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Liu W, Zhu M, Liu J, Su S, Zeng X, Fu F, Lu Y, Rao Z, Chen Y. Comparison of the effects of monounsaturated fatty acids and polyunsaturated fatty acids on the lipotoxicity of islets. Front Endocrinol (Lausanne) 2024; 15:1368853. [PMID: 38501107 PMCID: PMC10945794 DOI: 10.3389/fendo.2024.1368853] [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: 01/11/2024] [Accepted: 02/12/2024] [Indexed: 03/20/2024] Open
Abstract
Background Monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) have been reported to combat saturated fatty acid (SFA)-induced cellular damage, however, their clinical effects on patients with metabolic diseases such as diabetes and hyperlipidemia are still controversial. Since comparative studies of the effects of these two types of unsaturated fatty acids (UFAs) are still limited. In this study, we aimed to compare the protective effects of various UFAs on pancreatic islets under the stress of SFA-induced metabolic disorder and lipotoxicity. Methods Rat insulinoma cell line INS-1E were treated with palmitic acid (PA) with or without UFAs including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), and oleic acid (OA) to determine cell viability, apoptosis, endoplasmic reticulum (ER) stress, and inflammatory. In vivo, male C57BL/6 mice were fed a 60% high-fat diet (HFD) for 12 w. Then the lard in HFD was partially replaced with fish oil (FO) and olive oil (OO) at low or high proportions of energy (5% or 20%) to observe the ameliorative effects of the UFA supplement. Results All UFAs significantly improved PA-induced cell viability impairment in INS-1E cells, and their alleviation on PA induced apoptosis, ER stress and inflammation were confirmed. Particularly, OA had better effects than EPA, DHA, and AA on attenuating cellular ER stress. In vivo, the diets with a low proportion of UFAs (5% of energy) had limited effects on HFD induced metabolic disorder, except for a slight improved intraperitoneal glucose tolerance in obese mice. However, when fed diets containing a high proportion of UFAs (20% of energy), both the FO and OO groups exhibited substantially improved glucose and lipid metabolism, such as decrease in total cholesterol (TC), low-density lipoprotein (LDL), fasting blood glucose (FBG), and fasting blood insulin (FBI)) and improvement of insulin sensitivity evidenced by intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT). Unexpectedly, FO resulted in abnormal elevation of the liver function index aspartate aminotransferase (AST) in serum. Pathologically, OO attenuated HFD-induced compensatory hyperplasia of pancreatic islets, while this effect was not obvious in the FO group. Conclusions Both MUFAs and PUFAs can effectively protect islet β cells from SFA-induced cellular lipotoxicity. In particular, both OA in vitro and OO in vivo showed superior activities on protecting islets function and enhance insulin sensitivity, suggesting that MUFAs might have greater potential for nutritional intervention on diabetes.
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Affiliation(s)
- Wen Liu
- Department of Clinical Nutrition and Key Laboratory of Transplant Engineering and Immunology, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Min Zhu
- Department of Clinical Nutrition and Key Laboratory of Transplant Engineering and Immunology, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jingyi Liu
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Shan Su
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Xin Zeng
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Fudong Fu
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Yanrong Lu
- Department of Clinical Nutrition and Key Laboratory of Transplant Engineering and Immunology, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Zhiyong Rao
- Department of Clinical Nutrition, West China Hospital, Sichuan University, Chengdu, China
| | - Younan Chen
- Department of Clinical Nutrition and Key Laboratory of Transplant Engineering and Immunology, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
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Nguyen HT, Wiederkehr A, Wollheim CB, Park KS. Regulation of autophagy by perilysosomal calcium: a new player in β-cell lipotoxicity. Exp Mol Med 2024; 56:273-288. [PMID: 38297165 PMCID: PMC10907728 DOI: 10.1038/s12276-024-01161-x] [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: 05/03/2023] [Revised: 10/16/2023] [Accepted: 11/09/2023] [Indexed: 02/02/2024] Open
Abstract
Autophagy is an essential quality control mechanism for maintaining organellar functions in eukaryotic cells. Defective autophagy in pancreatic beta cells has been shown to be involved in the progression of diabetes through impaired insulin secretion under glucolipotoxic stress. The underlying mechanism reveals the pathologic role of the hyperactivation of mechanistic target of rapamycin (mTOR), which inhibits lysosomal biogenesis and autophagic processes. Moreover, accumulating evidence suggests that oxidative stress induces Ca2+ depletion in the endoplasmic reticulum (ER) and cytosolic Ca2+ overload, which may contribute to mTOR activation in perilysosomal microdomains, leading to autophagic defects and β-cell failure due to lipotoxicity. This review delineates the antagonistic regulation of autophagic flux by mTOR and AMP-dependent protein kinase (AMPK) at the lysosomal membrane, and both of these molecules could be activated by perilysosomal calcium signaling. However, aberrant and persistent Ca2+ elevation upon lipotoxic stress increases mTOR activity and suppresses autophagy. Therefore, normalization of autophagy is an attractive therapeutic strategy for patients with β-cell failure and diabetes.
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Affiliation(s)
- Ha Thu Nguyen
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Korea
| | | | - Claes B Wollheim
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland.
- Department of Clinical Sciences, Lund University, Malmö, Sweden.
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea.
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Korea.
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Biondi G, Marrano N, Dipaola L, Borrelli A, Rella M, D'Oria R, Genchi VA, Caccioppoli C, Porreca I, Cignarelli A, Perrini S, Marchetti P, Vincenti L, Laviola L, Giorgino F, Natalicchio A. The p66Shc Protein Mediates Insulin Resistance and Secretory Dysfunction in Pancreatic β-Cells Under Lipotoxic Conditions. Diabetes 2022; 71:1763-1771. [PMID: 35612429 DOI: 10.2337/db21-1066] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 05/16/2022] [Indexed: 11/13/2022]
Abstract
We evaluated the role of the p66Shc redox adaptor protein in pancreatic β-cell insulin resistance that develops under lipotoxic conditions and with excess body fat. Prolonged exposure to palmitate in vitro or the presence of overweight/obesity augmented p66Shc expression levels and caused an impaired ability of exogenous insulin to increase cellular insulin content and secreted C-peptide levels in INS-1E cells and human and murine islets. In INS-1E cells, p66Shc knockdown resulted in enhanced insulin-induced augmentation of insulin content and C-peptide secretion and prevented the ability of palmitate to impair these effects of insulin. Conversely, p66Shc overexpression impaired insulin-induced augmentation of insulin content and C-peptide secretion in both the absence and presence of palmitate. Under lipotoxic condition, the effects of p66Shc are mediated by a p53-induced increase in p66Shc protein levels and JNK-induced p66Shc phosphorylation at Ser36 and appear to involve the phosphorylation of the ribosomal protein S6 kinase at Thr389 and of insulin receptor substrate 1 at Ser307, resulting in the inhibition of insulin-stimulated protein kinase B phosphorylation at Ser473. Thus, the p66Shc protein mediates the impaired β-cell function and insulin resistance induced by saturated fatty acids and excess body fat.
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Affiliation(s)
- Giuseppina Biondi
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Nicola Marrano
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Lucia Dipaola
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Anna Borrelli
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Martina Rella
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Rossella D'Oria
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Valentina A Genchi
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Cristina Caccioppoli
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Immacolata Porreca
- Genetic Research Centre "Gaetano Salvatore" BioGeM, Ariano Irpino, Italy
| | - Angelo Cignarelli
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Sebastio Perrini
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Leonardo Vincenti
- Division of General Surgery, University Hospital Polyclinic, Bari, Italy
| | - Luigi Laviola
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Francesco Giorgino
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Annalisa Natalicchio
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
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Moens C, Muller CJF, Bouwens L. In vitro comparison of various antioxidants and flavonoids from Rooibos as beta cell protectants against lipotoxicity and oxidative stress-induced cell death. PLoS One 2022; 17:e0268551. [PMID: 35580081 PMCID: PMC9113568 DOI: 10.1371/journal.pone.0268551] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/02/2022] [Indexed: 01/09/2023] Open
Abstract
Oxidative stress and lipotoxicity effects on pancreatic β cells play a major role in the pathogenesis of type 2 diabetes (T2D). Flavonoids and antioxidants are under study for their cytoprotective effects and antidiabetic potential. In this study, we aimed to compare the protective effect of the Rooibos components aspalathin, isoorientin, 3-hydroxyphloretin (3-OH) and green Rooibos extract (GRT) itself, and exendin-4 and N-acetylcysteine (NAC) as reference molecules, against lipotoxicity and oxidative stress. The insulin-producing β cell line INS1E was exposed to hydrogen peroxide or streptozotocin (STZ) to induce oxidative stress, and palmitate to induce lipotoxicity. Cell viability was assessed by a MTS cell viability assay. Antioxidant response and antiapoptotic gene expression was performed by qRT-PCR. Glucose transporter 2 (GLUT 2) transporter inhibition was assessed through 2-NBDG uptake. GRT and the flavonoids aspalathin and 3-hydroxyphloretin offered significant protection against oxidative stress and lipotoxicity. GRT downregulated expression of pro-apoptotic genes Txnip and Ddit3. The flavonoids aspalathin and 3-hydroxyphloretin also downregulated these genes and in addition upregulated expression of antioxidant response genes Hmox1, Nqo1 and Sod1. Isoorientin gave no cytoprotection. Cytoprotection by Rooibos components was significantly higher than by NAC or exendin-4. Rooibos components strongly protect INS1E β cells against diabetogenic stress. Cytoprotection was associated with the upregulation of antioxidant response genes of the NRF2/KEAP1 pathway or suppression of the TXN system. The Rooibos molecules offered better protection against these insults than exendin-4 and NAC, making them interesting candidates as β cell cytoprotectants for therapeutic or nutraceutical applications.
