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Wang KY, Wu SM, Yao ZJ, Zhu YX, Han X. Insufficient TRPM5 Mediates Lipotoxicity-induced Pancreatic β-cell Dysfunction. Curr Med Sci 2024; 44:346-354. [PMID: 38517672 DOI: 10.1007/s11596-023-2795-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 08/28/2023] [Indexed: 03/24/2024]
Abstract
OBJECTIVE While the reduction of transient receptor potential channel subfamily M member 5 (TRPM5) has been reported in islet cells from type 2 diabetic (T2D) mouse models, its role in lipotoxicity-induced pancreatic β-cell dysfunction remains unclear. This study aims to study its role. METHODS Pancreas slices were prepared from mice subjected to a high-fat-diet (HFD) at different time points, and TRPM5 expression in the pancreatic β cells was examined using immunofluorescence staining. Glucose-stimulated insulin secretion (GSIS) defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate (Palm). Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm, and the TRPM5 expression was detected using qRT-PCR and Western blotting. Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown. The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5 (Ad-Trpm5). RESULTS HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets. Palm reduced TRPM5 protein expression in a time- and dose-dependent manner in MIN6 cells. Palm also inhibited TRPM5 expression in primary mouse islets. Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis. Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique to β cells. CONCLUSION Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreatic β cells both in vivo and in vitro and, in turn, drives β-cell dysfunction.
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Affiliation(s)
- Kai-Yuan Wang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Shi-Mei Wu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Zheng-Jian Yao
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Yun-Xia Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China.
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China.
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Ye RZ, Montastier É, Noll C, Frisch F, Fortin M, Bouffard L, Phoenix S, Guérin B, Turcotte ÉE, Carpentier AC. Total Postprandial Hepatic Nonesterified and Dietary Fatty Acid Uptake Is Increased and Insufficiently Curbed by Adipose Tissue Fatty Acid Trapping in Prediabetes With Overweight. Diabetes 2022; 71:1891-1901. [PMID: 35748318 PMCID: PMC9862339 DOI: 10.2337/db21-1097] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 06/14/2022] [Indexed: 02/05/2023]
Abstract
Excessive lean tissue uptake of fatty acids (FAs) is important in the development of insulin resistance and may be caused by impaired dietary FA (DFA) storage and/or increased nonesterified FA (NEFA) flux from adipose tissue intracellular lipolysis. Cardiac and hepatic total postprandial FA uptake of NEFA+DFA has, however, never been reported in prediabetes with overweight. In this study, 20 individuals with impaired glucose tolerance (IGT) and 19 participants with normal glucose tolerance (NGT) and normal fasting glucose underwent postprandial studies with whole-body positron emission tomography/computed tomography (PET/CT) with oral [18F]fluoro-thia-heptadecanoic acid and dynamic PET/CT with intravenous [11C]palmitate. Hepatic (97 [range 36-215] mmol/6 h vs. 68 [23-132] mmol/6 h, P = 0.03) but not cardiac (11 [range 4-24] mmol/6 h vs. 8 [3-20] mmol/6 h, P = 0.09) uptake of most sources of postprandial FA (NEFA + DFA uptake) integrated over 6 h was higher in IGT versus NGT. DFA accounted for lower fractions of total cardiac (21% [5-47] vs. 25% [9-39], P = 0.08) and hepatic (19% [6-52] vs. 28% [14-50], P = 0.04) uptake in IGT versus NGT. Increased adipose tissue DFA trapping predicted lower hepatic DFA uptake and was associated with higher total cardiac FA uptake. Hence, enhanced adipose tissue DFA trapping in the face of increased postprandial NEFA flux is insufficient to fully curb increased postprandial lean organ FA uptake in prediabetes with overweight (ClinicalTrials.gov; NCT02808182).
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Affiliation(s)
- Run Zhou Ye
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie Montastier
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Christophe Noll
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Frédérique Frisch
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Mélanie Fortin
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Lucie Bouffard
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Serge Phoenix
- Department of Nuclear Medicine and Radiobiology, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Brigitte Guérin
- Department of Nuclear Medicine and Radiobiology, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Éric E. Turcotte
- Department of Nuclear Medicine and Radiobiology, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - André C. Carpentier
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
- Corresponding author: André C. Carpentier,
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Chueire VB, Muscelli E. Effect of free fatty acids on insulin secretion, insulin sensitivity and incretin effect - a narrative review. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2021; 65:24-31. [PMID: 33320449 PMCID: PMC10528699 DOI: 10.20945/2359-3997000000313] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 09/26/2020] [Indexed: 11/23/2022]
Abstract
Deleterious effects of free fatty acids, FFAs, on insulin sensitivity are observed in vivo studies in humans. Mechanisms include impaired insulin signaling, oxidative stress, inflammation, and mitochondrial dysfunction, but the effects on insulin secretion are less well known. Our aim was to review the relationship of increased FFAs with insulin resistance, secretion and mainly with the incretin effect in humans. Narrative review. Increased endogenous or administered FFAs induce insulin resistance. FFAs effects on insulin secretion are debatable; inhibition and stimulation have been reported, depending on the type and duration of lipids exposition and the study subjects. Chronically elevated FFAs seem to decrease insulin biosynthesis, glucose-stimulated insulin secretion and β-cell glucose sensitivity. Lipids infusion decreases the response to incretins with unchanged incretin levels in volunteers with normal glucose tolerance. In contrast, FFAs reduction by acipimox did not restore the incretin effect in type-2 diabetes, probably due to the dysfunctional β-cell. Possible mechanisms of FFAs excess on incretin effect include reduction of the expression and levels of GLP-1 (glucagon like peptide-1) receptor, reduction of connexin-36 expression thus the coordinated secretory activity in response to GLP-1, and GIP (glucose-dependent insulinotropic polypeptide) receptors downregulation in islets cells. Increased circulating FFAs impair insulin sensitivity. Effects on insulin secretion are complex and controversial. Deleterious effects on the incretin-induced potentiation of insulin secretion were reported. More investigation is needed to better understand the extent and mechanisms of β-cell impairment and insulin resistance induced by increased FFAs and how to prevent them.
