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Klingbeil EA, Schade R, Lee SH, Kirkland R, de La Serre CB. Manipulation of feeding patterns in high fat diet fed rats improves microbiota composition dynamics, inflammation and gut-brain signaling. Physiol Behav 2024; 285:114643. [PMID: 39059597 DOI: 10.1016/j.physbeh.2024.114643] [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: 03/07/2024] [Revised: 06/29/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
Chronic consumption of high fat (HF) diets has been shown to increase meal size and meal frequency in rodents, resulting in overeating. Reducing meal frequency and establishing periods of fasting, independently of caloric intake, may improve obesity-associated metabolic disorders. Additionally, diet-driven changes in microbiota composition have been shown to play a critical role in the development and maintenance of metabolic disorders. In this study, we used a pair-feeding paradigm to reduce meal frequency and snacking episodes while maintaining overall intake and body weight in HF fed rats. We hypothesized that manipulation of feeding patterns would improve microbiota composition and metabolic outcomes. Male Wistar rats were placed in three groups consuming either a HF, low fat diet (LF, matched for sugar), or pair-fed HF diet for 7 weeks (n = 11-12/group). Pair-fed animals received the same amount of food consumed by the HF fed group once daily before dark onset (HF-PF). Rats underwent oral glucose tolerance and gut peptide cholecystokinin sensitivity tests. Bacterial DNA was extracted from the feces collected during both dark and light cycles and sequenced via Illumina MiSeq sequencing of the 16S V4 region. Our pair-feeding paradigm reduced meal numbers, especially small meals in the inactive phase, without changing total caloric intake. This shift in feeding patterns reduced relative abundances of obesity-associated bacteria and maintained circadian fluctuations in microbial abundances. These changes were associated with improved gastrointestinal (GI) function, reduced inflammation, and improved glucose tolerance and gut to brain signaling. We concluded from these data that targeting snacking may help improve metabolic outcomes, independently of energy content of the diet and hyperphagia.
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Affiliation(s)
- E A Klingbeil
- Department of Nutritional Sciences, The University of Texas at Austin, United States
| | - R Schade
- Department of Microbiology and Immunology, Stanford University School of Medicine, United States
| | - S H Lee
- Department of Food Sciences, Sun Moon University, South Korea
| | - R Kirkland
- Office of Research, University of Georgia, United States
| | - C B de La Serre
- Department of Nutritional Sciences, University of Georgia, United States; Department of Biomedical Sciences, Colorado State University, United States.
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2
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Kar P, Çiftci G, Çiftci A. Potential benefit of Lactobacillus acidophilus supplementation to rats fed with a high-fat diet on serum lipid profile, kidney amyloid protein and tumor necrosis factor-alpha level. Prostaglandins Other Lipid Mediat 2024; 175:106911. [PMID: 39321864 DOI: 10.1016/j.prostaglandins.2024.106911] [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: 03/01/2024] [Accepted: 09/20/2024] [Indexed: 09/27/2024]
Abstract
AIM It was aimed to determine the potential effect of Lactobacillus acidophilus supplementation on rats exposed to an experimental high-fat diet on serum lipid profile and kidney total beta amyloid protein (TBAP) and Tumor Necrosis Factor-alpha (TNF-α) levels. METHODS 24 male Sprague-Dawley rats were used in the study to establish 4 groups. Standard rat food (SD) was provided to Group 1 as the control; Group 2 was fed a high-fat diet (HFD); Group 3 consumed SD and received L. acidophilus probiotics; Group 4 was fed HFD and received L. acidophilus probiotics. Body weights were determined weekly during the 12-week trial period. At the end of the experiment, TBP and TNF-α levels in the serum and kidney tissue of the rats were measured by ELISA method. Serum total cholesterol (TC), triglyceride (TG), HDL, LDL, urea and creatinine levels and paraoxanase, amylase and lipase activities were determined by spectrophotometric method on the analyzer device. RESULTS When the control (Group 1) group and Group 2 were compared at the end of the experiment, it was found that Group 2 had gained the most weight and that both the blood and kidney tissue levels of TNF-α and TBAP, as well as the quantities of TG, TK, LDL, and urea, were significantly greater (P<0.05). Serum HDL, PON and amylase levels were found to be significantly low (P>0.05). TG, TK, LDL, urea, and the levels of TNF-α and TBAP in serum and renal tissue were shown to be lower in the groups who received L. acidophilus probiotics (Groups 3, 4) when compared to Group 2 (P>0.05). It was observed that HDL, PON and amylase levels increased and approached the control group (P<0.05). CONCLUSION The study's findings showed that probiotic supplementation improved blood levels of TG, TC, HDL, LDL, urea, PON, and amylase as well as serum and kidney tissue levels of TNF-α and TBAP in obese rats fed a high-fat diet.