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Affiliation(s)
- Céline Moens
- Cell Differentiation Lab, Vrije Universiteit Brussel, Jette, Brussels, Belgium
- * E-mail:
| | - Christo J. F. Muller
- Biomedical Research and Innovation Platform (BRIP), South African Medical Research Council (MRC), Western Cape, Tygerberg, South Africa
- Centre for Cardiometabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa, Empangeni, South Africa
| | - Luc Bouwens
- Cell Differentiation Lab, Vrije Universiteit Brussel, Jette, Brussels, Belgium
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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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Lipke K, Kubis-Kubiak A, Piwowar A. Molecular Mechanism of Lipotoxicity as an Interesting Aspect in the Development of Pathological States-Current View of Knowledge. Cells 2022; 11:cells11050844. [PMID: 35269467 PMCID: PMC8909283 DOI: 10.3390/cells11050844] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 02/06/2023] Open
Abstract
Free fatty acids (FFAs) play numerous vital roles in the organism, such as contribution to energy generation and reserve, serving as an essential component of the cell membrane, or as ligands for nuclear receptors. However, the disturbance in fatty acid homeostasis, such as inefficient metabolism or intensified release from the site of storage, may result in increased serum FFA levels and eventually result in ectopic fat deposition, which is unfavorable for the organism. The cells are adjusted for the accumulation of FFA to a limited extent and so prolonged exposure to elevated FFA levels results in deleterious effects referred to as lipotoxicity. Lipotoxicity contributes to the development of diseases such as insulin resistance, diabetes, cardiovascular diseases, metabolic syndrome, and inflammation. The nonobvious organs recognized as the main lipotoxic goal of action are the pancreas, liver, skeletal muscles, cardiac muscle, and kidneys. However, lipotoxic effects to a significant extent are not organ-specific but affect fundamental cellular processes occurring in most cells. Therefore, the wider perception of cellular lipotoxic mechanisms and their interrelation may be beneficial for a better understanding of various diseases’ pathogenesis and seeking new pharmacological treatment approaches.
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Cignarelli A, Genchi VA, Le Grazie G, Caruso I, Marrano N, Biondi G, D’Oria R, Sorice GP, Natalicchio A, Perrini S, Laviola L, Giorgino F. Mini Review: Effect of GLP-1 Receptor Agonists and SGLT-2 Inhibitors on the Growth Hormone/IGF Axis. Front Endocrinol (Lausanne) 2022; 13:846903. [PMID: 35265043 PMCID: PMC8899086 DOI: 10.3389/fendo.2022.846903] [Citation(s) in RCA: 2] [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] [Received: 12/31/2021] [Accepted: 02/01/2022] [Indexed: 11/13/2022] Open
Abstract
Accumulating evidence supports the early use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium glucose transporter-2 inhibitors (SGLT-2is) for the treatment of type 2 diabetes. Indeed, these compounds exert numerous pleiotropic actions that favorably affect metabolism and diabetes comorbidities, showing an additional effect beyond glucose control. Although a substantial amount of knowledge has been generated regarding the mechanism of action of both drug classes, much remains to be understood. Growth hormone (GH) is an important driver for multiple endocrine responses involving changes in glucose and lipid metabolism, and affects several tissues and organs (e.g., bone, heart). It acts directly on several target tissues, including skeletal muscle and bone, but several effects are mediated indirectly by circulating (liver-derived) or locally produced IGF-1. In consideration of the multiple metabolic and cardiovascular effects seen in subjects treated with GLP-1RAs and SGLT-2is (e.g., reduction of hyperglycemia, weight loss, free/fat mass and bone remodeling, anti-atherosclerosis, natriuresis), it is reasonable to speculate that GH and IGF-1 may play a about a relevant role in this context. This narrative mini-review aims to describe the involvement of the GH/IGF-1/IGF-1R axis in either mediating or responding to the effects of each of the two drug classes.
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Xie S, Wang M, Zhang B, Weng S. Hypoglycemic mechanism of intestinal bypass surgery in type 2 diabetic rats. Sci Rep 2021; 11:21596. [PMID: 34732821 PMCID: PMC8566479 DOI: 10.1038/s41598-021-98714-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/14/2021] [Indexed: 11/09/2022] Open
Abstract
To investigate the effect of duodenal-jejunal bypass (DJB) surgery on postoperative blood glucose in type 2 diabetic rats, and further explore possible mechanisms for the effect of surgical treatment of type 2 diabetes. Forty rats with type 2 diabetes were randomly assigned to 4 groups (n = 10 rats per group), which subsequently underwent DJB, new biliopancreatic diversion (NBPD) or duodenal-jejunal exclusion (DJE) surgery or a sham operation (SHAM). Fasting glucose, 2-h postprandial glucose and blood lipids were measured, and the mRNA in liver and intestinal tissue for bile acid receptor (FXR), as well as the FXR protein expression in the liver tissues were determined. Postprandial blood glucose and fasting TG and FFA in the DJB and NBPD groups were significantly lower than those in the SHAM group and preoperative (p < 0.05) at 8 weeks postoperation. Liver FXR protein was expressed at significantly higher in the DJB and NBPD groups than in the other two (p < 0.05), and the intestinal FXR mRNA in the DJE group were highest. DJB up-regulates the expression of bile acid receptors in the liver and down-regulates those receptors in the intestinal tract via biliopancreatic diversion. This process reduces TG levels, and subsequently any lipotoxicity to islet cells to produce a hypoglycemic effect.
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Affiliation(s)
- Siqi Xie
- Hepatopancreatobiliary Surgery Department, The First Affiliated Hospital of Fujian Medical University, National Abdominal Surgery Institute of Fujian, No 20 Chazhong Road, Fuzhou City, Fujian, People's Republic of China
| | - MingChang Wang
- Department of Intensive Care Unit, The Second Affiliated Hospital of Fujian Medical University, No. 34, North Zhongshan Road, Licheng District, Quanzhou City, Fujian, People's Republic of China
| | - Bin Zhang
- Hepatopancreatobiliary Surgery Department, The First Affiliated Hospital of Fujian Medical University, National Abdominal Surgery Institute of Fujian, No 20 Chazhong Road, Fuzhou City, Fujian, People's Republic of China
| | - ShanGeng Weng
- Hepatopancreatobiliary Surgery Department, The First Affiliated Hospital of Fujian Medical University, National Abdominal Surgery Institute of Fujian, No 20 Chazhong Road, Fuzhou City, Fujian, People's Republic of China.
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Wang W, Zhang C. Targeting β-cell dedifferentiation and transdifferentiation: opportunities and challenges. Endocr Connect 2021; 10:R213-R228. [PMID: 34289444 PMCID: PMC8428079 DOI: 10.1530/ec-21-0260] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/21/2021] [Indexed: 12/02/2022]
Abstract
The most distinctive pathological characteristics of diabetes mellitus induced by various stressors or immune-mediated injuries are reductions of pancreatic islet β-cell populations and activity. Existing treatment strategies cannot slow disease progression; consequently, research to genetically engineer β-cell mimetics through bi-directional plasticity is ongoing. The current consensus implicates β-cell dedifferentiation as the primary etiology of reduced β-cell mass and activity. This review aims to summarize the etiology and proposed mechanisms of β-cell dedifferentiation and to explore the possibility that there might be a time interval from the onset of β-cell dysfunction caused by dedifferentiation to the development of diabetes, which may offer a therapeutic window to reduce β-cell injury and to stabilize functionality. In addition, to investigate β-cell plasticity, we review strategies for β-cell regeneration utilizing genetic programming, small molecules, cytokines, and bioengineering to transdifferentiate other cell types into β-cells; the development of biomimetic acellular constructs to generate fully functional β-cell-mimetics. However, the maturation of regenerated β-cells is currently limited. Further studies are needed to develop simple and efficient reprogramming methods for assembling perfectly functional β-cells. Future investigations are necessary to transform diabetes into a potentially curable disease.
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Affiliation(s)
- Wenrui Wang
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun, People’s Republic of China
| | - Chuan Zhang
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun, People’s Republic of China
- Correspondence should be addressed to C Zhang:
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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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Šrámek J, Němcová-Fürstová V, Kovář J. Molecular Mechanisms of Apoptosis Induction and Its Regulation by Fatty Acids in Pancreatic β-Cells. Int J Mol Sci 2021; 22:4285. [PMID: 33924206 PMCID: PMC8074590 DOI: 10.3390/ijms22084285] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cell failure and death contribute significantly to the pathogenesis of type 2 diabetes. One of the main factors responsible for β-cell dysfunction and subsequent cell death is chronic exposure to increased concentrations of FAs (fatty acids). The effect of FAs seems to depend particularly on the degree of their saturation. Saturated FAs induce apoptosis in pancreatic β-cells, whereas unsaturated FAs are well tolerated and are even capable of inhibiting the pro-apoptotic effect of saturated FAs. Molecular mechanisms of apoptosis induction by saturated FAs in β-cells are not completely elucidated. Saturated FAs induce ER stress, which in turn leads to activation of all ER stress pathways. When ER stress is severe or prolonged, apoptosis is induced. The main mediator seems to be the CHOP transcription factor. Via regulation of expression/activity of pro- and anti-apoptotic Bcl-2 family members, and potentially also through the increase in ROS production, CHOP switches on the mitochondrial pathway of apoptosis induction. ER stress signalling also possibly leads to autophagy signalling, which may activate caspase-8. Saturated FAs activate or inhibit various signalling pathways, i.e., p38 MAPK signalling, ERK signalling, ceramide signalling, Akt signalling and PKCδ signalling. This may lead to the activation of the mitochondrial pathway of apoptosis, as well. Particularly, the inhibition of the pro-survival Akt signalling seems to play an important role. This inhibition may be mediated by multiple pathways (e.g., ER stress signalling, PKCδ and ceramide) and could also consequence in autophagy signalling. Experimental evidence indicates the involvement of certain miRNAs in mechanisms of FA-induced β-cell apoptosis, as well. In the rather rare situations when unsaturated FAs are also shown to be pro-apoptotic, the mechanisms mediating this effect in β-cells seem to be the same as for saturated FAs. To conclude, FA-induced apoptosis rather appears to be preceded by complex cross talks of multiple signalling pathways. Some of these pathways may be regulated by decreased membrane fluidity due to saturated FA incorporation. Few data are available concerning molecular mechanisms mediating the protective effect of unsaturated FAs on the effect of saturated FAs. It seems that the main possible mechanism represents a rather inhibitory intervention into saturated FA-induced pro-apoptotic signalling than activation of some pro-survival signalling pathway(s) or metabolic interference in β-cells. This inhibitory intervention may be due to an increase of membrane fluidity.
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Affiliation(s)
- Jan Šrámek
- Department of Biochemistry, Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague, Czech Republic;
| | - Vlasta Němcová-Fürstová
- Department of Biochemistry, Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague, Czech Republic;
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Zhu M, Liu X, Liu W, Lu Y, Cheng J, Chen Y. β cell aging and age-related diabetes. Aging (Albany NY) 2021; 13:7691-7706. [PMID: 33686020 PMCID: PMC7993693 DOI: 10.18632/aging.202593] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/23/2020] [Indexed: 02/05/2023]
Abstract
Type 2 diabetes is characterized by insulin resistance and loss of β cell mass and function. Aging is considered as a major risk factor for development of type 2 diabetes. However, the roles of pancreatic β cell senescence and systemic aging in the pathogenesis of type 2 diabetes in elderly people remain poorly understood. In this review, we aimed to discuss the current findings and viewpoints focusing on β cell aging and the development of type 2 diabetes.