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Affiliation(s)
- Valeria Bahdur Chueire
- Departamento de Endocrinologia, Hospital da Pontifícia Universidade Católica de Campinas, Campinas, SP, Brasil,
| | - Elza Muscelli
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brasil
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Hyun J, Park MH, Lee YH, Lee Y, Jeong SJ, Choi SS, Khim KW, Eom HJ, Hur JH, Park CY, Kim JI, Park J, Ryu HW, Jang HJ, Oh SR, Choi JH. Vernicia fordii (Hemsl.) Airy Shaw extract stimulates insulin secretion in pancreatic β-cells and improves insulin sensitivity in diabetic mice. JOURNAL OF ETHNOPHARMACOLOGY 2021; 278:114238. [PMID: 34048878 DOI: 10.1016/j.jep.2021.114238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/15/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Vernicia fordii (Hemsl.) Airy Shaw (V. fordii) is also known as the tung tree and its leaves and fruit are used as an oriental treatment for dyspepsia, edema, and skin diseases, which are known as diabetic complications. AIM OF THE STUDY In this study, we aimed to investigate the methanolic extract (VF5) of the leaves of V. fordii as an insulin secretagogue and its probable mechanism and verify the effect in HFD-fed mice. MATERIALS AND METHODS The insulin secretagogue activity of different doses of VF5 (0.1, 0.3 and 1.0 μg/ml) was assessed using in vitro insulin secretion assay and confirmed the anti-diabetic effect in mice fed HFD for 4 weeks with different doses of VF5 (10, 20 and 50 mg/kg oral) for another 6 weeks. Glbenclamide (30 mg/kg, oral) was used as positive control drug. The possible mechanisms were evaluated by using Gö6983 (10 μM), U73122 (10 μM) and nifedipine (10 μM). The major constituents of VF5 were analyzed by UPLC-QToF-MS and 1H and 13C NMR spectroscopy. RESULTS UPLC-QToF-MS and NMR spectroscopy analysis indicated that one of the main active components of VF5 was tigliane-diterpene esters. VF5 functioned as an insulin secretagogue and enhanced mitochondria respiration and insulin homeostasis. We confirmed that VF5 preserved the β-cell and reduced the β-cell expansion which caused by metabolic stress under HFD. The antidiabetic role of VF5 in HFD fed mice was assessed by glucose tolerance test (GTT) and insulin tolerance test (ITT), fasting plasma insulin level, fasting blood glucose level, AKT signal in peripheral tissue in the absence of toxic effects. Mechanistically, insulinotropic effect of VF5 was mediated by activation of PKCα via intracellular Ca2+ influx and enhanced mitochondria function. CONCLUSION VF5 exhibits potent insulin secretagogue function and improves insulin sensitivity and protection of pancreatic β-cells from metabolic stress without toxicity. Taken together, our study suggests that VF5 could be potentially used for treating diabetes and metabolic diseases through improving β-cell function.
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Affiliation(s)
- Jimin Hyun
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Mi Hyeon Park
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju Si, Chungcheongbuk-do, 28116, Republic of Korea
| | - Yo Han Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Youngeun Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Su Ji Jeong
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sun Sil Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Keon Woo Khim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Hye Jin Eom
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jin-Hoe Hur
- UNIST-Optical Biomed Imaging Center (UOBC), UNIST, Ulsan, 44919, Republic of Korea
| | - Chan Young Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jae-Ick Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jiyoung Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Hyung Won Ryu
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju Si, Chungcheongbuk-do, 28116, Republic of Korea
| | - Hyun-Jun Jang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
| | - Sei-Ryang Oh
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju Si, Chungcheongbuk-do, 28116, Republic of Korea.
| | - Jang Hyun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
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Marfella R, Sardu C, Mansueto G, Napoli C, Paolisso G. Evidence for human diabetic cardiomyopathy. Acta Diabetol 2021; 58:983-988. [PMID: 33791873 PMCID: PMC8272696 DOI: 10.1007/s00592-021-01705-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/11/2021] [Indexed: 12/12/2022]
Abstract
Growing interest has been accumulated in the definition of worsening effects of diabetes in the cardiovascular system. This is associated with epidemiological data regarding the high incidence of heart failure (HF) in diabetic patients. To investigate the detrimental effects both of hyperglycemia and insulin resistance, a lot of preclinical models were developed. However, the evidence of pathogenic and histological alterations of the so-called diabetic cardiomyopathy (DCM) is still poorly understood in humans. Here, we provide a stringent literature analysis to investigate unique data regarding human DCM. This approach established that lipotoxic-related events might play a central role in the initiation and progression of human DCM. The major limitation in the acquisition of human data is due to the fact of heart specimen availability. Postmortem analysis revealed the end stage of the disease; thus, we need to gain knowledge on the pathogenic events from the early stages until cardiac fibrosis underlying the end-stage HF.
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Affiliation(s)
- Raffaele Marfella
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Piazza Miraglia 2, 80131, Naples, Italy.
| | - Celestino Sardu
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Piazza Miraglia 2, 80131, Naples, Italy
| | - Gelsomina Mansueto
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Piazza Miraglia 2, 80131, Naples, Italy
| | - Claudio Napoli
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Piazza Miraglia 2, 80131, Naples, Italy
| | - Giuseppe Paolisso
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Piazza Miraglia 2, 80131, Naples, Italy
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6
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Montastier É, Ye RZ, Noll C, Bouffard L, Fortin M, Frisch F, Phoenix S, Guérin B, Turcotte ÉE, Lewis GF, Carpentier AC. Increased postprandial nonesterified fatty acid efflux from adipose tissue in prediabetes is offset by enhanced dietary fatty acid adipose trapping. Am J Physiol Endocrinol Metab 2021; 320:E1093-E1106. [PMID: 33870714 DOI: 10.1152/ajpendo.00619.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mechanism of increased postprandial nonesterified fatty acid (NEFA) appearance in the circulation in impaired glucose tolerance (IGT) is due to increased adipose tissue lipolysis but could also be contributed to by reduced adipose tissue (AT) dietary fatty acid (DFA) trapping and increased "spillover" into the circulation. Thirty-one subjects with IGT (14 women, 17 men) and 29 with normal glucose tolerance (NGT, 15 women, 14 men) underwent a meal test with oral and intravenous palmitate tracers and the oral [18F]-fluoro-thia-heptadecanoic acid positron emission tomography method. Postprandial palmitate appearance (Rapalmitate) was higher in IGT versus NGT (P < 0.001), driven exclusively by Rapalmitate from obesity-associated increase in intracellular lipolysis (P = 0.01), as Rapalmitate from DFA spillover was not different between the groups (P = 0.19) and visceral AT DFA trapping was even higher in IGT versus NGT (P = 0.02). Plasma glycerol appearance was lower in IGT (P = 0.01), driven down by insulin resistance and increased insulin secretion. Thus, we found higher AT DFA trapping, limiting spillover to lean organs and in part offsetting the increase in Rapalmitate from intracellular lipolysis. Whether similar findings occur in frank diabetes, a condition also characterized by insulin resistance but relative insulin deficiency, requires further investigation (Clinicaltrials.gov: NCT04088344, NCT02808182).NEW & NOTEWORTHY We found higher adipose tissue dietary fatty acid trapping, limiting spillover to lean organs, that in part offsets the increase in appearance rate of palmitate from intracellular lipolysis in prediabetes. These results point to the adaptive nature of adipose tissue trapping and dietary fatty acid spillover as a protective mechanism against excess obesity-related palmitate appearance rate from intracellular adipose tissue lipolysis.
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Affiliation(s)
- Émilie Montastier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Run Zhou Ye
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Christophe Noll
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Lucie Bouffard
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Mélanie Fortin
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Frédérique Frisch
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | | | - Brigitte Guérin
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Éric E Turcotte
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Gary F Lewis
- Division of Endocrinology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - André C Carpentier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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7
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Benito-Vicente A, Jebari-Benslaiman S, Galicia-Garcia U, Larrea-Sebal A, Uribe KB, Martin C. Molecular mechanisms of lipotoxicity-induced pancreatic β-cell dysfunction. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 359:357-402. [PMID: 33832653 DOI: 10.1016/bs.ircmb.2021.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes (T2D), a heterogeneous disorder derived from metabolic dysfunctions, leads to a glucose overflow in the circulation due to both defective insulin secretion and peripheral insulin resistance. One of the critical risk factor for T2D is obesity, which represents a global epidemic that has nearly tripled since 1975. Obesity is characterized by chronically elevated free fatty acid (FFA) levels, which cause deleterious effects on glucose homeostasis referred to as lipotoxicity. Here, we review the physiological FFA roles onto glucose-stimulated insulin secretion (GSIS) and the pathological ones affecting many steps of the mechanisms and modulation of GSIS. We also describe in vitro and in vivo experimental evidences addressing lipotoxicity in β-cells and the role of saturation and chain length of FFA on the potency of GSIS stimulation. The molecular mechanisms underpinning lipotoxic-β-cell dysfunction are also reviewed. Among them, endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, inflammation, impaired autophagy and β-cell dedifferentiation. Finally therapeutic strategies for the β-cells dysfunctions such as the use of metformin, glucagon-like peptide 1, thiazolidinediones, anti-inflammatory drugs, chemical chaperones and weight are discussed.
