adipocytes, respectively, while ghrelin failed to enhance tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10 and adiponectin secretions. In addition, Akt phosphorylation on Ser473 and c-Jun NH2 -terminal protein kinase (JNK) phosphorylation on Thr183/Tyr185 were markedly enhanced 1.4-fold (p < 0.01) and 1.6-fold (p < 0.01) in the ghrelin-stimulated adipocytes, respectively. Furthermore, the treatment with LY294002 (50 μmol/L) and Wortmannin (10nmol/L), inhibitors of phosphatidylinositol 3-kinase (PI3K), significantly decreased the amplified VEGF(120) secretion by 29% (p < 0.01) and 28% (p < 0.01) relative to the cells stimulated by ghrelin alone, respectively, whereas these inhibitors had no effects on increased MCP-1 release. On the other hand, JNK inhibitor SP600125 (10 μmol/L) clearly reduced the increased MCP-1, but not VEGF(120), release by 35% relative to the only ghrelin-stimulated cells (p < 0.01). In conclusion, ghrelin can enhance the secretions of proinflammatory adipokines, VEGF(120) and MCP-1, but fails to affect IL-10 and adiponectin which are considered to be anti-inflammatory adipokines. Moreover, this augmented VEGF(120) release is invited through the activation of PI3K pathways and the MCP-1 is through JNK pathways. Consequently, our results strongly suggest that ghrelin can induce the development of diabetes via its direct-action in peripheral tissues as well as via in CNS.
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Ghrelin promotes hepatic lipogenesis by activation of mTOR-PPARγ signaling pathway. Proc Natl Acad Sci U S A 2014; 111:13163-8. [PMID: 25157160 DOI: 10.1073/pnas.1411571111] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although ghrelin has been demonstrated to stimulate energy intake and storage through a central mechanism, its effect on hepatic lipid metabolism remains largely uncharacterized. Ghrelin receptor antagonism or gene deletion significantly decreased obesity-associated hepatic steatosis by suppression of de novo lipogenesis, whereas exogenous ghrelin stimulated lipogenesis, leading to hepatic lipid accumulation in mice. The effects of ghrelin were mediated by direct activation of its receptor on hepatocytes. Cultured hepatocytes responded to ghrelin with increased lipid content and expression of lipogenesis-related genes. Ghrelin increased phosphorylation of S6, the downstream target of mammalian target of rapamycin (mTOR) signaling in cultured hepatocytes, whereas ghrelin receptor antagonism reduced hepatic phosphorylation of S6 in db/db mice. Inhibition of mTOR signaling by rapamycin markedly attenuated ghrelin-induced up-regulation of lipogenesis in hepatocytes, whereas activation of hepatic mTOR signaling by deletion of TSC1 increased hepatic lipogenesis. By interacting with peroxisome proliferator-activated receptor-γ (PPARγ), mTOR mediates the ghrelin-induced up-regulation of lipogenesis in hepatocytes. The stimulatory effect of ghrelin on hepatic lipogenesis was significantly attenuated by PPARγ antagonism in cultured hepatocytes and in PPARγ gene-deficient mice. Our study indicates that ghrelin activates its receptor on hepatocytes to promote lipogenesis via a mechanism involving the mTOR-PPARγ signaling pathway.
