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Mitra A, Mandal S, Bose B, Shenoy P S. Unlocking the Potential of Obestatin: A Novel Peptide Intervention for Skeletal Muscle Regeneration and Prevention of Atrophy. Mol Biotechnol 2024; 66:948-959. [PMID: 38198052 DOI: 10.1007/s12033-023-01011-7] [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: 10/01/2023] [Accepted: 11/27/2023] [Indexed: 01/11/2024]
Abstract
Obestatin is derived from the same gene as that of ghrelin and their functions were perceived to be antagonistic. Recent developments have shown that although they are known to have contradictory functions, effect of obestatin on skeletal muscle regeneration is similar to that of ghrelin. Obestatin works through a receptor called GPR39, a ghrelin and motilin family receptor and transduces signals in skeletal muscle similar to that of ghrelin. Not only there is a similarity in the receptor family, but also obestatin targets similar proteins and transcription factors as that of ghrelin (for example, FoxO family members) for salvaging skeletal muscle atrophy. Moreover, like ghrelin, obestatin also works by inducing the transcription of Pax7 which is required for muscle stem cell mobilisation. Hence, there are quite some evidences which points to the fact that obestatin can be purposed as a peptide intervention to prevent skeletal muscle wasting and induce myogenesis. This review elaborates these aspects of obestatin which can be further exploited and addressed to bring obestatin as a clinical intervention towards preventing skeletal muscle atrophy and sarcopenia.
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Affiliation(s)
- Akash Mitra
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Deralakatte, Mangalore, Karnataka, 575018, India
| | - Samanwita Mandal
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Deralakatte, Mangalore, Karnataka, 575018, India
| | - Bipasha Bose
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Deralakatte, Mangalore, Karnataka, 575018, India
| | - Sudheer Shenoy P
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Deralakatte, Mangalore, Karnataka, 575018, India.
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2
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Cao B, Wang J, Feng J. Signaling pathway mechanisms of neurological diseases induced by G protein-coupled receptor 39. CNS Neurosci Ther 2023; 29:1470-1483. [PMID: 36942516 PMCID: PMC10173710 DOI: 10.1111/cns.14174] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/14/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND G protein-coupled receptor 39 (GPR39) is a transmembrane zinc receptor with two splice variants, which belongs to the G-protein-coupled receptor growth hormone-releasing peptide family. Its expression is induced by zinc, which activates GPR39, and its activation mediates cell proliferation, ion homeostasis, and anti-inflammatory, antioxidant, and other pathophysiological effects via different signaling pathways. AIMS The article reviews the latest literature in this field. In particular, the role of GPR39 in nervous system is discussed. MATERIALS AND METHODS GPR39 can be a promising target in neurological diseases for targeted therapy, which will help doctors overcome the associated problems. DISCUSSION GPR39 is expressed in vivo at several sites. Increasing evidence suggests that GPR39 plays an important role as a neuroprotective agent in vivo and regulates various neurological functions, including neurodegeneration, neuroelectrophysiology, and neurovascular homeostasis. CONCLUSION This review aims to provide an overview of the functions, signal transduction pathways, and pathophysiological role of GPR39 in neurological diseases and summarize the GPR39 agonists that have been identified in the recent years.
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Affiliation(s)
- Bin Cao
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jue Wang
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Juan Feng
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, China
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3
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Noh JY, Herrera M, Patil BS, Tan XD, Wright GA, Sun Y. The expression and function of growth hormone secretagogue receptor in immune cells: A current perspective. Exp Biol Med (Maywood) 2022; 247:2184-2191. [PMID: 36151745 PMCID: PMC9899990 DOI: 10.1177/15353702221121635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The orexigenic hormone ghrelin and its receptor, growth hormone secretagogue receptor (GHS-R), have been extensively studied in the last two decades, revealing that ghrelin signaling has important implications in health and disease. Metabolic diseases, such as obesity and diabetes, are often accompanied by low-grade chronic inflammation, that has been coined as "meta-inflammation." Immune cells are key cellular mediators of meta-inflammation, controlling both initiation and resolution of inflammation. Immune cells exhibit dynamic changes in cellular characteristics and functional output in response to the stimuli/insults from their surrounding microenvironment. Emerging evidence shows that ghrelin has an important effect on inflammation, in addition to its well-known effects on metabolism. However, the cellular/molecular mechanism of ghrelin signaling in immunity is largely unknown because the knowledge in regard to the expression and function of GHS-R in immune cells is currently sparse. In this review, we have accumulated the recent findings related to the expression and functions of GHS-R in various immune cells under different physiological and pathological states. This review aims to inspire further investigation of the immunological roles of ghrelin signaling and advance the therapeutic applications of ghrelin signaling in meta-inflammation.