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Affiliation(s)
- Asier Benito-Vicente
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Shifa Jebari-Benslaiman
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Unai Galicia-Garcia
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Molecular Biophysics, Fundación Biofísica Bizkaia, Leioa, Spain
| | - Asier Larrea-Sebal
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Molecular Biophysics, Fundación Biofísica Bizkaia, Leioa, Spain
| | - Kepa B Uribe
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Donostia San Sebastián, Spain
| | - Cesar Martin
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.
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8
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Kalra S, Unnikrishnan AG, Baruah MP, Sahay R, Bantwal G. Metabolic and Energy Imbalance in Dysglycemia-Based Chronic Disease. Diabetes Metab Syndr Obes 2021; 14:165-184. [PMID: 33488105 PMCID: PMC7816219 DOI: 10.2147/dmso.s286888] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/02/2020] [Indexed: 12/16/2022] Open
Abstract
Metabolic flexibility is the ability to efficiently adapt metabolism based on nutrient availability and requirement that is essential to maintain homeostasis in times of either caloric excess or restriction and during the energy-demanding state. This regulation is orchestrated in multiple organ systems by the alliance of numerous metabolic pathways under the master control of the insulin-glucagon-sympathetic neuro-endocrine axis. This, in turn, regulates key metabolic enzymes and transcription factors, many of which interact closely with and culminate in the mitochondrial energy generation machinery. Metabolic flexibility is compromised due to the continuous mismatch between availability and intake of calorie-dense foods and reduced metabolic demand due to sedentary lifestyle and age-related metabolic slowdown. The resultant nutrient overload leads to mitochondrial trafficking of substrates manifesting as mitochondrial dysfunction characterized by ineffective substrate switching and incomplete substrate utilization. At the systemic level, the manifestation of metabolic inflexibility comprises reduced skeletal muscle glucose disposal rate, impaired suppression of hepatic gluconeogenesis and adipose tissue lipolysis manifesting as insulin resistance. This is compounded by impaired β-cell function and progressively reduced β-cell mass. A consequence of insulin resistance is the upregulation of the mitogen-activated protein kinase pathway leading to a pro-hypertensive, atherogenic, and thrombogenic environment. This is further aggravated by oxidative stress, advanced glycation end products, and inflammation, which potentiates the risk of micro- and macro-vascular complications. This review aims to elucidate underlying mechanisms mediating the onset of metabolic inflexibility operating at the main target organs and to understand the progression of metabolic diseases. This could potentially translate into a pharmacological tool that can manage multiple interlinked conditions of dysglycemia, hypertension, and dyslipidemia by restoring metabolic flexibility. We discuss the breadth and depth of metabolic flexibility and its impact on health and disease.
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Affiliation(s)
- Sanjay Kalra
- Department of Endocrinology, Bharti Hospital, Karnal, India
- Department of Endocrinology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
| | | | - Manash P Baruah
- Department of Endocrinology, Excel Hospitals, Guwahati, India
| | - Rakesh Sahay
- Department of Endocrinology, Osmania Medical College, Hyderabad, Telangana, India
| | - Ganapathi Bantwal
- Department of Endocrinology, St. John’s Medical College and Hospital, Bangalore, Karnataka, India
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9
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Oxidative-Antioxidant Imbalance and Impaired Glucose Metabolism in Schizophrenia. Biomolecules 2020; 10:biom10030384. [PMID: 32121669 PMCID: PMC7175146 DOI: 10.3390/biom10030384] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 02/07/2023] Open
Abstract
Schizophrenia is a neurodevelopmental disorder featuring chronic, complex neuropsychiatric features. The etiology and pathogenesis of schizophrenia are not fully understood. Oxidative-antioxidant imbalance is a potential determinant of schizophrenia. Oxidative, nitrosative, or sulfuric damage to enzymes of glycolysis and tricarboxylic acid cycle, as well as calcium transport and ATP biosynthesis might cause impaired bioenergetics function in the brain. This could explain the initial symptoms, such as the first psychotic episode and mild cognitive impairment. Another concept of the etiopathogenesis of schizophrenia is associated with impaired glucose metabolism and insulin resistance with the activation of the mTOR mitochondrial pathway, which may contribute to impaired neuronal development. Consequently, cognitive processes requiring ATP are compromised and dysfunctions in synaptic transmission lead to neuronal death, preceding changes in key brain areas. This review summarizes the role and mutual interactions of oxidative damage and impaired glucose metabolism as key factors affecting metabolic complications in schizophrenia. These observations may be a premise for novel potential therapeutic targets that will delay not only the onset of first symptoms but also the progression of schizophrenia and its complications.
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10
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Noll C, Montastier É, Amrani M, Kunach M, Frisch F, Fortin M, Bouffard L, Dubreuil S, Phoenix S, Cunnane SC, Guérin B, Turcotte EE, Laville M, Carpentier AC. Seven-day overfeeding enhances adipose tissue dietary fatty acid storage and decreases myocardial and skeletal muscle dietary fatty acid partitioning in healthy subjects. Am J Physiol Endocrinol Metab 2020; 318:E286-E296. [PMID: 31891539 DOI: 10.1152/ajpendo.00474.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Increased myocardial partitioning of dietary fatty acids (DFA) and decreased left ventricular (LV) function is associated with insulin resistance in prediabetes. We hypothesized that enhanced myocardial DFA partitioning and reduced LV function might be induced concomitantly with reduced insulin sensitivity upon a 7-day hypercaloric (+50% in caloric intake), high-saturated fat (~11%energy), and simple carbohydrates (~54%energy) diet (HIGHCAL) versus an isocaloric diet (ISOCAL) with a moderate amount of saturated fat (~8%energy) and carbohydrates (~50%energy). Thirteen healthy subjects (7 men/6 women) underwent HIGHCAL versus ISOCAL in a randomized crossover design, with organ-specific DFA partitioning and LV function measured using the oral 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid and [11C]acetate positron emission tomography methods at the end of both interventions. HIGHCAL induced a decrease in insulin sensitivity indexes with no significant change in body composition. HIGHCAL led to increased subcutaneous abdominal (+4.2 ± 1.6%, P < 0.04) and thigh (+2.4 ± 1.2%, P < 0.08) adipose tissue storage and reduced cardiac (-0.31 ± 0.11 mean standard uptake value [(SUV), P < 0.03] and skeletal muscle (-0.17 ± 0.08 SUV, P < 0.05) DFA partitioning without change in LV function. We conclude that early increase in adipose tissue DFA storage protects the heart and skeletal muscles from potential deleterious effects of DFA.
