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Coant N, Rendja K, Bellini L, Flamment M, Lherminier J, Portha B, Codogno P, Le Stunff H. Role of Sphingosine Kinase 1 in Glucolipotoxicity-Induced Early Activation of Autophagy in INS-1 Pancreatic β Cells. Cells 2024; 13:636. [PMID: 38607078 PMCID: PMC11011436 DOI: 10.3390/cells13070636] [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: 10/24/2023] [Revised: 03/04/2024] [Accepted: 03/27/2024] [Indexed: 04/13/2024] Open
Abstract
Insulin-producing pancreatic β cells play a crucial role in the regulation of glucose homeostasis, and their failure is a key event for diabetes development. Prolonged exposure to palmitate in the presence of elevated glucose levels, termed gluco-lipotoxicity, is known to induce β cell apoptosis. Autophagy has been proposed to be regulated by gluco-lipotoxicity in order to favor β cell survival. However, the role of palmitate metabolism in gluco-lipotoxcity-induced autophagy is presently unknown. We therefore treated INS-1 cells for 6 and 24 h with palmitate in the presence of low and high glucose concentrations and then monitored autophagy. Gluco-lipotoxicity induces accumulation of LC3-II levels in INS-1 at 6 h which returns to basal levels at 24 h. Using the RFP-GFP-LC3 probe, gluco-lipotoxicity increased both autophagosomes and autolysosmes structures, reflecting early stimulation of an autophagy flux. Triacsin C, a potent inhibitor of the long fatty acid acetyl-coA synthase, completely prevents LC3-II formation and recruitment to autophagosomes, suggesting that autophagic response requires palmitate metabolism. In contrast, etomoxir and bromo-palmitate, inhibitors of fatty acid mitochondrial β-oxidation, are unable to prevent gluco-lipotoxicity-induced LC3-II accumulation and recruitment to autophagosomes. Moreover, bromo-palmitate and etomoxir potentiate palmitate autophagic response. Even if gluco-lipotoxicity raised ceramide levels in INS-1 cells, ceramide synthase 4 overexpression does not potentiate LC3-II accumulation. Gluco-lipotoxicity also still stimulates an autophagic flux in the presence of an ER stress repressor. Finally, selective inhibition of sphingosine kinase 1 (SphK1) activity precludes gluco-lipotoxicity to induce LC3-II accumulation. Moreover, SphK1 overexpression potentiates autophagic flux induced by gluco-lipotxicity. Altogether, our results indicate that early activation of autophagy by gluco-lipotoxicity is mediated by SphK1, which plays a protective role in β cells.
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Affiliation(s)
- Nicolas Coant
- Unité BFA, Université Paris Cité, CNRS UMR 8251, 75006 Paris, France; (N.C.); (B.P.)
- Department of Pathology and Stony Brook Cancer Center, Stony Brook University Renaissance School of Medicine, Stony Brook, NY 11794, USA
| | - Karima Rendja
- Unité BFA, Université Paris Cité, CNRS UMR 8251, 75006 Paris, France; (N.C.); (B.P.)
| | - Lara Bellini
- Unité BFA, Université Paris Cité, CNRS UMR 8251, 75006 Paris, France; (N.C.); (B.P.)
| | - Mélissa Flamment
- Inserm, UMR-S 872, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - Jeannine Lherminier
- INRA, UMR1347 Agroécologie, ERL CNRS 6300, Plateforme DImaCell, Centre de Microscopie INRA/Université de Bourgogne, 21065 Dijon, France
| | - Bernard Portha
- Unité BFA, Université Paris Cité, CNRS UMR 8251, 75006 Paris, France; (N.C.); (B.P.)
| | - Patrice Codogno
- INSERM U1151-CNRS UMR 8253, Institut Necker Enfants-Malades, University Paris Descartes, 75006 Paris, France
| | - Hervé Le Stunff
- Unité BFA, Université Paris Cité, CNRS UMR 8251, 75006 Paris, France; (N.C.); (B.P.)
- CNRS UMR 9197, Institut des Neurosciences Paris-Saclay, Saclay, University Paris, 91400 Saclay, France
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Lei Y, Yu H, Ding S, Liu H, Liu C, Fu R. Molecular mechanism of ATF6 in unfolded protein response and its role in disease. Heliyon 2024; 10:e25937. [PMID: 38434326 PMCID: PMC10907738 DOI: 10.1016/j.heliyon.2024.e25937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/04/2024] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Activating transcription factor 6 (ATF6), an important signaling molecule in unfolded protein response (UPR), plays a role in the pathogenesis of several diseases, including diseases such as congenital retinal disease, liver fibrosis and ankylosing spondylitis. After endoplasmic reticulum stress (ERS), ATF6 is activated after separation from binding immunoglobulin protein (GRP78/BiP) in the endoplasmic reticulum (ER) and transported to the Golgi apparatus to be hydrolyzed by site 1 and site 2 proteases into ATF6 fragments, which localize to the nucleus and regulate the transcription and expression of ERS-related genes. In these diseases, ERS leads to the activation of UPR, which ultimately lead to the occurrence and development of diseases by regulating the physiological state of cells through the ATF6 signaling pathway. Here, we discuss the evidence for the pathogenic importance of ATF6 signaling in different diseases and discuss preclinical results.
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Affiliation(s)
| | | | - Shaoxue Ding
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Hui Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Chunyan Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Rong Fu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
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Yu Q, Yang Y, Xu T, Cai Y, Yang Z, Yuan F. Palmitoleic acid protects microglia from palmitate-induced neurotoxicity in vitro. PLoS One 2024; 19:e0297031. [PMID: 38241239 PMCID: PMC10798504 DOI: 10.1371/journal.pone.0297031] [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: 10/18/2023] [Accepted: 12/26/2023] [Indexed: 01/21/2024] Open
Abstract
Although palmitoleic acid (POA) is a lipokine with beneficial effects on obesity and is produced as a byproduct from the manufacture of prescription omega-3 fatty acids, its role in nervous system inflammation is still unknown. This study aims to examine the mechanisms and protective effects of POA against palmitic acid (PA)-induced microglial death. PA-induced microglial death was used as a model for POA intervention. Various inhibitors were employed to suppress potential routes of PA entry into the cell. Immunofluorescence staining and Western blotting were conducted to elucidate the protective pathways involved. The results suggest POA has the potential to eliminate PA-induced lactate dehydrogenase (LDH) release, which decreases the overall number of propidium iodide (PI)-positive cells compared with control. Moreover, POA has the potential to significantly increase lipid droplets (LDs) in the cytoplasm, without causing any lysosomal damage. POA inhibited both canonical and non-canonical gasdermin D (GSDMD)-mediated pyroptosis and gasdermin E (GSDME)-mediated pyroptosis, which PA typically induces. Additionally, POA inhibited the endoplasmic reticulum (ER) stress and apoptosis-related proteins induced by PA. Based on the findings, POA can exert a protective effect on microglial death induced by PA via pathways related to pyroptosis, apoptosis, ER stress, and LDs.
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Affiliation(s)
- Qingting Yu
- Department of Pharmacy, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China
| | - Yanzhuo Yang
- Department of Pharmacy, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China
| | - Ting Xu
- Department of Pharmacy, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China
| | | | - Zuisu Yang
- Department of Pharmacy, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China
| | - Falei Yuan
- Department of Pharmacy, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China
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Wei Y, Li J, Li J, Liu C, Guo X, Liu Z, Zhang L, Bao S, Wu X, Su W, Wang X, Zhang J, Dong W. Dietary long-chain fatty acids promote colitis by regulating palmitoylation of STAT3 through CD36-mediated endocytosis. Cell Death Dis 2024; 15:60. [PMID: 38233383 PMCID: PMC10794235 DOI: 10.1038/s41419-024-06456-5] [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: 09/12/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/19/2024]
Abstract
The Western diet, characterized by its high content of long-chain fatty acids (LCFAs), is widely recognized as a significant triggering factor for inflammatory bowel disease (IBD). While the link between a high-fat diet and colitis has been observed, the specific effects and mechanisms remain incompletely understood. Our study provides evidence that the diet rich in LCFAs can disrupt the integrity of the intestinal barrier and exacerbate experimental colitis in mice. Mechanistically, LCFAs upregulate the signal transducer and activator of transcription-3 (STAT3) pathway in the inflammatory model, and STAT3 knockout effectively counters the pro-inflammatory effects of LCFAs on colitis. Specifically, palmitic acid (PA), a representative LCFA, enters intestinal epithelial cells via the cluster of differentiation 36 (CD36) pathway and participates in the palmitoylation cycle of STAT3. Inhibiting this cycle using pharmacological inhibitors like 2-Bromopalmitate (2-BP) and ML349, as well as DHHC7 knockdown, has the ability to alleviate inflammation induced by PA. These findings highlight the significant role of dietary LCFAs, especially PA, in the development and progression of IBD. Diet adjustments and targeted modulation offer potential therapeutic strategies for managing this condition. Model of LCFAs involvement in the palmitoylation cycle of STAT3 upon internalization into cells. Following cellular uptake through CD36, LCFAs are converted to palmitoyl-CoA. In the presence of DHHC7, palmitoyl-CoA binds to STAT3 at the C108 site, forming palmitoylated STAT3. Palmitoylation further promotes phosphorylation at the Y705 site of STAT3. Subsequently, palmitoylated STAT3 undergoes depalmitoylation by APT2 and translocates to the nucleus to exert its biological functions.
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Affiliation(s)
- Yuping Wei
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Jinting Li
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Jiao Li
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Chuan Liu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
| | - Xingzhou Guo
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Zhengru Liu
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Luyun Zhang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Shenglan Bao
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Xiaohan Wu
- Key Laboratory of Hubei Province for Digestive System Disease, Wuhan, Hubei Province, China
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Wenhao Su
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Xiaoli Wang
- Department of Plastic Surgery, Renmin hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Jixiang Zhang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
| | - Weiguo Dong
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
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Liu Y, Wang D, Liu YP. Metabolite profiles of diabetes mellitus and response to intervention in anti-hyperglycemic drugs. Front Endocrinol (Lausanne) 2023; 14:1237934. [PMID: 38027178 PMCID: PMC10644798 DOI: 10.3389/fendo.2023.1237934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) has become a major health problem, threatening the quality of life of nearly 500 million patients worldwide. As a typical multifactorial metabolic disease, T2DM involves the changes and interactions of various metabolic pathways such as carbohydrates, amino acid, and lipids. It has been suggested that metabolites are not only the endpoints of upstream biochemical processes, but also play a critical role as regulators of disease progression. For example, excess free fatty acids can lead to reduced glucose utilization in skeletal muscle and induce insulin resistance; metabolism disorder of branched-chain amino acids contributes to the accumulation of toxic metabolic intermediates, and promotes the dysfunction of β-cell mitochondria, stress signal transduction, and apoptosis. In this paper, we discuss the role of metabolites in the pathogenesis of T2DM and their potential as biomarkers. Finally, we list the effects of anti-hyperglycemic drugs on serum/plasma metabolic profiles.
