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Xiao X, Deng H, Lin X, Ali ASM, Viscardi A, Guo Z, Qiao L, He Y, Han J. Selenium nanoparticles: Properties, preparation methods, and therapeutic applications. Chem Biol Interact 2023; 378:110483. [PMID: 37044285 DOI: 10.1016/j.cbi.2023.110483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/26/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Selenium nanoparticles (SeNPs) are a unique type of nano-sized elemental selenium that have recently found wide application in biomedicine. It has been shown that the properties of SeNPs can be varied by different fabrication methods. Moreover, SeNPs have various therapeutic effects in medical applications due to their excellent biological and adaptable physical properties. At the same time, SeNPs can be used as a carrier medium for various therapeutic substances, which can bring out the full curative effects of the drugs. In this review, the differences in bioactivity properties of SeNPs prepared from different substances were reviewed; the therapeutic effects and mechanisms of SeNPs in cancer, inflammation, neurodegenerative diseases, diabetes, reproductive diseases, cardiovascular diseases, and other diseases were discussed; and the importance of the development of SeNPs was further emphasized.
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Affiliation(s)
- Xiang Xiao
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Huan Deng
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Xue Lin
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Ahmed Sameir Mohamed Ali
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, PR China.
| | - Angelo Viscardi
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Ziwei Guo
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Lichun Qiao
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Yujie He
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
| | - Jing Han
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China.
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Wei C, Zhang Z, Fu Q, He Y, Yang T, Sun M. The reversible effects of free fatty acids on sulfonylurea-stimulated insulin secretion are related to the expression and dynamin-mediated endocytosis of KATP channels in pancreatic β cells. Endocr Connect 2023; 12:e220221. [PMID: 36398885 PMCID: PMC9782416 DOI: 10.1530/ec-22-0221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/19/2022]
Abstract
Objective Lipotoxicity-induced pancreatic β cell-dysfunction results in decreased insulin secretion in response to multiple stimulus. In this study, we investigated the reversible effects of palmitate (PA) or oleate (OA) on insulin secretion and the relationship with pancreatic β-cell ATP-sensitive potassium (KATP) channels. Methods MIN6 cells were treated with PA and OA for 48 h and then washed out for 24 h to determine the changes in expression and endocytosis of the KATP channels and glucose-stimulated insulin secretion (GSIS) and sulfonylurea-stimulated insulin secretion (SU-SIS). Results MIN6 cells exposed to PA or OA showed both impaired GSIS and SU-SIS; the former was not restorable, while the latter was reversible with washout of PA or OA. Decreased expressions of both total and surface Kir6.2 and SUR1 and endocytosis of KATP channels were observed, which were also recoverable after washout. When MIN6 cells exposed to free fatty acids (FFAs) were cotreated with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or dynasore, we found that endocytosis of KATP channels did not change significantly by AICAR but was almost completely blocked by dynasore. Meanwhile, the inhibition of endocytosis of KATP channels after washout could be activated by PIP2. The recovery of SU-SIS after washout was significantly weakened by PIP2, but the decrease of SU-SIS induced by FFAs was not alleviated by dynasore. Conclusions FFAs can cause reversible impairment of SU-SIS on pancreatic β cells. The reversibility of the effects is partial because of the changes of expression and endocytosis of Kir6.2 and SUR1 which was mediated by dynamin.
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Affiliation(s)
- Chenmin Wei
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
- Department of Endocrinology, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zichen Zhang
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qi Fu
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yunqiang He
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Tao Yang
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Min Sun
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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Zaric BL, Macvanin MT, Isenovic ER. Free radicals: Relationship to Human Diseases and Potential Therapeutic applications. Int J Biochem Cell Biol 2023; 154:106346. [PMID: 36538984 DOI: 10.1016/j.biocel.2022.106346] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/06/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Reactive species are highly-reactive enzymatically, or non-enzymatically produced compounds with important roles in physiological and pathophysiological cellular processes. Although reactive species represent an extensively researched topic in biomedical sciences, many aspects of their roles and functions remain unclear. This review aims to systematically summarize findings regarding the biochemical characteristics of various types of reactive species and specify the localization and mechanisms of their production in cells. In addition, we discuss the specific roles of free radicals in cellular physiology, focusing on the current lines of research that aim to identify the reactive oxygen species-initiated cascades of reactions resulting in adaptive or pathological cellular responses. Finally, we present recent findings regarding the therapeutic modulations of intracellular levels of reactive oxygen species, which may have substantial significance in developing novel agents for treating several diseases.
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Affiliation(s)
- Bozidarka L Zaric
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia.
| | - Mirjana T Macvanin
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Esma R Isenovic
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
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4
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Fuller H, Iles M, Moore JB, Zulyniak MA. Unique Metabolic Profiles Associate with Gestational Diabetes and Ethnicity in Low- and High-Risk Women Living in the UK. J Nutr 2022; 152:2186-2197. [PMID: 35883228 PMCID: PMC9535440 DOI: 10.1093/jn/nxac163] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/28/2022] [Accepted: 07/20/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Gestational diabetes mellitus (GDM) is the most common global pregnancy complication; however, prevalence varies substantially between ethnicities, with South Asians (SAs) experiencing up to 3 times the risk of the disease compared with white Europeans (WEs). Factors driving this discrepancy are unclear, although the metabolome is of great interest as GDM is known to be characterized by metabolic dysregulation. OBJECTIVES The primary aim was to characterize and compare the metabolic profiles of GDM in SA and WE women (at <28 wk of gestation) from the Born in Bradford (BIB) prospective birth cohort in the United Kingdom. METHODS In total, 146 fasting serum metabolites, from 2,668 pregnant WE and 2,671 pregnant SA women (average BMI 26.2 kg/m2, average age 27.3 y) were analyzed using partial least squares discriminatory analyses to characterize GDM status. Linear associations between metabolite values and post-oral glucose tolerance test measures of dysglycemia (fasting glucose and 2 h postglucose) were also examined. RESULTS Seven metabolites associated with GDM status in both ethnicities (variable importance in projection ≥1), whereas 6 additional metabolites associated with GDM only in WE women. Unique metabolic profiles were observed in healthy-weight women who later developed GDM, with distinct metabolite patterns identified by ethnicity and BMI status. Of the metabolite values analyzed in relation to dysglycemia, lactate, histidine, apolipoprotein A1, HDL cholesterol, and HDL2 cholesterol associated with decreased glucose concentration, whereas DHA and the diameter of very low-density lipoprotein particles (nm) associated with increased glucose concertation in WE women, and in SAs, albumin alone associated with decreased glucose concentration. CONCLUSIONS This study shows that the metabolic risk profile for GDM differs between WE and SA women enrolled in BiB in the United Kingdom. This suggests that etiology of the disease differs between ethnic groups and that ethnic-appropriate prevention strategies may be beneficial.
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Affiliation(s)
- Harriett Fuller
- Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Leeds, UK
| | - Mark Iles
- Leeds Institute of Medical Research, University of Leeds, Leeds, UK
- Leeds Institute for Data Analytics, University of Leeds, Leeds, UK
| | - J Bernadette Moore
- Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Leeds, UK
| | - Michael A Zulyniak
- Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Leeds, UK
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Todero JE, Koch-Laskowski K, Shi Q, Kanke M, Hung YH, Beck R, Styblo M, Sethupathy P. Candidate master microRNA regulator of arsenic-induced pancreatic beta cell impairment revealed by multi-omics analysis. Arch Toxicol 2022; 96:1685-1699. [PMID: 35314868 PMCID: PMC9095563 DOI: 10.1007/s00204-022-03263-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/17/2022] [Indexed: 02/05/2023]
Abstract
Arsenic is a pervasive environmental toxin that is listed as the top priority for investigation by the Agency for Toxic Substance and Disease Registry. While chronic exposure to arsenic is associated with type 2 diabetes (T2D), the underlying mechanisms are largely unknown. We have recently demonstrated that arsenic treatment of INS-1 832/13 pancreatic beta cells impairs glucose-stimulated insulin secretion (GSIS), a T2D hallmark. We have also shown that arsenic alters the microRNA profile of beta cells. MicroRNAs have a well-established post-transcriptional regulatory role in both normal beta cell function and T2D pathogenesis. We hypothesized that there are microRNA master regulators that shape beta cell gene expression in pathways pertinent to GSIS after exposure to arsenicals. To test this hypothesis, we first treated INS-1 832/13 beta cells with either inorganic arsenic (iAsIII) or monomethylarsenite (MAsIII) and confirmed GSIS impairment. We then performed multi-omic analysis using chromatin run-on sequencing, RNA-sequencing, and small RNA-sequencing to define profiles of transcription, gene expression, and microRNAs, respectively. Integrating across these data sets, we first showed that genes downregulated by iAsIII treatment are enriched in insulin secretion and T2D pathways, whereas genes downregulated by MAsIII treatment are enriched in cell cycle and critical beta cell maintenance factors. We also defined the genes that are subject primarily to post-transcriptional control in response to arsenicals and demonstrated that miR-29a is the top candidate master regulator of these genes. Our results highlight the importance of microRNAs in arsenical-induced beta cell dysfunction and reveal both shared and unique mechanisms between iAsIII and MAsIII.
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Affiliation(s)
- Jenna E Todero
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Kieran Koch-Laskowski
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Qing Shi
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matt Kanke
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Yu-Han Hung
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Rowan Beck
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Miroslav Styblo
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
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Newsholme P, Rowlands J, Rose’Meyer R, Cruzat V. Metabolic Adaptions/Reprogramming in Islet Beta-Cells in Response to Physiological Stimulators—What Are the Consequences. Antioxidants (Basel) 2022; 11:antiox11010108. [PMID: 35052612 PMCID: PMC8773416 DOI: 10.3390/antiox11010108] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/25/2022] Open
Abstract
Irreversible pancreatic β-cell damage may be a result of chronic exposure to supraphysiological glucose or lipid concentrations or chronic exposure to therapeutic anti-diabetic drugs. The β-cells are able to respond to blood glucose in a narrow concentration range and release insulin in response, following activation of metabolic pathways such as glycolysis and the TCA cycle. The β-cell cannot protect itself from glucose toxicity by blocking glucose uptake, but indeed relies on alternative metabolic protection mechanisms to avoid dysfunction and death. Alteration of normal metabolic pathway function occurs as a counter regulatory response to high nutrient, inflammatory factor, hormone or therapeutic drug concentrations. Metabolic reprogramming is a term widely used to describe a change in regulation of various metabolic enzymes and transporters, usually associated with cell growth and proliferation and may involve reshaping epigenetic responses, in particular the acetylation and methylation of histone proteins and DNA. Other metabolic modifications such as Malonylation, Succinylation, Hydroxybutyrylation, ADP-ribosylation, and Lactylation, may impact regulatory processes, many of which need to be investigated in detail to contribute to current advances in metabolism. By describing multiple mechanisms of metabolic adaption that are available to the β-cell across its lifespan, we hope to identify sites for metabolic reprogramming mechanisms, most of which are incompletely described or understood. Many of these mechanisms are related to prominent antioxidant responses. Here, we have attempted to describe the key β-cell metabolic adaptions and changes which are required for survival and function in various physiological, pathological and pharmacological conditions.