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Affiliation(s)
- Min Zhu
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xiaohong Liu
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Wen Liu
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Yanrong Lu
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Jingqiu Cheng
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Younan Chen
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, P.R. China
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, P.R. China
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13
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Marrano N, Biondi G, Borrelli A, Cignarelli A, Perrini S, Laviola L, Giorgino F, Natalicchio A. Irisin and Incretin Hormones: Similarities, Differences, and Implications in Type 2 Diabetes and Obesity. Biomolecules 2021; 11:286. [PMID: 33671882 PMCID: PMC7918991 DOI: 10.3390/biom11020286] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 12/11/2022] Open
Abstract
Incretins are gut hormones that potentiate glucose-stimulated insulin secretion (GSIS) after meals. Glucagon-like peptide-1 (GLP-1) is the most investigated incretin hormone, synthesized mainly by L cells in the lower gut tract. GLP-1 promotes β-cell function and survival and exerts beneficial effects in different organs and tissues. Irisin, a myokine released in response to a high-fat diet and exercise, enhances GSIS. Similar to GLP-1, irisin augments insulin biosynthesis and promotes accrual of β-cell functional mass. In addition, irisin and GLP-1 share comparable pleiotropic effects and activate similar intracellular pathways. The insulinotropic and extra-pancreatic effects of GLP-1 are reduced in type 2 diabetes (T2D) patients but preserved at pharmacological doses. GLP-1 receptor agonists (GLP-1RAs) are therefore among the most widely used antidiabetes drugs, also considered for their cardiovascular benefits and ability to promote weight loss. Irisin levels are lower in T2D patients, and in diabetic and/or obese animal models irisin administration improves glycemic control and promotes weight loss. Interestingly, recent evidence suggests that both GLP-1 and irisin are also synthesized within the pancreatic islets, in α- and β-cells, respectively. This review aims to describe the similarities between GLP-1 and irisin and to propose a new potential axis-involving the gut, muscle, and endocrine pancreas that controls energy homeostasis.
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Affiliation(s)
| | | | | | | | | | | | - Francesco Giorgino
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; (N.M.); (G.B.); (A.B.); (A.C.); (S.P.); (L.L.); (A.N.)
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14
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Gallic acid: Pharmacological activities and molecular mechanisms involved in inflammation-related diseases. Biomed Pharmacother 2021; 133:110985. [DOI: 10.1016/j.biopha.2020.110985] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022] Open
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15
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Drzazga A, Cichońska E, Koziołkiewicz M, Gendaszewska-Darmach E. Formation of βTC3 and MIN6 Pseudoislets Changes the Expression Pattern of Gpr40, Gpr55, and Gpr119 Receptors and Improves Lysophosphatidylcholines-Potentiated Glucose-Stimulated Insulin Secretion. Cells 2020; 9:E2062. [PMID: 32917053 PMCID: PMC7565006 DOI: 10.3390/cells9092062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/01/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
The impaired spatial arrangement and connections between cells creating islets of Langerhans as well as altered expression of G protein-coupled receptors (GPCRs) often lead to dysfunction of insulin-secreting pancreatic β cells and can significantly contribute to the development of diabetes. Differences in glucose-stimulated insulin secretion (GSIS) are noticeable not only in diabetic individuals but also in model pancreatic β cells, e.g., βTC3 and MIN6 β cell lines with impaired and normal insulin secretion, respectively. Now, we compare the ability of GPCR agonists (lysophosphatidylcholines bearing fatty acid chains of different lengths) to potentiate GSIS in βTC3 and MIN6 β cell models, cultured as adherent monolayers and in a form of pseudoislets (PIs) with pancreatic MS1 endothelial cells. Our aim was also to investigate differences in expression of the GPCRs responsive to LPCs in these experimental systems. Aggregation of β cells into islet-like structures greatly enhanced the expression of Gpr40, Gpr55, and Gpr119 receptors. In contrast, the co-culture of βTC3 cells with endothelial cells converted the GPCR expression pattern closer to the pattern observed in MIN6 cells. Additionally, the efficiencies of various LPC species in βTC3-MS1 PIs also shifted toward the MIN6 cell model.
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Affiliation(s)
- Anna Drzazga
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (E.C.); (M.K.)
| | | | | | - Edyta Gendaszewska-Darmach
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (E.C.); (M.K.)
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16
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Marrano N, Biondi G, Cignarelli A, Perrini S, Laviola L, Giorgino F, Natalicchio A. Functional loss of pancreatic islets in type 2 diabetes: How can we halt it? Metabolism 2020; 110:154304. [PMID: 32599081 DOI: 10.1016/j.metabol.2020.154304] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/14/2020] [Accepted: 06/25/2020] [Indexed: 02/08/2023]
Abstract
The loss of beta-cell functional mass is a necessary and early condition in the development of type 2 diabetes (T2D). In T2D patients, beta-cell function is already reduced by about 50% at diagnosis and further declines thereafter. Beta-cell mass is also reduced in subjects with T2D, and islets from diabetic donors are smaller compared to non-diabetic donors. Thus, beta-cell regeneration and/or preservation of the functional islet integrity should be highly considered for T2D treatment and possibly cure. To date, the available anti-diabetes drugs have been developed as "symptomatic" medications since they act to primarily reduce elevated blood glucose levels. However, a truly efficient anti-diabetes medication, capable to prevent the onset and progression of T2D, should stop beta-cell loss and/or promote the restoration of fully functional beta-cell mass, independently of reducing hyperglycemia and ameliorating glucotoxicity on the pancreatic islets. This review provides a view of the experimental and clinical evidence on the ability of available anti-diabetes drugs to exert protective effects on beta-cells, with a specific focus on human pancreatic islets and clinical trials. Potential explanations for the lack of concordance between evidence of beta-cell protection in vitro and of persistent amelioration of beta-cell function in vivo are also discussed.
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Affiliation(s)
- Nicola Marrano
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Giuseppina Biondi
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Angelo Cignarelli
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Sebastio Perrini
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Luigi Laviola
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Francesco Giorgino
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Annalisa Natalicchio
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
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Lytrivi M, Ghaddar K, Lopes M, Rosengren V, Piron A, Yi X, Johansson H, Lehtiö J, Igoillo-Esteve M, Cunha DA, Marselli L, Marchetti P, Ortsäter H, Eizirik DL, Cnop M. Combined transcriptome and proteome profiling of the pancreatic β-cell response to palmitate unveils key pathways of β-cell lipotoxicity. BMC Genomics 2020; 21:590. [PMID: 32847508 PMCID: PMC7448506 DOI: 10.1186/s12864-020-07003-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/19/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prolonged exposure to elevated free fatty acids induces β-cell failure (lipotoxicity) and contributes to the pathogenesis of type 2 diabetes. In vitro exposure of β-cells to the saturated free fatty acid palmitate is a valuable model of lipotoxicity, reproducing features of β-cell failure observed in type 2 diabetes. In order to map the β-cell response to lipotoxicity, we combined RNA-sequencing of palmitate-treated human islets with iTRAQ proteomics of insulin-secreting INS-1E cells following a time course exposure to palmitate. RESULTS Crossing transcriptome and proteome of palmitate-treated β-cells revealed 85 upregulated and 122 downregulated genes at both transcript and protein level. Pathway analysis identified lipid metabolism, oxidative stress, amino-acid metabolism and cell cycle pathways among the most enriched palmitate-modified pathways. Palmitate induced gene expression changes compatible with increased free fatty acid mitochondrial import and β-oxidation, decreased lipogenesis and modified cholesterol transport. Palmitate modified genes regulating endoplasmic reticulum (ER) function, ER-to-Golgi transport and ER stress pathways. Furthermore, palmitate modulated cAMP/protein kinase A (PKA) signaling, inhibiting expression of PKA anchoring proteins and downregulating the GLP-1 receptor. SLC7 family amino-acid transporters were upregulated in response to palmitate but this induction did not contribute to β-cell demise. To unravel critical mediators of lipotoxicity upstream of the palmitate-modified genes, we identified overrepresented transcription factor binding sites and performed network inference analysis. These identified LXR, PPARα, FOXO1 and BACH1 as key transcription factors orchestrating the metabolic and oxidative stress responses to palmitate. CONCLUSIONS This is the first study to combine transcriptomic and sensitive time course proteomic profiling of palmitate-exposed β-cells. Our results provide comprehensive insight into gene and protein expression changes, corroborating and expanding beyond previous findings. The identification of critical drivers and pathways of the β-cell lipotoxic response points to novel therapeutic targets for type 2 diabetes.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium.,Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Kassem Ghaddar
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Miguel Lopes
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Victoria Rosengren
- Diabetes Research Unit, Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Anthony Piron
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Xiaoyan Yi
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Henrik Johansson
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology, Karolinska Institutet, Science for Life Laboratory, 171 21, Solna, Sweden
| | - Janne Lehtiö
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology, Karolinska Institutet, Science for Life Laboratory, 171 21, Solna, Sweden
| | - Mariana Igoillo-Esteve
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Daniel A Cunha
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Henrik Ortsäter
- Diabetes Research Unit, Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Miriam Cnop
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium. .,Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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18
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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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19
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Shen X, Luo L, Yang M, Lin Y, Li J, Yang L. Exendin‑4 inhibits lipotoxicity‑induced oxidative stress in β‑cells by inhibiting the activation of TLR4/NF‑κB signaling pathway. Int J Mol Med 2020; 45:1237-1249. [PMID: 32124969 DOI: 10.3892/ijmm.2020.4490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/02/2019] [Indexed: 11/05/2022] Open
Abstract
The present study aimed to investigate the relationship between the protective effects of exendin‑4 (EX‑4) on lipotoxicity‑induced oxidative stress and meta‑inflammation in β‑cells and the toll‑like receptor 4 (TLR4)/NF‑κB signaling pathway. Lipotoxicity, hydrogen peroxide (H2O2)‑induced oxidative stress in β cells, obese Sprague Dawley rats and TLR4 truncation rats were utilized in the present study. The expression levels were detected by western blotting; cell apoptosis was detected by TUNEL assay; and the intracellular reactive oxygen species (ROS) levels were analyzed using a ROS assay kit. The findings of the present study showed that EX‑4 inhibited the expression of TLR4, NF‑κB p65 subunit and p47phox in a concentration‑dependent manner, and decreased the intracellular level of ROS. Additionally, silencing of TLR4 expression enhanced the protective effects of EX‑4, while overexpression of TLR4 attenuated these protective influences. Simultaneously, it was demonstrated that TLR4 was involved in the process of EX‑4 intervention to inhibit H2O2‑induced oxidative stress in islet β‑cells. Moreover, it was found that EX‑4 also inhibited TLR4‑ or NF‑κB agonist‑induced oxidative stress. These results were also confirmed in an animal model of obese rats, in which EX‑4 was able to improve the function of β‑cells, attenuate oxidative stress, and inhibit the expression levels of TLR4 and NF‑κB p65 subunit in the pancreas of the diet‑induced obese rats. Furthermore, truncation of the TLR4 gene in SD rats delayed the aforementioned damage. In summary, EX‑4 may inhibit lipotoxicity‑induced oxidative stress in β‑cells by inhibiting the activation of the TLR4/NF‑κB signaling pathway.