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Affiliation(s)
| | | | - Yi-Ping Liu
- Provincial University Key Laboratory of Sport and Health Science, School of Physical Education and Sport Sciences, Fujian Normal University, Fuzhou, China
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Kim JW, Roh E, Choi KM, Yoo HJ, Hwang HJ, Baik SH. GPR40 Agonism Modulates Inflammatory Reactions in Vascular Endothelial Cells. Diabetes Metab J 2022; 46:506-511. [PMID: 35067013 PMCID: PMC9171169 DOI: 10.4093/dmj.2021.0092] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 12/04/2022] Open
Abstract
Endothelial dysfunction is strongly linked with inflammatory responses, which can impact cardiovascular disease. Recently, G protein-coupled receptor 40 (GPR40) has been investigated as a modulator of metabolic stress; however, the function of GPR40 in vascular endothelial cells has not been reported. We analyzed whether treatment of GPR40-specific agonists modulated the inflammatory responses in human umbilical vein endothelial cells (HUVECs). Treatment with LY2922470, a GPR40 agonist, significantly reduced lipopolysaccharide (LPS)-mediated nuclear factor-kappa B (NF-κB) phosphorylation and movement into the nucleus from the cytosol. However, treatment with another GPR40 agonist, TAK875, did not inhibit LPS-induced NF-κB activation. LPS treatment induced expression of adhesion molecules vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and attachment of THP-1 cells to HUVECs, which were all decreased by LY2922470 but not TAK875. Our results showed that ligand-dependent agonism of GPR40 is a promising therapeutic target for overcoming inflammatory reactions in the endothelium.
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Affiliation(s)
- Joo Won Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Korea
| | - Eun Roh
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Kyung Mook Choi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Hye Jin Yoo
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Hwan-Jin Hwang
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Korea
| | - Sei Hyun Baik
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
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Cyanidin-3-O-Glucoside Ameliorates Palmitic-Acid-Induced Pancreatic Beta Cell Dysfunction by Modulating CHOP-Mediated Endoplasmic Reticulum Stress Pathways. Nutrients 2022; 14:nu14091835. [PMID: 35565803 PMCID: PMC9103664 DOI: 10.3390/nu14091835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/23/2022] [Accepted: 04/24/2022] [Indexed: 11/17/2022] Open
Abstract
Cyanidin-3-O-glucoside (C3G) is a natural colorant with anti-diabetic properties, while its underlying mechanisms remain far from clear. Here, we investigated the protective role of C3G on palmitic acid (PA)-induced pancreatic beta cell dysfunction and further decipher its possible molecular mechanisms. Both primary isolated mouse islets and the INS-1E cell were used, and treated with a mixture of PA (0.5 mM) and C3G (12.5 µM, 25 µM, 50 µM) for different durations (12, 24, 48 h). We found that C3G could dose-dependently ameliorate beta cell secretory function and further alleviate cell apoptosis. Mechanistically, the primary role of the PKR-like ER kinase (PERK) endoplasmic reticulum (ER) stress pathway was detected by RNA sequencing, and the PERK-pathway-related protein expression, especially the pro-apoptotic marker C/EBP homologous protein (CHOP) expression, was significantly downregulated by C3G treatment. The critical role of CHOP in mediating the protective effect of C3G was further validated by small interfering RNA. Conclusively, C3G could ameliorate PA-induced pancreatic beta cell dysfunction targeting the CHOP-related ER stress pathway, which might be used as a nutritional intervention for the preservation of beta cell dysfunction in type 2 diabetes mellitus.
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Zhao YF. Free fatty acid receptors in the endocrine regulation of glucose metabolism: Insight from gastrointestinal-pancreatic-adipose interactions. Front Endocrinol (Lausanne) 2022; 13:956277. [PMID: 36246919 PMCID: PMC9554507 DOI: 10.3389/fendo.2022.956277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/14/2022] [Indexed: 11/25/2022] Open
Abstract
Glucose metabolism is primarily controlled by pancreatic hormones, with the coordinated assistance of the hormones from gastrointestine and adipose tissue. Studies have unfolded a sophisticated hormonal gastrointestinal-pancreatic-adipose interaction network, which essentially maintains glucose homeostasis in response to the changes in substrates and nutrients. Free fatty acids (FFAs) are the important substrates that are involved in glucose metabolism. FFAs are able to activate the G-protein coupled membrane receptors including GPR40, GPR120, GPR41 and GPR43, which are specifically expressed in pancreatic islet cells, enteroendocrine cells as well as adipocytes. The activation of FFA receptors regulates the secretion of hormones from pancreas, gastrointestine and adipose tissue to influence glucose metabolism. This review presents the effects of the FFA receptors on glucose metabolism via the hormonal gastrointestinal-pancreatic-adipose interactions and the underlying intracellular mechanisms. Furthermore, the development of therapeutic drugs targeting FFA receptors for the treatment of abnormal glucose metabolism such as type 2 diabetes mellitus is summarized.
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Oberhauser L, Maechler P. Lipid-Induced Adaptations of the Pancreatic Beta-Cell to Glucotoxic Conditions Sustain Insulin Secretion. Int J Mol Sci 2021; 23:324. [PMID: 35008750 PMCID: PMC8745448 DOI: 10.3390/ijms23010324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 12/16/2022] Open
Abstract
Over the last decades, lipotoxicity and glucotoxicity emerged as established mechanisms participating in the pathophysiology of obesity-related type 2 diabetes in general, and in the loss of β-cell function in particular. However, these terms hold various potential biological processes, and it is not clear what precisely they refer to and to what extent they might be clinically relevant. In this review, we discuss the basis and the last advances of research regarding the role of free fatty acids, their metabolic intracellular pathways, and receptor-mediated signaling related to glucose-stimulated insulin secretion, as well as lipid-induced β-cell dysfunction. We also describe the role of chronically elevated glucose, namely, glucotoxicity, which promotes failure and dedifferentiation of the β cell. Glucolipotoxicity combines deleterious effects of exposures to both high glucose and free fatty acids, supposedly provoking synergistic defects on the β cell. Nevertheless, recent studies have highlighted the glycerolipid/free fatty acid cycle as a protective pathway mediating active storage and recruitment of lipids. Finally, we discuss the putative correspondence of the loss of functional β cells in type 2 diabetes with a natural, although accelerated, aging process.
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Affiliation(s)
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, Faculty Diabetes Center, University of Geneva Medical Center, 1206 Geneva, Switzerland;
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Urso C, Zhou H. Palmitic Acid Lipotoxicity in Microglia Cells Is Ameliorated by Unsaturated Fatty Acids. Int J Mol Sci 2021; 22:ijms22169093. [PMID: 34445796 PMCID: PMC8396597 DOI: 10.3390/ijms22169093] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 01/04/2023] Open
Abstract
Obesity and metabolic syndrome are associated with cognitive decline and dementia. Palmitic acid (PA) is increased in the cerebrospinal fluid of obese patients with cognitive impairment. This study was therefore designed to examine fatty acid (FA) lipotoxicity in BV2 microglia cells. We found that PA induced time- and dose-dependent decrease in cell viability and increase in cell death without affecting the cell cycle profile and that PA lipotoxicity did not depend on cell surface free fatty acid receptors but rather on FA uptake. Treatment with sulfosuccinimidyl oleate (SSO), an irreversible inhibitor of fatty acid translocase CD36, significantly inhibited FA uptake in BSA- and PA-treated cells and blocked PA-induced decrease in cell viability. Inhibition of ER stress or treatment with N-acetylcysteine was not able to rescue PA lipotoxicity. Our study also showed that unsaturated fatty acids (UFAs), such as linoleic acid (LA), oleic acid (OA), α-linolenic acid (ALA), and docosahexaenoic acid (DHA), were not lipotoxic but instead protected microglia against PA-induced decrease in cell viability. Co-treatment of PA with LA, OA, and DHA significantly inhibited FA uptake in PA-treated cells. All UFAs tested induced the incorporation of FAs into and the amount of neutral lipids, while PA did not significantly affect the amount of neutral lipids compared with BSA control.
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Nunes Marsiglio-Librais G, Aparecida Vilas-Boas E, Carlein C, Hoffmann MDA, Roma LP, Carpinelli AR. Evidence for NADPH oxidase activation by GPR40 in pancreatic β-cells. Redox Rep 2021; 25:41-50. [PMID: 32354273 PMCID: PMC7241480 DOI: 10.1080/13510002.2020.1757877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Objective: Investigate the involvement of the fatty acids receptor GPR40 in the assembly and activation of NADPH oxidase and the implications on pancreatic β-cell function. Methods: BRIN-BD11 β-cells were exposed to GPR40 agonist (GW9508) or linoleic acid in different glucose concentrations. Superoxide and H2O2 were analyzed, respectively, by DHE fluorescence and by fluorescence of the H2O2 sensor, roGFP2-Orp1. Protein contents of p47phox in plasma membrane and cytosol were analyzed by western blot. NADPH oxidase role was evaluated by p22phox siRNA or by pharmacological inhibition with VAS2870. NOX2 KO islets were used to measure total cytosolic calcium and insulin secretion. Results: GW9508 and linoleic acid increased superoxide and H2O2 contents at 5.6 and 8.3 mM of glucose. In addition, in 5.6 mM, but not at 16.7 mM of glucose, activation of GPR40 led to the translocation of p47phox to the plasma membrane. Knockdown of p22phox abolished the increase in superoxide after GW9508 and linoleic acid. No differences in insulin secretion were found between wild type and NOX2 KO islets treated with GW9508 or linoleic acid. Discussion: We report for the first time that acute activation of GPR40 leads to NADPH oxidase activation in pancreatic β-cells, without impact on insulin secretion.