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Affiliation(s)
- Philip Newsholme
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Jordan Rowlands
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Roselyn Rose’Meyer
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia;
| | - Vinicius Cruzat
- Faculty of Health, Torrens University Australia, Brisbane, QLD 4006, Australia;
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Galán B, Serdan T, Rodrigues L, Manoel R, Gorjão R, Masi L, Pithon-Curi T, Curi R, Hirabara S. Reviewing physical exercise in non-obese diabetic Goto-Kakizaki rats. Braz J Med Biol Res 2022; 55:e11795. [PMID: 35648976 PMCID: PMC9150428 DOI: 10.1590/1414-431x2022e11795] [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: 09/25/2021] [Accepted: 03/09/2022] [Indexed: 11/26/2022] Open
Abstract
There is a high incidence of non-obese type 2 diabetes mellitus (non-obese-T2DM) cases, particularly in Asian countries, for which the pathogenesis remains mainly unclear. Interestingly, Goto-Kakizaki (GK) rats spontaneously develop insulin resistance (IR) and non-obese-T2DM, making them a lean diabetes model. Physical exercise is a non-pharmacological therapeutic approach to reduce adipose tissue mass, improving peripheral IR, glycemic control, and quality of life in obese animals or humans with T2DM. In this narrative review, we selected and analyzed the published literature on the effects of physical exercise on the metabolic features associated with non-obese-T2DM. Only randomized controlled trials with regular physical exercise training, freely executed physical activity, or skeletal muscle stimulation protocols in GK rats published after 2008 were included. The results indicated that exercise reduces plasma insulin levels, increases skeletal muscle glycogen content, improves exercise tolerance, protects renal and myocardial function, and enhances blood oxygen flow in GK rats.
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Affiliation(s)
- B.S.M. Galán
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - T.D.A. Serdan
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil; New York University, USA
| | - L.E. Rodrigues
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - R. Manoel
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - R. Gorjão
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - L.N. Masi
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - T.C. Pithon-Curi
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
| | - R. Curi
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil; Instituto Butantan, Brasil
| | - S.M. Hirabara
- Instituto de Atividade Física e Esportes, Universidade Cruzeiro do Sul, Brasil
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Zhao YF. Free fatty acid receptors in the endocrine regulation of glucose metabolism: Insight from gastrointestinal-pancreatic-adipose interactions. Front Endocrinol (Lausanne) 2022; 13:956277. [PMID: 36246919 PMCID: PMC9554507 DOI: 10.3389/fendo.2022.956277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/14/2022] [Indexed: 11/25/2022] Open
Abstract
Glucose metabolism is primarily controlled by pancreatic hormones, with the coordinated assistance of the hormones from gastrointestine and adipose tissue. Studies have unfolded a sophisticated hormonal gastrointestinal-pancreatic-adipose interaction network, which essentially maintains glucose homeostasis in response to the changes in substrates and nutrients. Free fatty acids (FFAs) are the important substrates that are involved in glucose metabolism. FFAs are able to activate the G-protein coupled membrane receptors including GPR40, GPR120, GPR41 and GPR43, which are specifically expressed in pancreatic islet cells, enteroendocrine cells as well as adipocytes. The activation of FFA receptors regulates the secretion of hormones from pancreas, gastrointestine and adipose tissue to influence glucose metabolism. This review presents the effects of the FFA receptors on glucose metabolism via the hormonal gastrointestinal-pancreatic-adipose interactions and the underlying intracellular mechanisms. Furthermore, the development of therapeutic drugs targeting FFA receptors for the treatment of abnormal glucose metabolism such as type 2 diabetes mellitus is summarized.
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Vilas-Boas EA, Almeida DC, Roma LP, Ortis F, Carpinelli AR. Lipotoxicity and β-Cell Failure in Type 2 Diabetes: Oxidative Stress Linked to NADPH Oxidase and ER Stress. Cells 2021; 10:cells10123328. [PMID: 34943836 PMCID: PMC8699655 DOI: 10.3390/cells10123328] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022] Open
Abstract
A high caloric intake, rich in saturated fats, greatly contributes to the development of obesity, which is the leading risk factor for type 2 diabetes (T2D). A persistent caloric surplus increases plasma levels of fatty acids (FAs), especially saturated ones, which were shown to negatively impact pancreatic β-cell function and survival in a process called lipotoxicity. Lipotoxicity in β-cells activates different stress pathways, culminating in β-cells dysfunction and death. Among all stresses, endoplasmic reticulum (ER) stress and oxidative stress have been shown to be strongly correlated. One main source of oxidative stress in pancreatic β-cells appears to be the reactive oxygen species producer NADPH oxidase (NOX) enzyme, which has a role in the glucose-stimulated insulin secretion and in the β-cell demise during both T1 and T2D. In this review, we focus on the acute and chronic effects of FAs and the lipotoxicity-induced β-cell failure during T2D development, with special emphasis on the oxidative stress induced by NOX, the ER stress, and the crosstalk between NOX and ER stress.
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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 05508-000, Brazil
- Department of Biochemistry, Institute of Chemistry, University of São Paulo (USP), São Paulo 05508-900, Brazil
- Correspondence: (E.A.V.-B.); (A.R.C.); Tel.: +55-(11)-3091-7246 (A.R.C.)
| | - Davidson Correa Almeida
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-000, Brazil; (D.C.A.); (F.O.)
| | - Leticia Prates Roma
- Center for Human and Molecular Biology (ZHMB), Department of Biophysics, Saarland University, 66424 Homburg, Germany;
| | - Fernanda Ortis
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-000, Brazil; (D.C.A.); (F.O.)
| | - Angelo Rafael Carpinelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-000, Brazil
- Correspondence: (E.A.V.-B.); (A.R.C.); Tel.: +55-(11)-3091-7246 (A.R.C.)
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Vanderkruk B, Hoffman BG. Metabolism as a central regulator of β-cell chromatin state. FEBS J 2020; 288:3683-3693. [PMID: 32926557 DOI: 10.1111/febs.15562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/06/2020] [Accepted: 09/07/2020] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells are critical mediators of glucose homeostasis in the body, and proper cellular nutrient metabolism is critical to β-cell function. Several interacting signaling networks that uniquely control β-cell metabolism produce essential substrates and co-factors for catalytic reactions, including reactions that modify chromatin. Chromatin modifications, in turn, regulate gene expression. The reactions that modify chromatin are therefore well-positioned to adjust gene expression programs according to nutrient availability. It follows that dysregulation of nutrient metabolism in β-cells may impact chromatin state and gene expression through altering the availability of these substrates and co-factors. Metabolic disorders such as type 2 diabetes (T2D) can significantly alter metabolite levels in cells. This suggests that a driver of β-cell dysfunction during T2D may be the altered availability of substrates or co-factors necessary to maintain β-cell chromatin state. Induced changes in the β-cell chromatin modifications may then lead to dysregulation of gene expression, in turn contributing to the downward cascade of events that leads to the loss of functional β-cell mass, and loss of glucose homeostasis, that occurs in T2D.
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Affiliation(s)
- Ben Vanderkruk
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Brad G Hoffman
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
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11
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Yari Z, Behrouz V, Zand H, Pourvali K. New Insight into Diabetes Management: From Glycemic Index to Dietary Insulin Index. Curr Diabetes Rev 2020; 16:293-300. [PMID: 31203801 DOI: 10.2174/1573399815666190614122626] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/05/2019] [Accepted: 05/03/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Despite efforts to control hyperglycemia, diabetes management is still challenging. This may be due to focusing on reducing hyperglycemia and neglecting the importance of hyperinsulinemia; while insulin resistance and resultant hyperinsulinemia preceded diabetes onset and may contribute to disease pathogenesis. OBJECTIVE The present narrative review attempts to provide a new insight into the management of diabetes by exploring different aspects of glycemic index and dietary insulin index. RESULTS The current data available on this topic is limited and heterogeneous. Conventional diet therapy for diabetes management is based on reducing postprandial glycemia through carbohydrate counting, choosing foods with low-glycemic index and low-glycemic load. Since these indicators are only reliant on the carbohydrate content of foods and do not consider the effects of protein and fat on the stimulation of insulin secretion, they cannot provide a comprehensive approach to determine the insulin requirements. CONCLUSION Selecting foods based on carbohydrate counting, glycemic index or glycemic load are common guides to control glycemia in diabetic patients, but neglect the insulin response, thus leading to failure in diabetes management. Therefore, paying attention to insulinemic response along with glycemic response seems to be more effective in managing diabetes.
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Affiliation(s)
- Zahra Yari
- Student Research Committee, Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Vahideh Behrouz
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Zand
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Katayoun Pourvali
- Department of Cellular and Molecular Nutrition, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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12
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Bell KJ, Fio CZ, Twigg S, Duke SA, Fulcher G, Alexander K, McGill M, Wong J, Brand-Miller J, Steil GM. Amount and Type of Dietary Fat, Postprandial Glycemia, and Insulin Requirements in Type 1 Diabetes: A Randomized Within-Subject Trial. Diabetes Care 2020; 43:59-66. [PMID: 31455688 DOI: 10.2337/dc19-0687] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/21/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The American Diabetes Association recommends individuals with type 1 diabetes (T1D) adjust insulin for dietary fat; however, optimal adjustments are not known. This study aimed to determine 1) the relationship between the amount and type of dietary fat and glycemia and 2) the optimal insulin adjustments for dietary fat. RESEARCH DESIGN AND METHODS Adults with T1D using insulin pump therapy attended the research clinic on 9-12 occasions. On the first six visits, participants consumed meals containing 45 g carbohydrate with 0 g, 20 g, 40 g, or 60 g fat and either saturated, monounsaturated, or polyunsaturated fat. Insulin was dosed using individual insulin/carbohydrate ratio as a dual-wave 50/50% over 2 h. On subsequent visits, participants repeated the 20-60-g fat meals with the insulin dose estimated using a model predictive bolus, up to twice per meal, until glycemic control was achieved. RESULTS With the same insulin dose, increasing the amount of fat resulted in a significant dose-dependent reduction in incremental area under the curve for glucose (iAUCglucose) in the early postprandial period (0-2 h; P = 0.008) and increase in iAUCglucose in the late postprandial period (2-5 h; P = 0.004). The type of fat made no significant difference to the 5-h iAUCglucose. To achieve glycemic control, on average participants required dual-wave insulin bolus: for 20 g fat, +6% insulin, 74/26% over 73 min; 40 g fat, +6% insulin, 63/37% over 75 min; and 60 g fat, +21% insulin, 49/51% over 105 min. CONCLUSIONS This study provides clinical guidance for mealtime insulin dosing recommendations for dietary fat in T1D.