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Qin Y, Li Z, Wang Z, Li Y, Zhao J, Mulholland M, Zhang W. Ghrelin contributes to protection of hepatocellular injury induced by ischaemia/reperfusion. Liver Int 2014; 34:567-75. [PMID: 23998356 DOI: 10.1111/liv.12286] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 07/24/2013] [Indexed: 12/24/2022]
Abstract
BACKGROUND & AIMS Ghrelin, a gut hormone with pleiotropic effects, may act as a protective signal in parenchymal cells. We investigated the protective effects of ghrelin on hepatocytes after ischaemia/reperfusion (I/R). METHODS Hepatic injury was assessed by measurement of plasma alanine aminotransferase (ALT) and lactate dehydrogenase (LDH), histological analysis, and TUNEL assay. Effects of exogenous ghrelin and ghrelin receptor gene deletion on I/R induced injury of liver were evaluated. RESULTS Ischaemia/reperfusion induced a profound injury to hepatocytes. This was accompanied by elevations in plasma ALT and LDH. Pretreatment with ghrelin significantly reduced elevations in plasma ALT and LDH, and attenuated tissue damage induced by hepatic I/R in mice. Hepatic injury induced by I/R was more pronounced in ghrelin receptor gene null mice. Ghrelin administration blocked the up-regulation of AMP-activated protein kinase (AMPK) activity induced by hepatic I/R. CONCLUSIONS This study demonstrates that ghrelin contributes to the cytoprotection during hepatic I/R.
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Affiliation(s)
- Yan Qin
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China; Department of Physiology and Pathophysiology, School of Basic Medicine, Da Li University, Dali, Yunnan, China
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Zhang W, Zhang C, Fritze D, Chai B, Li J, Mulholland MW. Modulation of food intake by mTOR signalling in the dorsal motor nucleus of the vagus in male rats: focus on ghrelin and nesfatin-1. Exp Physiol 2013; 98:1696-704. [PMID: 23955309 DOI: 10.1113/expphysiol.2013.074930] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Previous studies have demonstrated that mammalian target of rapamycin (mTOR) signalling in the hypothalamus is involved in the control of energy homeostasis. The aim of this study was to characterize the effect of mTOR signalling in the dorsal motor nucleus of the vagus (DMNV) on energy intake. Phospho-mTOR was detected in the DMNV neurons, and its levels were increased by energy deprivation. Rapamycin significantly inhibited mTOR activity and reduced food intake when administrated into the fourth ventricle. Exposure of DMNV neurons to ghrelin increased the phosphorylation of mTOR. Injection of ghrelin into the fourth ventricle significantly increased food intake relative to the control vehicle. Pretreatment with rapamycin for 15 min attenuated the orexigenic effect of ghrelin. A reduction in the phosphorylation of mTOR was observed following injection of nesfatin-1 into the fourth ventricle. When administrated by injection into the fourth ventricle, nesfatin-1 suppressed food intake in comparison with the control vehicle. The anorexigenic effect of nesfatin-1 was significantly attenuated by pretreatment with leucine for 15 min. All these findings suggest that mTOR signalling in the DMNV neurons regulates both the nutrient and the hormonal signals for the modulation of food intake.
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Affiliation(s)
- Weizhen Zhang
- W. Zhang: University of Michigan, Department of Surgery, 1150 West Medical Center Drive, 1520B MSRB I, Ann Arbor, MI 48109, USA.
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Li Z, Li Y, Zhang W. Ghrelin receptor in energy homeostasis and obesity pathogenesis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:45-87. [PMID: 23317782 DOI: 10.1016/b978-0-12-386933-3.00002-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ghrelin receptor, also known as growth hormone secretagogue receptor (GHS-R), was identified in porcine and rat anterior pituitary membranes, where the synthetic secretagogue MK-0677 causes amplified pulsatile growth hormone (GH) release. In addition to its function in the stimulation of GH secretion, ghrelin, the natural ligand of ghrelin receptor is now recognized as a peptide hormone with fundamental influence on energy homeostasis. Despite the potential existence of multiple subtypes of ghrelin receptor, the effects of ghrelin on energy metabolism, obesity, and diabetes are mediated by its classical receptor GHS-R1a, whose activation requires the n-octanoylation of ghrelin. Here we review the current understanding of the role of the ghrelin receptor in the regulation of energy homeostasis. An overview of the ghrelin receptor is presented first, followed by the discussion on its effects on food intake, glucose homeostasis, and lipid metabolism. Finally, potential strategies for treating obesity and diabetes via manipulation of the ghrelin/ghrelin receptor axis are explored.
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Affiliation(s)
- Ziru Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China
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