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Affiliation(s)
| | - Eloisa Aparecida Vilas-Boas
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, Brazil.,Department of Biophysics, Center for Human and Molecular Biology, CIPMM, Saarland University, Homburg/Saar, Germany
| | - Christopher Carlein
- Department of Biophysics, Center for Human and Molecular Biology, CIPMM, Saarland University, Homburg/Saar, Germany
| | | | - Leticia Prates Roma
- Department of Biophysics, Center for Human and Molecular Biology, CIPMM, Saarland University, Homburg/Saar, Germany
| | - Angelo Rafael Carpinelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, Brazil
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Huang JS, Guo BB, Wang GH, Zeng LM, Hu YH, Wang T, Wang HY. DGAT1 inhibitors protect pancreatic β-cells from palmitic acid-induced apoptosis. Acta Pharmacol Sin 2021; 42:264-271. [PMID: 32737468 DOI: 10.1038/s41401-020-0482-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 07/14/2020] [Indexed: 12/24/2022] Open
Abstract
Previous studies demonstrated that prolonged exposure to elevated levels of free fatty acids (FFA), especially saturated fatty acids, could lead to pancreatic β-cell apoptosis, which plays an important role in the progression of type 2 diabetes (T2D). Diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the final step of triglyceride (TG) synthesis, has been reported as a novel target for the treatment of multiple metabolic diseases. In this study we evaluated the potential beneficial effects of DGAT1 inhibitors on pancreatic β-cells, and further verified their antidiabetic effects in db/db mice. We showed that DGAT1 inhibitors (4a and LCQ908) at the concentration of 1 μM significantly ameliorated palmitic acid (PA)-induced apoptosis in MIN6 pancreatic β-cells and primary cultured mouse islets; oral administration of a DGAT1 inhibitor (4a) (100 mg/kg) for 4 weeks significantly reduced the apoptosis of pancreatic islets in db/db mice. Meanwhile, 4a administration significantly decreased fasting blood glucose and TG levels, and improved glucose tolerance and insulin tolerance in db/db mice. Furthermore, we revealed that pretreatment with 4a (1 μM) significantly alleviated PA-induced intracellular lipid accumulation, endoplasmic reticulum (ER) stress, and proinflammatory responses in MIN6 cells, which might contribute to the protective effects of DGAT1 inhibitors on pancreatic β-cells. These findings provided a better understanding of the antidiabetic effects of DGAT1 inhibitors.
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Vilas-Boas EA, Karabacz N, Marsiglio-Librais GN, Valle MMR, Nalbach L, Ampofo E, Morgan B, Carpinelli AR, Roma LP. Chronic activation of GPR40 does not negatively impact upon BRIN-BD11 pancreatic β-cell physiology and function. Pharmacol Rep 2020; 72:1725-1737. [PMID: 32274767 PMCID: PMC7704488 DOI: 10.1007/s43440-020-00101-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/18/2020] [Accepted: 03/21/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Free fatty acids (FFAs) are known for their dual effects on insulin secretion and pancreatic β-cell survival. Short-term exposure to FFAs, such as palmitate, increases insulin secretion. On the contrary, long-term exposure to saturated FFAs results in decreased insulin secretion, as well as triggering oxidative stress and endoplasmic reticulum (ER) stress, culminating in cell death. The effects of FFAs can be mediated either via their intracellular oxidation and consequent effects on cellular metabolism or via activation of the membrane receptor GPR40. Both pathways are likely to be activated upon both short- and long-term exposure to FFAs. However, the precise role of GPR40 in β-cell physiology, especially upon chronic exposure to FFAs, remains unclear. METHODS We used the GPR40 agonist (GW9508) and antagonist (GW1100) to investigate the impact of chronically modulating GPR40 activity on BRIN-BD11 pancreatic β-cells physiology and function. RESULTS We observed that chronic activation of GPR40 did not lead to increased apoptosis, and both proliferation and glucose-induced calcium entry were unchanged compared to control conditions. We also observed no increase in H2O2 or superoxide levels and no increase in the ER stress markers p-eIF2α, CHOP and BIP. As expected, palmitate led to increased H2O2 levels, decreased cell viability and proliferation, as well as decreased metabolism and calcium entry. These changes were not counteracted by the co-treatment of palmitate-exposed cells with the GPR40 antagonist GW1100. CONCLUSIONS Chronic activation of GPR40 using GW9508 does not negatively impact upon BRIN-BD11 pancreatic β-cells physiology and function. The GPR40 antagonist GW1100 does not protect against the deleterious effects of chronic palmitate exposure. We conclude that GPR40 is probably not involved in mediating the toxicity associated with chronic palmitate exposure.
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Affiliation(s)
- Eloisa Aparecida Vilas-Boas
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo (USP), Sao Paulo, SP, Brazil.,Department of Biophysics, Center for Human and Molecular Biology, Saarland University, Universität Des Saarlandes, CIPMM, Geb. 48, 66421, Homburg/Saar, Germany
| | - Noémie Karabacz
- Department of Biophysics, Center for Human and Molecular Biology, Saarland University, Universität Des Saarlandes, CIPMM, Geb. 48, 66421, Homburg/Saar, Germany
| | | | - Maíra Melo Rezende Valle
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo (USP), Sao Paulo, SP, Brazil
| | - Lisa Nalbach
- Institute for Clinical and Experimental Surgery, Saarland University, 66421, Homburg/Saar, Germany
| | - Emmanuel Ampofo
- Institute for Clinical and Experimental Surgery, Saarland University, 66421, Homburg/Saar, Germany
| | - Bruce Morgan
- Institute of Biochemistry, Center for Human and Molecular Biology (ZHMB), Saarland University, 66123, Saarbrücken, Germany
| | - Angelo Rafael Carpinelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo (USP), Sao Paulo, SP, Brazil
| | - Leticia Prates Roma
- Department of Biophysics, Center for Human and Molecular Biology, Saarland University, Universität Des Saarlandes, CIPMM, Geb. 48, 66421, Homburg/Saar, Germany.
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14
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Lee EJ, Chiang WCJ, Kroeger H, Bi CX, Chao DL, Skowronska-Krawczyk D, Mastey RR, Tsang SH, Chea L, Kim K, Lambert SR, Grandjean JM, Baumann B, Audo I, Kohl S, Moore AT, Wiseman RL, Carroll J, Lin JH. Multiexon deletion alleles of ATF6 linked to achromatopsia. JCI Insight 2020; 5:136041. [PMID: 32271167 PMCID: PMC7205249 DOI: 10.1172/jci.insight.136041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/04/2020] [Indexed: 12/20/2022] Open
Abstract
Achromatopsia (ACHM) is an autosomal recessive disease that results in severe visual loss. Symptoms of ACHM include impaired visual acuity, nystagmus, and photoaversion starting from infancy; furthermore, ACHM is associated with bilateral foveal hypoplasia and absent or severely reduced cone photoreceptor function on electroretinography. Here, we performed genetic sequencing in 3 patients from 2 families with ACHM, identifying and functionally characterizing 2 mutations in the activating transcription factor 6 (ATF6) gene. We identified a homozygous deletion covering exons 8-14 of the ATF6 gene from 2 siblings from the same family. In another patient from a different family, we identified a heterozygous deletion covering exons 2 and 3 of the ATF6 gene found in trans with a previously identified ATF6 c.970C>T (p.Arg324Cys) ACHM disease allele. Recombinant ATF6 proteins bearing these exon deletions showed markedly impaired transcriptional activity by qPCR and RNA-Seq analysis compared with WT-ATF6. Finally, RNAscope revealed that ATF6 and the related ATF6B transcripts were expressed in cones as well as in all retinal layers in normal human retina. Overall, our data identify loss-of-function ATF6 disease alleles that cause human foveal disease.
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Affiliation(s)
- Eun-Jin Lee
- Department of Ophthalmology, Shiley Eye Institute, and
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Wei-Chieh Jerry Chiang
- Department of Pathology, UCSD, San Diego, California, USA
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Heike Kroeger
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | | | | | | | - Rebecca R. Mastey
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Stephen H. Tsang
- Departments of Ophthalmology and Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Leon Chea
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Kyle Kim
- Department of Pathology, UCSD, San Diego, California, USA
| | - Scott R. Lambert
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Julia M.D. Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC1423, Paris, France
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Anthony T. Moore
- Department of Ophthalmology, UCSF, San Francisco, California, USA
| | - R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jonathan H. Lin
- Department of Ophthalmology, Stanford University, Stanford, California, USA
- Department of Pathology, Stanford University, Stanford, California, USA
- VA Palo Alto Healthcare System, Palo Alto, California, USA
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15
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Shen X, Fan B, Hu X, Luo L, Yan Y, Yang L. Metformin Reduces Lipotoxicity-Induced Meta-Inflammation in β-Cells through the Activation of GPR40-PLC-IP3 Pathway. J Diabetes Res 2019; 2019:7602427. [PMID: 31950065 PMCID: PMC6948338 DOI: 10.1155/2019/7602427] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/01/2019] [Accepted: 09/04/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Metformin, a widely used antidiabetic drug, has been shown to have anti-inflammatory properties; nevertheless, its influence on β-cell meta-inflammation remains unclear. The following study investigated the effects of metformin on meta-inflammatory in β-cells and whether the underlying mechanisms were associated with the G protein-coupled receptor 40-phospholipase C-inositol 1, 4, 5-trisphosphate (GPR40-PLC-IP3) pathway. MATERIALS AND METHODS Lipotoxicity-induced β-cells and the high-fat diet-induced obese rat model were used in the study. RESULTS Metformin-reduced lipotoxicity-induced β-cell meta-inflammatory injury was associated with the expression of GPR40. GPR40 was involved in metformin reversing metabolic inflammation key marker TLR4 activation-mediated β-cell injury. Furthermore, downstream signaling protein PLC-IP3 of GPR40 was involved in the protective effect of metformin on meta-inflammation, and the above process of metformin was partially regulated by AMPK activity. In addition, the anti-inflammatory effects of metformin were observed in obese rats. CONCLUSION Metformin can reduce lipotoxicity-induced meta-inflammation in β-cells through the regulation of the GPR40-PLC-IP3 pathway and partially via the regulation of AMPK activity.