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Affiliation(s)
- Kirstine J Bell
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Chantelle Z Fio
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Stephen Twigg
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia.,Royal Prince Alfred Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Sally-Anne Duke
- Royal North Shore Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Gregory Fulcher
- Royal North Shore Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Kylie Alexander
- Royal North Shore Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Margaret McGill
- Royal Prince Alfred Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Jencia Wong
- Royal Prince Alfred Hospital Diabetes Centre, Sydney, New South Wales, Australia
| | - Jennie Brand-Miller
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Garry M Steil
- Harvard Medical School, Boston, MA.,Boston Children's Hospital, Boston, MA
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13
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Liu X, Zheng Y, Guasch-Ferré M, Ruiz-Canela M, Toledo E, Clish C, Liang L, Razquin C, Corella D, Estruch R, Fito M, Gómez-Gracia E, Arós F, Ros E, Lapetra J, Fiol M, Serra-Majem L, Papandreou C, Martínez-González MA, Hu FB, Salas-Salvadó J. High plasma glutamate and low glutamine-to-glutamate ratio are associated with type 2 diabetes: Case-cohort study within the PREDIMED trial. Nutr Metab Cardiovasc Dis 2019; 29:1040-1049. [PMID: 31377179 PMCID: PMC9257877 DOI: 10.1016/j.numecd.2019.06.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/24/2019] [Accepted: 06/06/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIMS Glutamate, glutamine are involved in energy metabolism, and have been related to cardiometabolic disorders. However, their roles in the development of type-2 diabetes (T2D) remain unclear. The aim of this study was to examine the effects of Mediterranean diet on associations between glutamine, glutamate, glutamine-to-glutamate ratio, and risk of new-onset T2D in a Spanish population at high risk for cardiovascular disease (CVD). METHODS AND RESULTS The present study was built within the PREDIMED trial using a case-cohort design including 892 participants with 251 incident T2D cases and 641 non-cases. Participants (mean age 66.3 years; female 62.8%) were non diabetic and at high risk for CVD at baseline. Plasma levels of glutamine and glutamate were measured at baseline and after 1-year of intervention. Higher glutamate levels at baseline were associated with increased risk of T2D with a hazard ratio (HR) of 2.78 (95% CI, 1.43-5.41, P for trend = 0.0002). In contrast, baseline levels of glutamine (HR: 0.64, 95% CI, 0.36-1.12; P for trend = 0.04) and glutamine-to-glutamate ratio (HR: 0.31, 95% CI, 0.16-0.57; P for trend = 0.0001) were inversely associated with T2D risk when comparing extreme quartiles. The two Mediterranean diets (MedDiet + EVOO and MedDiet + mixed nuts) did not alter levels of glutamine and glutamate after intervention for 1 year. However, MedDiet mitigated the positive association between higher baseline plasma glutamate and T2D risk (P for interaction = 0.01). CONCLUSION Higher levels of glutamate and lower levels of glutamine were associated with increased risk of T2D in a Spanish population at high risk for CVD. Mediterranean diet might mitigate the association between the imbalance of glutamine and glutamate and T2D risk. This trial is registered at http://www.controlled-trials.com, ISRCTN35739639.
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Affiliation(s)
- Xiaoran Liu
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Yan Zheng
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA; State Key Laboratory of Genetic Engineering, Human Phenome Institute and School of Life Sciences, Fudan University, Shanghai, China
| | - Marta Guasch-Ferré
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Miguel Ruiz-Canela
- University of Navarra, Department of Preventive Medicine and Public Health, IDISNA (Instituto de Investigación Sanitaria de Navarra), Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain
| | - Estefanía Toledo
- University of Navarra, Department of Preventive Medicine and Public Health, IDISNA (Instituto de Investigación Sanitaria de Navarra), Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain
| | - Clary Clish
- Broad Institute of MIT and Harvard University, Cambridge, MA, USA
| | - Liming Liang
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Cristina Razquin
- University of Navarra, Department of Preventive Medicine and Public Health, IDISNA (Instituto de Investigación Sanitaria de Navarra), Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain
| | - Dolores Corella
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Department of Preventive Medicine, University of Valencia, Valencia, Spain
| | - Ramón Estruch
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Department of Internal Medicine, Department of Endocrinology and Nutrition Institut d'Investigacions Biomediques August Pi Sunyer (IDI- BAPS), Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Montserrat Fito
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Cardiovascular and Nutrition Research Group (Regicor Study Group), Institut de Recerca-Hospital del Mar (IMIM), Barcelona, Spain
| | - Enrique Gómez-Gracia
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Department of Preventive Medicine, University of Málaga, Málaga, Spain
| | - Fernando Arós
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Department of Cardiology, University Hospital of Alava, Vitoria, Spain
| | - Emilio Ros
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Lipid Clinic, Endocrinology and Nutrition Service, Institut d'Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - José Lapetra
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Department of Family Medicine, Research Unit, Primary Care Division of Sevilla, Sevilla, Spain
| | - Miquel Fiol
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Institute of Health Sciences IUNICS, University of Balearic Islands and Hospital Son Espases, Palma de Mallorca, Spain
| | - Lluis Serra-Majem
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Christopher Papandreou
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Rovira i Virgili University, Reus, Spain
| | - Miguel A Martínez-González
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA; University of Navarra, Department of Preventive Medicine and Public Health, IDISNA (Instituto de Investigación Sanitaria de Navarra), Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain
| | - Frank B Hu
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jordi Salas-Salvadó
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III, Madrid, Spain; Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Rovira i Virgili University, Reus, Spain.
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14
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Zarkasi KA, Jen-Kit T, Jubri Z. Molecular Understanding of the Cardiomodulation in Myocardial Infarction and the Mechanism of Vitamin E Protections. Mini Rev Med Chem 2019; 19:1407-1426. [DOI: 10.2174/1389557519666190130164334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 11/10/2018] [Accepted: 01/12/2019] [Indexed: 12/13/2022]
Abstract
:
Myocardial infarction is a major cause of deaths globally. Modulation of several molecular
mechanisms occurs during the initial stages of myocardial ischemia prior to permanent cardiac tissue
damage, which involves both pathogenic as well as survival pathways in the cardiomyocyte. Currently,
there is increasing evidence regarding the cardioprotective role of vitamin E in alleviating the disease.
This fat-soluble vitamin does not only act as a powerful antioxidant; but it also has the ability to regulate
several intracellular signalling pathways including HIF-1, PPAR-γ, Nrf-2, and NF-κB that influence
the expression of a number of genes and their protein products. Essentially, it inhibits the molecular
progression of tissue damage and preserves myocardial tissue viability. This review aims to summarize
the molecular understanding of the cardiomodulation in myocardial infarction as well as the
mechanism of vitamin E protection.
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Affiliation(s)
- Khairul Anwar Zarkasi
- Department of Biochemistry, Faculty of Medicine, UKM Medical Centre, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia
| | - Tan Jen-Kit
- Department of Biochemistry, Faculty of Medicine, UKM Medical Centre, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia
| | - Zakiah Jubri
- Department of Biochemistry, Faculty of Medicine, UKM Medical Centre, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia
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15
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Feng J, Zhao H, Du M, Wu X. The effect of apelin-13 on pancreatic islet beta cell mass and myocardial fatty acid and glucose metabolism of experimental type 2 diabetic rats. Peptides 2019; 114:1-7. [PMID: 30954534 DOI: 10.1016/j.peptides.2019.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 03/20/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023]
Abstract
Apelin, a new identified adipokine, and its G protein-coupled receptor named APJ are widely expressed in various tissues. Apelin has been found to play important roles in the physiopathology of multiple diseases. Our aim is to assess the effect of long-term apelin treatment on serum insulin level and pancreatic islet beta-cell mass in the late stage of type 2 diabetes without hyperinsulinemia and to investigate the role of apelin in myocardial fatty acid and glucose metabolism. In the present study, the high-fat diet fed-streptozotocin-induced experimental type 2 diabetic rats were given once daily intraperitoneal injection of apelin-13 (0.1 μmol/kg) for 10 weeks. We observed that apelin significantly improved serum insulin reduction and reduced hyperglycemia. Histologic analysis showed that long-term apelin treatment significantly increased pancreatic islet beta cell mass. Exogenous apelin failed to change dyslipidaemia of type 2 diabetic rats. Apelin treatment markedly decreased elevated myocardial FFA and glycogen content. Treatment of type 2 diabetic rats with apelin markedly reduced increased gene expressions of the cardiac fatty acid transporter CD36, CPT-1, and Peroxisome proliferator-activated receptor (PPAR)-α. Whereas the gene levels of citrate synthase and peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1-α), a transcriptional coactivator, mediating mitochondrial biogenesis in heart were unaltered in response to exogenous apelin. Taken together, longer-term apelin treatment prevented pancreatic beta-cell loss or failure in experimental type 2 diabetic rats. Apelin can regulate myocardial metabolism. Apelin reduced myocadial fatty acid uptake and oxidation through inhibiting PPAR-α but did not affect myocardial mitochondrial biogenesis in type 2 diabetic rats.
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Affiliation(s)
- Jinghui Feng
- Department of Geratology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China
| | - Hang Zhao
- Department of Geratology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China
| | - Mengze Du
- Department of Geratology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China
| | - Xiuping Wu
- Department of Geratology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China.
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16
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Das UN. Polyunsaturated fatty acids and sepsis. Nutrition 2019; 65:39-43. [PMID: 31029920 DOI: 10.1016/j.nut.2019.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 02/05/2019] [Accepted: 02/15/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Undurti N Das
- UND Life Sciences, Battle Ground, Washington, USA; BioScience Research Centre and Department of Medicine, GVP Medical College and Hospital, Visakhapatnam, India.
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17
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Nemecz M, Constantin A, Dumitrescu M, Alexandru N, Filippi A, Tanko G, Georgescu A. The Distinct Effects of Palmitic and Oleic Acid on Pancreatic Beta Cell Function: The Elucidation of Associated Mechanisms and Effector Molecules. Front Pharmacol 2019; 9:1554. [PMID: 30719005 PMCID: PMC6348268 DOI: 10.3389/fphar.2018.01554] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 12/20/2018] [Indexed: 12/13/2022] Open
Abstract
In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis.
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Affiliation(s)
- Miruna Nemecz
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Alina Constantin
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Madalina Dumitrescu
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Nicoleta Alexandru
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Alexandru Filippi
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Gabriela Tanko
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
| | - Adriana Georgescu
- Department of Pathophysiology and Pharmacology, Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of Romanian Academy, Bucharest, Romania
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18
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Liu M, Weiss MA, Arunagiri A, Yong J, Rege N, Sun J, Haataja L, Kaufman RJ, Arvan P. Biosynthesis, structure, and folding of the insulin precursor protein. Diabetes Obes Metab 2018; 20 Suppl 2:28-50. [PMID: 30230185 PMCID: PMC6463291 DOI: 10.1111/dom.13378] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/04/2018] [Accepted: 05/23/2018] [Indexed: 02/06/2023]
Abstract
Insulin synthesis in pancreatic β-cells is initiated as preproinsulin. Prevailing glucose concentrations, which oscillate pre- and postprandially, exert major dynamic variation in preproinsulin biosynthesis. Accompanying upregulated translation of the insulin precursor includes elements of the endoplasmic reticulum (ER) translocation apparatus linked to successful orientation of the signal peptide, translocation and signal peptide cleavage of preproinsulin-all of which are necessary to initiate the pathway of proper proinsulin folding. Evolutionary pressures on the primary structure of proinsulin itself have preserved the efficiency of folding ("foldability"), and remarkably, these evolutionary pressures are distinct from those protecting the ultimate biological activity of insulin. Proinsulin foldability is manifest in the ER, in which the local environment is designed to assist in the overall load of proinsulin folding and to favour its disulphide bond formation (while limiting misfolding), all of which is closely tuned to ER stress response pathways that have complex (beneficial, as well as potentially damaging) effects on pancreatic β-cells. Proinsulin misfolding may occur as a consequence of exuberant proinsulin biosynthetic load in the ER, proinsulin coding sequence mutations, or genetic predispositions that lead to an altered ER folding environment. Proinsulin misfolding is a phenotype that is very much linked to deficient insulin production and diabetes, as is seen in a variety of contexts: rodent models bearing proinsulin-misfolding mutants, human patients with Mutant INS-gene-induced Diabetes of Youth (MIDY), animal models and human patients bearing mutations in critical ER resident proteins, and, quite possibly, in more common variety type 2 diabetes.