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Affiliation(s)
- Ximei Shen
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Liufen Luo
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Meng Yang
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Yuxi Lin
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Jing Li
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Liyong Yang
- Endocrinology Department, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
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Abstract
Islets of Langerhans are clusters of endocrine cells embedded within the exocrine pancreas. Islets constitute only approximately 1-2% of the total pancreas mass in all species, so methods have been developed to digest the pancreas and purify islets from the surrounding acinar cells. This chapter provides detailed protocols for isolation of mouse islets and their in vitro functional characterization in terms of assessments of islet viability, hormone content and secretion, second messenger generation and β-cell proliferation.
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Affiliation(s)
- Patricio Atanes
- Department of Diabetes, School of Life Course Sciences, King's College London, London, UK
| | | | - Oladapo E Olaniru
- Department of Diabetes, School of Life Course Sciences, King's College London, London, UK
| | - Shanta J Persaud
- Department of Diabetes, School of Life Course Sciences, King's College London, London, UK.
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21
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Lytrivi M, Castell AL, Poitout V, Cnop M. Recent Insights Into Mechanisms of β-Cell Lipo- and Glucolipotoxicity in Type 2 Diabetes. J Mol Biol 2019; 432:1514-1534. [PMID: 31628942 DOI: 10.1016/j.jmb.2019.09.016] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
The deleterious effects of chronically elevated free fatty acid (FFA) levels on glucose homeostasis are referred to as lipotoxicity, and the concurrent exposure to high glucose may cause synergistic glucolipotoxicity. Lipo- and glucolipotoxicity have been studied for over 25 years. Here, we review the current evidence supporting the role of pancreatic β-cell lipo- and glucolipotoxicity in type 2 diabetes (T2D), including lipid-based interventions in humans, prospective epidemiological studies, and human genetic findings. In addition to total FFA quantity, the quality of FFAs (saturation and chain length) is a key determinant of lipotoxicity. We discuss in vitro and in vivo experimental models to investigate lipo- and glucolipotoxicity in β-cells and describe experimental pitfalls. Lipo- and glucolipotoxicity adversely affect many steps of the insulin production and secretion process. The molecular mechanisms underpinning lipo- and glucolipotoxic β-cell dysfunction and death comprise endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, impaired autophagy, and inflammation. Crosstalk between these stress pathways exists at multiple levels and may aggravate β-cell lipo- and glucolipotoxicity. Lipo- and glucolipotoxicity are therapeutic targets as several drugs impact the underlying stress responses in β-cells, potentially contributing to their glucose-lowering effects in T2D.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Anne-Laure Castell
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Vincent Poitout
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada.
| | - Miriam Cnop
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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22
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Kimura I, Ichimura A, Ohue-Kitano R, Igarashi M. Free Fatty Acid Receptors in Health and Disease. Physiol Rev 2019; 100:171-210. [PMID: 31487233 DOI: 10.1152/physrev.00041.2018] [Citation(s) in RCA: 442] [Impact Index Per Article: 88.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Fatty acids are metabolized and synthesized as energy substrates during biological responses. Long- and medium-chain fatty acids derived mainly from dietary triglycerides, and short-chain fatty acids (SCFAs) produced by gut microbial fermentation of the otherwise indigestible dietary fiber, constitute the major sources of free fatty acids (FFAs) in the metabolic network. Recently, increasing evidence indicates that FFAs serve not only as energy sources but also as natural ligands for a group of orphan G protein-coupled receptors (GPCRs) termed free fatty acid receptors (FFARs), essentially intertwining metabolism and immunity in multiple ways, such as via inflammation regulation and secretion of peptide hormones. To date, several FFARs that are activated by the FFAs of various chain lengths have been identified and characterized. In particular, FFAR1 (GPR40) and FFAR4 (GPR120) are activated by long-chain saturated and unsaturated fatty acids, while FFAR3 (GPR41) and FFAR2 (GPR43) are activated by SCFAs, mainly acetate, butyrate, and propionate. In this review, we discuss the recent reports on the key physiological functions of the FFAR-mediated signaling transduction pathways in the regulation of metabolism and immune responses. We also attempt to reveal future research opportunities for developing therapeutics for metabolic and immune disorders.
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Affiliation(s)
- Ikuo Kimura
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan; and Department of Biochemistry, Kyoto University Graduate School of Pharmaceutical Science, Sakyo, Kyoto, Japan
| | - Atsuhiko Ichimura
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan; and Department of Biochemistry, Kyoto University Graduate School of Pharmaceutical Science, Sakyo, Kyoto, Japan
| | - Ryuji Ohue-Kitano
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan; and Department of Biochemistry, Kyoto University Graduate School of Pharmaceutical Science, Sakyo, Kyoto, Japan
| | - Miki Igarashi
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan; and Department of Biochemistry, Kyoto University Graduate School of Pharmaceutical Science, Sakyo, Kyoto, Japan
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Xiao T, Zhou Y, Li H, Xiong L, Wang J, Wang ZH, Liu LH. MiR-125b suppresses the carcinogenesis of osteosarcoma cells via the MAPK-STAT3 pathway. J Cell Biochem 2019; 120:2616-2626. [PMID: 30277613 DOI: 10.1002/jcb.27568] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/06/2018] [Indexed: 01/24/2023]
Abstract
The microRNA (miRNA) miR-125b is abnormally expressed in many different types of tumors, including osteosarcoma (OS). How aberrantly expressed miR-125b participates in regulating the initiation and progression of OS is still poorly understood. In the current study, we found that in OS, miR-125b can suppress the expression of MAP kinase kinase 7 (MKK7), which can dephosphorylate and inactivate signal transducer and activator of transcription 3 (STAT3). We also identified an elevated expression level of MKK7 in OS and an association between MKK7 expression and poor prognosis. Further, miR-125b inhibited OS cell proliferation and invasion by targeting and downregulating MKK7 in vitro and suppressed tumor formation in vivo. Moreover, using Western blot analysis, we preliminarily proved that the activation (phosphorylation) of STAT3 was regulated by MKK7 at the epigenetic level. MKK7 was overexpressed in OS and associated with poor clinical results. The miR-125b-MAPK-STAT3 axis may be one of the mechanisms of OS oncogenesis and a potential target for the treatment of OS.
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Affiliation(s)
- Tao Xiao
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - You Zhou
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hui Li
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liang Xiong
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jing Wang
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Orthopedics, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Zhi-Hua Wang
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Orthopedics, Chenzhou No. 1 People's Hospital, Chenzhou, China
| | - Li-Hong Liu
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
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Azhar S, Bittner S, Hu J, Shen WJ, Cortez Y, Hao X, Han L, Lagerstedt JO, Kraemer FB, Johansson JO. Novel ABCA1 peptide agonists with antidiabetic action. Mol Cell Endocrinol 2019; 480:1-11. [PMID: 30290217 PMCID: PMC6626528 DOI: 10.1016/j.mce.2018.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/19/2018] [Accepted: 09/30/2018] [Indexed: 12/26/2022]
Abstract
Previously, apoE-derived ABCA1 agonist peptides have been shown to possess anti-atherosclerotic and possibly antidiabetic properties. Here we assessed the in vitro and in vivo actions of a second generation of ABCA1 peptide agonists, CS6253 and T6991-2, on glucose homeostasis. The results show that these two peptides improve glucose tolerance in a prediabetic diet-induced obesity mouse model by enhancing insulin secretion. It was further demonstrated that T6991-2 also improved glucose tolerance in leptin-deficient (ob/ob) mice. CS6253 increased insulin secretion both under basal conditions and in response to high glucose stimulation in pancreatic INS-1 β-cells rendered leptin receptor deficient with specific siRNA. Additional in vitro cell studies suggest that the CS6253 agonist attenuates hepatic gluconeogenesis and glucose transport. It also potentiates insulin-stimulated glucose uptake and utilization. These observed anti-diabetic actions suggest additional benefits of the CS6253 and T6991-2 ABCA1 peptide agonists for cardiovascular disease beyond their direct anti-atherosclerosis properties previously described.
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Affiliation(s)
- Salman Azhar
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Stefanie Bittner
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA
| | - Jie Hu
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; PCET Division, Aragen Bioscience, 260, Chocrane Circle, Morgan Hill, CA, 94307, USA
| | - Wen-Jun Shen
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Yuan Cortez
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA
| | - Xiao Hao
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Endocrinology, The First Affiliated Hospital of the Medical College of Zhengzhou University, Zhengzhou, China
| | - Lu Han
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA
| | - Jens O Lagerstedt
- Department of Experimental Medical Research, Biomedical Center Floor C13, Tornavagen 10, Lund University, S-221 84, Lund, Sweden
| | - Fredric B Kraemer
- Geriatric Research, Education, and Clinical Center (GRECC), VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, CA, 94305, USA
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Astragaloside IV inhibits palmitate-mediated oxidative stress and fibrosis in human glomerular mesangial cells via downregulation of CD36 expression. Pharmacol Rep 2018; 71:319-329. [PMID: 30826573 DOI: 10.1016/j.pharep.2018.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/11/2018] [Accepted: 12/19/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND The increased influx of free fatty acids (FFAs) into the kidney is a risk factor for diabetes nephropathy (DN). In the present study we investigated the effects of astragaloside IV (AS-IV) on FFA-induced lipid accumulation, oxidative stress, and activation of TGF-β1 signaling in human glomerular mesangial cells (HMCs). METHODS A DN model was induced in Sprague Dawley rats by the administration of a high-fat diet and streptozocin, and HMCs were stimulated with palmitate. Lipid accumulation and FFA uptake were detected using Oil Red O and BODIPY™ FL C16 staining, respectively. The expression levels of TGF-β1, p-Smad2/3, FN, Col4 A1, NOX4, p22phox, and CD36 were evaluated by western blotting or immunofluorescence/immunohistochemistry. The level of reactive oxygen species (ROS) was detected using 2',7'-dichlorofluorescein diacetate and dihydroethidium. RESULTS Exposure to palmitate induced marked lipid accumulation in HMCs, whereas co-treatment with AS-IV significantly attenuated this phenomenon. Moreover, AS-IV suppressed palmitate-induced expression of TGF-β1, p-Smad2/3, FN, Col4 A1, NOX4, and p22phox, in addition to ROS production. Notably, AS-IV reduced the palmitate-induced expression of CD36 in HMCs and DN rats. Treatment of HMCs with the CD36 inhibitor, sulfo-N-succinimidyl oleate (SSO), significantly attenuated FFA uptake, oxidative stress, and fibrosis. Nevertheless, the combined use of SSO and AS-IV did not enhance the efficacy. CONCLUSION AS-IV inhibited palmitate-induced HMCs oxidative stress and fibrosis via the downregulation of CD36 expression, mediating FFA uptake and lipid accumulation.