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Affiliation(s)
- Ximei Shen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
| | - Beibei Fan
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Xin Hu
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Liufen Luo
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Yuanli Yan
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Liyong Yang
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
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16
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Chen X, Yan Y, Weng Z, Chen C, Lv M, Lin Q, Du Q, Shen X, Yang L. TAK-875 Mitigates β-Cell Lipotoxicity-Induced Metaflammation Damage through Inhibiting the TLR4-NF- κB Pathway. J Diabetes Res 2019; 2019:5487962. [PMID: 31934590 PMCID: PMC6942802 DOI: 10.1155/2019/5487962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 09/03/2019] [Indexed: 01/09/2023] Open
Abstract
Metabolic inflammatory damage, characterized by Toll-like receptor 4 (TLR4) signaling activation, is a major mechanism underlying lipotoxicity-induced β-cell damage. The present study is aimed at determining whether G protein-coupled receptor 4 (GPR40) agonist can improve β-cell lipotoxicity-induced damage by inhibiting the TLR4-NF-κB pathway. Lipotoxicity, inflammation-damaged β-cells, obese SD, and TLR4KO rat models were used in the study. In vitro, TAK-875 inhibited the lipotoxicity- and LPS-induced β-cell apoptosis in a concentration-dependent manner, improved the insulin secretion, and inhibited the expression of TLR4 and NF-κB subunit P65. Besides, silencing of TLR4 expression enhanced the protective effects of TAK-875, while TLR4 overexpression attenuated this protective effect. Activation of TLR4 or NF-κB attenuated the antagonism of TAK-875 on PA-induced damage. Moreover, the above process of TAK-875 was partially independent of GPR40 expression. TAK-875 reduced the body weight and inflammatory factors, rebalanced the number and distribution of α or β-cells, inhibited the apoptosis of islet cells, and inhibited the expression of TLR4 and NF-κB subunit P65 in obese rats. Further knockout of the rat TLR4 gene delayed the damage induced by the high-fat diet and synergy with the action of TAK-875. These data suggest that GPR40 agonists antagonized the lipotoxicity β-cell damage by inhibiting the TLR4-NF-κB pathway.
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Affiliation(s)
- Xide Chen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Yuanli Yan
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Zhiyan Weng
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Chao Chen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Miaoru Lv
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Qingwen Lin
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Qiuxia Du
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
| | - Ximei Shen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
| | - Liyong Yang
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 Fujian, China
- Diabetes Research Institute of Fujian Province, Fuzhou, 350005 Fujian, China
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17
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Sargsyan E, Cen J, Roomp K, Schneider R, Bergsten P. Identification of early biological changes in palmitate-treated isolated human islets. BMC Genomics 2018; 19:629. [PMID: 30134843 PMCID: PMC6106933 DOI: 10.1186/s12864-018-5008-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 08/14/2018] [Indexed: 12/13/2022] Open
Abstract
Background Long-term exposure to elevated levels of free fatty acids (FFAs) is deleterious for beta-cell function and may contribute to development of type 2 diabetes mellitus (T2DM). Whereas mechanisms of impaired glucose-stimulated insulin secretion (GSIS) in FFA-treated beta-cells have been intensively studied, biological events preceding the secretory failure, when GSIS is accentuated, are poorly investigated. To identify these early events, we performed genome-wide analysis of gene expression in isolated human islets exposed to fatty acid palmitate for different time periods. Results Palmitate-treated human islets showed decline in beta-cell function starting from day two. Affymetrix Human Transcriptome Array 2.0 identified 903 differentially expressed genes (DEGs). Mapping of the genes onto pathways using KEGG pathway enrichment analysis predicted four islet biology-related pathways enriched prior but not after the decline of islet function and three pathways enriched both prior and after the decline of islet function. DEGs from these pathways were analyzed at the transcript level. The results propose that in palmitate-treated human islets, at early time points, protective events, including up-regulation of metallothioneins, tRNA synthetases and fatty acid-metabolising proteins, dominate over deleterious events, including inhibition of fatty acid detoxification enzymes, which contributes to the enhanced GSIS. After prolonged exposure of islets to palmitate, the protective events are outweighed by the deleterious events, which leads to impaired GSIS. Conclusions The study identifies temporal order between different cellular events, which either promote or protect from beta-cell failure. The sequence of these events should be considered when developing strategies for prevention and treatment of the disease. Electronic supplementary material The online version of this article (10.1186/s12864-018-5008-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ernest Sargsyan
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123, Uppsala, Sweden. .,Molecular Neuroscience Group, Institute of Molecular Biology, National Academy of Sciences, 0014, Yerevan, Armenia.
| | - Jing Cen
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123, Uppsala, Sweden
| | - Kirsten Roomp
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Campus Belval, 7 avenue des Hauts fourneaux, 4362 Esch-Belval, Luxembourg City, Luxembourg
| | - Reinhard Schneider
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Campus Belval, 7 avenue des Hauts fourneaux, 4362 Esch-Belval, Luxembourg City, Luxembourg
| | - Peter Bergsten
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123, Uppsala, Sweden
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18
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Recio C, Lucy D, Iveson P, Iqbal AJ, Valaris S, Wynne G, Russell AJ, Choudhury RP, O'Callaghan C, Monaco C, Greaves DR. The Role of Metabolite-Sensing G Protein-Coupled Receptors in Inflammation and Metabolic Disease. Antioxid Redox Signal 2018; 29:237-256. [PMID: 29117706 DOI: 10.1089/ars.2017.7168] [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] [Indexed: 12/12/2022]
Abstract
SIGNIFICANCE Great attention has been placed on the link between metabolism and immune function giving rise to the term "immunometabolism." It is widely accepted that inflammation and oxidative stress are key processes that underlie metabolic complications during obesity, diabetes, and atherosclerosis. Therefore, identifying the mechanisms and mediators that are involved in the regulation of both inflammation and metabolic homeostasis is of high scientific and therapeutic interest. Recent Advances: G protein-coupled receptors (GPCRs) that signal in response to metabolites have emerged as attractive therapeutic targets in inflammatory disease. Critical Issues and Future Directions: In this review, we discuss recent findings about the physiological role of the main metabolite-sensing GPCRs, their implication in immunometabolic disorders, their principal endogenous and synthetic ligands, and their potential as drug targets in inflammation and metabolic disease. Antioxid. Redox Signal. 29, 237-256.
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Affiliation(s)
- Carlota Recio
- 1 Sir William Dunn School of Pathology, University of Oxford , Oxford, Great Britain
| | - Daniel Lucy
- 2 Department of Chemistry, University of Oxford , Oxford, Great Britain
| | - Poppy Iveson
- 1 Sir William Dunn School of Pathology, University of Oxford , Oxford, Great Britain
| | - Asif J Iqbal
- 1 Sir William Dunn School of Pathology, University of Oxford , Oxford, Great Britain
| | - Sophia Valaris
- 1 Sir William Dunn School of Pathology, University of Oxford , Oxford, Great Britain
| | - Graham Wynne
- 2 Department of Chemistry, University of Oxford , Oxford, Great Britain
| | - Angela J Russell
- 2 Department of Chemistry, University of Oxford , Oxford, Great Britain
| | - Robin P Choudhury
- 3 Radcliffe Department of Medicine, University of Oxford , Oxford, Great Britain
| | - Chris O'Callaghan
- 4 Nuffield Department of Medicine, University of Oxford , Oxford, Great Britain
| | - Claudia Monaco
- 5 Kennedy Institute for Rheumatology, University of Oxford , Oxford, Great Britain
| | - David R Greaves
- 1 Sir William Dunn School of Pathology, University of Oxford , Oxford, Great Britain
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19
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Fatty Acid-Stimulated Insulin Secretion vs. Lipotoxicity. Molecules 2018; 23:molecules23061483. [PMID: 29921789 PMCID: PMC6100479 DOI: 10.3390/molecules23061483] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 12/29/2022] Open
Abstract
Fatty acid (FA)-stimulated insulin secretion (FASIS) is reviewed here in contrast to type 2 diabetes etiology, resulting from FA overload, oxidative stress, intermediate hyperinsulinemia, and inflammation, all converging into insulin resistance. Focusing on pancreatic islet β-cells, we compare the physiological FA roles with the pathological ones. Considering FAs not as mere amplifiers of glucose-stimulated insulin secretion (GSIS), but as parallel insulin granule exocytosis inductors, partly independent of the KATP channel closure, we describe the FA initiating roles in the prediabetic state that is induced by retardations in the glycerol-3-phosphate (glucose)-promoted glycerol/FA cycle and by the impaired GPR40/FFA1 (free FA1) receptor pathway, specifically in its amplification by the redox-activated mitochondrial phospholipase, iPLA2γ. Also, excessive dietary FAs stimulate intestine enterocyte incretin secretion, further elevating GSIS, even at low glucose levels, thus contributing to diabetic hyperinsulinemia. With overnutrition and obesity, the FA overload causes impaired GSIS by metabolic dysbalance, paralleled by oxidative and metabolic stress, endoplasmic reticulum stress and numerous pro-apoptotic signaling, all leading to decreased β-cell survival. Lipotoxicity is exerted by saturated FAs, whereas ω-3 polyunsaturated FAs frequently exert antilipotoxic effects. FA-facilitated inflammation upon the recruitment of excess M1 macrophages into islets (over resolving M2 type), amplified by cytokine and chemokine secretion by β-cells, leads to an inevitable failure of pancreatic β-cells.
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20
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El Ayed M, Kadri S, Smine S, Elkahoui S, Limam F, Aouani E. Protective effects of grape seed and skin extract against high-fat-diet-induced lipotoxicity in rat lung. Lipids Health Dis 2017; 16:174. [PMID: 28903761 PMCID: PMC5598067 DOI: 10.1186/s12944-017-0561-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 09/04/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Obesity is a public health problem characterized by increased fat accumulation in different tissues. Obesity is directly linked to breathing problems and medical complications with lung, including obstructive sleep apnea syndrome, obesity hypoventilation syndrome, chronic obstructive pulmonary disease, asthma….In the present work, we aimed to investigate the effect of high fat diet (HFD) on lung lipotoxicity, oxidative stress, fatty acid composition and proportions in lung and implication in asthma development. The likely protection provided by grape seed extract (GSSE) was also investigated. METHODS In order to assess HFD effect on lung and GSSE protection we used a rat model. We analyzed the lipid plasma profile, lung peroxidation and antioxidant activities (SOD, CAT and POD). We also analyzed transition metals (Ca2+, Mg2+, Zn2+ and iron) and lung free fatty acids using gas chromatography coupled to mass spectrometry (GC-MS). RESULTS HFD induced lipid profile imbalance increasing cholesterol and VLDL-C. HFD also induced an oxidative stress assessed by elevated MDA level and the drop of antioxidant activities such as SOD, CAT and POD. Moreover, HFD induced mineral disturbances by decreasing magnesium level and increasing Calcium and iron levels. HFD induced also disturbances in lung fatty acid composition by increasing oleic, stearic and arachidonic acids. Interestingly, GSSE alleviated all these deleterious effects of HFD treatment. CONCLUSION As a whole, GSSE had a significant preventive effect against HFD-induced obesity, and hence may be used as an anti-obesity agent, and a benefic agent with potential applications against damages in lung tissue.