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Affiliation(s)
- Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202 IN USA
- Department of Biochemistry, Case-Western Reserve University, Cleveland 44016 OH USA
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Jing Yong
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92307 USA
| | - Nischay Rege
- Department of Biochemistry, Case-Western Reserve University, Cleveland 44016 OH USA
| | - Jinhong Sun
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92307 USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
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19
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Gezginci-Oktayoglu S, Onay-Ucar E, Sancar-Bas S, Karatug-Kacar A, Arda ESN, Bolkent S. Involvement of dying beta cell originated messenger molecules in differentiation of pancreatic mesenchymal stem cells under glucotoxic and glucolipotoxic conditions. J Cell Physiol 2017; 233:4235-4244. [PMID: 29058819 DOI: 10.1002/jcp.26242] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022]
Abstract
Beta cell mass regulation represents a critical issue for understanding and treatment of diabetes. The most important process in the development of diabetes is beta cell death, generally induced by glucotoxicity or glucolipotoxicity, and the regeneration mechanism of new beta cells that will replace dead beta cells is still not fully understood. The aim of this study was to investigate the generation mechanism of new beta cells by considering the compensation phase of type 2 diabetes mellitus. In this study, pancreatic islet derived mesenchymal stem cells (PI-MSCs) were isolated from adult rats and characterized. Then, beta cells isolated from rats were co-cultured with PI-MSCs and they were exposed to glucotoxicity, lipotoxicity and glucolipotoxicity conditions for 72 hr. As the results apoptotic and necrotic cell death were increased in both PI-MSCs and beta cells especially by the exposure of glucotoxic and glucolipotoxic conditions to the co-culture systems. Glucotoxicity induced-differentiated beta cells were functional due to their capability of insulin secretion in response to rising glucose concentrations. Moreover, beta cell proliferation was induced in the glucotoxicity-treated co-culture system whereas suppressed in lipotoxicity or glucolipotoxicity-treated co-culture systems. In addition, 11 novel proteins, that may release from dead beta cells and have the ability to stimulate PI-MSCs in the direction of differentiation, were determined in media of glucotoxicity or glucolipotoxicity-treated co-culture systems. In conclusion, these molecules were considered as important for understanding cellular mechanism of beta cell differentiation and diabetes. Thus, they may be potential targets for diagnosis and cellular or therapeutic treatment of diabetes.
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Affiliation(s)
- Selda Gezginci-Oktayoglu
- Molecular Biology Section, Department of Biology, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Evren Onay-Ucar
- Department of Molecular Biology and Genetic, Faculty of Science, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Serap Sancar-Bas
- Molecular Biology Section, Department of Biology, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Ayse Karatug-Kacar
- Molecular Biology Section, Department of Biology, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Emine S N Arda
- Department of Molecular Biology and Genetic, Faculty of Science, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Sehnaz Bolkent
- Molecular Biology Section, Department of Biology, Istanbul University, Vezneciler, Istanbul, Turkey
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20
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Liu C, Fu Y, Li CE, Chen T, Li X. Phycocyanin-Functionalized Selenium Nanoparticles Reverse Palmitic Acid-Induced Pancreatic β Cell Apoptosis by Enhancing Cellular Uptake and Blocking Reactive Oxygen Species (ROS)-Mediated Mitochondria Dysfunction. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:4405-4413. [PMID: 28510423 DOI: 10.1021/acs.jafc.7b00896] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Accumulation of palmitic acid (PA) in human bodies could cause damage to pancreatic β cells and lead to chronic diseases by generation of reactive oxygen species (ROS). Therefore, it is of great significance to search for nutrition-available agents with antioxidant activity to protect pancreatic islet cells against PA-induced damage. Phycocyanin (PC) and selenium (Se) have been reported to have excellent antioxidant activity. In this study, PC-functionalized selenium nanoparticles (PC-SeNPs) were synthesized to investigate the in vitro protective effects on INS-1E rat insulinoma β cells against PA-induced cell death. A potent protective effect was achieved by regulation of particle size and PC content. Among three PC-SeNPs (165, 235, and 371 nm), PC-SeNPs-235 nm showed the highest cellular uptake and the best protective activities. For cell cycle analysis, PC-SeNPs showed a better protective effect on PA-induced INS-1E cell apoptosis than PC or SeNPs, and PC-SeNPs-235 nm exhibited the best effect. Further mechanistic studies demonstrated that PA induced overproduction of intracellular ROS, mitochondria fragmentation, activation of caspase-3, -8, and -9, and cleavage of PARP. However, pretreatment of the cells with PC-SeNPs effectively blocked these intracellular events, which suggests that PC-SeNPs could protect INS-1E cells against PA-induced cell apoptosis via attenuating oxidative stress and downstream signaling pathways. This finding provides a great promising nutritional approach for protection against diseases related to islet damage.
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Affiliation(s)
- Chang Liu
- Department of Chemistry, Jinan University , Guangzhou 510632, China
| | - Yuanting Fu
- Department of Chemistry, Jinan University , Guangzhou 510632, China
| | - Chang-E Li
- Department of Chemistry, Jinan University , Guangzhou 510632, China
| | - Tianfeng Chen
- Department of Chemistry, Jinan University , Guangzhou 510632, China
| | - Xiaoling Li
- Institute of Food Safety and Nutrition, Jinan University , Guangzhou 510632, China
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21
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Abstract
The pancreatic β-cell secretes insulin in response to elevated plasma glucose. This review applies an external bioenergetic critique to the central processes of glucose-stimulated insulin secretion, including glycolytic and mitochondrial metabolism, the cytosolic adenine nucleotide pool, and its interaction with plasma membrane ion channels. The control mechanisms responsible for the unique responsiveness of the cell to glucose availability are discussed from bioenergetic and metabolic control standpoints. The concept of coupling factor facilitation of secretion is critiqued, and an attempt is made to unravel the bioenergetic basis of the oscillatory mechanisms controlling secretion. The need to consider the physiological constraints operating in the intact cell is emphasized throughout. The aim is to provide a coherent pathway through an extensive, complex, and sometimes bewildering literature, particularly for those unfamiliar with the field.
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Affiliation(s)
- David G Nicholls
- Buck Institute for Research on Aging, Novato, California; and Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, Malmo, Sweden
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22
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Initial hyperinsulinemia and subsequent β-cell dysfunction is associated with elevated palmitate levels. Pediatr Res 2016; 80:267-74. [PMID: 27064244 DOI: 10.1038/pr.2016.80] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/03/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND The prevalence of obesity-related diabetes in childhood is increasing and circulating levels of nonesterified fatty acids may constitute a link. Here, the association between palmitate and insulin secretion was investigated in vivo and in vitro. METHODS Obese and lean children and adolescents (n = 80) were included. Palmitate was measured at fasting; insulin and glucose during an oral glucose tolerance test (OGTT). Human islets were cultured for 0 to 7 d in presence of 0.5 mmol/l palmitate. Glucose-stimulated insulin secretion (GSIS), insulin content and apoptosis were measured. RESULTS Obese subjects had fasting palmitate levels between 0.10 and 0.33 mmol/l, with higher average levels compared to lean subjects. While obese children with elevated palmitate (>0.20 mmol/l) had accentuated insulin levels during OGTT, obese adolescents with high palmitate had delayed first-phase insulin response. In human islets exposed to palmitate for 2 d GSIS was twofold enhanced, but after 7 d attenuated. Intracellular insulin content decreased time-dependently in islets cultured in the presence of palmitate and cleaved caspase 3 increased. CONCLUSION The rapid accentuated and delayed insulin secretory responses observed in obese children and adolescents, respectively, with high palmitate levels may reflect changes in islet secretory activity and integrity induced by extended exposure to the fatty acid.
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Algorithms to Improve the Prediction of Postprandial Insulinaemia in Response to Common Foods. Nutrients 2016; 8:210. [PMID: 27070641 PMCID: PMC4848679 DOI: 10.3390/nu8040210] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/29/2016] [Accepted: 04/01/2016] [Indexed: 12/21/2022] Open
Abstract
Dietary patterns that induce excessive insulin secretion may contribute to worsening insulin resistance and beta-cell dysfunction. Our aim was to generate mathematical algorithms to improve the prediction of postprandial glycaemia and insulinaemia for foods of known nutrient composition, glycemic index (GI) and glycemic load (GL). We used an expanded database of food insulin index (FII) values generated by testing 1000 kJ portions of 147 common foods relative to a reference food in lean, young, healthy volunteers. Simple and multiple linear regression analyses were applied to validate previously generated equations for predicting insulinaemia, and develop improved predictive models. Large differences in insulinaemic responses within and between food groups were evident. GL, GI and available carbohydrate content were the strongest predictors of the FII, explaining 55%, 51% and 47% of variation respectively. Fat, protein and sugar were significant but relatively weak predictors, accounting for only 31%, 7% and 13% of the variation respectively. Nutritional composition alone explained only 50% of variability. The best algorithm included a measure of glycemic response, sugar and protein content and explained 78% of variation. Knowledge of the GI or glycaemic response to 1000 kJ portions together with nutrient composition therefore provides a good approximation for ranking of foods according to their “insulin demand”.
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Bell KJ, Gray R, Munns D, Petocz P, Steil G, Howard G, Colagiuri S, Brand-Miller JC. Clinical Application of the Food Insulin Index for Mealtime Insulin Dosing in Adults with Type 1 Diabetes: A Randomized Controlled Trial. Diabetes Technol Ther 2016; 18:218-25. [PMID: 26840067 DOI: 10.1089/dia.2015.0254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND The Food Insulin Index (FII) is a novel algorithm for ranking foods based on their insulin demand relative to an isoenergetic reference food. We compared the effect of carbohydrate counting (CC) versus the FII algorithm for estimating insulin dosage on glycemic control in type 1 diabetes. MATERIALS AND METHODS In a randomized, controlled trial, adults (n = 26) using insulin pump therapy were assigned to using either traditional CC or the novel Food Insulin Demand (FID) counting for 12 weeks. Subjects participated in group education and individual sessions. At baseline and on completion of the trial, glycated hemoglobin A1c (HbA1c), day-long glycemia (6-day continuous glucose monitoring), fasting lipids, and C-reactive protein were determined. RESULTS Changes in HbA1c from baseline to 12 weeks were small and not significant in both groups (mean ± SEM; FII vs. CC, -0.1 ± 0.1% vs. -0.3 ± 0.2%; P = 0.855). The incremental area under the curve following breakfast declined significantly among the FID counters with no change in the CC group (FID vs. CC, -93 ± 41 mmol/L/min [P = 0.043] vs. 4 ± 50 mmol/L/min [P = 0.938]; between groups, P = 0.143). The mean amplitude of the glycemic excursion (MAGE) was significantly reduced among the FID counters (FID vs. CC, -6.1 ± 1.0 vs. -1.3 ± 1.0 mmol/L; P = 0.003), and only the FID counters experienced a trend (-44% vs. +11%; P = 0.057) to reduced hypoglycemia. CONCLUSIONS In a 12-week pilot study, MAGE and postprandial glycemia following breakfast were significantly improved with FII counting versus CC, despite no significant differences in HbA1c.