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Affiliation(s)
- Christophe Noll
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie Montastier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Mehdi Amrani
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Margaret Kunach
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Frédérique Frisch
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Mélanie Fortin
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Lucie Bouffard
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stéphanie Dubreuil
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Serge Phoenix
- Department of Nuclear Medicine and Radiobiology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stephen C Cunnane
- Research Center on Aging, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Brigitte Guérin
- Department of Nuclear Medicine and Radiobiology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Eric E Turcotte
- Department of Nuclear Medicine and Radiobiology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Martine Laville
- Department of Endocrinology, Diabetology and Nutrition, Groupement Hospitalier Lyon Sud, Fédération Hospitalo-Universitaire DO-IT, Hospices Civils de Lyon, Pierre Bénite, France
| | - André C Carpentier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Lytrivi M, Castell AL, Poitout V, Cnop M. Recent Insights Into Mechanisms of β-Cell Lipo- and Glucolipotoxicity in Type 2 Diabetes. J Mol Biol 2019; 432:1514-1534. [PMID: 31628942 DOI: 10.1016/j.jmb.2019.09.016] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
The deleterious effects of chronically elevated free fatty acid (FFA) levels on glucose homeostasis are referred to as lipotoxicity, and the concurrent exposure to high glucose may cause synergistic glucolipotoxicity. Lipo- and glucolipotoxicity have been studied for over 25 years. Here, we review the current evidence supporting the role of pancreatic β-cell lipo- and glucolipotoxicity in type 2 diabetes (T2D), including lipid-based interventions in humans, prospective epidemiological studies, and human genetic findings. In addition to total FFA quantity, the quality of FFAs (saturation and chain length) is a key determinant of lipotoxicity. We discuss in vitro and in vivo experimental models to investigate lipo- and glucolipotoxicity in β-cells and describe experimental pitfalls. Lipo- and glucolipotoxicity adversely affect many steps of the insulin production and secretion process. The molecular mechanisms underpinning lipo- and glucolipotoxic β-cell dysfunction and death comprise endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, impaired autophagy, and inflammation. Crosstalk between these stress pathways exists at multiple levels and may aggravate β-cell lipo- and glucolipotoxicity. Lipo- and glucolipotoxicity are therapeutic targets as several drugs impact the underlying stress responses in β-cells, potentially contributing to their glucose-lowering effects in T2D.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Anne-Laure Castell
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Vincent Poitout
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada.
| | - Miriam Cnop
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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12
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Liquiritigenin prevents palmitate-induced beta-cell apoptosis via estrogen receptor-mediated AKT activation. Biomed Pharmacother 2018; 101:348-354. [DOI: 10.1016/j.biopha.2018.02.097] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/20/2018] [Accepted: 02/21/2018] [Indexed: 12/21/2022] Open
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13
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Wang Y, Meng X, Deng X, Okekunle AP, Wang P, Zhang Q, Ding L, Guo X, Lv M, Sun C, Li Y. Postprandial Saturated Fatty Acids Increase the Risk of Type 2 Diabetes: A Cohort Study in a Chinese Population. J Clin Endocrinol Metab 2018; 103:1438-1446. [PMID: 29409024 DOI: 10.1210/jc.2017-01904] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/26/2018] [Indexed: 02/13/2023]
Abstract
CONTEXT Experimental evidence suggests saturated fatty acids (SFAs) are associated with insulin resistance, but results from epidemiological studies on fasting SFAs-diabetes risk are inconsistent. OBJECTIVE We investigated SFA (fasting and 2-hour postprandial) profiles and diabetes risk. DESIGN SETTING A total of 8940 participants were recruited for the Harbin People's Health Study in 2008. Serum SFAs (fasting and 2-hour postprandial) at baseline in Chinese men and women without diabetes were profiled, and type 2 diabetes was ascertained using World Health Organization criteria after 4 to 7 years of follow-up. OUTCOME Associations between 2-hour postprandial SFA (2h-SFA) and diabetes. RESULTS At baseline, incident cases of diabetes were older with a higher body mass index and waist circumference. After a mean follow-up of 6.7 years, 658 incident cases of diabetes occurred. After propensity score computation and inverse probability of treatment weighting (IPTW) estimation, fasting SFAs were unrelated to diabetes risk but IPTW-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the highest tertile of 2-hour postprandial stearic acid (2h-SA), 2-hour postprandial palmitic acid (2h-PA), and 2h-SFA for diabetes risk were 2.50 (2.08 to 3.16), 1.56 (1.23 to 2.02), and 1.70 (1.34 to 2.17), respectively (P-trend < 0.0001). Similarly, 2h-SA/fasting SA, 2h-PA/fasting PA, and 2h-SFA/fasting SFA ratios [IPTW-adjusted OR (95% CI): 2.94 (2.39 to 3.58), 2.31 (1.80 to 2.93), and 2.42 (1.91 to 3.11), respectively; P-trend < 0.0001] predicted the diabetes risk. CONCLUSIONS Higher serum 2h-SFA (but not fasting SFA) independently predicted diabetes risk.
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Affiliation(s)
- Yanjiao Wang
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Xing Meng
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Xinrui Deng
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Akinkunmi Paul Okekunle
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Peng Wang
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Qiao Zhang
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Lingyu Ding
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Xinxin Guo
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Mengfan Lv
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Changhao Sun
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
| | - Ying Li
- National Key Discipline Laboratory, Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang Province, People's Republic of China
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Oh YS, Bae GD, Baek DJ, Park EY, Jun HS. Fatty Acid-Induced Lipotoxicity in Pancreatic Beta-Cells During Development of Type 2 Diabetes. Front Endocrinol (Lausanne) 2018; 9:384. [PMID: 30061862 PMCID: PMC6054968 DOI: 10.3389/fendo.2018.00384] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/25/2018] [Indexed: 12/20/2022] Open
Abstract
Type 2 diabetes is caused by chronic insulin resistance and progressive decline in beta-cell function. Optimal beta-cell function and mass is essential for glucose homeostasis and beta-cell impairment leads to the development of diabetes. Elevated levels of circulating fatty acids (FAs) and disturbances in lipid metabolism regulation are associated with obesity, and they are major factors influencing the increase in the incidence of type 2 diabetes. Chronic free FA (FFA) treatment induces insulin resistance and beta-cell dysfunction; therefore, reduction of elevated plasma FFA levels might be an important therapeutic target in obesity and type 2 diabetes. Lipid signals via receptors, and intracellular mechanisms are involved in FFA-induced apoptosis. In this paper, we discuss lipid actions in beta cells, including effects on metabolic pathways and stress responses, to help further understand the molecular mechanisms of lipotoxicity-induced type 2 diabetes.