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Tse EK, Belsham DD. Palmitate induces neuroinflammation, ER stress, and Pomc mRNA expression in hypothalamic mHypoA-POMC/GFP neurons through novel mechanisms that are prevented by oleate. Mol Cell Endocrinol 2018; 472:40-49. [PMID: 29180108 DOI: 10.1016/j.mce.2017.11.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/10/2017] [Accepted: 11/23/2017] [Indexed: 01/17/2023]
Abstract
Dietary fats can modulate brain function. How free fatty acids (FFAs) alter hypothalamic pro-opiomelanocortin (POMC) neurons remain undefined. The saturated FFA, palmitate, increased neuroinflammatory and ER stress markers, as well as Pomc mRNA levels, but did not affect insulin signaling, in mHypoA-POMC/GFP-2 neurons. This effect was mediated through the MAP kinases JNK and ERK. Further, the increase in Pomc was dependent on palmitoyl-coA synthesis, but not de novo ceramide synthesis, as inhibition of SPT enhanced palmitate-induced Pomc expression, while methylpalmitate had no effect. While palmitate concomitantly induces neuroinflammation and ER stress, these effects were independent of changes in Pomc expression. Palmitate thus has direct acute effects on Pomc, which appears to be important for negative feedback, but not directly related to neuroinflammation. The monounsaturated FFA oleate completely blocked the palmitate-mediated increase in neuroinflammation, ER stress, and Pomc mRNAs. This study provides insight into the complex central metabolic regulation by FFAs.
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Affiliation(s)
- Erika K Tse
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Denise D Belsham
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada; Departments of Medicine and Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
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27
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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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Candeias E, Sebastião I, Cardoso S, Carvalho C, Santos MS, Oliveira CR, Moreira PI, Duarte AI. Brain GLP-1/IGF-1 Signaling and Autophagy Mediate Exendin-4 Protection Against Apoptosis in Type 2 Diabetic Rats. Mol Neurobiol 2018; 55:4030-4050. [PMID: 28573460 DOI: 10.1007/s12035-017-0622-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/16/2017] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes (T2D) is a modern socioeconomic burden, mostly due to its long-term complications affecting nearly all tissues. One of them is the brain, whose dysfunctional intracellular quality control mechanisms (namely autophagy) may upregulate apoptosis, leading to cognitive dysfunction and Alzheimer disease (AD). Since impaired brain insulin signaling may constitute the crosslink between T2D and AD, its restoration may be potentially therapeutic herein. Accordingly, the insulinotropic anti-T2D drugs from glucagon-like peptide-1 (GLP-1) mimetics, namely, exendin-4 (Ex-4), could be a promising therapy. In line with this, we hypothesized that peripherally administered Ex-4 rescues brain intracellular signaling pathways, promoting autophagy and ultimately protecting against chronic T2D-induced apoptosis. Thus, we aimed to explore the effects of chronic, continuous, subcutaneous (s.c.) exposure to Ex-4 in brain cortical GLP-1/insulin/insulin-like growth factor-1 (IGF-1) signaling, and in autophagic and cell death mechanisms in middle-aged (8 months old), male T2D Goto-Kakizaki (GK) rats. We used brain cortical homogenates obtained from middle-aged (8 months old) male Wistar (control) and T2D GK rats. Ex-4 was continuously administered for 28 days, via s.c. implanted micro-osmotic pumps (5 μg/kg/day; infusion rate 2.5 μL/h). Peripheral characterization of the animal models was given by the standard biochemical analyses of blood or plasma, the intraperitoneal glucose tolerance test, and the heart rate. GLP-1, insulin, and IGF-1, their downstream signaling and autophagic markers were evaluated by specific ELISA kits and Western blotting. Caspase-like activities and other apoptotic markers were given by colorimetric methods and Western blotting. Chronic Ex-4 treatment attenuated peripheral features of T2D in GK rats, including hyperglycemia and insulin resistance. Furthermore, s.c. Ex-4 enhanced their brain cortical GLP-1 and IGF-1 levels, and subsequent signaling pathways. Specifically, Ex-4 stimulated protein kinase A (PKA) and phosphoinositide 3-kinase (PI3K)/Akt signaling, increasing cGMP and AMPK levels, and decreasing GSK3β and JNK activation in T2D rat brains. Moreover, Ex-4 regulated several markers for autophagy in GK rat brains (as mTOR, PI3K class III, LC3 II, Atg7, p62, LAMP-1, and Parkin), ultimately protecting against apoptosis (by decreasing several caspase-like activities and mitochondrial cytochrome c, and increasing Bcl2 levels upon T2D). Altogether, this study demonstrates that peripheral Ex-4 administration may constitute a promising therapy against the chronic complications of T2D affecting the brain.
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Affiliation(s)
- Emanuel Candeias
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Inês Sebastião
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
| | - Susana Cardoso
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Cristina Carvalho
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Maria Sancha Santos
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Life Sciences Department, University of Coimbra, Largo Marquês de Pombal, 3004-517, Coimbra, Portugal
| | - Catarina Resende Oliveira
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal
| | - Paula I Moreira
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal.
- Institute of Physiology, Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal.
| | - Ana I Duarte
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal.
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal.
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Xu H, Wang Q, Sun Q, Qin Y, Han A, Cao Y, Yang Q, Yang P, Lu J, Liu Q, Xiang Q. In type 2 diabetes induced by cigarette smoking, activation of p38 MAPK is involved in pancreatic β-cell apoptosis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:9817-9827. [PMID: 29372523 DOI: 10.1007/s11356-018-1337-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/18/2018] [Indexed: 06/07/2023]
Abstract
Type 2 diabetes (T2D) is a chronic disease caused by pancreatic β-cell dysfunction and insulin resistance. Exposure to smoke is a risk factor for diabetes; however, its mechanisms are unclear. In an epidemiological study, we determined the relationship between cigarette smoking and β-cell function. T2D patients had a history of heavier smoking than people without T2D, and heavy smokers had more abnormal glucose metabolism. For various smoking populations, there was a dose-effect relationship between decreases of homeostatic model assessment (HOMA)-β levels or the increases of HOMA-insulin resistance (IR) levels and amount of smoking (pack-years), which indicated that smoking induced β-cell dysfunction. For MIN6 cells, cigarette smoke extract (CSE) decreased insulin secretion and content; enhanced apoptosis, as illustrated by decreases of BCL-2 levels, increases of BAX and cleaved caspase-3 levels, and an increased apoptotic index; and activated the p38 MAPK pathway. For MIN6 cells, inhibition of p-p38 MAPK by SB203580 prevented enhanced apoptosis and the dysfunction of insulin secretion induced by CSE. In sum, activation of p38 MAPK is involved in the apoptosis of pancreatic β-cells induced by cigarette smoking, which is a possible mechanism for induction of T2D by cigarette smoke.
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Affiliation(s)
- Hui Xu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
- The Key Laboratory of Modern Toxicology, Ministry of Education, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
| | - Qiushi Wang
- School of Public Health, Southeast University, Nanjing, 210009, Jiangsu, People's Republic of China
| | - Qian Sun
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
- The Key Laboratory of Modern Toxicology, Ministry of Education, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
| | - Yu Qin
- Institute of Chronic Non-Communicable Disease Control, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu, People's Republic of China
| | - Aohan Han
- School of Public Health, Southeast University, Nanjing, 210009, Jiangsu, People's Republic of China
| | - Ye Cao
- School of Public Health, Southeast University, Nanjing, 210009, Jiangsu, People's Republic of China
| | - Qianlei Yang
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
- The Key Laboratory of Modern Toxicology, Ministry of Education, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China
| | - Ping Yang
- School of Public Health, Institute for Chemical Carcinogenesis, Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Jiachun Lu
- School of Public Health, Institute for Chemical Carcinogenesis, Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Qizhan Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China.
- The Key Laboratory of Modern Toxicology, Ministry of Education, Nanjing Medical University, Nanjing, 211166, Jiangsu, People's Republic of China.
| | - Quanyong Xiang
- Institute of Chronic Non-Communicable Disease Control, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu, People's Republic of China.
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Arden C. A role for Glucagon-Like Peptide-1 in the regulation of β-cell autophagy. Peptides 2018; 100:85-93. [PMID: 29412836 DOI: 10.1016/j.peptides.2017.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/11/2022]
Abstract
Autophagy is a highly conserved intracellular recycling pathway that serves to recycle damaged organelles/proteins or superfluous nutrients during times of nutritional stress to provide energy to maintain intracellular homeostasis and sustain core metabolic functions. Under these conditions, autophagy functions as a cell survival mechanism but impairment of this pathway can lead to pro-death stimuli. Due to their role in synthesising and secreting insulin, pancreatic β-cells have a high requirement for robust degradation pathways. Recent research suggests that functional autophagy is required to maintain β-cell survival and function in response to high fat diet suggesting a pro-survival role. However, a role for autophagy has also been implicated in the pathogenesis of type 2 diabetes. Thus, the pro-survival vs pro-death role of autophagy in regulating β-cell mass requires discussion. Emerging evidence suggests that Glucagon-Like Peptide-1 (GLP-1) may exert beneficial effects on glucose homeostasis via autophagy-dependent pathways both in pancreatic β-cells and in other cell types. The aim of the current review is to: i) summarise the literature surrounding β-cell autophagy and its pro-death vs pro-survival role in regulating β-cell mass; ii) review the literature describing the impact of GLP-1 on β-cell autophagy and in other cell types; iii) discuss the potential underlying mechanisms.