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Affiliation(s)
- Ji Yeon Noh
- Department of Nutrition, Texas A&M
University, College Station, TX 77843, USA
| | - Matthew Herrera
- Department of Nutrition, Texas A&M
University, College Station, TX 77843, USA
| | - Bhimanagouda S Patil
- Vegetable and Fruit Improvement Center,
Department of Horticultural Sciences, Texas A&M University, College Station, TX
77843, USA
| | - Xiao-Di Tan
- Department of Pediatrics, Feinberg
School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Gus A Wright
- Department of Veterinary Pathobiology,
Texas A&M University, College Station, TX 77843, USA
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M
University, College Station, TX 77843, USA
- USDA/ARS Children’s Nutrition Research
Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030,
USA
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4
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Villarreal D, Pradhan G, Zhou Y, Xue B, Sun Y. Diverse and Complementary Effects of Ghrelin and Obestatin. Biomolecules 2022; 12:biom12040517. [PMID: 35454106 PMCID: PMC9028691 DOI: 10.3390/biom12040517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023] Open
Abstract
Ghrelin and obestatin are two “sibling proteins” encoded by the same preproghrelin gene but possess an array of diverse and complex functions. While there are ample literature documenting ghrelin’s functions, the roles of obestatin are less clear and controversial. Ghrelin and obestatin have been perceived to be antagonistic initially; however, recent studies challenge this dogma. While they have opposing effects in some systems, they function synergistically in other systems, with many functions remaining debatable. In this review, we discuss their functional relationship under three “C” categories, namely complex, complementary, and contradictory. Their functions in food intake, weight regulation, hydration, gastrointestinal motility, inflammation, and insulin secretion are complex. Their functions in pancreatic beta cells, cardiovascular, muscle, neuroprotection, cancer, and digestive system are complementary. Their functions in white adipose tissue, thermogenesis, and sleep regulation are contradictory. Overall, this review accumulates the multifaceted functions of ghrelin and obestatin under both physiological and pathological conditions, with the intent of contributing to a better understanding of these two important gut hormones.
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Affiliation(s)
- Daniel Villarreal
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
| | - Geetali Pradhan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao 266071, China;
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
| | - Yuxiang Sun
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Correspondence: ; Tel.: +1-979-862-9143
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5
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A review of glucoregulatory hormones potentially applicable to the treatment of Alzheimer’s disease: mechanism and brain delivery. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2022. [DOI: 10.1007/s40005-022-00566-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Mechanistic Investigation of GHS-R Mediated Glucose-Stimulated Insulin Secretion in Pancreatic Islets. Biomolecules 2022; 12:biom12030407. [PMID: 35327599 PMCID: PMC8945998 DOI: 10.3390/biom12030407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/19/2022] [Accepted: 02/27/2022] [Indexed: 02/07/2023] Open
Abstract
Ghrelin receptor, a growth hormone secretagogue receptor (GHS-R), is expressed in the pancreas. Emerging evidence indicates that GHS-R is involved in the regulation of glucose-stimulated insulin secretion (GSIS), but the mechanism by which GHS-R regulates GSIS in the pancreas is unclear. In this study, we investigated the role of GHS-R on GSIS in detail using global Ghsr−/− mice (in vivo) and Ghsr-ablated pancreatic islets (ex vivo). GSIS was attenuated in both Ghsr−/− mice and Ghsr-ablated islets, while the islet morphology was similar between WT and Ghsr−/− mice. To elucidate the mechanism underpinning Ghsr-mediated GSIS, we investigated the key steps of the GSIS signaling cascade. The gene expression of glucose transporter 2 (Glut2) and the glucose-metabolic intermediate—glucose-6-phosphate (G6P) were reduced in Ghsr-ablated islets, supporting decreased glucose uptake. There was no difference in mitochondrial DNA content in the islets of WT and Ghsr−/− mice, but the ATP/ADP ratio in Ghsr−/− islets was significantly lower than that of WT islets. Moreover, the expression of pancreatic and duodenal homeobox 1 (Pdx1), as well as insulin signaling genes of insulin receptor (IR) and insulin receptor substrates 1 and 2 (IRS1/IRS2), was downregulated in Ghsr−/− islets. Akt is the key mediator of the insulin signaling cascade. Concurrently, Akt phosphorylation was reduced in the pancreas of Ghsr−/− mice under both insulin-stimulated and homeostatic conditions. These findings demonstrate that GHS-R ablation affects key components of the insulin signaling pathway in the pancreas, suggesting the existence of a cross-talk between GHS-R and the insulin signaling pathway in pancreatic islets, and GHS-R likely regulates GSIS via the Akt-Pdx1-GLUT2 pathway.