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Affiliation(s)
- Pınar Kar
- Department of Veterinary Biochemistry, Faculty of Veterinary Medicine, University of Ondokuz Mayıs, Samsun, Turkey
| | - Gülay Çiftci
- Department of Veterinary Biochemistry, Faculty of Veterinary Medicine, University of Ondokuz Mayıs, Samsun, Turkey.
| | - Alper Çiftci
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Ondokuz Mayıs, Samsun, Turkey
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3
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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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4
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Huang Q, Zou X, Chen Y, Gao L, Cai X, Zhou L, Gao F, Zhou J, Jia W, Ji L. Personalized glucose-lowering effect of chiglitazar in type 2 diabetes. iScience 2023; 26:108195. [PMID: 37942014 PMCID: PMC10628820 DOI: 10.1016/j.isci.2023.108195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/13/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023] Open
Abstract
Chiglitazar (carfloglitazar) is a peroxisome proliferator-activated receptor pan-agonist presenting non-inferior glucose-lowering efficacy with sitagliptin in patients with type 2 diabetes. To delineate the subgroup of patients with greater benefit from chiglitazar, we conducted a machine learning-based post-hoc analysis in two randomized controlled trials. We established a character phenomap based on 13 variables and estimated HbA1c decline to the effects of chiglitazar in reference to sitagliptin. Out of 1,069 patients, 63.3% were found to have greater reduction in HbA1c levels with chiglitazar, while 36.7% showed greater reduction with sitagliptin. This distinction in treatment response was statistically significant between groups (pinteraction<0.001). To identify patients who would gain the most glycemic control benefit from chiglitazar, we developed a machine learning model, ML-PANPPAR, which demonstrated robust performance using sex, BMI, HbA1c, HDL, and fasting insulin. The phenomapping-derived tool successfully identified chiglitazar responders and enabled personalized drug allocation in patients with drug-naïve diabetes.
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Affiliation(s)
- Qi Huang
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Xiantong Zou
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Yingli Chen
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Leili Gao
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Xiaoling Cai
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Lingli Zhou
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
| | - Fei Gao
- Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China
| | - Jian Zhou
- Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China
| | - Weiping Jia
- Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Beijing 100044, China
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5
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Ağagündüz D, Icer MA, Yesildemir O, Koçak T, Kocyigit E, Capasso R. The roles of dietary lipids and lipidomics in gut-brain axis in type 2 diabetes mellitus. J Transl Med 2023; 21:240. [PMID: 37009872 PMCID: PMC10068184 DOI: 10.1186/s12967-023-04088-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/25/2023] [Indexed: 04/04/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM), one of the main types of Noncommunicable diseases (NCDs), is a systemic inflammatory disease characterized by dysfunctional pancreatic β-cells and/or peripheral insulin resistance, resulting in impaired glucose and lipid metabolism. Genetic, metabolic, multiple lifestyle, and sociodemographic factors are known as related to high T2DM risk. Dietary lipids and lipid metabolism are significant metabolic modulators in T2DM and T2DM-related complications. Besides, accumulated evidence suggests that altered gut microbiota which plays an important role in the metabolic health of the host contributes significantly to T2DM involving impaired or improved glucose and lipid metabolism. At this point, dietary lipids may affect host physiology and health via interaction with the gut microbiota. Besides, increasing evidence in the literature suggests that lipidomics as novel parameters detected with holistic analytical techniques have important roles in the pathogenesis and progression of T2DM, through various mechanisms of action including gut-brain axis modulation. A better understanding of the roles of some nutrients and lipidomics in T2DM through gut microbiota interactions will help develop new strategies for the prevention and treatment of T2DM. However, this issue has not yet been entirely discussed in the literature. The present review provides up-to-date knowledge on the roles of dietary lipids and lipidomics in gut-brain axis in T2DM and some nutritional strategies in T2DM considering lipids- lipidomics and gut microbiota interactions are given.