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Affiliation(s)
- Mohamed El Ayed
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia.
| | - Safwen Kadri
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia
| | - Selima Smine
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia.,Proteomic Platform PISSARO, Institut de Recherche et d'Innovation Biomédicale (IRIB), University of Rouen, 76821, Mont Saint Aignan, Cedex, France
| | - Salem Elkahoui
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia
| | - Ferid Limam
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia
| | - Ezzedine Aouani
- Bioactive Substances Laboratory, Biotechnology Centre, Technopolis Borj-Cedria, BP-901, 2050, Hammam-Lif, Tunisia
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21
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Krizhanovskii C, Fred RG, Oskarsson ME, Westermark GT, Welsh N. Addition of exogenous sodium palmitate increases the IAPP/insulin mRNA ratio via GPR40 in human EndoC-βH1 cells. Ups J Med Sci 2017; 122:149-159. [PMID: 28980863 PMCID: PMC5649320 DOI: 10.1080/03009734.2017.1368745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Enhanced IAPP production may contribute to islet amyloid formation in type 2 diabetes. The objective of this study was to determine the effects of the saturated fatty acid palmitate on IAPP levels in human β-cells. METHODS EndoC-βH1 cells and human islets were cultured in the presence of sodium palmitate. Effects on IAPP/insulin mRNA expression and secretion were determined using real-time qPCR/ELISA. Pharmacological activators and/or inhibitors and RNAi were used to determine the underlying mechanisms. RESULTS We observed that EndoC-βH1 cells exposed to palmitate for 72 h displayed decreased expression of Pdx-1 and MafA and increased expression of thioredoxin-interacting protein (TXNIP), reduced insulin mRNA expression and glucose-induced insulin secretion, as well as increased IAPP mRNA expression and secretion. Further, these effects were independent of fatty acid oxidation, but abolished in response to GPR40 inhibition/downregulation. In human islets both a high glucose concentration and palmitate promoted increased IAPP mRNA levels, resulting in an augmented IAPP/insulin mRNA ratio. This was paralleled by elevated IAPP/insulin protein secretion and content ratios. CONCLUSIONS Addition of exogenous palmitate to human β-cells increased the IAPP/insulin expression ratio, an effect contributed to by activation of GPR40. These findings may be pertinent to our understanding of the islet amyloid formation process.
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Affiliation(s)
- Camilla Krizhanovskii
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden;
- Södertälje Hospital, Department of Internal Medicine, Södertälje, Sweden
- CONTACT Camilla Krizhanovskii Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Box 571, SE-751 23 Uppsala, Sweden
| | - Rikard G. Fred
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden;
| | - Marie E. Oskarsson
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden;
| | - Gunilla T. Westermark
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden;
| | - Nils Welsh
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden;
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22
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Qian J, Gu Y, Wu C, Yu F, Chen Y, Zhu J, Yao X, Bei C, Zhu Q. Agonist-induced activation of human FFA1 receptor signals to extracellular signal-regulated kinase 1 and 2 through Gq- and Gi-coupled signaling cascades. Cell Mol Biol Lett 2017; 22:13. [PMID: 28747926 PMCID: PMC5522598 DOI: 10.1186/s11658-017-0043-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 07/07/2017] [Indexed: 12/18/2022] Open
Abstract
Background FFA1 is abundantly expressed in the liver, skeletal muscle, monocytes and nervous system, but is particularly abundant in pancreatic β cells. It is widely believed that FFA1 exerts its regulatory roles in a variety of physiological and pathological functions. In response to oleic acid, FFA1 has been shown to induce the activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) through a mechanism involving EGFR transactivation in a breast cancer cell line. However, the underlying molecular mechanism for ERK1/2 activation mediated by n-6 free fatty acid (LA) in HEK293 cells remains to be further elucidated. Methods A FLAG-FFA1 vector was stably expressed in HEK293 cells. Western blot analysis was applied to investigate the change in LA-induced ERK1/2 phosphorylation change in response to kinase inhibitors. Arrestin-2/3-specific siRNA was used to analyze the effect of arrestin-2/3 knockdown on FFA1-mediated ERK1/2 activation. Results We proved that activation of ERK1/2 by LA was rapid, peaking at 5 min. Further experiments proved that FFA1 couples to a Gq protein and activates PI-PLC, which induces the IP3/Ca2+ and DAG/PKC signal pathways, both of which are involved in ERK1/2 activation. We also showed that there is no EGFR transactivation, arrestin-2/3 or Gβγ pathway participation in ERK1/2 phosphorylation. Treating cells with PTX abolished ERK1/2 activation at a late time point (≥20 min), indicating a critical role for Gi subunits in FFA1-mediated ERK1/2 activation. Conclusions Our study provides a detailed delineation of the LA-mediated activation of ERK1/2 in HEK293 cells that are stably transfected with human FFA1. We also present evidence of Gi/Gq-induced synergism in the regulation of ERK1/2 phosphorylation. These observations may provide new insights into the pharmacological effects of FFA1 and the physiological functions modulated by FFA1-mediated activation of ERK1/2. Electronic supplementary material The online version of this article (doi:10.1186/s11658-017-0043-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jing Qian
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Yuyang Gu
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Chun Wu
- Institute of Biochemistry, College of Life Science, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058 China
| | - Feng Yu
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Yuqi Chen
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Jingmei Zhu
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Xingyi Yao
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Chen Bei
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
| | - Qingqing Zhu
- Huzhou University Schools of Nursing and Medicine, Huzhou University, HuZhou, 313000 China
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Gong JP, Yang L, Tang JW, Sun P, Hu Q, Qin JW, Xu XM, Sun BC, Tang JH. Overexpression of microRNA-24 increases the sensitivity to paclitaxel in drug-resistant breast carcinoma cell lines via targeting ABCB9. Oncol Lett 2016; 12:3905-3911. [PMID: 27895747 PMCID: PMC5104208 DOI: 10.3892/ol.2016.5139] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
Paclitaxel has been widely used in the treatment of breast cancer. However, the development of drug resistance often increases the failure of chemotherapy. Growing evidence has reported the significant role of microRNAs (miRs) in drug resistance. The present study identified that miR-24 was significantly downregulated in paclitaxel-resistant (PR) breast cancer patients and in MCF-7/PR human breast carcinoma cells, and that overexpression of miR-24 could increase the effect of paclitaxel on drug-resistant breast carcinoma cells. Furthermore, miR-24 could directly bind to the 3′-untranslated region of ATP binding cassette B9 to downregulate its expression, thereby reducing drug transportation and improving the anti-tumor effect of paclitaxel on breast cancer cells. In vivo experiments also demonstrated that overexpression of miR-24 could increase the sensitivity of drug-resistant MCF-7 cells to paclitaxel. In conclusion, the present results suggested a novel function for miR-24 in reducing paclitaxel resistance in breast cancer, which may be of important clinical significance.
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Affiliation(s)
- Jian-Ping Gong
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
| | - Liu Yang
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
| | - Jun-Wei Tang
- Liver Transplantation Center of The First Affiliated Hospital and Cancer Center, Nanjing Medical University, Nanjing, Jiangsu 210009, P.R. China
| | - Peng Sun
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Qing Hu
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
| | - Jian-Wei Qin
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
| | - Xiao-Ming Xu
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
| | - Bei-Cheng Sun
- Liver Transplantation Center of The First Affiliated Hospital and Cancer Center, Nanjing Medical University, Nanjing, Jiangsu 210009, P.R. China
| | - Jin-Hai Tang
- Department of General Surgery and Breast Cancer Center, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu 210009, P.R. China
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24
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Sargsyan E, Artemenko K, Manukyan L, Bergquist J, Bergsten P. Oleate protects beta-cells from the toxic effect of palmitate by activating pro-survival pathways of the ER stress response. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1151-1160. [PMID: 27344025 DOI: 10.1016/j.bbalip.2016.06.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 06/11/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022]
Abstract
Long-term exposure of beta cells to saturated fatty acids impairs insulin secretion and increases apoptosis. In contrast, unsaturated fatty acids protect beta-cells from the long-term negative effects of saturated fatty acids. We aimed to identify the mechanisms underlying this protective action of unsaturated fatty acids. To address the aim, insulin-secreting MIN6 cells were exposed to palmitate in the absence or presence of oleate and analyzed by using nano-LC MS/MS based proteomic approach. Important findings were validated by using alternative approaches. Proteomic analysis identified 34 proteins differentially expressed in the presence of palmitate compared to control samples. These proteins play a role in insulin processing, mitochondrial function, metabolism of biomolecules, calcium homeostasis, exocytosis, receptor signaling, ER protein folding, antioxidant activity and anti-apoptotic function. When oleate was also present during culture, expression of 15 proteins was different from the expression in the presence of palmitate alone. Most of the proteins affected by oleate are targets of the ER stress response and play a pro-survival role in beta cells such as protein folding and antioxidative defence. We conclude that restoration of pro-survival pathways of the ER stress response is a major mechanism underlying the protective effect of unsaturated fatty acids in beta-cells treated with saturated fatty acids.
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Affiliation(s)
- Ernest Sargsyan
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden.
| | | | - Levon Manukyan
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden
| | - Jonas Bergquist
- Department of Chemistry, Uppsala University, Uppsala, Sweden; SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Peter Bergsten
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden
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25
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Milligan G, Shimpukade B, Ulven T, Hudson BD. Complex Pharmacology of Free Fatty Acid Receptors. Chem Rev 2016; 117:67-110. [PMID: 27299848 DOI: 10.1021/acs.chemrev.6b00056] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) are historically the most successful family of drug targets. In recent times it has become clear that the pharmacology of these receptors is far more complex than previously imagined. Understanding of the pharmacological regulation of GPCRs now extends beyond simple competitive agonism or antagonism by ligands interacting with the orthosteric binding site of the receptor to incorporate concepts of allosteric agonism, allosteric modulation, signaling bias, constitutive activity, and inverse agonism. Herein, we consider how evolving concepts of GPCR pharmacology have shaped understanding of the complex pharmacology of receptors that recognize and are activated by nonesterified or "free" fatty acids (FFAs). The FFA family of receptors is a recently deorphanized set of GPCRs, the members of which are now receiving substantial interest as novel targets for the treatment of metabolic and inflammatory diseases. Further understanding of the complex pharmacology of these receptors will be critical to unlocking their ultimate therapeutic potential.
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Affiliation(s)
- Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow G12 8QQ, Scotland, United Kingdom
| | - Bharat Shimpukade
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, DK-5230 Odense M, Denmark
| | - Trond Ulven
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, DK-5230 Odense M, Denmark
| | - Brian D Hudson
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow G12 8QQ, Scotland, United Kingdom
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26
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Munshi S, Dahl R. Cytoprotective small molecule modulators of endoplasmic reticulum stress. Bioorg Med Chem 2016; 24:2382-2388. [PMID: 27091069 DOI: 10.1016/j.bmc.2016.03.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 03/21/2016] [Accepted: 03/27/2016] [Indexed: 01/03/2023]
Abstract
Cellular health depends on the normal function of the endoplasmic reticulum (ER) to fold, assemble, and modify critical proteins to maintain viability. When the ER cannot process proteins effectively, a condition known as ER stress ensues. When this stress is excessive or prolonged, cell death via apoptotic pathways is triggered. Interestingly, most major diseases have been shown to be intimately linked to ER stress, including diabetes, stroke, neurodegeneration, and many cancers. Thus, controlling ER stress presents a significant strategy for drug development for these diseases. The goal of this review is to present various small molecules that alleviate ER stress with the intention that they may serve as useful starting points for therapeutic agent development.