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Gastrointestinal Motility and Gut Hormone Secretion in response to Shenhuang Plaster in a Postoperative Ileus Rat Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:8859579. [PMID: 34122608 PMCID: PMC8189788 DOI: 10.1155/2021/8859579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 04/28/2021] [Accepted: 05/07/2021] [Indexed: 12/28/2022]
Abstract
Postoperative ileus (POI), a gastrointestinal function disorder, is a complication that arises from surgery. Shenhuang plaster (SHP) application to the Shenque acupoint (CV8) to promote the recovery of gastrointestinal function has achieved definite curative effects in clinical settings; however, the underlying pharmacological mechanism remains unknown. In this study, we evaluated the effects of SHP using a Sprague Dawley rat POI model. Then, gastrointestinal transit in different rat groups was evaluated by the movement of fluorescein-labelled dextran. Ghrelin, obestatin, motilin (MTL), and vasoactive intestinal peptide (VIP) plasma concentrations were measured via a radioimmunoassay. The expression of the ghrelin and obestatin receptors (GHS-R1α and GPR39) in the intestinal muscularis of rats in different groups was comparatively identified via western blotting. The results indicated that SHP application improved gastrointestinal motility in POI model rats. SHP application significantly increased ghrelin concentration and the expression of its receptor and inhibited obestatin concentration and the expression of its receptor in blood. Further, ghrelin concentration and the capability of gastrointestinal transit were positively correlated. Simultaneously, SHP application also promoted the secretion of other gastrointestinal motility hormones, such as MTL and VIP. Hence, these results provide evidence that SHP can promote the recovery of gastrointestinal transmission in POI rat models through regulation of ghrelin and other intestinal hormones.
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8
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Liu H, Li X, Chen R, Liu D, Tong C. Effect of left gastric artery embolization on obesity and ghrelin/leptin levels in pigs. Am J Transl Res 2021; 13:5368-5373. [PMID: 34150132 PMCID: PMC8205667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
OBJECTIVE To investigate the influence of left gastric artery embolization (LGAE) on obesity and Ghrelin/Leptin levels in pigs. METHODS Healthy female Wuzhishan piglets aged 3-4 months were allocated into obesity + LGAE group, obesity group, control group (fed with a normal diet; n=8 for each group). Body weight, serum Ghrelin, Leptin, glucose and insulin levels were compared before surgery, 1 month and 3 months after surgery. RESULTS Piglets in obesity group and obesity + LGAE group were heavier than those in control group before and 1 month after surgery (P<0.001), and in obesity group were heavier than those in obesity + LGAE group 1 month after surgery (P<0.05). A significant decrease in body weight was observed in obesity + LGAE group 3 months after surgery (P<0.05), and the obesity group showed heavier weight than the other two groups (P<0.001). Ghrelin levels in obesity group and obesity + LGAE group were higher than those in control group before and 1 month after surgery (P<0.001), and in obesity group were higher than those in obesity + LGAE group 1 month after surgery (P<0.05). They showed an evident decrease in obesity + LGAE group 3 months after surgery (P<0.05), and in obesity group were higher than that in the other two groups (P<0.01). Leptin levels in obesity group and obesity + LGAE group were higher than those in control group before surgery (P<0.01) and 1 month after surgery (P<0.05). They decreased significantly in obesity + LGAE group 3 months after surgery (P<0.01), and in obesity group were higher than those in the other two groups (P<0.01). CONCLUSION LGAE greatly contributes to weight loss possibly by reducing the secretion of Ghrelin and Leptin.
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Affiliation(s)
- Hui Liu
- Department of Interventional Radiology, Central South University, Xiangya School of Medicine Affiliated Haikou HospitalHaikou, Hainan Province, China
| | - Xiangying Li
- Department of Radiology, Central South University, Xiangya School of Medicine Affiliated Haikou HospitalHaikou, Hainan Province, China
| | - Rihui Chen
- Department of Interventional Radiology, Central South University, Xiangya School of Medicine Affiliated Haikou HospitalHaikou, Hainan Province, China
| | - Dingcheng Liu
- Department of Interventional Radiology, Central South University, Xiangya School of Medicine Affiliated Haikou HospitalHaikou, Hainan Province, China
| | - Chao Tong
- Department of Interventional Radiology, Central South University, Xiangya School of Medicine Affiliated Haikou HospitalHaikou, Hainan Province, China
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9
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Montégut L, Lopez-Otin C, Magnan C, Kroemer G. Old Paradoxes and New Opportunities for Appetite Control in Obesity. Trends Endocrinol Metab 2021; 32:264-294. [PMID: 33707095 DOI: 10.1016/j.tem.2021.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022]
Abstract
Human obesity is accompanied by alterations in the blood concentrations of multiple circulating appetite regulators. Paradoxically, most of the appetite-inhibitory hormones are elevated in nonsyndromic obesity, while most of the appetite stimulatory hormones are reduced, perhaps reflecting vain attempts of regulation by inefficient feedback circuitries. In this context, it is important to understand which appetite regulators exhibit a convergent rather than paradoxical behavior and hence are likely to contribute to the maintenance of the obese state. Pharmacological interventions in obesity should preferentially consist of the supplementation of deficient appetite inhibitors or the neutralization of excessive appetite stimulators. Here, we critically analyze the current literature on appetite-regulatory peptide hormones. We propose a short-list of appetite modulators that may constitute the best candidates for therapeutic interventions.