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Affiliation(s)
- Duygu Ağagündüz
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, 06490, Ankara, Turkey.
| | - Mehmet Arif Icer
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Amasya University, 05100, Amasya, Turkey
| | - Ozge Yesildemir
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Bursa Uludag University, 16059, Bursa, Turkey
| | - Tevfik Koçak
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, 06490, Ankara, Turkey
| | - Emine Kocyigit
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Ordu University, 52200, Ordu, Turkey
| | - Raffaele Capasso
- Department of Agricultural Sciences, University of Naples Federico II, Portici, 80055, Naples, Italy.
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Salau VF, Erukainure OL, Olofinsan KO, Bharuth V, Ijomone OM, Islam MS. Ferulic acid improves glucose homeostasis by modulation of key diabetogenic activities and restoration of pancreatic architecture in diabetic rats. Fundam Clin Pharmacol 2023; 37:324-339. [PMID: 36541946 DOI: 10.1111/fcp.12860] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
There are increasing concerns on the rising cases of diabetes mellitus with type 2 diabetes (T2D) being of major interest as well as the cost of its treatment. Plant phenolic compounds are natural and potent antioxidants that have been widely reported for their antidiabetic activities properties, one of which is ferulic acid. The effect of ferulic acid (FA) on major diabetogenic activities and pancreatic architecture linked to T2D was investigated in T2D rats. T2D was induced in male Sprague-Dawley rats using the fructose-streptozotocin model. Diabetic rats were treated with FA at 150 or 300 mg/kg bodyweight (bw). Normal control consisted of rats administered with food and water, while diabetic control consisted of untreated diabetic rats. Metformin was used as the standard drug. The rats were humanely sacrificed after 5 weeks of treatment. Their blood, liver, and pancreas were collected for analysis. Total glycogen content and carbohydrate metabolic enzymes activities were analyzed in the liver, while the pancreas and serum from blood were analyzed for oxidative stress biomarkers, purinergic and cholinergic enzyme activities, and amylase and lipase activities. The pancreatic tissue was further subjected to microscopic and histological examinations. FA caused a significant (p < 0.05) decrease in blood glucose level, with concomitant increase in serum insulin level. Treatment with FA also led to elevated levels of GSH, HDL-c, SOD, and catalase activities, while concomitantly suppressing malondialdehyde, cholesterol, triglyceride, LDL-c, NO, ALT, AST, creatinine, urea, and uric acid levels, acetylcholinesterase, ATPase, ENTPDase, 5'-nucleotidase, lipase, glycogen phosphorylase, glucose-6-phosphatase, and fructose-1,6-biphosphatase activities. Histology analysis revealed an intact pancreatic morphology in FA-treated diabetic rats. While transmission electron microscopy (TEM) analysis revealed an intact pancreatic ultrastructure and increased number of insulin granules in β-cells. Taken together, these results portray that the antidiabetic potentials of ferulic acid involves modulation of major diabetogenic activities and maintenance of the pancreatic ultrastructure architecture.
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Affiliation(s)
- Veronica F Salau
- Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, (Westville Campus), Durban, South Africa.,Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - Ochuko L Erukainure
- Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - Kolawole O Olofinsan
- Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, (Westville Campus), Durban, South Africa
| | - Vishal Bharuth
- Microscopy and Microanalysis Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | | | - Md Shahidul Islam
- Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, (Westville Campus), Durban, South Africa
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7
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Kobi JBBS, Matias AM, Gasparini PVF, Torezani-Sales S, Madureira AR, da Silva DS, Correa CR, Garcia JL, Haese D, Nogueira BV, de Assis ALEM, Lima-Leopoldo AP, Leopoldo AS. High-fat, high-sucrose, and combined high-fat/high-sucrose diets effects in oxidative stress and inflammation in male rats under presence or absence of obesity. Physiol Rep 2023; 11:e15635. [PMID: 37032431 PMCID: PMC10083166 DOI: 10.14814/phy2.15635] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 04/11/2023] Open
Abstract
The study examines the influence of three types of hypercaloric diets on metabolic parameters, inflammatory markers, and oxidative stress in experimental model. Male Wistar rats (n = 40) were randomized in control (C), high-sucrose (HS), high-fat (HF), and high-fat with sucrose (HFHS) for 20 weeks. Nutritional, metabolic, hormonal, and biochemical profiles, as well as histological analysis of adipose and hepatic tissues were performed. Inflammation and oxidative stress were determined. HF model caused obesity and comorbidities as glucose intolerance and arterial hypertension. In relation to hormonal and biochemical parameters, there was no significant difference between the groups. All groups showed increased deposition of fat droplets in the hepatic tissue, even though adipocyte areas were similar. Biomarkers of oxidative stress in serum and adipose tissues were similar among the groups. HF model was effective in triggering associated obesity and comorbidities in male rats, but all hypercaloric diets were unable to promote oxidative stress and inflammation.