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Affiliation(s)
- Catherine Arden
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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31
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Natalicchio A, Marrano N, Biondi G, Spagnuolo R, Labarbuta R, Porreca I, Cignarelli A, Bugliani M, Marchetti P, Perrini S, Laviola L, Giorgino F. The Myokine Irisin Is Released in Response to Saturated Fatty Acids and Promotes Pancreatic β-Cell Survival and Insulin Secretion. Diabetes 2017; 66:2849-2856. [PMID: 28724742 DOI: 10.2337/db17-0002] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 07/12/2017] [Indexed: 12/29/2022]
Abstract
This study explored the role of irisin as a new pancreatic β-cell secretagogue and survival factor and its potential role in the communication between skeletal muscle and pancreatic β-cells under lipotoxic conditions. Recombinant irisin stimulated insulin biosynthesis and glucose-stimulated insulin secretion (GSIS) in a PKA-dependent manner and prevented saturated fatty acid-induced apoptosis in human and rat pancreatic β-cells, as well as in human and murine pancreatic islets, via AKT/BCL2 signaling. Treatment of myotubes with 0.5 mmol/L palmitate for 4 h, but not with oleate, promoted an increase in irisin release in the culture medium. Moreover, increased serum levels of irisin were observed in mice fed with a high-fat diet. Mouse serum rich in irisin and the conditioned medium from myotubes exposed to palmitate for 4 h significantly reduced apoptosis of murine pancreatic islets and insulin-secreting INS-1E cells, respectively, and this was abrogated in the presence of an irisin-neutralizing antibody. Finally, in vivo administration of irisin improved GSIS and increased β-cell proliferation. In conclusion, irisin can promote β-cell survival and enhance GSIS and may thus participate in the communication between skeletal muscle and β-cells under conditions of excess saturated fatty acids.
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Affiliation(s)
- Annalisa Natalicchio
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Nicola Marrano
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Giuseppina Biondi
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Rosaria Spagnuolo
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Rossella Labarbuta
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Immacolata Porreca
- Istituto di Ricerche Genetiche "Gaetano Salvatore" (IRGS), Biogem, Ariano Irpino, Italy
| | - Angelo Cignarelli
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Marco Bugliani
- Endocrinology and Metabolism of Transplantation, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy
| | - Piero Marchetti
- Endocrinology and Metabolism of Transplantation, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy
| | - Sebastio Perrini
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Luigi Laviola
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Francesco Giorgino
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
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32
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Leonardini A, D'Oria R, Incalza MA, Caccioppoli C, Andrulli Buccheri V, Cignarelli A, Paparella D, Margari V, Natalicchio A, Perrini S, Giorgino F, Laviola L. GLP-1 Receptor Activation Inhibits Palmitate-Induced Apoptosis via Ceramide in Human Cardiac Progenitor Cells. J Clin Endocrinol Metab 2017; 102:4136-4147. [PMID: 28938428 DOI: 10.1210/jc.2017-00970] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/11/2017] [Indexed: 11/19/2022]
Abstract
CONTEXT Increased apoptosis of cardiomyocytes and cardiac progenitor cells (CPCs) in response to saturated fatty acids (SFAs) can lead to myocardial damage and dysfunction. Ceramides mediate lipotoxicity-induced apoptosis. Glucagonlike peptide-1 receptor (GLP1R) agonists exert beneficial effects on cardiac cells in experimental models. OBJECTIVE To investigate the protective effects of GLP1R activation on SFA-mediated apoptotic death of human CPCs. DESIGN Human CPCs were isolated from cardiac appendages of nondiabetic donors and then exposed to palmitate with or without pretreatment with the GLP1R agonist exendin-4. Ceramide accumulation was evaluated by immunofluorescence. Expression of key enzymes in de novo ceramide biosynthesis was studied by quantitative reverse-transcription polymerase chain reaction and immunoblotting. Apoptosis was evaluated by measuring release of oligonucleosomes, caspase-3 cleavage, caspase activity, and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling. RESULTS Exposure of the CPCs to palmitate resulted in 2.3- and 1.9-fold higher expression of ceramide synthase 5 (CERS5) and ceramide desaturase-1, respectively (P < 0.05). This was associated with intracellular accumulation of ceramide and activation of c-Jun NH2-terminal protein kinase (JNK) signaling and apoptosis (P < 0.05). Both coincubation with fumonisin B1, a specific ceramide synthase inhibitor, and CERS5 knockdown prevented ceramide accumulation, JNK activation, and apoptosis in response to palmitate (P < 0.05). Exendin-4 also prevented the activation of the ceramide biosynthesis and JNK in response to palmitate, inhibiting apoptosis (P < 0.05). CONCLUSIONS Excess palmitate results in activation of ceramide biosynthesis, JNK signaling, and apoptosis in human CPCs. GLP1R activation counteracts this lipotoxic damage via inhibition of ceramide generation, and this may represent a cardioprotective mechanism.
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Affiliation(s)
- Anna Leonardini
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Rossella D'Oria
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Maria Angela Incalza
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Cristina Caccioppoli
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Valentina Andrulli Buccheri
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Angelo Cignarelli
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Domenico Paparella
- Department of Emergency and Organ Transplantation, Section of Cardiac Surgery, University of Bari Aldo Moro, I-70124 Bari, Italy
- Cardiac Surgery, Santa Maria Hospital, I-70124 Bari, Italy
| | - Vito Margari
- Cardiac Surgery, Santa Maria Hospital, I-70124 Bari, Italy
| | - Annalisa Natalicchio
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Sebastio Perrini
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Francesco Giorgino
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
| | - Luigi Laviola
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy
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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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Muscogiuri G, Balercia G, Barrea L, Cignarelli A, Giorgino F, Holst JJ, Laudisio D, Orio F, Tirabassi G, Colao A. Gut: A key player in the pathogenesis of type 2 diabetes? Crit Rev Food Sci Nutr 2017; 58:1294-1309. [PMID: 27892685 DOI: 10.1080/10408398.2016.1252712] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The gut regulates glucose and energy homeostasis; thus, the presence of ingested nutrients into the gut activates sensing mechanisms that affect both glucose homeostasis and regulate food intake. Increasing evidence suggest that gut may also play a key role in the pathogenesis of type 2 diabetes which may be related to both the intestinal microbiological profile and patterns of gut hormones secretion. Intestinal microbiota includes trillions of microorganisms but its composition and function may be adversely affected in type 2 diabetes. The intestinal microbiota may be responsible of the secretion of molecules that may impair insulin secretion/action. At the same time, intestinal milieu regulates the secretion of hormones such as GLP-1, GIP, ghrelin, gastrin, somatostatin, CCK, serotonin, peptide YY, GLP-2, all of which importantly influence metabolism in general and in particular glucose metabolism. Thus, the aim of this paper is to review the current evidence on the role of the gut in the pathogenesis of type 2 diabetes, taking into account both hormonal and microbiological aspects.
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Affiliation(s)
| | - Giancarlo Balercia
- b Division of Endocrinology, Department of Clinical and Molecular Sciences , Umberto I Hospital, Polytechnic University of Marche , Ancona , Italy
| | | | - Angelo Cignarelli
- c Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases , University of Bari Aldo Moro , Bari , Italy
| | - Francesco Giorgino
- c Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases , University of Bari Aldo Moro , Bari , Italy
| | - Jens J Holst
- d NNF Center for Basic Metabolic Research and Department of Biomedical Sciences , Panum Institute, University of Copenhagen, Copenhagen , Denmark
| | | | - Francesco Orio
- e Endocrinology, Department of Sports Science and Wellness , "Parthenope" University Naples , Naples , Italy
| | - Giacomo Tirabassi
- b Division of Endocrinology, Department of Clinical and Molecular Sciences , Umberto I Hospital, Polytechnic University of Marche , Ancona , Italy
| | - Annamaria Colao
- f Department of Clinical Medicine and Surgery , "Federico II" University of Naples , Naples , Italy
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Pedersen HK, Gudmundsdottir V, Brunak S. Pancreatic Islet Protein Complexes and Their Dysregulation in Type 2 Diabetes. Front Genet 2017; 8:43. [PMID: 28473845 PMCID: PMC5397424 DOI: 10.3389/fgene.2017.00043] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/27/2017] [Indexed: 12/18/2022] Open
Abstract
Type 2 diabetes (T2D) is a complex disease that involves multiple genes. Numerous risk loci have already been associated with T2D, although many susceptibility genes remain to be identified given heritability estimates. Systems biology approaches hold potential for discovering novel T2D genes by considering their biological context, such as tissue-specific protein interaction partners. Pancreatic islets are a key T2D tissue and many of the known genetic risk variants lead to impaired islet function, hence a better understanding of the islet-specific dysregulation in the disease-state is essential to unveil the full potential of person-specific profiles. Here we identify 3,692 overlapping pancreatic islet protein complexes (containing 10,805 genes) by integrating islet gene and protein expression data with protein interactions. We found 24 of these complexes to be significantly enriched for genes associated with diabetic phenotypes through heterogeneous evidence sources, including genetic variation, methylation, and gene expression in islets. The analysis specifically revealed ten T2D candidate genes with probable roles in islets (ANPEP, HADH, FAM105A, PDLIM4, PDLIM5, MAP2K4, PPP2R5E, SNX13, GNAS, and FRS2), of which the last six are novel in the context of T2D and the data that went into the analysis. Fifteen of the twenty-four complexes were further enriched for combined genetic associations with glycemic traits, exemplifying how perturbation of protein complexes by multiple small effects can give rise to diabetic phenotypes. The complex nature of T2D ultimately prompts an understanding of the individual patients at the network biology level. We present the foundation for such work by exposing a subset of the global interactome that is dysregulated in T2D and consequently provides a good starting point when evaluating an individual's alterations at the genome, transcriptome, or proteome level in relation to T2D in clinical settings.
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Affiliation(s)
- Helle Krogh Pedersen
- Department of Bio and Health Informatics, Technical University of DenmarkKgs Lyngby, Denmark
| | - Valborg Gudmundsdottir
- Department of Bio and Health Informatics, Technical University of DenmarkKgs Lyngby, Denmark
| | - Søren Brunak
- Department of Bio and Health Informatics, Technical University of DenmarkKgs Lyngby, Denmark
- Disease Systems Biology, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of CopenhagenCopenhagen, Denmark
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36
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Li Z, Xu X, Huang W, Qian H. Free Fatty Acid Receptor 1 (FFAR1) as an Emerging Therapeutic Target for Type 2 Diabetes Mellitus: Recent Progress and Prevailing Challenges. Med Res Rev 2017; 38:381-425. [DOI: 10.1002/med.21441] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/23/2017] [Accepted: 02/14/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Zheng Li
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Xue Xu
- Key Laboratory of Drug Quality Control and Pharmacovigilance; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Wenlong Huang
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Hai Qian
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
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37
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Kinase Signaling in Apoptosis Induced by Saturated Fatty Acids in Pancreatic β-Cells. Int J Mol Sci 2016; 17:ijms17091400. [PMID: 27626409 PMCID: PMC5037680 DOI: 10.3390/ijms17091400] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/18/2016] [Accepted: 08/22/2016] [Indexed: 12/12/2022] Open
Abstract
Pancreatic β-cell failure and death is considered to be one of the main factors responsible for type 2 diabetes. It is caused by, in addition to hyperglycemia, chronic exposure to increased concentrations of fatty acids, mainly saturated fatty acids. Molecular mechanisms of apoptosis induction by saturated fatty acids in β-cells are not completely clear. It has been proposed that kinase signaling could be involved, particularly, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), and Akt kinases and their pathways. In this review, we discuss these kinases and their signaling pathways with respect to their possible role in apoptosis induction by saturated fatty acids in pancreatic β-cells.