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Affiliation(s)
- Kirstine J Bell
- 1 Charles Perkins Centre, The University of Sydney , Sydney, New South Wales, Australia
- 2 School of Molecular Bioscience, The University of Sydney , Sydney, New South Wales, Australia
| | - Robyn Gray
- 3 Sydney Insulin Pump Clinic , Sydney, New South Wales, Australia
| | - Diane Munns
- 3 Sydney Insulin Pump Clinic , Sydney, New South Wales, Australia
| | - Peter Petocz
- 4 Department of Statistics, Macquarie University , Sydney, New South Wales, Australia
| | - Garry Steil
- 5 Harvard Medical School , Boston, Massachusetts
- 6 Children's Hospital , Boston, Massachusetts
| | - Gabrielle Howard
- 3 Sydney Insulin Pump Clinic , Sydney, New South Wales, Australia
| | - Stephen Colagiuri
- 1 Charles Perkins Centre, The University of Sydney , Sydney, New South Wales, Australia
- 2 School of Molecular Bioscience, The University of Sydney , Sydney, New South Wales, Australia
| | - Jennie C Brand-Miller
- 1 Charles Perkins Centre, The University of Sydney , Sydney, New South Wales, Australia
- 2 School of Molecular Bioscience, The University of Sydney , Sydney, New South Wales, Australia
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25
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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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PPARα Agonist Fenofibrate Reduced the Secreting Load of β-Cells in Hypertriglyceridemia Patients with Normal Glucose Tolerance. PPAR Res 2016; 2016:6232036. [PMID: 27034649 PMCID: PMC4789521 DOI: 10.1155/2016/6232036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/19/2016] [Accepted: 02/01/2016] [Indexed: 12/28/2022] Open
Abstract
Hypertriglyceridemia is an important risk factor associated with insulin resistance and β-cell dysfunction. This study investigated the effects of hypertriglyceridemia and fenofibrate treatment on insulin sensitivity and β-cell function in subjects with normal glucose tolerance. A total of 1974 subjects with normal glucose tolerance were divided into the normal TG group (NTG group, n = 1302) and hypertriglyceridemia group (HTG group, n = 672). Next, 92 patients selected randomly from 672 patients with hypertriglyceridemia were assigned to a 24-week fenofibrate treatment. The HTG group had increased waist circumference (WC), body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment of β-cell function (HOMA-β) and decreased high-density lipoprotein cholesterol (HDL-C) compared with the NTG group (all P < 0.01). The 24-week fenofibrate treatment significantly decreased the WC, BMI, TG, HOMA-IR, and HOMA-β levels and increased the HDL-C levels in the patients with hypertriglyceridemia (WC, BMI, and HOMA-IR: P < 0.05; TG, HDL-C, and HOMA-β: P < 0.01). The fenofibrate treatment significantly alleviated insulin resistance and reduced the secreting load of β-cells in the hypertriglyceridemia patients with normal glucose tolerance.
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27
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Hirata T, Kawai T, Hirose H, Tanaka K, Kurosawa H, Fujii C, Fujita H, Seto Y, Matsumoto H, Itoh H. Palmitic acid-rich diet suppresses glucose-stimulated insulin secretion (GSIS) and induces endoplasmic reticulum (ER) stress in pancreatic islets in mice. Endocr Res 2016; 41:8-15. [PMID: 26167855 DOI: 10.3109/07435800.2015.1038352] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The objective was to clarify whether dietary palmitic acid supplementation affects glucose-stimulated insulin secretion (GSIS) and the endoplasmic reticulum (ER) stress pathway in pancreatic islets in mice. Eight-week-old male C57BL/6J mice were randomly divided into three treatment diet groups: control diet, palmitic acid-supplemented diet (PAL) and oleic acid-supplemented diet (OLE). After 2 weeks of treatment, intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test were performed. GSIS was assessed by pancreatic perfusion in situ with basal (100 mg/dL) glucose followed by a high (300 mg/dL) glucose concentration. We measured mRNA levels of ER stress markers such as C/EBP homologous protein (CHOP), immunoglobulin heavy-chain binding protein (BIP) and X-box binding protein (XBP)-1 using real-time polymerase chain reaction (PCR) analyses in isolated islets. Immunohistochemical staining was also performed. Mice fed PAL showed significantly decreased glucose tolerance (p < 0.05). In the perfusion study, GSIS was significantly suppressed in the PAL group (p < 0.05). Semi-quantitative RT-PCR revealed that islet CHOP, BIP, and XBP-1 mRNA expression were significantly increased in the PAL group (p < 0.05). TUNEL-positive β-cells were not detected in all groups. Dietary palmitic acid-supplementation for 2 weeks might suppress GSIS and induce ER stress in pancreatic islets in mice, in the early stage of lipotoxicity.
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Affiliation(s)
- Takumi Hirata
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
| | - Toshihide Kawai
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
- b Institute for Integrated Sports Medicine, School of Medicine, Keio University , Tokyo , Japan , and
| | - Hiroshi Hirose
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
| | - Kumiko Tanaka
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
| | - Hideaki Kurosawa
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
| | - Chikako Fujii
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
| | - Haruhisa Fujita
- c Institute for Advanced Medical Research, School of Medicine, Keio University , Tokyo , Japan
| | - Yoshiko Seto
- c Institute for Advanced Medical Research, School of Medicine, Keio University , Tokyo , Japan
| | - Hideo Matsumoto
- b Institute for Integrated Sports Medicine, School of Medicine, Keio University , Tokyo , Japan , and
| | - Hiroshi Itoh
- a Department of Internal Medicine , School of Medicine, Keio University , Tokyo , Japan
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28
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Bell KJ, Bao J, Petocz P, Colagiuri S, Brand-Miller JC. Validation of the food insulin index in lean, young, healthy individuals, and type 2 diabetes in the context of mixed meals: an acute randomized crossover trial. Am J Clin Nutr 2015; 102:801-6. [PMID: 26354547 DOI: 10.3945/ajcn.115.112904] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/04/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The Food Insulin Index (FII) is a novel classification of single foods based on insulin responses in healthy subjects relative to an isoenergetic reference food. OBJECTIVE Our aim was to compare day-long responses to 2 nutrient-matched diets predicted to have either high or low insulin demand in healthy controls and individuals with type 2 diabetes (T2DM). DESIGN Twenty adults (10 healthy adults and 10 adults with T2DM) were recruited. On separate mornings, subjects consumed either a high- or low-FII diet in random order. Diets consisted of 3 consecutive meals (breakfast, morning tea, and lunch), matched for macronutrients, fiber, and glycemic index (GI), but with 2-fold difference in insulin demand as predicted by the FII of the component foods. Postprandial glycemia and insulinemia were measured in capillary plasma at regular intervals over 8 h. RESULTS As predicted by their GI, there were no differences in glycemic responses between the 2 diets in either group (mean ± SEM; healthy: 6.2 ± 0.2 compared with 6.1 ± 0.1 mmol/L · min, P = 0.429; T2DM: 9.9 ± 1.3 compared with 10.3 ± 1.6 mmol/L · min, P = 0.485). Compared with the high-FII diet, mean postprandial insulin response over 8 h was 53% lower with the low-FII diet in healthy subjects (mean ± SEM; incremental AUCinsulin 31,900 ± 4100 pmol/L · min compared with 68,100 ± 11,400 pmol/L · min, P = 0.003) and 41% lower in subjects with T2DM (mean ± SEM; incremental AUCinsulin 11,000 ± 1800 pmol/L · min compared with 18,700 ± 3100 pmol/L · min, P = 0.018). Incremental AUCinsulin was statistically significantly different between diets when groups were combined (P = 0.001). CONCLUSIONS The FII algorithm may be a useful tool for reducing postprandial hyperinsulinemia in T2DM, thereby potentially improving insulin resistance and β-cell function. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12611000654954.
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Affiliation(s)
- Kirstine J Bell
- Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and
| | - Jiansong Bao
- Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and
| | - Peter Petocz
- Department of Statistics, Macquarie University, Sydney, Australia
| | - Stephen Colagiuri
- Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and
| | - Jennie C Brand-Miller
- Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and
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29
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Tenenbaum A, Klempfner R, Fisman EZ. Hypertriglyceridemia: a too long unfairly neglected major cardiovascular risk factor. Cardiovasc Diabetol 2014; 13:159. [PMID: 25471221 PMCID: PMC4264548 DOI: 10.1186/s12933-014-0159-y] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 12/27/2022] Open
Abstract
The existence of an independent association between elevated triglyceride (TG) levels, cardiovascular (CV) risk and mortality has been largely controversial. The main difficulty in isolating the effect of hypertriglyceridemia on CV risk is the fact that elevated triglyceride levels are commonly associated with concomitant changes in high density lipoprotein (HDL), low density lipoprotein (LDL) and other lipoproteins. As a result of this problem and in disregard of the real biological role of TG, its significance as a plausible therapeutic target was unfoundedly underestimated for many years. However, taking epidemiological data together, both moderate and severe hypertriglyceridaemia are associated with a substantially increased long term total mortality and CV risk. Plasma TG levels partially reflect the concentration of the triglyceride-carrying lipoproteins (TRL): very low density lipoprotein (VLDL), chylomicrons and their remnants. Furthermore, hypertriglyceridemia commonly leads to reduction in HDL and increase in atherogenic small dense LDL levels. TG may also stimulate atherogenesis by mechanisms, such excessive free fatty acids (FFA) release, production of proinflammatory cytokines, fibrinogen, coagulation factors and impairment of fibrinolysis. Genetic studies strongly support hypertriglyceridemia and high concentrations of TRL as causal risk factors for CV disease. The most common forms of hypertriglyceridemia are related to overweight and sedentary life style, which in turn lead to insulin resistance, metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM). Intensive lifestyle therapy is the main initial treatment of hypertriglyceridemia. Statins are a cornerstone of the modern lipids-modifying therapy. If the primary goal is to lower TG levels, fibrates (bezafibrate and fenofibrate for monotherapy, and in combination with statin; gemfibrozil only for monotherapy) could be the preferable drugs. Also ezetimibe has mild positive effects in lowering TG. Initial experience with en ezetimibe/fibrates combination seems promising. The recently released IMPROVE-IT Trial is the first to prove that adding a non-statin drug (ezetimibe) to a statin lowers the risk of future CV events. In conclusion, the classical clinical paradigm of lipids-modifying treatment should be changed and high TG should be recognized as an important target for therapy in their own right. Hypertriglyceridemia should be treated.
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Affiliation(s)
- Alexander Tenenbaum
- Cardiac Rehabilitation Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel. .,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel. .,Cardiovascular Diabetology Research Foundation, 58484, Holon, Israel.
| | - Robert Klempfner
- Cardiac Rehabilitation Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel. .,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.
| | - Enrique Z Fisman
- Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel. .,Cardiovascular Diabetology Research Foundation, 58484, Holon, Israel.
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Loganathan G, Graham M, Spizzo T, Tiwari M, Lockridge A, Soltani S, Wilhelm J, Balamurugan A, Hering B. Pretreatment of Donor Pigs With a Diet Rich in Soybean Oil Increases the Yield of Isolated Islets. Transplant Proc 2014; 46:1945-9. [DOI: 10.1016/j.transproceed.2014.05.078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Abstract
Pancreatic β-cell function is of critical importance in the regulation of fuel homoeostasis, and metabolic dysregulation is a hallmark of diabetes mellitus (DM). The β-cell is an intricately designed cell type that couples metabolism of dietary sources of carbohydrates, amino acids and lipids to insulin secretory mechanisms, such that insulin release occurs at appropriate times to ensure efficient nutrient uptake and storage by target tissues. However, chronic exposure to high nutrient concentrations results in altered metabolism that impacts negatively on insulin exocytosis, insulin action and may ultimately lead to development of DM. Reduced action of insulin in target tissues is associated with impairment of insulin signalling and contributes to insulin resistance (IR), a condition often associated with obesity and a major risk factor for DM. The altered metabolism of nutrients by insulin-sensitive target tissues (muscle, adipose tissue and liver) can result in high circulating levels of glucose and various lipids, which further impact on pancreatic β-cell function, IR and progression of the metabolic syndrome. Here, we have considered the role played by the major nutrient groups, carbohydrates, amino acids and lipids, in mediating β-cell insulin secretion, while also exploring the interplay between amino acids and insulin action in muscle. We also focus on the effects of altered lipid metabolism in adipose tissue and liver resulting from activation of inflammatory processes commonly observed in DM pathophysiology. The aim of this review is to describe commonalities and differences in metabolism related to insulin secretion and action, pertinent to the development of DM.