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Affiliation(s)
- Yoon S. Oh
- Department of Food and Nutrition, Eulji University, Seongnam, South Korea
- *Correspondence: Yoon S. Oh
| | - Gong D. Bae
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
| | - Dong J. Baek
- College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Jeonnam, South Korea
| | - Eun-Young Park
- College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Jeonnam, South Korea
| | - Hee-Sook Jun
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
- Gachon Institute of Pharmaceutical Science, College of Pharmacy, Gachon University, Incheon, South Korea
- Gachon University Gil Medical Center, Gachon Medical and Convergence Institute, Incheon, South Korea
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Grenier-Larouche T, Carreau AM, Geloën A, Frisch F, Biertho L, Marceau S, Lebel S, Hould FS, Richard D, Tchernof A, Carpentier AC. Fatty Acid Metabolic Remodeling During Type 2 Diabetes Remission After Bariatric Surgery. Diabetes 2017; 66:2743-2755. [PMID: 28835473 DOI: 10.2337/db17-0414] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/10/2017] [Indexed: 11/13/2022]
Abstract
Hypertrophic remodeling of white adipose tissues is associated with overexposure of lean organs to circulating triglycerides (TGs) and nonesterified fatty acids (NEFAs), ultimately leading to insulin resistance. Bariatric surgery promotes type 2 diabetes (T2D) remission through a succession of weight loss-dependent and -independent mechanisms. However, the longitudinal contribution of adipocyte size reduction and fatty acid metabolic handling remain unknown. Here we show that severely obese participants with T2D display hypertriglyceridemia and excessive systemic lipolysis during intravenous lipid overload. Three days after biliopancreatic diversion with duodenal switch (DS), whole-body glycerol turnover was normalized and associated with lower HOMA-insulin resistance index. A mean excess weight loss of 84% was achieved 12 months after DS. The smaller subcutaneous adipocyte size predicted better glycemic control in T2D. TG disposal and acylcarnitine production during lipid overload, along with muscle insulin sensitivity, improved with weight loss. Nevertheless, systemic NEFA fluxes and NEFA spillover remained similar, suggesting that increased NEFA storage capacity per volume of adipose tissue exactly compensated for the decrease in fat mass during weight loss. In conclusion, T2D remission after DS is mainly associated with greater circulating TG disposal, lower systemic lipolysis, and better fatty acid handling by lean tissues.
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Affiliation(s)
- Thomas Grenier-Larouche
- Department of Medicine, Division of Endocrinology, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Anne-Marie Carreau
- Department of Medicine, Division of Endocrinology, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Alain Geloën
- University of Lyon, CARMEN INSERM U1060, INSA-Lyon, Villeurbanne, France
| | - Frédérique Frisch
- Department of Medicine, Division of Endocrinology, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Laurent Biertho
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Simon Marceau
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Stéfane Lebel
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Frédéric-Simon Hould
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - André Tchernof
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - André C Carpentier
- Department of Medicine, Division of Endocrinology, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
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Michaud A, Grenier-Larouche T, Caron-Dorval D, Marceau S, Biertho L, Simard S, Richard D, Tchernof A, Carpentier AC. Biliopancreatic diversion with duodenal switch leads to better postprandial glucose level and beta cell function than sleeve gastrectomy in individuals with type 2 diabetes very early after surgery. Metabolism 2017; 74:10-21. [PMID: 28764844 DOI: 10.1016/j.metabol.2017.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/16/2017] [Accepted: 06/17/2017] [Indexed: 12/29/2022]
Abstract
OBJECTIVE The aim of this study was to compare the short-term effect of sleeve gastrectomy (SG) and biliopancreatic diversion with duodenal switch (DS) in order to determine if exclusion of the upper gastrointestinal tract confers greater metabolic improvement, independent of weight loss. METHODS Standard meals were administered before and on day 3 and 4 after SG to assess insulin sensitivity, β-cell function and gastrointestinal hormone responses in matched normoglycemic (NG) and type 2 diabetes (T2D) participants. A third group of matched T2D participants who underwent DS with the same meal test administered prior to and 3days after surgery was also recruited. RESULTS Despite significant metabolic improvement, T2D participants failed to fully normalize insulin resistance and β-cell dysfunction 3 and 4days after SG. Our results demonstrate the superiority of DS over SG in terms of short-term improvement in postprandial glucose excursion and β-cell function 3days after the surgery, with similar improvement in hepatic insulin sensitivity. CONCLUSION Our findings support the notion that caloric restriction represents an important mechanism to explain the very early anti-diabetic effects observed after bariatric surgery. However, exclusion of the upper gastrointestinal tract also provides further metabolic improvements, possibly mediated by gastrointestinal hormonal responses and altered postprandial glucose absorption.
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Affiliation(s)
- Andréanne Michaud
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Thomas Grenier-Larouche
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada; Department of Medicine, Division of Endocrinology, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Québec, Canada
| | - Dominique Caron-Dorval
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
| | - Simon Marceau
- Department of Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Laurent Biertho
- Department of Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Serge Simard
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
| | - Denis Richard
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
| | - André Tchernof
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada.
| | - André C Carpentier
- Department of Medicine, Division of Endocrinology, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Québec, Canada.
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Rydén M, Arner P. Subcutaneous Adipocyte Lipolysis Contributes to Circulating Lipid Levels. Arterioscler Thromb Vasc Biol 2017; 37:1782-1787. [PMID: 28663255 PMCID: PMC5567402 DOI: 10.1161/atvbaha.117.309759] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/21/2017] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Objective— Fatty acids released via fat cell lipolysis can affect circulating lipid levels. However, the contribution of different lipolysis measures in adipose tissue is unknown and was presently examined in isolated subcutaneous adipocytes. Approach and Results— One thousand and sixty-six men and women were examined for lipolysis regulation in subcutaneous abdominal fat cells. Results were compared with fasting plasma levels of total cholesterol, high-density lipoprotein (HDL) cholesterol (HDL-C) and triglycerides. Spontaneous (basal) lipolysis and the effects of the major hormones stimulating (catecholamines and natriuretic peptides) and inhibiting lipolysis (insulin) were examined. Several statistically significant (P<0.0001) correlations between the different lipolysis parameters and plasma lipids were observed. However, physiologically relevant correlations (adjusted r2≥0.05) were only evident between basal or insulin-inhibited lipolysis and plasma triglycerides or HDL-C. Together, these lipolysis measures explained 14% of the variation in triglycerides or HDL-C, respectively. In comparison, a combination of established factors associated with variations in plasma lipids, that is, age; body mass index; waist circumference; waist-to-hip ratio; sex; nicotine use; fat cell volume; and pharmacotherapy against diabetes mellitus; hypertension; or hyperlipidemia explained 17% and 28%, respectively, of the variations in plasma triglycerides and HDL-C. Conclusions— Subcutaneous fat cell lipolysis is an important independent contributor to interindividual variations in plasma lipids. High spontaneous lipolysis activity and resistance to the antilipolytic effect of insulin associate with elevated triglyceride and low HDL-C concentrations. Thus, although several other factors also play a role, subcutaneous adipose tissue may have a causal influence on dyslipidemia.
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Affiliation(s)
- Mikael Rydén
- From the Department of Medicine, Karolinska Institutet at Karolinska University Hospital, Huddinge, Stockholm, Sweden.
| | - Peter Arner
- From the Department of Medicine, Karolinska Institutet at Karolinska University Hospital, Huddinge, Stockholm, Sweden.