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Affiliation(s)
- Léa Montégut
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France
| | - Carlos Lopez-Otin
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, 33006, Oviedo, Spain
| | | | - Guido Kroemer
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France; Unité de Biologie Fonctionnelle et Adaptative, Sorbonne Paris Cité, CNRS UMR8251, Université Paris Diderot, Paris, France; Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-, HP, Paris, France; Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China; Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden.
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10
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β Cell GHS-R Regulates Insulin Secretion and Sensitivity. Int J Mol Sci 2021; 22:ijms22083950. [PMID: 33920473 PMCID: PMC8069226 DOI: 10.3390/ijms22083950] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 12/14/2022] Open
Abstract
Growth hormone secretagogue receptor (GHS-R) is widely known to regulate food intake and adiposity, but its role in glucose homeostasis is unclear. In this study, we investigated the expression of GHS-R in mouse pancreatic islets and its role in glycemic regulation. We used Ghsr-IRES-tauGFP mice, with Green Fluorescent Protein (GFP) as a surrogate for GHS-R, to demonstrate the GFP co-localization with insulin and glucagon expression in pancreatic islets, confirming GHS-R expression in β and α cells. We then generated β-cell-specific GHSR-deleted mice with MIP-Cre/ERT and validated that GHS-R suppression was restricted to the pancreatic islets. MIP-Cre/ERT;Ghsrf/f mice showed normal energy homeostasis with similar body weight, body composition, and indirect calorimetry profile. Interestingly, MIP-Cre/ERT;Ghsrf/f mice exhibited an impressive phenotype in glucose homeostasis. Compared to controls, MIP-Cre/ERT;Ghsrf/f mice showed lower fasting blood glucose and insulin; reduced first-phase insulin secretion during a glucose tolerance test (GTT) and glucose-stimulated insulin secretion (GSIS) test in vivo. The isolated pancreatic islets of MIP-Cre/ERT;Ghsrf/f mice also showed reduced insulin secretion during GSIS ex vivo. Further, MIP-Cre/ERT;Ghsrf/f mice exhibited improved insulin sensitivity during insulin tolerance tests (ITT). Overall, our results confirmed GHS-R expression in pancreatic β and α cells; GHS-R cell-autonomously regulated GSIS and modulated systemic insulin sensitivity. In conclusion, β cell GHS-R was an important regulator of glucose homeostasis, and GHS-R antagonists may have therapeutic potential for Type 2 Diabetes.
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11
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B G M, Manjappara UV. Obestatin and Rosiglitazone Differentially Modulate Lipid Metabolism Through Peroxisome Proliferator-activated Receptor-γ (PPARγ) in Pre-adipose and Mature 3T3-L1 Cells. Cell Biochem Biophys 2021; 79:73-85. [PMID: 33432549 DOI: 10.1007/s12013-020-00958-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2020] [Indexed: 10/22/2022]
Abstract
Obestatin is a 23-residue peptide, obtained after posttranslational modification of preproghrelin. It has been shown, in Swiss albino mice, to upregulate glycerolipid metabolism and PPARγ signaling. It was opined that the by-products of increased glycerolipid metabolism triggered PPARγ signaling. It was hypothesized that obestatin upon co-administration with a full agonist of PPARγ should reveal the comparative significance or possible synergy in PPARγ signaling. We postulated they would act synergistically by obestatin increasing PPARγ expression and rosiglitazone enhancing PPARγ activity. We evaluated the combination in DIO-C57BL/6 mice and observed that obestatin completely reversed the increase in subcutaneous fat brought about by rosiglitazone. To understand their role at the adipocyte level, 3T3-L1 cells were treated with a combination of obestatin and rosiglitazone during (1) initiation of differentiation and (2) after 14 days from initiation of differentiation when the adipocytes were mature. Interestingly, their influence was mainly adipogenic and showed double lipid accumulation when estimated 14 days after initiation of differentiation. There was an upregulation of Pparγ by fourfold, Hsl by eightfold, Glut4 by fourfold, Leptin by 2.7-fold, Atgl by sixfold, Fasn by sixfold, and Fabp4 by sevenfold at the mRNA level, whereas in mature adipocytes there was a significant decrease in fat accumulation by 20%. There was downregulation of Pparγ, Hsl, Lpl, and Fasn by 0.5-fold at the mRNA level. These results show that the combined influence of obestatin and rosiglitazone is significant and the outcome is dependent on the metabolic stage of the adipocyte.
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Affiliation(s)
- Mallikarjuna B G
- Department of Lipid Science, CSIR-Central Food Technological Research Institute, Mysore, 570020, India
| | - Uma V Manjappara
- Department of Lipid Science, CSIR-Central Food Technological Research Institute, Mysore, 570020, India.