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Affiliation(s)
- Philip Newsholme
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Vinicius Cruzat
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Frank Arfuso
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Kevin Keane
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
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32
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Mahmoudabadi MMS, Rahbar AR. Effect of EPA and vitamin C on superoxide dismutase, glutathione peroxidase, total antioxidant capacity and malondialdehyde in type 2 diabetic patients. Oman Med J 2014; 29:39-45. [PMID: 24498481 DOI: 10.5001/omj.2014.09] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/23/2013] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVES The aim of this study is to investigate the effect of eicosapentaenoic acid combined with vitamin C in comparison with the pure form of eicosapentaenoic acid on the serum concentration of malondialdehyde, erythrocyte activity of superoxide dismutase, glutathione peroxidase, and the serum level of total antioxidant capacity in patients with type 2 diabetes. METHODS Eighty one male diabetic patients, aged 33-63 years, were randomly assigned to one of 4 groups. The subjects consumed 500 mg/d pure eicosapentaenoic acid, 200 mg/d vitamin C, 500 mg eicosapentaenoic acid and 200 mg/d vitamin C or placebo depending on their groups. In fasting blood samples, superoxide dismutase and glutathione peroxidase activities were determined via the enzymatic method (Randox kit) and the serum total antioxidant capacity, malondialdehyde and vitamin C concentrations were estimated by colorimetric methods. RESULTS Administration of pure eicosapentaenoic acid in diabetic patients increased superoxide dismutase by 4%, glutathione peroxidase 53%, total antioxidant capacity 36% and decreased malondialdehyde significantly by 25%. Prescription of eicosapentaenoic acid combined with vitamin C demonstrated a significant increment for superoxide dismutase activity by 3% and for glutathione peroxidase activity by 52% during the study, but no significant change was seen for total antioxidant capacity and malondialdehyde, respectively. There was a significant decrease in FBS and HbA1c following prescription of eicosapentaenoic acid with/without vitamin C along the study, although these changes were not significant between the study groups. CONCLUSION It is concluded that prescription of eicosapentaenoic acid in the pure form reduces oxidative stress in type 2 diabetic patients; albeit, it does not alleviate hyperglycemia. Combination of vitamin C and eicosapentaenoic acid does not improve antioxidant property of eicosapentaenoic acid.
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Affiliation(s)
| | - Ali Reza Rahbar
- Department of Nutrition, The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences, Bushehr, I.R. Iran
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Abstract
Regulation of metabolic fuel homeostasis is a critical function of β-cells, which are located in the islets of Langerhans of the animal pancreas. Impairment of this β-cell function is a hallmark of pancreatic β-cell failure and may lead to development of type 2 diabetes mellitus. β-Cells are essentially "fuel sensors" that monitor and react to elevated nutrient load by releasing insulin. This response involves metabolic activation and generation of metabolic coupling factors (MCFs) that relay the nutrient signal throughout the cell and induce insulin biosynthesis and secretion. Glucose is the most important insulin secretagogue as it is the primary fuel source in food. Glucose metabolism is central to generation of MCFs that lead to insulin release, most notably ATP. In addition, other classes of nutrients are able to augment insulin secretion and these include members of the lipid and amino acid family of nutrients. Therefore, it is important to investigate the interplay between glucose, lipid, and amino acid metabolism, as it is this mixed nutrient sensing that generate the MCFs required for insulin exocytosis. The mechanisms by which these nutrients are metabolized to generate MCFs, and how they impact on β-cell insulin release and function, are discussed in detail in this article.
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Affiliation(s)
- Kevin Keane
- School of Biomedical Sciences, CHIRI Biosciences Research Precinct, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Philip Newsholme
- School of Biomedical Sciences, CHIRI Biosciences Research Precinct, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia.
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Mazuy C, Ploton M, Eeckhoute J, Berrabah W, Staels B, Lefebvre P, Helleboid-Chapman A. Palmitate increases Nur77 expression by modulating ZBP89 and Sp1 binding to the Nur77 proximal promoter in pancreatic β-cells. FEBS Lett 2013; 587:S0014-5793(13)00781-3. [PMID: 24512852 DOI: 10.1016/j.febslet.2013.10.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 09/18/2013] [Accepted: 10/15/2013] [Indexed: 11/23/2022]
Abstract
Nur77 is a stress sensor in pancreatic β-cells, which negatively regulates glucose-stimulated insulin secretion. We recently showed that a lipotoxic shock caused by exposure of β-cells to the saturated fatty acid palmitate strongly increases Nur77 expression. Here, using dual luciferase reporter assays and Nur77 promoter deletion constructs, we identified a regulatory cassette between -1534 and -1512 bp upstream from the translational start site mediating Nur77 promoter activation in response to palmitate exposure. Chromatin immunoprecipitation, transient transfection and siRNA-mediated knockdown assays revealed that palmitate induced Nur77 promoter activation involves Sp1 recruitment and ZBP89 release from the gene promoter.
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Affiliation(s)
- Claire Mazuy
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Maheul Ploton
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Jérôme Eeckhoute
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Wahiba Berrabah
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Bart Staels
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Philippe Lefebvre
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
| | - Audrey Helleboid-Chapman
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; UNIV LILLE 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; IPL, F-59000 Lille, France
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Changes in food intake, metabolic parameters and insulin resistance are induced by an isoenergetic, medium-chain fatty acid diet and are associated with modifications in insulin signalling in isolated rat pancreatic islets. Br J Nutr 2012. [PMID: 23182275 DOI: 10.1017/s0007114512004576] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Long-chain fatty acids are capable of inducing alterations in the homoeostasis of glucose-stimulated insulin secretion (GSIS), but the effect of medium-chain fatty acids (MCFA) is poorly elucidated. In the present study, we fed a normoenergetic MCFA diet to male rats from the age of 1 month to the age of 4 months in order to analyse the effect of MCFA on body growth, insulin sensitivity and GSIS. The 45% MCFA substitution of whole fatty acids in the normoenergetic diet impaired whole body growth and resulted in increased body adiposity and hyperinsulinaemia, and reduced insulin-mediated glucose uptake in skeletal muscle. In addition, the isolated pancreatic islets from the MCFA-fed rats showed impaired GSIS and reduced protein kinase Ba (AKT1) protein expression and extracellular signal-related kinase isoforms 1 and 2 (ERK(1/2)) phosphorylation, which were accompanied by increased cellular death. Furthermore, there was a mildly increased cholinergic sensitivity to GSIS. We discuss these findings in further detail, and advocate that they might have a role in the mechanistic pathway leading to the compensatory hyperinsulinaemic status found in this animal model.
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Tenenbaum A, Fisman EZ. Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention? Cardiovasc Diabetol 2012; 11:140. [PMID: 23150952 PMCID: PMC3502168 DOI: 10.1186/1475-2840-11-140] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 10/31/2012] [Indexed: 01/11/2023] Open
Abstract
All fibrates are peroxisome proliferators-activated receptors (PPARs)-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C). However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta) at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones) are used to treat type 2 diabetes mellitus (T2DM). They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence) suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates). Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants, induced atherosclerotic plaque regression in thoracic and abdominal aorta and improved endothelial function. In addition, bezafibrate has important fibrinogen-related properties and anti-inflammatory effects. In clinical trials bezafibrate was highly effective for cardiovascular risk reduction in patients with metabolic syndrome and atherogenic dyslipidemia. The principal differences between bezafibrate and other fibrates are related to effects on glucose level and insulin resistance. Bezafibrate decreases blood glucose level, HbA1C, insulin resistance and reduces the incidence of T2DM compared to placebo or other fibrates. Currently statins are the cornerstone of the treatment and prevention of cardiovascular diseases related to atherosclerosis. However, despite the increasing use of statins as monotherapy for low density lipoprotein- cholesterol (LDL-C) reduction, a significant residual cardiovascular risk is still presented in patients with atherogenic dyslipidemia and insulin resistance, which is typical for T2DM and metabolic syndrome. Recently, concerns were raised regarding the development of diabetes in statin-treated patients. Combined bezafibrate/statin therapy is more effective in achieving a comprehensive lipid control and residual cardiovascular risk reduction. Based on the beneficial effects of pan-PPAR agonist bezafibrate on glucose metabolism and prevention of new-onset diabetes, one could expect a neutralization of the adverse pro-diabetic effect of statins using the strategy of a combined statin/fibrate therapy.
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Affiliation(s)
- Alexander Tenenbaum
- Cardiac Rehabilitation Institute, Sheba Medical Center, 52621 Tel-Hashomer, Israel.
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37
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Tenenbaum A, Fisman EZ. Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention? Cardiovasc Diabetol 2012. [PMID: 23150952 DOI: 10.1186/1475-2840-11-1401475-2840-11-140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
All fibrates are peroxisome proliferators-activated receptors (PPARs)-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C). However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta) at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones) are used to treat type 2 diabetes mellitus (T2DM). They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence) suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates). Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants, induced atherosclerotic plaque regression in thoracic and abdominal aorta and improved endothelial function. In addition, bezafibrate has important fibrinogen-related properties and anti-inflammatory effects. In clinical trials bezafibrate was highly effective for cardiovascular risk reduction in patients with metabolic syndrome and atherogenic dyslipidemia. The principal differences between bezafibrate and other fibrates are related to effects on glucose level and insulin resistance. Bezafibrate decreases blood glucose level, HbA1C, insulin resistance and reduces the incidence of T2DM compared to placebo or other fibrates. Currently statins are the cornerstone of the treatment and prevention of cardiovascular diseases related to atherosclerosis. However, despite the increasing use of statins as monotherapy for low density lipoprotein- cholesterol (LDL-C) reduction, a significant residual cardiovascular risk is still presented in patients with atherogenic dyslipidemia and insulin resistance, which is typical for T2DM and metabolic syndrome. Recently, concerns were raised regarding the development of diabetes in statin-treated patients. Combined bezafibrate/statin therapy is more effective in achieving a comprehensive lipid control and residual cardiovascular risk reduction. Based on the beneficial effects of pan-PPAR agonist bezafibrate on glucose metabolism and prevention of new-onset diabetes, one could expect a neutralization of the adverse pro-diabetic effect of statins using the strategy of a combined statin/fibrate therapy.
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Affiliation(s)
- Alexander Tenenbaum
- Cardiac Rehabilitation Institute, Sheba Medical Center, 52621 Tel-Hashomer, Israel.
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Impact of the carotenoid astaxanthin on phagocytic capacity and ROS/RNS production of human neutrophils treated with free fatty acids and high glucose. Int Immunopharmacol 2011; 11:2220-6. [DOI: 10.1016/j.intimp.2011.10.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 10/04/2011] [Indexed: 01/08/2023]
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Sargsyan E, Sol ERM, Bergsten P. UPR in palmitate-treated pancreatic beta-cells is not affected by altering oxidation of the fatty acid. Nutr Metab (Lond) 2011; 8:70. [PMID: 21978671 PMCID: PMC3197479 DOI: 10.1186/1743-7075-8-70] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 10/06/2011] [Indexed: 12/27/2022] Open
Abstract
Background Elevated levels of lipids are detrimental for beta-cell function and mass. One of the mechanisms of how fatty acids induce apoptosis is development of the unfolded protein response (UPR). It is still far from understood how fatty acids activate the UPR, however. Methods We examined how palmitate-induced activation of the UPR was affected by altering the metabolism of the fatty acid in insulin-secreting INS-1E and MIN6 cell lines and intact human islets. To increase oxidation, we used low glucose (5.5 mM) or AICAR; and to reduce oxidation, we used high glucose (25 mM) or etomoxir. UPR was measured after 3, 24 and 48 hours of palmitate treatment. Results Modulation of palmitate oxidation by either glucose or the pharmacological agents did not affect palmitate-induced UPR activation. Conclusion Our finding suggests that other factors than oxidation of palmitate play a role in the activation of UPR in fatty acid-treated beta-cells.