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Affiliation(s)
- Soumyabrata Munshi
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Russell Dahl
- Neurodon LLC, 5700 Tanager St., Schererville, IN 46375, USA.
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27
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Deng Y, Matsui Y, Pan W, Li Q, Lai ZC. Yap1 plays a protective role in suppressing free fatty acid-induced apoptosis and promoting beta-cell survival. Protein Cell 2016; 7:362-72. [PMID: 27000077 PMCID: PMC4853318 DOI: 10.1007/s13238-016-0258-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/23/2016] [Indexed: 02/07/2023] Open
Abstract
Mammalian pancreatic β-cells play a pivotal role in development and glucose homeostasis through the production and secretion of insulin. Functional failure or decrease in β-cell number leads to type 2 diabetes (T2D). Despite the physiological importance of β-cells, the viability of β-cells is often challenged mainly due to its poor ability to adapt to their changing microenvironment. One of the factors that negatively affect β-cell viability is high concentration of free fatty acids (FFAs) such as palmitate. In this work, we demonstrated that Yes-associated protein (Yap1) is activated when β-cells are treated with palmitate. Our loss- and gain-of-function analyses using rodent insulinoma cell lines revealed that Yap1 suppresses palmitate-induced apoptosis in β-cells without regulating their proliferation. We also found that upon palmitate treatment, re-arrangement of F-actin mediates Yap1 activation. Palmitate treatment increases expression of one of the Yap1 target genes, connective tissue growth factor (CTGF). Our gain-of-function analysis with CTGF suggests CTGF may be the downstream factor of Yap1 in the protective mechanism against FFA-induced apoptosis.
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Affiliation(s)
- Yaoting Deng
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Yurika Matsui
- Intercollege Graduate Degree Program in Molecular, Cellular and Integrative Biosciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Wenfei Pan
- Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China
| | - Qiu Li
- Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China.
| | - Zhi-Chun Lai
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA. .,Intercollege Graduate Degree Program in Molecular, Cellular and Integrative Biosciences, Pennsylvania State University, University Park, PA, 16802, USA. .,Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China. .,Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA.
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28
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Dusaulcy R, Handgraaf S, Heddad-Masson M, Visentin F, Vesin C, Reimann F, Gribble F, Philippe J, Gosmain Y. α-Cell Dysfunctions and Molecular Alterations in Male Insulinopenic Diabetic Mice Are Not Completely Corrected by Insulin. Endocrinology 2016; 157:536-47. [PMID: 26696123 PMCID: PMC7228809 DOI: 10.1210/en.2015-1725] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glucagon and α-cell dysfunction are critical in the development of hyperglycemia during diabetes both in humans and rodents. We hypothesized that α-cell dysfunction leading to dysregulated glucagon secretion in diabetes is due to both a lack of insulin and intrinsic defects. To characterize α-cell dysfunction in diabetes, we used glucagon-Venus transgenic male mice and induced insulinopenic hyperglycemia by streptozotocin administration leading to alterations of glucagon secretion. We investigated the in vivo impact of insulinopenic hyperglycemia on glucagon-producing cells using FACS-sorted α-cells from control and diabetic mice. We demonstrate that increased glucagonemia in diabetic mice is mainly due to increases of glucagon release and biosynthesis per cell compared with controls without changes in α-cell mass. We identified genes coding for proteins involved in glucagon biosynthesis and secretion, α-cell differentiation, and potential stress markers such as the glucagon, Arx, MafB, cMaf, Brain4, Foxa1, Foxa3, HNF4α, TCF7L2, Glut1, Sglt2, Cav2.1, Cav2.2, Nav1.7, Kir6.2/Sur1, Pten, IR, NeuroD1, GPR40, and Sumo1 genes, which were abnormally regulated in diabetic mice. Importantly, insulin treatment partially corrected α-cell function and expression of genes coding for proglucagon, or involved in glucagon secretion, glucose transport and insulin signaling but not those coding for cMAF, FOXA1, and α-cell differentiation markers as well as GPR40, NEUROD1, CAV2.1, and SUMO1. Our results indicate that insulinopenic diabetes induce marked α-cell dysfunction and molecular alteration, which are only partially corrected by in vivo insulin treatment.
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Affiliation(s)
- Rodolphe Dusaulcy
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
| | - Sandra Handgraaf
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
| | - Mounia Heddad-Masson
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
| | - Florian Visentin
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
| | - Christian Vesin
- Department of Cell Physiology and Metabolism, University of Geneva School of Medicine, 1211 Geneva, Switzerland
| | - Franck Reimann
- Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Addenbrooke’s Hospital, cambridge, U.K
| | - Fiona Gribble
- Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Addenbrooke’s Hospital, cambridge, U.K
| | - Jacques Philippe
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
| | - Yvan Gosmain
- Molecular Diabetes Laboratory, Division of Endocrinology-Diabetes-Hypertension and Nutrition, University Hospital/University of Geneva Medical School, Geneva, Switzerland
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29
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Nadler A, Yushchenko DA, Müller R, Stein F, Feng S, Mulle C, Carta M, Schultz C. Exclusive photorelease of signalling lipids at the plasma membrane. Nat Commun 2015; 6:10056. [PMID: 26686736 PMCID: PMC4703838 DOI: 10.1038/ncomms10056] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 10/28/2015] [Indexed: 12/17/2022] Open
Abstract
Photoactivation of caged biomolecules has become a powerful approach to study cellular signalling events. Here we report a method for anchoring and uncaging biomolecules exclusively at the outer leaflet of the plasma membrane by employing a photocleavable, sulfonated coumarin derivative. The novel caging group allows quantifying the reaction progress and efficiency of uncaging reactions in a live-cell microscopy setup, thereby greatly improving the control of uncaging experiments. We synthesized arachidonic acid derivatives bearing the new negatively charged or a neutral, membrane-permeant coumarin caging group to locally induce signalling either at the plasma membrane or on internal membranes in β-cells and brain slices derived from C57B1/6 mice. Uncaging at the plasma membrane triggers a strong enhancement of calcium oscillations in β-cells and a pronounced potentiation of synaptic transmission while uncaging inside cells blocks calcium oscillations in β-cells and causes a more transient effect on neuronal transmission, respectively. The precise subcellular site of arachidonic acid release is therefore crucial for signalling outcome in two independent systems. Caged signalling intermediates are powerful cell biological tools, however it can be challenging to precisely control where activation occurs. Nadler et al. develop a caging group that specifically targets the plasma membrane, and demonstrate spatially controlled activation of arachidonic acid signalling.
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Affiliation(s)
- André Nadler
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Dmytro A Yushchenko
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.,Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic
| | - Rainer Müller
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Frank Stein
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Suihan Feng
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Christophe Mulle
- Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297 Université Bordeaux 2, 146, rue Léo-Saignat, 33077 Bordeaux, France
| | - Mario Carta
- Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297 Université Bordeaux 2, 146, rue Léo-Saignat, 33077 Bordeaux, France
| | - Carsten Schultz
- European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
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30
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Kristinsson H, Bergsten P, Sargsyan E. Free fatty acid receptor 1 (FFAR1/GPR40) signaling affects insulin secretion by enhancing mitochondrial respiration during palmitate exposure. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3248-57. [DOI: 10.1016/j.bbamcr.2015.09.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/04/2015] [Accepted: 09/21/2015] [Indexed: 12/23/2022]
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31
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Zhou Y, Sun P, Wang T, Chen K, Zhu W, Wang H. Inhibition of Calcium Influx Reduces Dysfunction and Apoptosis in Lipotoxic Pancreatic β-Cells via Regulation of Endoplasmic Reticulum Stress. PLoS One 2015; 10:e0132411. [PMID: 26147439 PMCID: PMC4492560 DOI: 10.1371/journal.pone.0132411] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/12/2015] [Indexed: 01/12/2023] Open
Abstract
Lipotoxicity plays an important role in pancreatic β-cell failure during the development of type 2 diabetes. Prolonged exposure of β-cells to elevated free fatty acids level could cause deterioration of β-cell function and induce cell apoptosis. Therefore, inhibition of fatty acids-induced β-cell dysfunction and apoptosis might provide benefit for the therapy of type 2 diabetes. The present study examined whether regulation of fatty acids-triggered calcium influx could protect pancreatic β-cells from lipotoxicity. Two small molecule compounds, L-type calcium channel blocker nifedipine and potassium channel activator diazoxide were used to inhibit palmitic acid-induced calcium influx. And whether the compounds could reduce palmitic acid-induced β-cell failure and the underlying mechanism were also investigated. It was found that both nifedipine and diazoxide protected MIN6 pancreatic β-cells and primary cultured murine islets from palmitic acid-induced apoptosis. Meanwhile, the impaired insulin secretion was also recovered to varying degrees by these two compounds. Our results verified that nifedipine and diazoxide could reduce palmitic acid-induced endoplasmic reticulum stress to generate protective effects on pancreatic β-cells. More importantly, it suggested that regulation of calcium influx by small molecule compounds might provide benefits for the prevention and therapy of type 2 diabetes.
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Affiliation(s)
- Yuren Zhou
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
| | - Peng Sun
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Ting Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
| | - Kaixian Chen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Weiliang Zhu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
| | - Heyao Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 201203, China
- * E-mail:
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32
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Abstract
Achromatopsia (ACHM) is an early-onset retinal dystrophy characterized by photophobia, nystagmus, color blindness and severely reduced visual acuity. Currently mutations in five genes CNGA3, CNGB3, GNAT2, PDE6C and PDE6H have been implicated in ACHM. We performed homozygosity mapping and linkage analysis in a consanguineous Pakistani ACHM family and mapped the locus to a 15.12-Mb region on chromosome 1q23.1-q24.3 with a maximum LOD score of 3.6. A DNA sample from an affected family member underwent exome sequencing. Within the ATF6 gene, a single-base insertion variant c.355_356dupG (p.Glu119Glyfs*8) was identified, which completely segregates with the ACHM phenotype within the family. The frameshift variant was absent in public variant databases, in 130 exomes from unrelated Pakistani individuals, and in 235 ethnically matched controls. The variant is predicted to result in a truncated protein that lacks the DNA binding and transmembrane domains and therefore affects the function of ATF6 as a transcription factor that initiates the unfolded protein response during endoplasmic reticulum (ER) stress. Immunolabeling with anti-ATF6 antibodies showed localization throughout the mouse neuronal retina, including retinal pigment epithelium, photoreceptor cells, inner nuclear layer, inner and outer plexiform layers, with a more prominent signal in retinal ganglion cells. In contrast to cytoplasmic expression of wild-type protein, in heterologous cells ATF6 protein with the p.Glu119Glyfs*8 variant is mainly confined to the nucleus. Our results imply that response to ER stress as mediated by the ATF6 pathway is essential for color vision in humans.