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12
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Barrera M, Hiriart M, Cocho G, Villarreal C. Type 2 diabetes progression: A regulatory network approach. CHAOS (WOODBURY, N.Y.) 2020; 30:093132. [PMID: 33003944 DOI: 10.1063/5.0011125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
In order to elucidate central elements underlying type 2 diabetes, we constructed a regulatory network model involving 37 components (molecules, receptors, processes, etc.) associated to signaling pathways of pancreatic beta-cells. In a first approximation, the network topology was described by Boolean rules whose interacting dynamics predicted stationary patterns broadly classified as health, metabolic syndrome, and diabetes stages. A subsequent approximation based on a continuous logic analysis allowed us to characterize the progression of the disease as transitions between these states associated to alterations of cell homeostasis due to exhaustion or exacerbation of specific regulatory signals. The method allowed the identification of key transcription factors involved in metabolic stress as essential for the progression of the disease. Integration of the present analysis with existent mathematical models designed to yield accurate account of experimental data in human or animal essays leads to reliable predictions for beta-cell mass, insulinemia, glycemia, and glycosylated hemoglobin in diabetic fatty rats.
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Affiliation(s)
- M Barrera
- Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - M Hiriart
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - G Cocho
- Instituto de Física, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - C Villarreal
- Instituto de Física, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
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Belete TM. A Recent Achievement In the Discovery and Development of Novel Targets for the Treatment of Type-2 Diabetes Mellitus. J Exp Pharmacol 2020; 12:1-15. [PMID: 32021494 PMCID: PMC6959499 DOI: 10.2147/jep.s226113] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Type 2 diabetes (T2DM) is a chronic metabolic disorder. Impaired insulin secretion, enhanced hepatic glucose production, and suppressed peripheral glucose use are the main defects responsible for developing the disease. Besides, the pathophysiology of T2DM also includes enhanced glucagon secretion, decreased incretin secretion, increased renal glucose reabsorption, and adipocyte, and brain insulin resistance. The increasing prevalence of T2DM in the world beseeches an urgent need for better treatment options. The antidiabetic drugs focus on control of blood glucose concentration, but the future treatment goal is to delay disease progression and treatment failure, which causes poorer glycemic regulation. Recent treatment approaches target on several novel pathophysiological defects present in T2DM. Some of the promising novel targets being under clinical development include those that increase insulin sensitization (antagonists of glucocorticoids receptor), decreasing hepatic glucose production (glucagon receptor antagonist, inhibitors of glycogen phosphorylase and fructose-1,6-biphosphatase). This review summarizes studies that are available on novel targets being studied to treat T2DM with an emphasis on the small molecule drug design. The experience gathered from earlier studies and knowledge of T2DM pathways can guide the anti-diabetic drug development toward the discovery of drugs essential to treat T2DM.
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Affiliation(s)
- Tafere Mulaw Belete
- Department of Pharmacology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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14
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Villarreal D, Pradhan G, Wu CS, Allred CD, Guo S, Sun Y. A Simple High Efficiency Protocol for Pancreatic Islet Isolation from Mice. J Vis Exp 2019. [PMID: 31524856 DOI: 10.3791/57048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other important biological functions. The islets primarily consist of five types of hormone-secreting cells: α cells secrete glucagon, β cells secrete insulin, δ cells secrete somatostatin, ε cells secrete ghrelin, and PP cells secrete pancreatic polypeptide. Sixty to 80% of the cells in the islets are β cells, which are the most important cell population to study insulin secretion. Pancreatic islets are a crucial model system to study ex vivo insulin secretion. Acquiring high quality islets is of great importance for diabetes research. Most islet isolation procedures require technically difficult to access site of collagenase injection, harsh and complex digestion procedures, and multiple density gradient purification steps. This paper features a simple high yield mouse islet isolation method with detailed descriptions and realistic demonstrations, showing the following specific steps: 1) injection of collagenase P at the ampulla of Vater, a small area joining the pancreatic duct and the common bile duct, 2) enzymatic digestion and mechanical separation of the exocrine pancreas, and 3) a single gradient purification step. The advantages of this method are the injection of digestive enzyme using the more accessible ampulla of Vater, more complete digestion using combination of enzymatic and mechanical approaches, and a simpler single gradient purification step. This protocol produces approximately 250-350 islets per mouse; and islets are suitable for various ex vivo studies. Possible caveats of this procedure are potentially damaged islets due to enzymatic digestion and/or prolonged gradient incubation, all of which can be largely avoided by careful ad justification of incubation time.