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Abstract
Purpose Hepatocyte nuclear factor 1 alpha (HNF1α) defects cause Mature Onset Diabetes of the Young type 3 (MODY3), characterized by defects in beta-cell insulin secretion. However, HNF1α is involved in many other metabolic pathways with relevance for monogenic or polygenic type 2 diabetes. We aimed to investigate gut hormones, lipids, and insulin regulation in response to a meal test in HNF1α defect carriers (MODY3) compared to non-diabetic subjects (controls) and type 2 diabetes (T2D). Methods We administered a standardized liquid meal to each participant. Over 6 hours, we measured post-meal responses of insulin regulation (blood glucose, c-peptide, insulin), gut hormones (ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1) and lipids (non-esterified fatty acids [NEFA] and triglycerides). Results We found that MODY3 participants had lower insulin secretion indices than controls and T2D participants, showing the expected β-cell defect. MODY3 had similar glycated hemoglobin levels (HbA1c median [IQR]: 6.5 [5.6–7.6]%) compared to T2D (median: 6.6 [6.2–6.9]%; P<0.05). MODY3 had greater insulin sensitivity (Matsuda index: 71.9 [29.6; 125.5]) than T2D (3.2 [4.0; 6.0]; P<0.05). MODY3 experienced a larger decrease in the ratio of NEFA to insulin (NEFA 30–0 / insulin 30–0: -39 [-78; -30] x104) in the early post-prandial period (0–30 minutes) compared to controls and to T2D (-2.0 [-0.6; -6.4] x104; P<0.05). MODY3 had lower fasting (0.66 [0.46; 1.2] mM) and post-meal triglycerides levels compared to T2D (fasting: 2.3 [1.7; 2.7] mM; P<0.05). We did not detect significant post-meal differences in ghrelin and incretins between MODY3 and other groups. Conclusion In response to a standard meal test, MODY3 showed greater early post-prandial NEFA diminution in response to relatively low early insulin secretion, and they maintained very low post-prandial triglycerides levels.
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White MG, Shaw JAM, Taylor R. Type 2 Diabetes: The Pathologic Basis of Reversible β-Cell Dysfunction. Diabetes Care 2016; 39:2080-2088. [PMID: 27926891 DOI: 10.2337/dc16-0619] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 08/23/2016] [Indexed: 02/03/2023]
Abstract
The reversible nature of early type 2 diabetes has been demonstrated in in vivo human studies. Recent in vivo and in vitro studies of β-cell biology have established that the β-cell loses differentiated characteristics, including glucose-mediated insulin secretion, under metabolic stress. Critically, the β-cell dedifferentiation produced by long-term excess nutrient supply is reversible. Weight loss in humans permits restoration of first-phase insulin secretion associated with the return to normal of the elevated intrapancreatic triglyceride content. However, in type 2 diabetes of duration greater than 10 years, the cellular changes appear to pass a point of no return. This review summarizes the evidence that early type 2 diabetes can be regarded as a reversible β-cell response to chronic positive calorie balance.
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Affiliation(s)
- Michael G White
- Regenerative Medicine for Diabetes Group and Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, U.K
| | - James A M Shaw
- Regenerative Medicine for Diabetes Group and Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, U.K
| | - Roy Taylor
- Regenerative Medicine for Diabetes Group and Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, U.K.
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Gordon JW, Dolinsky VW, Mughal W, Gordon GRJ, McGavock J. Targeting skeletal muscle mitochondria to prevent type 2 diabetes in youth. Biochem Cell Biol 2015; 93:452-65. [PMID: 26151290 DOI: 10.1139/bcb-2015-0012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The prevalence of type 2 diabetes (T2D) has increased dramatically over the past two decades, not only among adults but also among adolescents. T2D is a systemic disorder affecting every organ system and is especially damaging to the cardiovascular system, predisposing individuals to severe cardiac and vascular complications. The precise mechanisms that cause T2D are an area of active research. Most current theories suggest that the process begins with peripheral insulin resistance that precedes failure of the pancreatic β-cells to secrete sufficient insulin to maintain normoglycemia. A growing body of literature has highlighted multiple aspects of mitochondrial function, including oxidative phosphorylation, lipid homeostasis, and mitochondrial quality control in the regulation of peripheral insulin sensitivity. Whether the cellular mechanisms of insulin resistance in adults are comparable to that in adolescents remains unclear. This review will summarize both clinical and basic studies that shed light on how alterations in skeletal muscle mitochondrial function contribute to whole body insulin resistance and will discuss the evidence supporting high-intensity exercise training as a therapy to circumvent skeletal muscle mitochondrial dysfunction to restore insulin sensitivity in both adults and adolescents.
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Affiliation(s)
- Joseph W Gordon
- a Department of Human Anatomy and Cell Science, College of Nursing, Faculty of Health Sciences, University of Manitoba, The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
| | - Vernon W Dolinsky
- b Department of Pharmacology and Therapeutics, The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
| | - Wajihah Mughal
- c Department of Human Anatomy and Cell Science, The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
| | - Grant R J Gordon
- d Hotchkiss Brain Institute, Health Research Innovation Centre, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada.,e Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Jonathan McGavock
- f Department of Pediatrics and Child Health, The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
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Mateu-de Antonio J, Florit-Sureda M. New Strategy to Reduce Hypertriglyceridemia During Parenteral Nutrition While Maintaining Energy Intake. JPEN J Parenter Enteral Nutr 2014; 40:705-12. [DOI: 10.1177/0148607114549253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/12/2014] [Indexed: 11/17/2022]
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Plourde CÉ, Grenier-Larouche T, Caron-Dorval D, Biron S, Marceau S, Lebel S, Biertho L, Tchernof A, Richard D, Carpentier AC. Biliopancreatic diversion with duodenal switch improves insulin sensitivity and secretion through caloric restriction. Obesity (Silver Spring) 2014; 22:1838-46. [PMID: 24760439 DOI: 10.1002/oby.20771] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/07/2014] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To assess the rapid improvement of insulin sensitivity and β-cell function following biliopancreatic diversion with duodenal switch (BPD-DS) and determine the role played by caloric restriction in these changes. METHODS Standard meals were administrated before and on day 3, 4, and 5 after BPD-DS to measure total caloric intake, glucose excursion, insulin sensitivity, and secretion in matched type 2 diabetes and normoglycemic (NG) subjects. In a second set of study, other subjects with type 2 diabetes had the same meal tests prior to and after a 3-day caloric restriction identical to that observed after BPD-DS and then 3 days after actually undergoing BPD-DS. RESULTS Improvement of HOMA-IR occurred at day 3 after BPD-DS in diabetes and after 3 days of caloric restriction. The disposition index (DI) improved rapidly in diabetes after BPD-DS and to a similar extent after caloric restriction. DI was higher and did not change after BPD-DS in NG. Changes in glucagon-like peptide-1, gastric inhibitory peptide, peptide tyrosine tyrosine, ghrelin, and pancreatic polypeptide levels were not associated with modulation of DI in the participants. CONCLUSIONS Caloric restriction is the major mechanism underlying the early improvement of insulin sensitivity and β-cell function after BPD-DS in type 2 diabetes.