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33
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Lu Z, Li Y, Jin J, Zhang X, Hannun YA, Huang Y. GPR40/FFA1 and neutral sphingomyelinase are involved in palmitate-boosted inflammatory response of microvascular endothelial cells to LPS. Atherosclerosis 2015; 240:163-73. [PMID: 25795558 PMCID: PMC4397186 DOI: 10.1016/j.atherosclerosis.2015.03.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/25/2015] [Accepted: 03/08/2015] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Increased levels of both saturated fatty acids (SFAs) and lipopolysaccharide (LPS) are associated with type 2 diabetes. However, it remains largely unknown how SFAs interact with LPS to regulate inflammatory responses in microvascular endothelial cells (MIC ECs) that are critically involved in atherosclerosis as a diabetic complication. In this study, we compared the effects of LPS, palmitic acid (PA), the most abundant saturated fatty acid, or the combination of LPS and PA on interleukin (IL)-6 expression by MIC ECs and explored the underlying mechanisms. METHODS Human cardiac MIC ECs were treated with LPS, PA and LPS plus PA and the regulatory pathways including receptors, signal transduction, transcription and post-transcription, and sphingolipid metabolism for IL-6 expression were investigated. RESULTS G protein-coupled receptor (GPR)40 or free fatty acid receptor 1 (FFA1), but not toll-like receptor 4, was involved in PA-stimulated IL-6 expression. PA not only stimulated IL-6 expression by itself, but also remarkably enhanced LPS-stimulated IL-6 expression via a cooperative stimulation on mitogen-activated protein kinase and nuclear factor kappa B signaling pathways, and both transcriptional and post-transcriptional activation. Furthermore, PA induced a robust neutral sphingomyelinase (nSMase)-mediated sphingomyelin hydrolysis that was involved in PA-augmented IL-6 upregulation. CONCLUSION PA boosted inflammatory response of microvascular endothelial cells to LPS via GPR40 and nSMase.
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Affiliation(s)
- Zhongyang Lu
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Yanchun Li
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Junfei Jin
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, People's Republic of China
| | - Xiaoming Zhang
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Yusuf A Hannun
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yan Huang
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA; Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.
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Li L, Xu Y, Wang B. Liriodenine induces the apoptosis of human laryngocarcinoma cells via the upregulation of p53 expression. Oncol Lett 2014; 9:1121-1127. [PMID: 25663867 PMCID: PMC4314988 DOI: 10.3892/ol.2014.2834] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 11/13/2014] [Indexed: 11/25/2022] Open
Abstract
Laryngocarcinoma is one of the most aggressive cancers that affects the head and neck region. The survival rate of patients with laryngocarcinoma is low due to late metastases and the resistance of the disease to chemotherapy and radiotherapy. Liriodenine, an alkaloid extracted from a number of plant species, has demonstrated antitumor effects on multiple types of cancer. However, the effects of liriodenine upon laryngocarcinoma, and the underlying mechanisms, are yet to be elucidated. The present study therefore investigated the potential antitumor effects of liriodenine on HEp-2 human laryngocarcinoma cells in vitro and HEp-2-implanted nude mice in vivo. Liriodenine induced significant apoptosis and inhibition of cell migration in the HEp-2 cells. Furthermore, the rate of tumor growth in the HEp-2-implanted nude mice was inhibited by the administration of liriodenine. The potential mechanism underlying the antitumor effects of liriodenine may result from an upregulative effect upon p53 expression, which ultimately induces cellular apoptosis. By contrast, the downregulation of p53 significantly reduced the antitumor effects of liriodenine. Together, these results suggest that liriodenine exhibits potent antitumor activities in laryngocarcinoma HEp-2 cells, in vitro and in vivo, via the upregulation of p53 expression. Liriodenine may therefore be a potential therapy for the treatment of laryngocarcinoma.
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Affiliation(s)
- Liang Li
- Department of Otolaryngology, Head and Neck Surgery, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210011, P.R. China ; Department of Otolaryngology, Head and Neck Surgery, The First Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Ying Xu
- Department of Otolaryngology, Head and Neck Surgery, The First Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Binquan Wang
- Department of Otolaryngology, Head and Neck Surgery, The First Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
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Overexpression of microRNA-30b improves adenovirus-mediated p53 cancer gene therapy for laryngeal carcinoma. Int J Mol Sci 2014; 15:19729-40. [PMID: 25356506 PMCID: PMC4264135 DOI: 10.3390/ijms151119729] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 11/17/2022] Open
Abstract
MicroRNAs play important roles in laryngeal carcinoma and other cancers. However, the expression of microRNAs in paracancerous tissue has been studied less. Here, using laser capture microdissection (LCM), we detected the expression of microRNAs in paracancerous tissues. Among all down-regulated microRNAs in the center area of tumor tissues, only miR-30b expression was significantly reduced in paracancerous tissues compared to surgical margins. Therefore, to further investigate the effect of miR-30b on laryngeal carcinoma, we stably overexpressed miR-30b in laryngeal carcinoma cell line HEp-2 cells. It was found that although there was no significant difference in cell viability between miR-30b overexpressed cells and control HEp-2 cells, p53 expression was obviously enhanced in miR-30b overexpressed cells. Whether miR-30b could improve the anti-tumor effect of adenovirus-p53 (Ad-p53) in laryngeal carcinoma and other cancer cell lines was also evaluated. It was found that in miR-30b overexpressed HEp-2 cells, p53-mediated tumor cell apoptosis was obviously increased both in vitro and in vivo. MDM2-p53 interaction might be involved in miR-30b-mediated anti-tumor effect. Together, results suggested that miR-30b could modulate p53 pathway and enhance p53 gene therapy-induced apoptosis in laryngeal carcinoma, which could provide a novel microRNA target in tumor therapy.
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Dranse HJ, Kelly MEM, Hudson BD. Drugs or diet?--Developing novel therapeutic strategies targeting the free fatty acid family of GPCRs. Br J Pharmacol 2014; 170:696-711. [PMID: 23937426 DOI: 10.1111/bph.12327] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 02/07/2023] Open
Abstract
Free fatty acids (FFAs) are metabolic intermediates that may be obtained through the diet, synthesized endogenously, or produced via fermentation of carbohydrates by gut microbiota. In addition to serving as an important source of energy, FFAs are known to produce a variety of both beneficial and detrimental effects on metabolic and inflammatory processes. While historically, FFAs were believed to produce these effects only through intracellular targets such as peroxisome proliferator-activated receptors, it has now become clear that FFAs are also agonists for several GPCRs, including a family of four receptors now termed FFA1-4. Increasing evidence suggests that FFA1-4 mediate many of the beneficial properties of FFAs and not surprisingly, this has generated significant interest in the potential of these receptors as therapeutic targets for the treatment of a variety of metabolic and inflammatory disorders. In addition to the traditional strategy of developing small-molecule therapeutics targeting these receptors, there has also been some consideration given to alternate therapeutic approaches, specifically by manipulating endogenous FFA concentrations through alteration of either dietary intake, or production by gut microbiota. In this review, the current state of knowledge for FFA1-4 will be discussed, together with their potential as therapeutic targets in the treatment of metabolic and inflammatory disorders. In particular, the evidence in support of small molecule versus dietary and microbiota-based therapeutic approaches will be considered to provide insight into the development of novel multifaceted strategies targeting the FFA receptors for the treatment of metabolic and inflammatory disorders.
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Affiliation(s)
- H J Dranse
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
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37
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Wang T, Sun P, Chen L, Huang Q, Chen K, Jia Q, Li Y, Wang H. Cinnamtannin D-1 protects pancreatic β-cells from palmitic acid-induced apoptosis by attenuating oxidative stress. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:5038-5045. [PMID: 24815044 DOI: 10.1021/jf500387d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In previous studies, A-type procyanidin oligomers isolated from Cinnamomum tamala were proved to possess antidiabetic effect and protect pancreatic β-cells in vivo. The aim of this study was to unveil the mechanisms of protecting pancreatic β-cells from palmitic acid-induced apoptosis by cinnamtannin D-1 (CD1), one of the main A-type procyanidin oligomers in C. tamala. CD1 was discovered to dose-dependently reduce palmitic acid- or H2O2-induced apoptosis and oxidative stress in INS-1 cells, MIN6 cells, and primary cultured murine islets. Moreover, CD1 could reverse palmitic acid-induced dysfunction of glucose-stimulated insulin secretion in primary cultured islets. These results indicate that reduction of apoptosis and oxidative stress might account for the protection effect of CD1, which provided a better understanding of the mechanisms of the antidiabetic effects of procyanidin oligomers.
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Affiliation(s)
- Ting Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China
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38
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Abstract
Free fatty acids (FFAs) exert both positive and negative effects on beta cell survival and insulin secretory function, depending on concentration, duration, and glucose abundance. Lipid signals are mediated not only through metabolic pathways, but also through cell surface and nuclear receptors. Toxicity is modulated by positive signals arising from circulating factors such as hormones, growth factors and incretins, as well as negative signals such as inflammatory mediators and cytokines. Intracellular mechanisms of lipotoxicity include metabolic interference and cellular stress responses such as oxidative stress, endoplasmic reticulum (ER) stress, and possibly autophagy. New findings strengthen an old hypothesis that lipids may also impair compensatory beta cell proliferation. Clinical observations continue to support a role for lipid biology in the risk and progression of both type 1 (T1D) and type 2 diabetes (T2D). This review summarizes recent work in this important, rapidly evolving field.