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38
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Giorgino F, Bonadonna RC, Gentile S, Vettor R, Pozzilli P. Treatment intensification in patients with inadequate glycemic control on basal insulin: rationale and clinical evidence for the use of short-acting and other glucagon-like peptide-1 receptor agonists. Diabetes Metab Res Rev 2016; 32:497-511. [PMID: 26787264 PMCID: PMC5071744 DOI: 10.1002/dmrr.2775] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/07/2015] [Accepted: 12/18/2015] [Indexed: 12/17/2022]
Abstract
A substantial proportion of patients with type 2 diabetes mellitus do not reach glycemic targets, despite treatment with oral anti-diabetic drugs and basal insulin therapy. Several options exist for treatment intensification beyond basal insulin, and the treatment paradigm is complex. In this review, the options for treatment intensification will be explored, focusing on drug classes that act via the incretin system and paying particular attention to the short-acting glucagon-like peptide-1 receptor agonists exenatide and lixisenatide. Current treatment guidelines will be summarized and discussed. © 2016 The Authors. Diabetes/Metabolism Research and Reviews Published by John Wiley & Sons Ltd.
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Affiliation(s)
- Francesco Giorgino
- Dipartimento dell'Emergenza e dei Trapianti di Organi, Sezione di Medicina Interna, Endocrinologia, Andrologia e Malattie MetabolicheUniversità degli Studi di Bari Aldo MoroBariItaly
| | - Riccardo C. Bonadonna
- Dipartimento di Medicina Clinica e Sperimentale, Divisione di EndocrinologiaUniversità degli Studi di Parma, and AOU di ParmaParmaItaly
| | - Sandro Gentile
- Dipartimento di Medicina Clinica e SperimentaleSeconda Università degli Studi di NapoliNaplesItaly
| | - Roberto Vettor
- Dipartimento di Medicina – DIMED, Clinica Medica 3Università di PadovaPadovaItaly
| | - Paolo Pozzilli
- Department of Endocrinology & DiabetesUniversità Campus Bio‐MedicoRomeItaly
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39
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Bertrand R, Wolf A, Ivashchenko Y, Löhn M, Schäfer M, Brönstrup M, Gotthardt M, Derdau V, Plettenburg O. Synthesis and Characterization of a Promising Novel FFAR1/GPR40 Targeting Fluorescent Probe for β-Cell Imaging. ACS Chem Biol 2016; 11:1745-54. [PMID: 27115176 DOI: 10.1021/acschembio.5b00791] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Diabetes affects an increasing number of patients worldwide and is responsible for a significant rise in healthcare expenses. Imaging of β-cells bears the potential to contribute to an improved understanding, diagnosis, and development of new treatment options for diabetes. Here, we describe the first small molecule fluorescent probe targeting the free fatty acid receptor 1 (FFAR1/GPR40). This receptor is highly expressed on β-cells, and was up to now unexplored for imaging purposes. We designed a novel probe by facile modification of the selective and potent FFAR1 agonist TAK-875. Effective and specific binding of the probe was demonstrated using FFAR1 overexpressing cells. We also successfully labeled FFAR1 on MIN6 and INS1E cells, two widely used β-cell models, by applying an effective amplification protocol. Finally, we showed that the probe is capable of inducing insulin secretion in a glucose-dependent manner, thus demonstrating that functional activity of the probe was maintained. These results suggest that our probe represents a first important step to successful β-cell imaging by targeting FFAR1. The developed probe may prove to be particularly useful for in vitro and ex vivo studies of diabetic cellular and animal models to gain new insights into disease pathogenesis.
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Affiliation(s)
- Romain Bertrand
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
- Department
of Nuclear Medicine, Radboud UMC, Nijmegen 6525, The Netherlands
| | - Andrea Wolf
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
| | - Yuri Ivashchenko
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
| | - Matthias Löhn
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
| | - Matthias Schäfer
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
| | - Mark Brönstrup
- DSAR/Drug
Disposition, Sanofi GmbH, Frankfurt am Main 65926, Germany
- Helmholtz Centre
for Infection Research, Braunschweig 38124, Germany
| | - Martin Gotthardt
- Department
of Nuclear Medicine, Radboud UMC, Nijmegen 6525, The Netherlands
| | - Volker Derdau
- DSAR/Drug
Disposition, Sanofi GmbH, Frankfurt am Main 65926, Germany
| | - Oliver Plettenburg
- Diabetes Division, Research & Translational Medicine, Sanofi GmbH, Frankfurt am Main 65926, Germany
- Institute
of Medicinal Chemistry, Helmholtz Zentrum München, Ingolstaedter
Landstr. 1, Neuherberg 85764, Germany
- Leibniz University
Hannover, Schneiderberg 1 B, Hannover 30167, Germany
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40
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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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41
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Natalicchio A, Biondi G, Marrano N, Labarbuta R, Tortosa F, Spagnuolo R, D'Oria R, Carchia E, Leonardini A, Cignarelli A, Perrini S, Laviola L, Giorgino F. Long-Term Exposure of Pancreatic β-Cells to Palmitate Results in SREBP-1C-Dependent Decreases in GLP-1 Receptor Signaling via CREB and AKT and Insulin Secretory Response. Endocrinology 2016; 157:2243-58. [PMID: 27035653 DOI: 10.1210/en.2015-2003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of prolonged exposure of pancreatic β-cells to high saturated fatty acids on glucagon-like peptide-1 (GLP-1) action were investigated. Murine islets, human pancreatic 1.1B4 cells, and rat INS-1E cells were exposed to palmitate for 24 hours. mRNA and protein expression/phosphorylation were measured by real-time RT-PCR and immunoblotting, respectively. Specific short interfering RNAs were used to knockdown expression of the GLP-1 receptor (Glp1r) and Srebf1. Insulin release was assessed with a specific ELISA. Exposure of murine islets, as well as of human and INS-1E β-cells, to palmitate reduced the ability of exendin-4 to augment insulin mRNA levels, protein content, and release. In addition, palmitate blocked exendin-4-stimulated cAMP-response element-binding protein and v-akt murine thymoma viral oncogene homolog phosphorylation, whereas phosphorylation of MAPK-ERK kinase-1/2 and ERK-1/2 was not altered. Similarly, RNA interference-mediated suppression of Glp1r expression prevented exendin-4-induced cAMP-response element-binding protein and v-akt murine thymoma viral oncogene homolog phosphorylation, but did not impair exendin-4 stimulation of MAPK-ERK kinase-1/2 and ERK-1/2. Both islets from mice fed a high fat diet and human and INS-1E β-cells exposed to palmitate showed reduced GLP-1 receptor and pancreatic duodenal homeobox-1 (PDX-1) and increased sterol regulatory element-binding protein (SREBP-1C) mRNA and protein levels. Furthermore, suppression of SREBP-1C protein expression prevented the reduction of PDX-1 and GLP-1 receptor levels and restored exendin-4 signaling and action. Finally, treatment of INS-1E cells with metformin for 24 h resulted in inhibition of SREBP-1C expression, increased PDX-1 and GLP-1 receptor levels, consequently, enhancement of exendin-4-induced insulin release. Palmitate impairs exendin-4 effects on β-cells by reducing PDX-1 and GLP-1 receptor expression and signaling in a SREBP-1C-dependent manner. Metformin counteracts the impairment of GLP-1 receptor signaling induced by palmitate.
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Affiliation(s)
- Annalisa Natalicchio
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Giuseppina Biondi
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Nicola Marrano
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Rossella Labarbuta
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Federica Tortosa
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Rosaria Spagnuolo
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Rossella D'Oria
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Emanuele Carchia
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Anna Leonardini
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Angelo Cignarelli
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Sebastio Perrini
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Luigi Laviola
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
| | - Francesco Giorgino
- Department of Emergency and Organ Transplantation (A.N., G.B., N.M., R.L., F.T., R.S., R.D., A.L., A.C., S.P., L.L., F.G.), Section of Internal Medicine, Endocrinology, Andrology, and Metabolic Diseases, University of Bari Aldo Moro, I-70124 Bari, Italy; and IRGS Biogem (E.C.), I-83031 Ariano Irpino, Avellino, Italy
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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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p38 MAPK Is Activated but Does Not Play a Key Role during Apoptosis Induction by Saturated Fatty Acid in Human Pancreatic β-Cells. Int J Mol Sci 2016; 17:159. [PMID: 26861294 PMCID: PMC4783893 DOI: 10.3390/ijms17020159] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 12/29/2015] [Accepted: 01/22/2016] [Indexed: 12/25/2022] Open
Abstract
Saturated stearic acid (SA) induces apoptosis in the human pancreatic β-cells NES2Y. However, the molecular mechanisms involved are unclear. We showed that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway in these cells. Therefore, we tested the role of p38 MAPK signaling pathway activation in apoptosis induction by SA in NES2Y cells. Crosstalk between p38 MAPK pathway activation and accompanying ERK pathway inhibition after SA application was also tested. The inhibition of p38 MAPK expression by siRNA silencing resulted in a decrease in MAPKAPK-2 activation after SA application, but it had no significant effect on cell viability or the level of phosphorylated ERK pathway members. The inhibition of p38 MAPK activity by the specific inhibitor SB202190 resulted in inhibition of MAPKAPK-2 activation and noticeable activation of ERK pathway members after SA treatment but in no significant effect on cell viability. p38 MAPK overexpression by plasmid transfection produced an increase in MAPKAPK-2 activation after SA exposure but no significant influence on cell viability or ERK pathway activation. The activation of p38 MAPK by the specific activator anisomycin resulted in significant activation of MAPKAPK-2. Concerning the effect on cell viability, application of the activator led to apoptosis induction similar to application of SA (PARP cleavage and caspase-7, -8, and -9 activation) and in inhibition of ERK pathway members. We demonstrated that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway and that this activation could be involved in apoptosis induction by SA in the human pancreatic β-cells NES2Y. However, this involvement does not seem to play a key role. Crosstalk between p38 MAPK pathway activation and ERK pathway inhibition in NES2Y cells seems likely. Thus, the ERK pathway inhibition by p38 MAPK activation does not also seem to be essential for SA-induced apoptosis.