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Affiliation(s)
- Ernest Sargsyan
- Department of Medical Cell Biology, Uppsala University, Box 571, SE-75123, Uppsala, Sweden.
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Størling J, Juntti-Berggren L, Olivecrona G, Prause MC, Berggren PO, Mandrup-Poulsen T. Apolipoprotein CIII reduces proinflammatory cytokine-induced apoptosis in rat pancreatic islets via the Akt prosurvival pathway. Endocrinology 2011; 152:3040-8. [PMID: 21693679 DOI: 10.1210/en.2010-1422] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Apolipoprotein CIII (ApoCIII) is mainly synthesized in the liver and is important for triglyceride metabolism. The plasma concentration of ApoCIII is elevated in patients with type 1 diabetes (T1D), and in vitro ApoCIII causes apoptosis in pancreatic β-cells in the absence of inflammatory stress. Here, we investigated the effects of ApoCIII on function, signaling, and viability in intact rat pancreatic islets exposed to proinflammatory cytokines to model the intraislet inflammatory milieu in T1D. In contrast to earlier observations in mouse β-cells, exposure of rat islets to ApoCIII alone (50 μg/ml) did not cause apoptosis. In the presence of the islet-cytotoxic cytokines IL-1β + interferon-γ, ApoCIII reduced cytokine-mediated islet cell death and impairment of β-cell function. ApoCIII had no effects on mitogen-activated protein kinases (c-Jun N-terminal kinase, p38, and ERK) and had no impact on IL-1β-induced c-Jun N-terminal kinase activation. However, ApoCIII augmented cytokine-mediated nitric oxide (NO) production and inducible NO synthase expression. Further, ApoCIII caused degradation of the nuclear factor κB-inhibitor inhibitor of κB and stimulated Ser473-phosphorylation of the survival serine-threonine kinase Akt. Inhibition of the Akt signaling pathway by the phosphatidylinositol 3 kinase inhibitor LY294002 counteracted the antiapoptotic effect of ApoCIII on cytokine-induced apoptosis. We conclude that ApoCIII in the presence of T1D-relevant proinflammatory cytokines reduces rat pancreatic islet cell apoptosis via Akt.
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Affiliation(s)
- Joachim Størling
- Hagedorn Research Institute, Niels Steensens Vej 1, 2820 Gentofte, Denmark.
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Lipotoxicity is glucose-dependent in INS-1E cells but not in human islets and MIN6 cells. Lipids Health Dis 2011; 10:115. [PMID: 21745359 PMCID: PMC3141549 DOI: 10.1186/1476-511x-10-115] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 07/11/2011] [Indexed: 12/12/2022] Open
Abstract
Background Prolonged elevated levels of lipids have negative effects on beta-cell function and mass (lipotoxicity). To what extent exposure to high glucose concentration is important in the harmful effects of lipids (glucolipotoxicity) has been debated. Methods We addressed beta-cell lipotoxicity by measuring apoptosis in isolated intact control human islets and insulin-secreting cell lines MIN6 and INS-1E cultured in the presence of palmitate and low (5.5 mM) or high (25 mM) glucose for 48 hours. Results In both cell lines and human islets palmitate induced apoptosis after culture at low glucose. Palmitate-induced apoptosis was not increased after culture at high compared to low glucose in human islets and MIN6 cells but glucose-induced rise in apoptosis was observed in INS-1E cells. The rise in apoptosis in INS-1E cells was partially reversed by inclusion of AMPK-agonist AICAR. When CPT1-inhibitor etomoxir was included during culture at low glucose palmitate-triggered apoptosis was accentuated both in the islets and the cell lines. Palmitate oxidation in human islets and the cell lines was comparable after culture at low glucose. At high glucose, palmitate oxidation was reduced by 30% in human islets and MIN6 cells but by 80% in INS-1E cells. In INS-1E cells, AICAR increased oxidation of palmitate. Presence of etomoxir at low glucose decreased palmitate oxidation both in the islets and the cell lines. Conclusions In summary, lipotoxicity is evident not only in the presence of high but also low glucose concentrations. Additional effects of glucose are prominent in INS-1E but not in MIN6 cells and intact control human islets, which are able to efficiently oxidize fatty acids at high glucose and in this way avoid glucolipotoxicity.
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Zhang W, Wang XP, Yu ZW, Wang LS, Zhu Y, Yu XF, Wu K, Zeng Y, Xu MY. Hyperlipidemic versus healthy pancreases: a proteomic analysis using an animal model. IUBMB Life 2011; 62:781-9. [PMID: 20981735 DOI: 10.1002/iub.384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hyperlipidemia is associated with a variety of pancreatic diseases; however, the underlying pathophysiology and molecular mechanisms remain undefined. Here, we performed a comparative proteomic analysis of pancreatic tissue obtained from hyperlipidemic rats to identify proteins that may be involved in mediating hyperlipidemia-associated pancreatic injury. Rats were fed a high-fat diet to induce hyperlipidemia. Control rats were fed a diet with normal fat content. Pancreatic tissue samples were obtained after 6 or 12 weeks and comparative proteomic analysis, using gel electrophoresis and mass spectrometry, was conducted to identify proteins, the expression of which were altered in pancreases from hyperlipidemic compared with control rat pancreases. The expression levels of 3 of 13 proteins were significantly altered in pancreatic samples from hyperlipidemic rats. Alpha-amylase and arginase II were dysregulated by more than twofold. These modulations persisted in pancreatic tissue obtained from late-stage hyperlipidemic rats. The levels of alpha-amylase and arginase II were significantly altered in pancreases obtained from rats with hyperlipidemia. These enzymes may be putative biomarkers of hyperlipidemia-mediated pancreatic injury.
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Affiliation(s)
- Wei Zhang
- Department of Gastroenterology, Hua Dong Hospital, Fu Dan University School of Medical Sciences, Shanghai, China
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Lang F, Ullrich S, Gulbins E. Ceramide formation as a target in beta-cell survival and function. Expert Opin Ther Targets 2011; 15:1061-71. [PMID: 21635197 DOI: 10.1517/14728222.2011.588209] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Ceramide may be synthesized de novo or generated by sphingomyelinase-dependent hydrolysis of sphingomyelin. AREAS COVERED The role of ceramide, ceramide-sensitive signaling and ion channels in β-cell apoptosis, lipotoxicity and amyloid-induced β-cell death. EXPERT OPINION Ceramide participates in β-cell dysfunction and apoptosis after exposure to TNFα, IL-1β and IFN-γ, excessive amyloid and islet amyloid polypeptide or non-esterified fatty acids (lipotoxicity). Knockout of sphingomyelin synthase 1, which converts ceramide to sphingomyelin, leads to impairment of insulin secretion. Increased ceramidase activity or pharmacological inhibition of ceramide synthetase, inhibits β-cell apoptosis. Ceramide contributes to endoplasmatic reticulum (ER) stress, decreased mitochondrial membrane potential in insulin-secreting cells and mitochondrial release of cytochrome c into the cytosol, which are all triggers of apoptotic cell death. Ceramide-dependent signaling involves activation of extracellularly regulated kinases 1 and 2 (ERK1/2), downregulation of Period (Per)-aryl hydrocarbon receptor nuclear translocator (Arnt)-single-minded (Sim) kinase (PASK), activation of okadaic-acid-sensitive protein phosphatase 2A (PP2A) and stimulation of NADPH-oxidase with generation of superoxides and lipid peroxides. Ceramide reduces the activity of voltage gated potassium (Kv)-channels in insulin-secreting cells. The role of ceramide in β-cell survival and function may be therapeutically relevant, because ceramide formation can be suppressed by pharmacological inhibition of ceramide synthetase and/or sphingomyelinase.
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Affiliation(s)
- Florian Lang
- University of Tübingen, Institute of Physiology, Germany.
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De Silva NMG, Freathy RM, Palmer TM, Donnelly LA, Luan J, Gaunt T, Langenberg C, Weedon MN, Shields B, Knight BA, Ward KJ, Sandhu MS, Harbord RM, McCarthy MI, Smith GD, Ebrahim S, Hattersley AT, Wareham N, Lawlor DA, Morris AD, Palmer CN, Frayling TM. Mendelian randomization studies do not support a role for raised circulating triglyceride levels influencing type 2 diabetes, glucose levels, or insulin resistance. Diabetes 2011; 60:1008-18. [PMID: 21282362 PMCID: PMC3046819 DOI: 10.2337/db10-1317] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The causal nature of associations between circulating triglycerides, insulin resistance, and type 2 diabetes is unclear. We aimed to use Mendelian randomization to test the hypothesis that raised circulating triglyceride levels causally influence the risk of type 2 diabetes and raise normal fasting glucose levels and hepatic insulin resistance. RESEARCH DESIGN AND METHODS We tested 10 common genetic variants robustly associated with circulating triglyceride levels against the type 2 diabetes status in 5,637 case and 6,860 control subjects and four continuous outcomes (reflecting glycemia and hepatic insulin resistance) in 8,271 nondiabetic individuals from four studies. RESULTS Individuals carrying greater numbers of triglyceride-raising alleles had increased circulating triglyceride levels (SD 0.59 [95% CI 0.52-0.65] difference between the 20% of individuals with the most alleles and the 20% with the fewest alleles). There was no evidence that the carriers of greater numbers of triglyceride-raising alleles were at increased risk of type 2 diabetes (per weighted allele odds ratio [OR] 0.99 [95% CI 0.97-1.01]; P = 0.26). In nondiabetic individuals, there was no evidence that carriers of greater numbers of triglyceride-raising alleles had increased fasting insulin levels (SD 0.00 per weighted allele [95% CI -0.01 to 0.02]; P = 0.72) or increased fasting glucose levels (0.00 [-0.01 to 0.01]; P = 0.88). Instrumental variable analyses confirmed that genetically raised circulating triglyceride levels were not associated with increased diabetes risk, fasting glucose, or fasting insulin and, for diabetes, showed a trend toward a protective association (OR per 1-SD increase in log(10) triglycerides: 0.61 [95% CI 0.45-0.83]; P = 0.002). CONCLUSIONS Genetically raised circulating triglyceride levels do not increase the risk of type 2 diabetes or raise fasting glucose or fasting insulin levels in nondiabetic individuals. One explanation for our results is that raised circulating triglycerides are predominantly secondary to the diabetes disease process rather than causal.