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Affiliation(s)
| | - Amanda Martins Matias
- Postgraduate Program in Nutrition and Health, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | | | - Suellem Torezani-Sales
- Postgraduate Program in Physiological Science, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | - Amanda Rangel Madureira
- Postgraduate Program in Nutrition and Health, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | - Daniel Sesana da Silva
- Postgraduate Program in Physical Education, Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | | | | | - Douglas Haese
- University of Vila Velha, Vila Velha, Espírito Santo, Brazil
| | - Breno Valentim Nogueira
- Department of Morphology, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | | | - Ana Paula Lima-Leopoldo
- Postgraduate Program in Nutrition and Health, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
- Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | - André Soares Leopoldo
- Postgraduate Program in Nutrition and Health, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
- Postgraduate Program in Physiological Science, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
- Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
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8
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Mukhuty A, Fouzder C, Kundu R. Fetuin-A excess expression amplifies lipid induced apoptosis and β-cell damage. J Cell Physiol 2021; 237:532-550. [PMID: 34224584 DOI: 10.1002/jcp.30499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 04/27/2021] [Accepted: 06/24/2021] [Indexed: 01/09/2023]
Abstract
Fetuin-A, a hepato-adipokine, is associated with lipid-mediated islet inflammation and inflicts β-cell death but the underlying mechanisms are still unclear. In an earlier report, it was shown that fetuin-A promotes lipid-induced insulin resistance by acting as an endogenous ligand of toll like receptor 4. Recently, we have also reported that β-cells secrete fetuin-A on stimulation by palmitate causing β-cell dysfunction. The aim of this study was twofold: (a) screening the role of fetuin-A in survival of murine β-cells, and (b) to validate the effect of fetuin-A release and lipid induced apoptosis in mouse insulinoma cell line MIN6. Excess of lipid and fetuin-A in circulation induced significant deterioration of islet histoarchitecture and impeded insulin secretion by 2.7 ± 0.5-folds in 20 weeks high fat diet mice. Administration of fetuin-A (0.7 mg/g) along with 4 weeks of HFD produced similar results as 20 weeks of high fat feeding. Treating high doses of palmitate alone (0.50 mM) as well as in combination with fetuin-A (100 µg/ml) for 24 h inflicted apoptosis in MIN6 through the mitochondrial pathway. Knockdown of fetuin-A gene partially inhibited palmitate inflicted apoptosis in MIN6 by 1.83 ± 0.25 times, however, fetuin-A when added in the medium caused re-emergence of apoptosis. Notably, apoptosis induced by palmitate conditioned media from MIN6, 3T3L1, and HepG2, was partially inhibited in fetuin-A KD MIN6. These results confirmed the critical role of circulatory fetuin-A and β-cell secreted fetuin-A in β-cell dysfunction and apoptosis under hyperlipidemic conditions.