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Affiliation(s)
| | - Geetali Pradhan
- Children's Nutrition Research Center, Baylor College of Medicine
| | - Chia-Shan Wu
- Department of Nutrition and Food Science, Texas A&M University; Children's Nutrition Research Center, Baylor College of Medicine
| | | | - Shaodong Guo
- Department of Nutrition and Food Science, Texas A&M University
| | - Yuxiang Sun
- Department of Nutrition and Food Science, Texas A&M University; Children's Nutrition Research Center, Baylor College of Medicine;
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15
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Orsso CE, Butler AA, Muehlbauer MJ, Cui HN, Rubin DA, Pakseresht M, Butler MG, Prado CM, Freemark M, Haqq AM. Obestatin and adropin in Prader-Willi syndrome and nonsyndromic obesity: Associations with weight, BMI-z, and HOMA-IR. Pediatr Obes 2019; 14:e12493. [PMID: 30589518 PMCID: PMC7456601 DOI: 10.1111/ijpo.12493] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/29/2018] [Accepted: 11/05/2018] [Indexed: 11/29/2022]
Abstract
The roles of obestatin and adropin in paediatric obesity are poorly understood. We compared obestatin and adropin concentrations in younger (n = 21) and older children (n = 14) with Prader-Willi syndrome (PWS) and age and BMI-z-matched controls (n = 31). Fasting plasma obestatin and adropin were higher in younger children with PWS than controls; adropin was also higher in older children with PWS. Growth hormone treatment had no effects on obestatin or adropin in PWS. The ratio of ghrelin to obestatin declined from early to late childhood but was higher in older PWS than older controls. Adropin correlated with fasting glucose in the PWS group only. Changes in the ratio of ghrelin to obestatin may suggest changes in the processing of preproghrelin to ghrelin and obestatin during development and differential processing of preproghrelin in PWS.
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Affiliation(s)
- C. E. Orsso
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - A. A. Butler
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis University, St. Louis, Missouri, United States
| | - M. J. Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, United States
| | - H. N. Cui
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, United States
| | - D. A. Rubin
- Department of Kinesiology, California State University, Fullerton, California, United States
| | - M. Pakseresht
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - M. G. Butler
- Departments of Psychiatry, Behavioral Sciences, and Pediatrics, Kansas University Medical Center, Kansas City, Kansas, United States
| | - C. M. Prado
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada
| | - M. Freemark
- Division of Pediatric Endocrinology, Duke University Medical Center, Durham, North Carolina, United States
| | - A. M. Haqq
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada,Department of Pediatrics, University of Alberta, Edmonton, Canada
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16
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Zhang K, Guo X, Yan H, Wu Y, Pan Q, Shen JZ, Li X, Chen Y, Li L, Qi Y, Xu Z, Xie W, Zhang W, Threadgill D, He L, Villarreal D, Sun Y, White MF, Zheng H, Guo S. Phosphorylation of Forkhead Protein FoxO1 at S253 Regulates Glucose Homeostasis in Mice. Endocrinology 2019; 160:1333-1347. [PMID: 30951171 PMCID: PMC6482038 DOI: 10.1210/en.2018-00853] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/29/2019] [Indexed: 01/04/2023]
Abstract
The transcription factor forkhead box O1 (FoxO1) is a key mediator in the insulin signaling pathway and controls multiple physiological functions, including hepatic glucose production (HGP) and pancreatic β-cell function. We previously demonstrated that S256 in human FOXO1 (FOXO1-S256), equivalent to S253 in mouse FoxO1 (FoxO1-S253), is a key phosphorylation site mediating the effect of insulin as a target of protein kinase B on suppression of FOXO1 activity and expression of target genes responsible for gluconeogenesis. Here, we investigated the role of FoxO1-S253 phosphorylation in control of glucose homeostasis in vivo by generating global FoxO1-S253A/A knockin mice, in which FoxO1-S253 alleles were replaced with alanine (A substitution) blocking FoxO1-S253 phosphorylation. FoxO1-S253A/A mice displayed mild increases in feeding blood glucose and insulin levels but decreases in fasting blood glucose and glucagon concentrations, as well as a reduction in the ratio of pancreatic α-cells/β-cells per islet. FoxO1-S253A/A mice exhibited a slight increase in energy expenditure but barely altered food intake and glucose uptake among tissues. Further analyses revealed that FoxO1-S253A/A enhances FoxO1 nuclear localization and promotes the effect of glucagon on HGP. We conclude that dephosphorylation of S253 in FoxO1 may reflect a molecular basis of pancreatic plasticity during the development of insulin resistance.