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Affiliation(s)
- Rohit B Sharma
- Diabetes Center of Excellence, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
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Shen X, Yang L, Yan S, Wei W, Liang L, Zheng H, Cai X. The effect of FFAR1 on pioglitazone-mediated attenuation of palmitic acid-induced oxidative stress and apoptosis in βTC6 cells. Metabolism 2014; 63:335-51. [PMID: 24360748 DOI: 10.1016/j.metabol.2013.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/24/2013] [Accepted: 11/04/2013] [Indexed: 01/27/2023]
Abstract
OBJECTIVE We sought to determine whether free fatty acid receptor 1 (FFAR1), a receptor for free fatty acids on the β-cell membrane, can mediate the pioglitazone (PIO)-attenuating effect on lipoapoptosis in β cells and its relationship to oxidative stress. METHODS The glucose-sensitive mouse beta pancreatic cell line βTC6 was used to investigate the effect of FFAR1 on PIO-attenuating palmitic acid (PA)-induced oxidative stress and apoptosis. RESULTS (1) PIO reduced PA-induced lipoapoptosis in β cells and upregulated the expression of FFAR1 at the mRNA and protein levels in a dose- and time-dependent manner. Silencing of FFAR1 expression was shown to weaken the protective effect of PIO on PA-induced lipoapoptosis in βTC6 cells; while lentiviral-mediated overexpression of FFAR1 was shown to enhance the protective effect of PIO against lipoapoptosis in β cells. (2) Downregulation of FFAR1 expression reduced the attenuating effect of PIO on the expression of NAPDH oxidase subunit p47(phox), Bax, cleaved caspase 3, and the production of reactive oxygen specific (ROS) induced by lipotoxicity, thereby preventing the upregulation of the expression of bcl-2. Inducing the overexpression of FFAR1 enhanced the anti-oxidative stress effect of PIO. Similarly, these effects of FFAR1 on PIO were reproduced under conditions of oxidative stress and apoptosis in βTC6 cells that were induced by H2O2. (3) PIO was found to increase the expression of PLCγ, ERK1/2, and PPARγ in lipotoxic β cells. Silencing FFAR1 expression reduced the PIO-mediated increases in the expression of above proteins; while inducing FFAR1 overexpression showed the opposite effect. Use of an inhibitor of PLCγ, ERK1/2, PPARγ was shown to restrict the protective effect of PIO on oxidative stress and lipoapoptosis of β cells. CONCLUSIONS FFAR1 can mediate PIO suppression of β-cell lipoapoptosis through anti-oxidative stress, which may be related to the activation of the PLCγ-ERK1/2-PPARγ pathway.
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Affiliation(s)
- Ximei Shen
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China; Department of Endocrinology, The First Clinical Medical College of Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Liyong Yang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China.
| | - Sunjie Yan
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Wenfeng Wei
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Liyu Liang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Huanhuan Zheng
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Xiuhui Cai
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
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40
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Kristinsson H, Smith DM, Bergsten P, Sargsyan E. FFAR1 is involved in both the acute and chronic effects of palmitate on insulin secretion. Endocrinology 2013; 154:4078-88. [PMID: 24035997 DOI: 10.1210/en.2013-1352] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Free fatty acids (FFAs) have pleiotropic effects on the pancreatic β-cell. Although acute exposure to FFAs stimulates glucose-stimulated insulin secretion (GSIS), prolonged exposure impairs GSIS and causes apoptosis. FFAs exert their effects both via intracellular metabolism and interaction with the FFA receptor 1 (FFAR1/GPR40). Here we studied the role of FFAR1 in acute and long-term effects of palmitate on GSIS and insulin content in isolated human islets by using the FFAR1 agonist TAK-875 and the antagonist ANT203. Acute palmitate exposure potentiated GSIS approximately 3-fold, whereas addition of the antagonist decreased this potentiation to approximately 2-fold. In the absence of palmitate, the agonist caused a 40% increase in GSIS. Treatment with palmitate for 7 days decreased GSIS to 70% and insulin content to 25% of control level. These negative effects of long-term exposure to palmitate were ameliorated by FFAR1 inhibition and further aggravated by additional stimulation of the receptor. In the absence of extracellularly applied palmitate, long-term treatment with the agonist caused a modest increase in GSIS. The protective effect of FFAR1 inhibition was verified by using FFAR1-deficient MIN6 cells. Improved β-cell function by the antagonist was paralleled by the decreased apoptosis and lowered oxidation of palmitate, which may represent the potential mechanisms of protection. We conclude that FFAR1 in the pancreatic β-cell plays a substantial role not only in acute potentiation of GSIS by palmitate but also in the negative long-term effects of palmitate on GSIS and insulin content.
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Affiliation(s)
- Hjalti Kristinsson
- PhD, Department of Medical Cell Biology, Uppsala University, Box 571, SE-751 23 Uppsala, Sweden.
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41
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Natalicchio A, Labarbuta R, Tortosa F, Biondi G, Marrano N, Peschechera A, Carchia E, Orlando MR, Leonardini A, Cignarelli A, Marchetti P, Perrini S, Laviola L, Giorgino F. Exendin-4 protects pancreatic beta cells from palmitate-induced apoptosis by interfering with GPR40 and the MKK4/7 stress kinase signalling pathway. Diabetologia 2013; 56:2456-66. [PMID: 23995397 DOI: 10.1007/s00125-013-3028-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 07/29/2013] [Indexed: 12/24/2022]
Abstract
AIMS/HYPOTHESIS The mechanisms of the protective effects of exendin-4 on NEFA-induced beta cell apoptosis were investigated. METHODS The effects of exendin-4 and palmitate were evaluated in human and murine islets, rat insulin-secreting INS-1E cells and murine glucagon-secreting alpha-TC1-6 cells. mRNA and protein expression/phosphorylation were measured by real-time RT-PCR and immunoblotting or immunofluorescence, respectively. Small interfering (si)RNAs for Ib1 and Gpr40 were used. Cell apoptosis was quantified by two independent assays. Insulin release was assessed with an insulin ELISA. RESULTS Exposure of human and murine primary islets and INS-1E cells, but not alpha-TC1-6 cells, to exendin-4 inhibited phosphorylation of the stress kinases, c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), and prevented apoptosis in response to palmitate. Exendin-4 increased the protein content of islet-brain 1 (IB1), an endogenous JNK blocker; however, siRNA-mediated reduction of IB1 did not impair the ability of exendin-4 to inhibit JNK and prevent apoptosis. Exendin-4 reduced G-protein-coupled receptor 40 (GPR40) expression and inhibited palmitate-induced phosphorylation of mitogen-activated kinase kinase (MKK)4 and MKK7. The effects of exendin-4 were abrogated in the presence of the protein kinase A (PKA) inhibitors, H89 and KT5720. Knockdown of GPR40, as well as use of a specific GPR40 antagonist, resulted in diminished palmitate-induced JNK and p38 MAPK phosphorylation and apoptosis. Furthermore, inhibition of JNK and p38 MAPK activity prevented palmitate-induced apoptosis. CONCLUSIONS/INTERPRETATION Exendin-4 counteracts the proapoptotic effects of palmitate in beta cells by reducing GPR40 expression and inhibiting MKK7- and MKK4-dependent phosphorylation of the stress kinases, JNK and p38 MAPK, in a PKA-dependent manner.
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Affiliation(s)
- Annalisa Natalicchio
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Piazza Giulio Cesare, 11, 70124, Bari, Italy
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GW9508, a free fatty acid receptor agonist, specifically induces cell death in bone resorbing precursor cells through increased oxidative stress from mitochondrial origin. Exp Cell Res 2013; 319:3035-41. [DOI: 10.1016/j.yexcr.2013.08.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/18/2022]
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43
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Sun P, Wang T, Zhou Y, Liu H, Jiang H, Zhu W, Wang H. DC260126: a small-molecule antagonist of GPR40 that protects against pancreatic β-Cells dysfunction in db/db mice. PLoS One 2013; 8:e66744. [PMID: 23776696 PMCID: PMC3679087 DOI: 10.1371/journal.pone.0066744] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/10/2013] [Indexed: 12/30/2022] Open
Abstract
G protein-coupled receptor 40 (GPR40) mediates both acute and chronic effects of free fatty acids (FFAs) on insulin secretion. However, it remains controversial whether inhibition of GPR40 would be beneficial in prevention of type 2 diabetes. This study is designed to evaluate the potential effects of DC260126, a small molecule antagonist of GPR40, on β-cell function following administration of 10 mg/kg dose of DC260126 to obese diabetic db/db mice. Oral glucose tolerance test, glucose stimulated insulin secretion and insulin tolerance test were used to investigate the pharmacological effects of DC260126 on db/db mice after 21-days treatment. Immunohistochemistry and serum biochemical analysis were also performed in this study. Although no significant change of blood glucose levels was found in DC260126-treated mice, DC260126 significantly inhibited glucose stimulated insulin secretion, reduced blood insulin level and improved insulin sensitivity after 3 weeks administration in db/db mice. Moreover, DC260126 reduced the proinsulin/insulin ratio and the apoptotic rate of pancreatic β-cells remarkably in DC260126-treated db/db mice compared to vehicle-treated mice (p<0.05, n = 8). The results suggest that although DC260126 could not provide benefit for improving hyperglycemia, it could protect against pancreatic β-cells dysfunction through reducing overload of β-cells, and it increases insulin sensitivity possibly via alleviation of hyperinsulinemia in db/db mice.
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Affiliation(s)
- Peng Sun
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ting Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yuren Zhou
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Hong Liu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Hualiang Jiang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Weiliang Zhu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (H. Wang); (W. Zhu)
| | - Heyao Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (H. Wang); (W. Zhu)
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Wu J, Sun P, Zhang X, Liu H, Jiang H, Zhu W, Wang H. Erratum: Inhibition of GPR40 protects MIN6 β cells from palmitate-induced ER stress and apoptosis. J Cell Biochem 2013. [DOI: 10.1002/jcb.24514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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45
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Feng XT, Leng J, Xie Z, Li SL, Zhao W, Tang QL. GPR40: a therapeutic target for mediating insulin secretion (review). Int J Mol Med 2012; 30:1261-6. [PMID: 23023155 DOI: 10.3892/ijmm.2012.1142] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/26/2012] [Indexed: 11/05/2022] Open
Abstract
G-protein-coupled receptor 40 (GPR40), known as free fatty acid receptor 1, is mainly expressed in pancreatic β-cells and activated by medium- and long-chain fatty acids. Increasing evidence indicates that the activation of GPR40 in cells causes insulin secretion, and GPR40 has become an attractive therapeutic target for type 2 diabetes. Recently, certain novel GPR40 agonists have been identified that regulate glucose-stimulated insulin secretion, leading to the development of new drugs for the treatment of type 2 diabetes. In this review, we focus on progress in the physiological role of GPR40 and potential drugs targeting GPR40 over the past decade.
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Affiliation(s)
- Xiao-Tao Feng
- Guangxi Scientific Experimental Center of Traditional Chinese Medicine, Guangxi University of Chinese Medicine, Nanning, P.R. China
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