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Affiliation(s)
- Charles-Étienne Plourde
- Department of Medicine, Division of Endocrinology, Centre de recherche clinique Étienne-Le Bel, Université de Sherbrooke, Québec, Canada; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
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Abstract
OBJECTIVES Little is known about pancreatic fat accumulation and its possible associations with metabolic syndrome (MetS) and glucose metabolism. The aim of the present study was to quantify pancreatic fat fraction (PFF) in lean and obese adolescents and explore its relation to metabolic parameters. METHODS We recruited 25 lean and 24 obese adolescents. PFF and visceral adipose tissue (VAT) were determined using magnetic resonance imaging. We measured blood pressure, fasting glucose, insulin, liver enzymes, leptin, and lipid levels. Obese subjects underwent an oral glucose tolerance test. RESULTS PFF was significantly higher in obese than in lean subjects (4.8±1.2 vs 3.6±0.9; P<0.001) and was associated with VAT, γ-glutamyltransferase, triglycerides, high-density lipoprotein cholesterol, leptin concentrations, and MetS (P<0.05 for all). None of the obese subjects had glucose intolerance, but when adjusted for VAT, the following 3 parameters correlated negatively with PFF: fasting and 30- minute and 120-minute insulin levels. We divided subjects into 3 groups: group I, lean without MetS; group II, obese without MetS; and group III, obese with MetS, and observed that PFF increased gradually among groups (I: 3.56%±0.88%; II: 4.70%±1.06%; III: 5.34%±1.49%; P<0.001). CONCLUSIONS Obese adolescents accumulate fat in the pancreas. PFF correlates with the presence of MetS. Even in the absence of glucose intolerance, pancreatic fat deposition is associated with impaired insulin response to glucose overload. This suggests that β-cell dysfunction may already be present in nondiabetic obese adolescents, mirroring what has been shown in adults, and that pancreatic fat accumulation may participate in obesity-associated pancreatic endocrine dysfunction.
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Carpentier AC, Labbé SM, Grenier-Larouche T, Noll C. Abnormal dietary fatty acid metabolic partitioning in insulin resistance and Type 2 diabetes. ACTA ACUST UNITED AC 2011. [DOI: 10.2217/clp.11.60] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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25
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Labbé SM, Croteau E, Grenier-Larouche T, Frisch F, Ouellet R, Langlois R, Guérin B, Turcotte EE, Carpentier AC. Normal postprandial nonesterified fatty acid uptake in muscles despite increased circulating fatty acids in type 2 diabetes. Diabetes 2011; 60:408-15. [PMID: 21228312 PMCID: PMC3028339 DOI: 10.2337/db10-0997] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Postprandial plasma nonesterified fatty acid (NEFA) appearance is increased in type 2 diabetes. Our objective was to determine whether skeletal muscle uptake of plasma NEFA is abnormal during the postprandial state in type 2 diabetes. RESEARCH DESIGN AND METHODS Thigh muscle blood flow and oxidative metabolism indexes and NEFA uptake were determined using positron emission tomography coupled with computed tomography (PET/CT) with [(11)C]acetate and 14(R,S)-[(18)F]fluoro-6-thia-heptadecanoic acid ((18)FTHA) in seven healthy control subjects (CON) and seven subjects with type 2 diabetes during continuous oral intake of a liquid meal to achieve steady postprandial NEFA levels with insulin infusion to maintain similar plasma glucose levels in both groups. RESULTS In the postprandial state, plasma NEFA level was higher in type 2 diabetic subjects versus CON (P < 0.01), whereas plasma glucose was at the same level in both groups. Muscle NEFA fractional extraction and blood flow index levels were 56% (P < 0.05) and 24% (P = 0.27) lower in type 2 diabetes, respectively. However, muscle NEFA uptake was similar to that of CON (quadriceps femoris [QF] 1.47 ± 0.23 vs. 1.37 ± 0.24 nmol·g(-1)·min(-1), P = 0.77; biceps femoris [BF] 1.54 ± 0.26 vs. 1.46 ± 0.28 nmol·g(-1)·min(-1), P = 0.85). Muscle oxidative metabolism was similar in both groups. Muscle NEFA fractional extraction and blood flow index were strongly and positively correlated (r = 0.79, P < 0.005). CONCLUSIONS Postprandial muscle NEFA uptake is normal despite elevated systemic NEFA levels and acute normalization of plasma glucose in type 2 diabetes. Lower postprandial muscle blood flow with resulting reduction in muscle NEFA fractional extraction may explain this phenomenon.
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Affiliation(s)
- Sébastien M. Labbé
- Department of Medicine, Division of Endocrinology, Université de Sherbrooke, Québec, Canada
| | - Etienne Croteau
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Québec, Canada
| | | | - Frédérique Frisch
- Department of Medicine, Division of Endocrinology, Université de Sherbrooke, Québec, Canada
| | - René Ouellet
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Québec, Canada
| | - Réjean Langlois
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Québec, Canada
| | - Brigitte Guérin
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Québec, Canada
| | - Eric E. Turcotte
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Québec, Canada
| | - André C. Carpentier
- Department of Medicine, Division of Endocrinology, Université de Sherbrooke, Québec, Canada
- Corresponding author: André C. Carpentier,
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Giacca A, Xiao C, Oprescu AI, Carpentier AC, Lewis GF. Lipid-induced pancreatic β-cell dysfunction: focus on in vivo studies. Am J Physiol Endocrinol Metab 2011; 300:E255-62. [PMID: 21119027 DOI: 10.1152/ajpendo.00416.2010] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The phenomenon of lipid-induced pancreatic β-cell dysfunction ("lipotoxicity") has been very well documented in numerous in vitro experimental systems and has become widely accepted. In vivo demonstration of β-cell lipotoxicity, on the other hand, has not been consistently demonstrated, and there remains a lack of consensus regarding the in vivo effects of chronically elevated free fatty acids (FFA) on β-cell function. Much of the disagreement relates to how insulin secretion is quantified in vivo and in particular whether insulin secretion is assessed in relation to whole body insulin sensitivity, which is clearly reduced by elevated FFA. By correcting for changes in in vivo insulin sensitivity, we and others have shown that prolonged elevation of FFA impairs β-cell secretory function. Prediabetic animal models and humans with a positive family history of type 2 diabetes are more susceptible to this impairment, whereas those with severe impairment of β-cell function (such as individuals with type 2 diabetes) demonstrate no additional impairment of β-cell function when FFA are experimentally raised. Glucolipotoxicity (i.e., the combined β-cell toxicity of elevated glucose and FFA) has been amply demonstrated in vitro and in some animal studies but not in humans, perhaps because there are limitations in experimentally raising plasma glucose to sufficiently high levels for prolonged periods of time. We and others have shown that therapies directed toward diminishing oxidative stress and ER stress have the potential to reduce lipid-induced β-cell dysfunction in animals and humans. In conclusion, lipid-induced pancreatic β-cell dysfunction is likely to be one contributor to the complex array of genetic and metabolic insults that result in the relentless decline in pancreatic β-cell function in those destined to develop type 2 diabetes, and mechanisms involved in this lipotoxicity are promising therapeutic targets.
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Affiliation(s)
- Adria Giacca
- Dept. of Physiology, Univ. of Toronto, ON, Canada.