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Affiliation(s)
- Kebin Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Xiaoqin Guo
- Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Hui Yan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Yuxin Wu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
- Queens University Belfast School of Biological Sciences, Belfast, United Kingdom
| | - Quan Pan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - James Zheng Shen
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Xiaopeng Li
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Yunmei Chen
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Ling Li
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Yajuan Qi
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Zihui Xu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Wei Xie
- Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Weiping Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - David Threadgill
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Ling He
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Daniel Villarreal
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Yuxiang Sun
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Morris F White
- Division of Endocrinology, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Hongting Zheng
- Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Shaodong Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
- Correspondence: Shaodong Guo, PhD, Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, 123A Cater-Mattil Hall, College Station, Texas 77843. E-mail:
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17
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Ghrelin, a gastrointestinal hormone, regulates energy balance and lipid metabolism. Biosci Rep 2018; 38:BSR20181061. [PMID: 30177523 PMCID: PMC6153372 DOI: 10.1042/bsr20181061] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/13/2018] [Accepted: 08/28/2018] [Indexed: 01/06/2023] Open
Abstract
Ghrelin, an acylated peptide hormone of 28 amino acids, is an endogenous ligand of the released growth hormone secretagogue receptor (GHSR). Ghrelin has been isolated from human and rat stomach and is also detected in the hypothalamic arcuate nucleus. Ghrelin receptor is primarily located in the neuropeptide Y and agouti-related protein neurons. Many previous studies have shown that ghrelin and GHSR are involved in the regulation of energy homeostasis, and its administration can increase food intake and body weight gain. AMP-activated protein kinase is activated by ghrelin in the hypothalamus, which contributes to lower intracellular long-chain fatty acid level. Ghrelin appears to modulate the response to food cues via a neural network involved in the regulation of feeding and in the appetitive response to food cues. It also increases the response of brain areas involved in visual processing, attention, and memory to food pictures. Ghrelin is also an important factor linking the central nervous system with peripheral tissues that regulate lipid metabolism. It promotes adiposity by the activation of hypothalamic orexigenic neurons and stimulates the expression of fat storage-related proteins in adipocytes. Meanwhile, ghrelin exerts direct peripheral effects on lipid metabolism, including increase in white adipose tissue mass, stimulation of lipogenesis in the liver, and taste sensitivity modulation.
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18
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Yu AP, Ugwu FN, Tam BT, Lee PH, Lai CW, Wong CSC, Lam WW, Sheridan S, Siu PM. One Year of Yoga Training Alters Ghrelin Axis in Centrally Obese Adults With Metabolic Syndrome. Front Physiol 2018; 9:1321. [PMID: 30294284 PMCID: PMC6158302 DOI: 10.3389/fphys.2018.01321] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 08/31/2018] [Indexed: 12/25/2022] Open
Abstract
Introduction: Metabolic syndrome (MetS) is a multiplex cardiometabolic manifestation associated with type 2 diabetes mellitus and cardiovascular diseases. Yoga training has been shown to alleviate MetS. Recently, circulatory ghrelin profile was demonstrated to be associated with MetS. This study examined the effects of 1 year of yoga training on β-cell function and insulin resistance, and the involvement of metabolic peptides, including unacylated ghrelin (UnAG), acylated ghrelin (AG), obestatin, growth hormone (GH), and insulin, in the beneficial effects of yoga training in centrally obese adults with MetS. Methods: This was a follow up study, in which data of risk factors of MetS, physical performance tests [resting heart rate (HR), chair stand test (CS), chair sit and reach test (CSR), back scratch test (BS), and single leg stand tests (SLS)] and serum samples of 79 centrally obese MetS subjects aged 58 ± 8 years (39 subjects received 1-year yoga training and 40 subjects received no training) were retrieved for analyses. β-cell function and insulin resistance were examined by Homeostasis Model Assessment (HOMA). Circulating levels of UnAG, AG, obestatin, GH, and insulin were determined by enzyme-linked immunosorbent assay using fasting serum samples. Generalized estimating equation analysis and Mann-Whitney U-test were used to detect statistically significant differences between groups. Results: Waist circumference (WC) was significantly decreased after yoga intervention (control: +2%; yoga: -4%). Significant improvements in HR (control: +2%; yoga: -5%), CS (control: -1%; yoga: +24%), CSR left (control: worsen by 0.90 cm; yoga: improved by 4.21 cm), CSR right (control: worsen by 0.75 cm; yoga: improved by 4.28 cm), right side of BS (control: improved by 0.19 cm; yoga: improved by 4.31 cm), SLS left (control: -10%; yoga: +86%), and SLS right (control: -6%; yoga: +47%) were observed after 1-year yoga training. No significant difference was found between the two groups in insulin, HOMA indices, and disposition index. Yoga training significantly increased circulating GH (control: -3%; yoga: +22%), total circulating ghrelin (control: -26%; yoga: +13%), and UnAG (control: -27%; yoga: +14%), whereas decreased AG (control: -7%; yoga: -33%) and obestatin (control: +24%; yoga: -29%). Conclusion: One-year of yoga training modulated total ghrelin, UnAG, AG, obestatin, and GH while exerting beneficial effects on physical functions and central obesity in adults with MetS. The beneficial effects of yoga may be associated with the alteration of ghrelin gene product and GH.