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Affiliation(s)
- N. Maneka G. De Silva
- Genetics of Complex Traits, Institute of Biomedical and Clinical Sciences, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Rachel M. Freathy
- Genetics of Complex Traits, Institute of Biomedical and Clinical Sciences, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Tom M. Palmer
- Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social
and Community Medicine, University of Bristol, Bristol, U.K
| | - Louise A. Donnelly
- Biomedical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, U.K
| | - Jian'an Luan
- MRC, Epidemiology Unit, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, U.K
| | - Tom Gaunt
- Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social
and Community Medicine, University of Bristol, Bristol, U.K
| | - Claudia Langenberg
- MRC, Epidemiology Unit, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, U.K
| | - Michael N. Weedon
- Genetics of Complex Traits, Institute of Biomedical and Clinical Sciences, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Beverley Shields
- Peninsula National Institute for Health Research (NIHR) Clinical Research Facility, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Beatrice A. Knight
- Peninsula National Institute for Health Research (NIHR) Clinical Research Facility, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Kirsten J. Ward
- Department of Twin Research and Genetic Epidemiology, King’s College London, St. Thomas’ Hospital Campus, London, U.K
| | - Manjinder S. Sandhu
- MRC, Epidemiology Unit, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, U.K
- Department of Public Health and Primary Care, Strangeways Research Laboratory, University of Cambridge, Cambridge, U.K
| | - Roger M. Harbord
- Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social
and Community Medicine, University of Bristol, Bristol, U.K
- School of Social and Community Medicine, University of Bristol, Bristol, U.K
| | - Mark I. McCarthy
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Oxford, U.K
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
- Oxford NIHR, Biomedical Research Centre, Churchill Hospital, Oxford, U.K
| | - George Davey Smith
- Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social
and Community Medicine, University of Bristol, Bristol, U.K
| | - Shah Ebrahim
- Department of Twin Research and Genetic Epidemiology, King’s College London, St. Thomas’ Hospital Campus, London, U.K
| | - Andrew T. Hattersley
- Peninsula National Institute for Health Research (NIHR) Clinical Research Facility, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
| | - Nicholas Wareham
- MRC, Epidemiology Unit, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, U.K
| | - Debbie A. Lawlor
- Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social
and Community Medicine, University of Bristol, Bristol, U.K
| | - Andrew D. Morris
- Biomedical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, U.K
| | - Colin N.A. Palmer
- Biomedical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, U.K
| | - Timothy M. Frayling
- Genetics of Complex Traits, Institute of Biomedical and Clinical Sciences, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, U.K
- Corresponding author: Timothy M. Frayling,
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Effects of pharmacological inhibition of NADPH oxidase or iNOS on pro-inflammatory cytokine, palmitic acid or H2O2-induced mouse islet or clonal pancreatic β-cell dysfunction. Biosci Rep 2011; 30:445-53. [PMID: 20178457 DOI: 10.1042/bsr20090138] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Various pancreatic β-cell stressors including cytokines and saturated fatty acids are known to induce oxidative stress, which results in metabolic disturbances and a reduction in insulin secretion. However, the key mechanisms underlying dysfunction are unknown. We investigated the effects of prolonged exposure (24 h) to pro-inflammatory cytokines, H(2)O(2) or PA (palmitic acid) on β-cell insulin secretion, ATP, the NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) component p47phox and iNOS (inducible nitric oxide synthase) levels using primary mouse islets or clonal rat BRIN-BD11 β-cells. Addition of a pro-inflammatory cytokine mixture [IL-1β (interleukin-1β), TNF-α (tumour necrosis factor-α) and IFN-γ (interferon-γ)] or H(2)O(2) (at sub-lethal concentrations) inhibited chronic (24 h) levels of insulin release by at least 50% (from islets and BRIN-BD11 cells), while addition of the saturated fatty acid palmitate inhibited acute (20 min) stimulated levels of insulin release from mouse islets. H(2)O(2) decreased ATP levels in the cell line, but elevated p47phox and iNOS levels as did cytokine addition. Similar effects were observed in mouse islets with respect to elevation of p47phox and iNOS levels. Addition of antioxidants SOD (superoxide dismutase), Cat (catalase) and NAC (N-acetylcysteine) attenuated H(2)O(2) or the saturated fatty acid palmitate-dependent effects, but not cytokine-induced dysfunction. However, specific chemical inhibitors of NADPH oxidase and/or iNOS appear to significantly attenuate the effects of cytokines, H(2)O(2) or fatty acids in islets. While pro-inflammatory cytokines are known to increase p47phox and iNOS levels in β-cells, we now report that H(2)O(2) can increase levels of the latter two proteins, suggesting a key role for positive-feedback redox sensitive regulation of β-cell dysfunction.
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Hornbak M, Banasik K, Justesen JM, Krarup NT, Sandholt CH, Andersson Å, Sandbæk A, Lauritzen T, Pisinger C, Witte DR, Sørensen TAA, Pedersen O, Hansen T. The minor C-allele of rs2014355 in ACADS is associated with reduced insulin release following an oral glucose load. BMC MEDICAL GENETICS 2011; 12:4. [PMID: 21211036 PMCID: PMC3022800 DOI: 10.1186/1471-2350-12-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 01/06/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND A genome-wide association study (GWAS) using metabolite concentrations as proxies for enzymatic activity, suggested that two variants: rs2014355 in the gene encoding short-chain acyl-coenzyme A dehydrogenase (ACADS) and rs11161510 in the gene encoding medium-chain acyl-coenzyme A dehydrogenase (ACADM) impair fatty acid β-oxidation. Chronic exposure to fatty acids due to an impaired β-oxidation may down-regulate the glucose-stimulated insulin release and result in an increased risk of type 2 diabetes (T2D). We aimed to investigate whether the two variants associate with altered insulin release following an oral glucose load or with T2D. METHODS The variants were genotyped using KASPar® PCR SNP genotyping system and investigated for associations with estimates of insulin release and insulin sensitivity following an oral glucose tolerance test (OGTT) in a random sample of middle-aged Danish individuals (nACADS = 4,324; nACADM = 4,337). The T2D-case-control study involved a total of ~8,300 Danish individuals (nACADS = 8,313; nACADM = 8,344). RESULTS In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS associated with reduced measures of serum insulin at 30 min following an oral glucose load (per allele effect (β) = -3.8% (-6.3%;-1.3%), P = 0.003), reduced incremental area under the insulin curve (β = -3.6% (-6.3%;-0.9%), P = 0.009), reduced acute insulin response (β = -2.2% (-4.2%;0.2%), P = 0.03), and with increased insulin sensitivity ISIMatsuda (β = 2.9% (0.5%;5.2%), P = 0.02). The C-allele did not associate with two other measures of insulin sensitivity or with a derived disposition index. The C-allele was not associated with T2D in the case-control analysis (OR 1.07, 95% CI 0.96-1.18, P = 0.21). rs11161510 of ACADM did not associate with any indices of glucose-stimulated insulin release or with T2D. CONCLUSIONS In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS was associated with reduced measures of glucose-stimulated insulin release during an OGTT, a finding which in part may be mediated through an impaired β-oxidation of fatty acids.
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Affiliation(s)
- Malene Hornbak
- Marie Krogh Center for Metabolic Research, Section of Metabolic Genetics, Faculty of Health Sciences, University of Copenhagen, Denmark
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Yuan H, Zhang X, Huang X, Lu Y, Tang W, Man Y, Wang S, Xi J, Li J. NADPH oxidase 2-derived reactive oxygen species mediate FFAs-induced dysfunction and apoptosis of β-cells via JNK, p38 MAPK and p53 pathways. PLoS One 2010; 5:e15726. [PMID: 21209957 PMCID: PMC3012098 DOI: 10.1371/journal.pone.0015726] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 11/20/2010] [Indexed: 01/08/2023] Open
Abstract
Dysfunction of β-cell is one of major characteristics in the pathogenesis of type 2 diabetes. The combination of obesity and type 2 diabetes, characterized as ‘diabesity’, is associated with elevated plasma free fatty acids (FFAs). Oxidative stress has been implicated in the pathogenesis of FFA-induced β-cell dysfunction. However, molecular mechanisms linking between reactive oxygen species (ROS) and FFA-induced β-cell dysfunction and apoptosis are less clear. In the present study, we test the hypothesis that NOX2-derived ROS may play a critical role in dysfunction and apoptosis of β-cells induced by FFA. Our results show that palmitate and oleate (0.5 mmol/L, 48 h) induced JNK activation and AKT inhibition which resulted in decreased phosphorylation of FOXO1 following nuclear localization and the nucleocytoplasmic translocation of PDX-1, leading to the reducing of insulin and ultimately dysfunction of pancreatic NIT-1 cells. We also found that palmitate and oleate stimulated apoptosis of NIT-1 cells through p38MAPK, p53 and NF-κB pathway. More interestingly, our data suggest that suppression of NOX2 may restore FFA-induced dysfunction and apoptosis of NIT-1 cells. Our findings provide a new insight of the NOX2 as a potential new therapeutic target for preservation of β-cell mass and function.
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Affiliation(s)
- Huiping Yuan
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
| | - Xiaoyong Zhang
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Xiuqing Huang
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
| | - Yonggang Lu
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Weiqing Tang
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
| | - Yong Man
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
| | - Shu Wang
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
| | - Jianzhong Xi
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
- * E-mail: (JL); (JX)
| | - Jian Li
- Peking University Fifth School of Clinical Medicine, Beijing Hospital, Beijing, China
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
- * E-mail: (JL); (JX)
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Adipose tissue and reproduction in women. Fertil Steril 2010; 94:795-825. [DOI: 10.1016/j.fertnstert.2009.03.079] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 03/20/2009] [Accepted: 03/24/2009] [Indexed: 12/20/2022]
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Gao D, Nong S, Huang X, Lu Y, Zhao H, Lin Y, Man Y, Wang S, Yang J, Li J. The effects of palmitate on hepatic insulin resistance are mediated by NADPH Oxidase 3-derived reactive oxygen species through JNK and p38MAPK pathways. J Biol Chem 2010; 285:29965-73. [PMID: 20647313 DOI: 10.1074/jbc.m110.128694] [Citation(s) in RCA: 228] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Elevated plasma free fatty acid (FFA) levels in obesity may play a pathogenic role in the development of insulin resistance. However, molecular mechanisms linking FFA to insulin resistance remain poorly understood. Oxidative stress acts as a link between FFA and hepatic insulin resistance. NADPH oxidase 3 (NOX3)-derived reactive oxygen species (ROS) may mediate the effect of TNF-α on hepatocytes, in particular the drop in cellular glycogen content. In the present study, we define the critical role of NOX3-derived ROS in insulin resistance in db/db mice and HepG2 cells treated with palmitate. The db/db mice displayed increased serum FFA levels, excess generation of ROS, and up-regulation of NOX3 expression, accompanied by increased lipid accumulation and impaired glycogen content in the liver. Similar results were obtained from palmitate-treated HepG2 cells. The exposure of palmitate elevated ROS production and NOX3 expression and, in turn, increased gluconeogenesis and reduced glycogen content in HepG2 cells. We found that palmitate induced hepatic insulin resistance through JNK and p38(MAPK) pathways, which are rescued by siRNA-mediated NOX3 reduction. In conclusion, our data demonstrate a critical role of NOX3-derived ROS in palmitate-induced insulin resistance in hepatocytes, indicating that NOX3 is the predominant source of palmitate-induced ROS generation and that NOX3-derived ROS may drive palmitate-induced hepatic insulin resistance through JNK and p38(MAPK) pathways.
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Affiliation(s)
- Dan Gao
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
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Morgan NG, Dhayal S. Unsaturated fatty acids as cytoprotective agents in the pancreatic beta-cell. Prostaglandins Leukot Essent Fatty Acids 2010; 82:231-6. [PMID: 20206490 DOI: 10.1016/j.plefa.2010.02.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
It is widely accepted that, in type 2 diabetes, elevated levels of free fatty acids and glucose contribute to a state of glucolipotoxicity in which beta-cell function declines and, ultimately, cell viability is compromised. This suggests that beta-cells do not readily tolerate chronic elevations in fatty acid levels. In vitro studies suggest, however, that beta-cells respond differentially to long chain fatty acids, such that saturated species are lipotoxic whereas long chain mono-unsaturated fatty acids can provide cytoprotection. This difference does not appear to be mediated by a mutual metabolic antagonism between saturated and unsaturated species (although differential alterations in neutral lipid disposition may occur in response to these fatty acids) and the mechanisms remain unclear. This review summaries the current understanding of the actions of mono-unsaturated fatty acids in beta-cells and highlights areas of controversy as well as key unresolved issues which require to be addressed.
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Affiliation(s)
- Noel G Morgan
- Institute of Biomedical & Clinical Science, Peninsula Medical School (University of Exeter), Plymouth, UK.
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