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Fontés G, Zarrouki B, Hagman DK, Latour MG, Semache M, Roskens V, Moore PC, Prentki M, Rhodes CJ, Jetton TL, Poitout V. Glucolipotoxicity age-dependently impairs beta cell function in rats despite a marked increase in beta cell mass. Diabetologia 2010; 53:2369-79. [PMID: 20628728 PMCID: PMC2947580 DOI: 10.1007/s00125-010-1850-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 06/18/2010] [Indexed: 01/25/2023]
Abstract
AIMS/HYPOTHESIS Prolonged exposure of pancreatic beta cells to excessive levels of glucose and fatty acids, referred to as glucolipotoxicity, is postulated to contribute to impaired glucose homeostasis in patients with type 2 diabetes. However, the relative contribution of defective beta cell function vs diminished beta cell mass under glucolipotoxic conditions in vivo remains a subject of debate. We therefore sought to determine whether glucolipotoxicity in rats is due to impaired beta cell function and/or reduced beta cell mass, and whether older animals are more susceptible to glucolipotoxic condition. METHODS Wistar rats (2 and 6 months old) received a 72 h infusion of glucose + intravenous fat emulsion or saline control. In vivo insulin secretion and sensitivity were assessed by hyperglycaemic clamps. Ex vivo insulin secretion, insulin biosynthesis and gene expression were measured in isolated islets. Beta cell mass and proliferation were examined by immunohistochemistry. RESULTS A 72 h infusion of glucose + intravenous fat emulsion in 2-month-old Wistar rats did not affect insulin sensitivity, insulin secretion or beta cell mass. In 6-month-old rats by contrast it led to insulin resistance and reduced insulin secretion in vivo, despite an increase in beta cell mass and proliferation. This was associated with: (1) diminished glucose-stimulated second-phase insulin secretion and proinsulin biosynthesis; (2) lower insulin content; and (3) reduced expression of beta cell genes in isolated islets. CONCLUSIONS/INTERPRETATION In this in vivo model, glucolipotoxicity is characterised by an age-dependent impairment of glucose-regulated beta cell function despite a marked increase in beta cell mass.
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Affiliation(s)
- G. Fontés
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - B. Zarrouki
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - D. K. Hagman
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - M. G. Latour
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
| | - M. Semache
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
- Department of Biochemistry, University of Montreal, Montreal, QC, Canada
| | - V. Roskens
- Division of Endocrinology, Diabetes and Metabolism, University of Vermont College of Medicine, Burlington, VT, USA
| | - P. C. Moore
- Kovler Diabetes Center, University of Chicago, Chicago, IL, USA
| | - M. Prentki
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4
- Department of Nutrition, University of Montreal, Montreal, QC, Canada
- Department of Biochemistry, University of Montreal, Montreal, QC, Canada
| | - C. J. Rhodes
- Kovler Diabetes Center, University of Chicago, Chicago, IL, USA
| | - T. L. Jetton
- Division of Endocrinology, Diabetes and Metabolism, University of Vermont College of Medicine, Burlington, VT, USA
| | - V. Poitout
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- CRCHUM–Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada H1W 4A4,
- Department of Medicine, University of Montreal, Montreal, QC, Canada
- Department of Nutrition, University of Montreal, Montreal, QC, Canada
- Department of Biochemistry, University of Montreal, Montreal, QC, Canada
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van Raalte DH, van der Zijl NJ, Diamant M. Pancreatic steatosis in humans: cause or marker of lipotoxicity? Curr Opin Clin Nutr Metab Care 2010; 13:478-85. [PMID: 20489606 DOI: 10.1097/mco.0b013e32833aa1ef] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Type 2 diabetes mellitus (T2DM) is characterized by impaired insulin secretion. Chronically increased levels of plasma nonesterified fatty acids (NEFA) and triglyceride-rich lipoproteins impair beta-cell function, a process referred to as lipotoxicity. Furthermore, when NEFA supply exceeds metabolic capacity, lipids accumulate in nonadipose tissues, such as pancreatic islets, inducing organ dysfunction. The purpose of this review is to describe the mechanisms underlying lipotoxicity in vitro, to discuss the evidence for lipotoxicity in vivo and to address whether pancreatic lipid accumulation interferes with insulin secretion in humans. RECENT FINDINGS Although numerous in-vitro studies have shown that chronically elevated NEFA levels induce beta-cell dysfunction and apoptosis, studies in humans are less conclusive. It has been acknowledged that concurrent hyperglycaemia amplifies the adverse effects of elevated plasma NEFA levels on beta-cell function; therefore glucolipotoxicity should be the preferred term. Lipid accumulation in pancreatic islets impaired beta-cell secretory capacity in leptin-deficient rodents. In humans, recent studies employing noninvasive magnetic resonance-technology and computed tomography-technology, lipid accumulation in the pancreas was increased in individuals with impaired glucose metabolism and T2DM. However, there was no clear association with beta-cell dysfunction. SUMMARY To date, it is difficult to provide evidence that intraislet lipid accumulation truly exists in humans and that it is indeed causal to beta-cell dysfunction. Additional research is warranted to further detail the nature and role of pancreatic lipid content in humans, its consequence for the postulated processes pertinent to glucolipotoxicity and its contribution to the progressive nature of beta-cell dysfunction in prediabetes.
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Affiliation(s)
- Daniël H van Raalte
- Diabetes Centre, Department of Internal Medicine, VU University Medical Centre, Amsterdam, The Netherlands.
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Normand-Lauzière F, Frisch F, Labbé SM, Bherer P, Gagnon R, Cunnane SC, Carpentier AC. Increased postprandial nonesterified fatty acid appearance and oxidation in type 2 diabetes is not fully established in offspring of diabetic subjects. PLoS One 2010; 5:e10956. [PMID: 20532041 PMCID: PMC2881041 DOI: 10.1371/journal.pone.0010956] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 05/07/2010] [Indexed: 12/15/2022] Open
Abstract
Background It has been proposed that abnormal postprandial plasma nonesterified fatty acid (NEFA) metabolism may participate in the development of tissue lipotoxicity and type 2 diabetes (T2D). We previously found that non-diabetic offspring of two parents with T2D display increased plasma NEFA appearance and oxidation rates during intravenous administration of a fat emulsion. However, it is currently unknown whether plasma NEFA appearance and oxidation are abnormal during the postprandial state in these subjects at high-risk of developing T2D. Methodology Palmitate appearance and oxidation rates and glycerol appearance rate were determined in eleven healthy offspring of two parents with T2D (positive family history, FH+), 13 healthy subjects without first-degree relatives with T2D (FH-) and 12 subjects with T2D at fasting, during normoglycemic hyperinsulinemic clamp and during continuous oral intake of a standard liquid meal to achieve steady postprandial NEFA and triacylglycerols (TG) without and with insulin infusion to maintain similar glycemia in all three groups. Principal Findings Plasma palmitate appearance and oxidation were higher at fasting and during the clamp conditions in the T2D group (all P<0.05). In the postprandial state, palmitate appearance, oxidative and non oxidative rates were all elevated in T2D (all P<0.05) but not in FH+. Both T2D and FH+ displayed elevated postprandial TG vs. FH- (P<0.001). Acute correction of hyperglycemia during the postprandial state did not affect these group differences. Increased waist circumference and BMI were positively associated with elevated postprandial plasma palmitate appearance and oxidation. Conclusions/Significance Postprandial plasma NEFA intolerance observed in subjects with T2D is not fully established in non-diabetic offspring of both parents with T2D, despite the presence of increased postprandial plasma TG in the later. Elevated postprandial plasma NEFA appearance and oxidation in T2D is observed despite acute correction of the exaggerated glycemic excursion in this group.
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Affiliation(s)
- François Normand-Lauzière
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Frédérique Frisch
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sébastien M. Labbé
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Patrick Bherer
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Division of Genetics, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - René Gagnon
- Division of Genetics, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | | | - André C. Carpentier
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
- * E-mail:
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