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Affiliation(s)
- Angus P. Yu
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Felix N. Ugwu
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Bjorn T. Tam
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Paul H. Lee
- School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Christopher W. Lai
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Cesar S. C. Wong
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Wendy W. Lam
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Sinead Sheridan
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Parco M. Siu
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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19
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Rahmani E, Akbarzadeh S, Broomand A, Torabi F, Motamed N, Zohrabi M. Serum Levels of Angiopoietin-Like Protein 2 and Obestatin in Iranian Women with Polycystic Ovary Syndrome and Normal Body Mass Index. J Clin Med 2018; 7:jcm7070159. [PMID: 29932432 PMCID: PMC6069096 DOI: 10.3390/jcm7070159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/16/2018] [Accepted: 06/17/2018] [Indexed: 11/16/2022] Open
Abstract
Background: Polycystic ovary syndrome (PCOS) is a common endocrine disease in women of reproduction age and a major cause of anovulatory infertility. Insulin resistance plays an important role in the development and durability of this disorder. ANGPTL2 is known as an inflammatory mediator derived from adipose tissue that links obesity to systemic insulin resistance, and obestatin has been identified as a hormone associated with insulin resistance that suppresses food reabsorption, inhibits gastric emptying and decreases weight gain. The aim of this study was to evaluate serum levels of ANGPTL2 and obestatin in PCOS women with normal body mass index (BMI). Methods: In this case-control study, 26 PCOS women based on the Rotterdam 2003 diagnostic criteria as the case group and 26 women with normal menstrual cycles as the control group were enrolled. Serum levels of ANGPTL2, obestatin, insulin and other hormone factors related with PCOS were measured by ELISA method and biochemical parameters were measured by an autoanalyzer. Data were analyzed by independent samples-T test, Chi Square, Correlation and a single sample Kolmogrov–Smirnov test using SPSS software, version 16. Results: There were no significant variations in the amount of ANGPTL2, obestatin, cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein, cholesterol, creatinine and dehydroepiandrosterone-sulfate between the two groups. There were significant increases in serum levels of fasting blood sugar (p = 0.01), insulin (p = 0.04), homeostasis model assessments of insulin resistance (p = 0.04), testosterone (p = 0.02), luteinizing hormone (p = 0.004), luteinizing hormone/follicle stimulating hormone (p = 0.006) and prolactin (p = 0.04) in case group compared to the control group. A significant positive correlation was observed between ANGPTL2 and insulin (p = 0.02), HOMA-IR (p = 0.01) and, on the other hand, a significant negative correlation was observed between obestatin and insulin (p = 0.01), HOMA-IR (p = 0.008) in PCOS group. Conclusions: In this study, no significant variations were observed in serum levels of ANGPTL2 and obestatin in PCOS women with normal BMI.
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Affiliation(s)
- Elham Rahmani
- Department of Obstetrics and Gynecology, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran.
| | - Samad Akbarzadeh
- Department of Biochemistry, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran.
| | - Ainaz Broomand
- Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran.
| | - Fatemeh Torabi
- Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran.
| | - Niloofar Motamed
- Department of Community Medicine, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran.
| | - Marzieh Zohrabi
- The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences, Bushehr 7514947932, Iran.
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20
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Green BD, Grieve DJ. Biochemical properties and biological actions of obestatin and its relevence in type 2 diabetes. Peptides 2018; 100:249-259. [PMID: 29412827 DOI: 10.1016/j.peptides.2017.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/15/2022]
Abstract
Obestatin was initially discovered in rat stomach extract, and although it is principally produced in the gastric mucosa, it can be found throughout the gastrointestinal tract. This 23-amino acid C-terminally amidated peptide is derived from preproghrelin and has been ascribed a wide range of metabolic effects relevant to type 2 diabetes. Obestatin reportedly inhibits gastrointestinal motility, reduces food intake and lowers body weight and improves lipid metabolism. Furthermore, it appears to exert actions on the pancreatic β-cell, most notably increasing β-cell mass and upregulating genes associated with insulin production and β-cell regeneration, with relevance to type 2 diabetes. It is becoming evident that obestatin also exerts pleiotropic effects on the cardiovascular system, possibly modulating blood pressure, endothelial function and triggering cardioprotective mechanisms, which may be important in determining cardiovascular outcomes in type 2 diabetes. Furthermore, it seems that like other gut peptides obestatin has neuroprotective properties. This review examines the biochemical properties of the obestatin peptide (its structure, sequence, stability and distribution) and the candidate receptors through which it may act. It provides a balanced examination of the reported pancreatic and extrapancreatic actions of obestatin and evaluates its potential relevance with respect to diabetes therapy, together with discussion of direct evidence linking alterations in obestatin signalling with obesity/diabetes and other diseases.
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Affiliation(s)
- Brian D Green
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5BN, UK.
| | - David J Grieve
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, BT9 7AE, UK
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