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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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Evaluation of low doses BPA-induced perturbation of glycemia by toxicogenomics points to a primary role of pancreatic islets and to the mechanism of toxicity. Cell Death Dis 2015; 6:e1959. [PMID: 26512966 PMCID: PMC5399181 DOI: 10.1038/cddis.2015.319] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 09/22/2015] [Accepted: 09/24/2015] [Indexed: 01/15/2023]
Abstract
Epidemiologic and experimental studies have associated changes of blood glucose homeostasis to Bisphenol A (BPA) exposure. We took a toxicogenomic approach to investigate the mechanisms of low-dose (1 × 10−9 M) BPA toxicity in ex vivo cultures of primary murine pancreatic islets and hepatocytes. Twenty-nine inhibited genes were identified in islets and none in exposed hepatocytes. Although their expression was slightly altered, their impaired cellular level, as a whole, resulted in specific phenotypic changes. Damage of mitochondrial function and metabolism, as predicted by bioinformatics analyses, was observed: BPA exposure led to a time-dependent decrease in mitochondrial membrane potential, to an increase of ROS cellular levels and, finally, to an induction of apoptosis, attributable to the bigger Bax/Bcl-2 ratio owing to activation of NF-κB pathway. Our data suggest a multifactorial mechanism for BPA toxicity in pancreatic islets with emphasis to mitochondria dysfunction and NF-κB activation. Finally, we assessed in vitro the viability of BPA-treated islets in stressing condition, as exposure to high glucose, evidencing a reduced ability of the exposed islets to respond to further damages. The result was confirmed in vivo evaluating the reduction of glycemia in hyperglycemic mice transplanted with control and BPA-treated pancreatic islets. The reported findings identify the pancreatic islet as the main target of BPA toxicity in impairing the glycemia. They suggest that the BPA exposure can weaken the response of the pancreatic islets to damages. The last observation could represent a broader concept whose consideration should lead to the development of experimental plans better reproducing the multiple exposure conditions.
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46
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Dai YL, Huang SL, Leng Y. AICAR and Metformin Exert AMPK-dependent Effects on INS-1E Pancreatic β-cell Apoptosis via Differential Downstream Mechanisms. Int J Biol Sci 2015; 11:1272-80. [PMID: 26435693 PMCID: PMC4582151 DOI: 10.7150/ijbs.12108] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 08/12/2015] [Indexed: 11/05/2022] Open
Abstract
The role of AMP-activated protein kinase (AMPK) in pancreatic β-cell apoptosis is still controversial, and the reasons for the discrepancies have not been clarified. In the current study, we observed the effects of two well-known AMPK activators 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and metformin, on apoptosis in rat insulinoma INS-1E cells, and further explored their possible mechanisms. Both AICAR and metformin protected INS-1E cells from palmitate-induced apoptosis, as reflected by decreases in both cleaved caspase 3 protein expression and caspase 3/7 activity, and these protective effects were abrogated by AMPK inhibitor compound C. The protective action of AICAR was probably mediated by the suppression of triacylglycerol accumulation, increase in Akt phosphorylation and decrease in p38 MAPK phosphorylation, while metformin might exert its protective effect on INS-1E cells by decreases in both JNK and p38 MAPK phosphorylation. All these regulations were dependent on AMPK activation. However, under standard culture condition, AICAR increased JNK phosphorylation and promoted INS-1E cell apoptosis in an AMPK-dependent manner, whereas metformin showed no effect on apoptosis. Our study revealed that AMPK activators AICAR and metformin exhibited different effects on INS-1E cell apoptosis under different culture conditions, which might be largely attributed to different downstream mediators. Our results provided new and informative clues for better understanding of the role of AMPK in β-cell apoptosis.
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Affiliation(s)
- Yu-Lu Dai
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road 555, Shanghai 201203, China
| | - Su-Ling Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road 555, Shanghai 201203, China
| | - Ying Leng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road 555, Shanghai 201203, China
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Carlessi R, Lemos NE, Dias AL, Oliveira FS, Brondani LA, Canani LH, Bauer AC, Leitão CB, Crispim D. Exendin-4 protects rat islets against loss of viability and function induced by brain death. Mol Cell Endocrinol 2015; 412:239-50. [PMID: 25976662 DOI: 10.1016/j.mce.2015.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 02/01/2023]
Abstract
Islet quality loss after isolation from brain-dead donors still hinders the implementation of human islet transplantation for treatment of type 1 diabetes. In this scenario, systemic inflammation elicited by donor brain death (BD) is among the main factors influencing islet viability and functional impairment. Exendin-4 is largely recognized to promote anti-inflammatory and cytoprotective effects on β-cells. Therefore, we hypothesized that administration of exendin-4 to brain-dead donors might improve islet survival and insulin secretory capabilities. Here, using a rat model of BD, we demonstrate that exendin-4 administration to the brain-dead donors increases both islet viability and glucose-stimulated insulin secretion. In this model, exendin-4 treatment produced a significant decrease in interleukin-1β expression in the pancreas. Furthermore, exendin-4 treatment increased the expression of superoxide dismutase-2 and prevented BD-induced elevation in uncoupling protein-2 expression. Such observations were accompanied by a reduction in gene expression of two genes often associated with endoplasmic reticulum (ER) stress response in freshly isolated islets from treated animals, C/EBP homologous protein and immunoglobulin heavy-chain binding protein. As ER stress response has been shown to be triggered by and to participate in cytokine-induced β-cell death, we suggest that exendin-4 might exert its beneficial effects through alleviation of pancreatic inflammation and oxidative stress, which in turn could prevent islet ER stress and β-cell death. Our findings might unveil a novel strategy to preserve islet quality from brain-dead donors. After testing in the human pancreatic islet transplantation setting, this approach might sum to the ongoing effort to achieve consistent and successful single-donor islet transplantation.
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Affiliation(s)
- Rodrigo Carlessi
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; School of Biomedical Sciences, CHIRI - Biosciences, Curtin University, Perth, Western Australia 6845, Australia
| | - Natália E Lemos
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ana L Dias
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Fernanda S Oliveira
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Letícia A Brondani
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Luis H Canani
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Andrea C Bauer
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Cristiane B Leitão
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Daisy Crispim
- Laboratory of Human Pancreatic Islet Biology, Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-Graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Han S, Englander EW, Gomez GA, Rastellini C, Quertermous T, Kundu RK, Greeley GH. Pancreatic Islet APJ Deletion Reduces Islet Density and Glucose Tolerance in Mice. Endocrinology 2015; 156:2451-60. [PMID: 25965959 DOI: 10.1210/en.2014-1631] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protection and replenishment of a functional pancreatic β-cell mass (BCM) are key goals of all diabetes therapies. Apelin, a small regulatory peptide, is the endogenous ligand for the apelin receptor (APJ) receptor. The apelin-APJ signaling system is expressed in rodent and human islet cells. Apelin exposure has been shown to inhibit and to stimulate insulin secretion. Our aim was to assess the influence of a selective APJ deletion in pancreatic islet cells on islet homeostasis and glucose tolerance in mice. Cre-LoxP strategy was utilized to mediate islet APJ deletion. APJ deletion in islet cells (APJ(Δislet)) resulted in a significantly reduced islet size, density and BCM. An ip glucose tolerance test showed significantly impaired glucose clearance in APJ(Δislet) mice. APJ(Δislet) mice were not insulin resistant and in vivo glucose-stimulated insulin secretion was reduced modestly. In vitro glucose-stimulated insulin secretion showed a significantly reduced insulin secretion by islets from APJ(Δislet) mice. Glucose clearance in response to ip glucose tolerance test in obese APJ(Δislet) mice fed a chronic high-fat (HF) diet, but not pregnant APJ(Δislet) mice, was impaired significantly. In addition, the obesity-induced adaptive elevations in mean islet size and fractional islet area were reduced significantly in obese APJ(Δislet) mice when compared with wild-type mice. Together, these findings demonstrate a stimulatory role for the islet cell apelin-APJ signaling axis in regulation of pancreatic islet homeostasis and in metabolic induced β-cell hyperplasia. The results indicate the apelin-APJ system can be exploited for replenishment of BCM.
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Affiliation(s)
- Song Han
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - Ella W Englander
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - Guillermo A Gomez
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - Cristiana Rastellini
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - Thomas Quertermous
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - Ramendra K Kundu
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
| | - George H Greeley
- Department of Surgery (S.H., E.W.E., G.A.G., C.R., G.H.G.), University of Texas Medical Branch, Galveston, Texas 77555; and School of Medicine (T.Q., R.K.K.), Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305
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Natalicchio A, Tortosa F, Labarbuta R, Biondi G, Marrano N, Carchia E, Leonardini A, Cignarelli A, Bugliani M, Marchetti P, Fadini GP, Giorgio M, Avogaro A, Perrini S, Laviola L, Giorgino F. The p66(Shc) redox adaptor protein is induced by saturated fatty acids and mediates lipotoxicity-induced apoptosis in pancreatic beta cells. Diabetologia 2015; 58:1260-71. [PMID: 25810038 DOI: 10.1007/s00125-015-3563-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/27/2015] [Indexed: 01/03/2023]
Abstract
AIMS/HYPOTHESIS The role of the redox adaptor protein p66(Shc) as a potential mediator of saturated fatty acid (FA)-induced beta cell death was investigated. METHODS The effects of the FA palmitate on p66(Shc) expression were evaluated in human and murine islets and in rat insulin-secreting INS-1E cells. p66(Shc) expression was also measured in islets from mice fed a high-fat diet (HFD) and from human donors with different BMIs. Cell apoptosis was quantified by two independent assays. The role of p66(Shc) was investigated using pancreatic islets from p66 (Shc-/-) mice and in INS-1E cells with knockdown of p66(Shc) or overexpression of wild-type and phosphorylation-defective p66(Shc). Production of reactive oxygen species (ROS) was evaluated by the dihydroethidium oxidation method. RESULTS Palmitate induced a selective increase in p66(Shc) protein expression and phosphorylation on Ser(36) and augmented apoptosis in human and mouse islets and in INS-1E cells. Inhibiting the tumour suppressor protein p53 prevented both the palmitate-induced increase in p66(Shc) expression and beta cell apoptosis. Palmitate-induced apoptosis was abrogated in islets from p66 (Shc-/-) mice and following p66 (Shc) knockdown in INS-1E cells; by contrast, overexpression of p66(Shc), but not that of the phosphorylation-defective p66(Shc) mutant, enhanced palmitate-induced apoptosis. The pro-apoptotic effects of p66(Shc) were dependent upon its c-Jun N-terminal kinase-mediated phosphorylation on Ser(36) and associated with generation of ROS. p66(Shc) protein expression and function were also elevated in islets from HFD-fed mice and from obese/overweight cadaveric human donors. CONCLUSIONS/INTERPRETATION p53-dependent augmentation of p66(Shc) expression and function represents a key signalling response contributing to beta cell apoptosis under conditions of lipotoxicity.
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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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50
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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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