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Affiliation(s)
- Alpana Mukhuty
- Cell Signaling Laboratory, Visva-Bharati University, Santiniketan, India
| | - Chandrani Fouzder
- Cell Signaling Laboratory, Visva-Bharati University, Santiniketan, India
| | - Rakesh Kundu
- Cell Signaling Laboratory, Visva-Bharati University, Santiniketan, India
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9
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Hu HQ, Qiao JT, Liu FQ, Wang JB, Sha S, He Q, Cui C, Song J, Zang N, Wang LS, Sun Z, Chen L, Hou XG. The STING-IRF3 pathway is involved in lipotoxic injury of pancreatic β cells in type 2 diabetes. Mol Cell Endocrinol 2020; 518:110890. [PMID: 32781250 DOI: 10.1016/j.mce.2020.110890] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
Abstract
Lipotoxic injury of pancreatic β cells is an important pathological feature in type 2 diabetes mellitus (T2DM). Stimulator of interferon genes (STING) can recognize its own DNA leaked into the cytoplasm from damaged mitochondria or nuclei of the host cell, thus activating its downstream factor interferon regulatory factor 3 (IRF3), causing inflammation and apoptosis. The STING-IRF3 signaling pathway is closely related to glycolipid metabolism, but its relationship with the lipotoxicity of pancreatic β cells has rarely been reported. Here, we investigated the role of the STING-IRF3 signaling pathway in lipotoxicity-induced inflammation, apoptosis, and dysfunction of pancreatic β cells. We examined the activation of STING and IRF3 in islets of db/db mice and identified the role of the STING-IRF3 signaling pathway in palmitic acid (PA)-induced lipotoxic injury of INS-1, a rat insulinoma cell line. STING and phosphorylated IRF3 including downstream interferon-β were upregulated in islets of db/db mice and PA-induced INS-1 cells. Gene silencing of STING or IRF3 ameliorated PA-induced INS-1 cell inflammation and apoptosis, and reversed impaired insulin synthesis. Additionally, PA induced downregulation of the phosphoinositide 3-kinase-AKT signaling pathway, and impaired high glucose-stimulated insulin secretion was reversed after knockdown of STING or IRF3. Our results suggest that activation of the STING-IRF3 pathway triggers inflammation and apoptosis of pancreatic β cells, leading to β-cell damage and dysfunction. Hence, inhibition of this signaling pathway may represent a novel approach for β-cell protection in T2DM.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Cells, Cultured
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/physiology
- Interferon Regulatory Factor-3/physiology
- Male
- Membrane Proteins/physiology
- Mice
- Mice, Transgenic
- Palmitic Acid/pharmacology
- Palmitic Acid/toxicity
- Phosphatidylinositol 3-Kinases/metabolism
- Signal Transduction/drug effects
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Affiliation(s)
- H Q Hu
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - J T Qiao
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - F Q Liu
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, China
| | - J B Wang
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - S Sha
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - Q He
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - C Cui
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - J Song
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - N Zang
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - L S Wang
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China
| | - Z Sun
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - L Chen
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, China.
| | - X G Hou
- Department of Endocrine and Metabolism, Qilu Hospital of Shandong University, Jinan, Shandong, China; Institute of Endocrinology and Metabolism, Shandong University, Jinan, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, China.
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10
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Prentki M, Peyot ML, Masiello P, Madiraju SRM. Nutrient-Induced Metabolic Stress, Adaptation, Detoxification, and Toxicity in the Pancreatic β-Cell. Diabetes 2020; 69:279-290. [PMID: 32079704 DOI: 10.2337/dbi19-0014] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/20/2019] [Indexed: 11/13/2022]
Abstract
Paraphrasing the Swiss physician and father of toxicology Paracelsus (1493-1541) on chemical agents used as therapeutics, "the dose makes the poison," it is now realized that this aptly applies to the calorigenic nutrients. The case here is the pancreatic islet β-cell presented with excessive levels of nutrients such as glucose, lipids, and amino acids. The short-term effects these nutrients exert on the β-cell are enhanced insulin biosynthesis and secretion and changes in glucose sensitivity. However, chronic fuel surfeit triggers additional compensatory and adaptive mechanisms by β-cells to cope with the increased insulin demand or to protect itself. When these mechanisms fail, toxicity due to the nutrient surplus ensues, leading to β-cell dysfunction, dedifferentiation, and apoptosis. The terms glucotoxicity, lipotoxicity, and glucolipotoxicity have been widely used, but there is some confusion as to what they mean precisely and which is most appropriate for a given situation. Here we address the gluco-, lipo-, and glucolipo-toxicities in β-cells by assessing the evidence both for and against each of them. We also discuss potential mechanisms and defend the view that many of the identified "toxic" effects of nutrient excess, which may also include amino acids, are in fact beneficial adaptive processes. In addition, candidate fuel-excess detoxification pathways are evaluated. Finally, we propose that a more general term should be used for the in vivo situation of overweight-associated type 2 diabetes reflecting both the adaptive and toxic processes to mixed calorigenic nutrients excess: "nutrient-induced metabolic stress" or, in brief, "nutri-stress."
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Affiliation(s)
- Marc Prentki
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Marie-Line Peyot
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Pellegrino Masiello
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - S R Murthy Madiraju
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
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11
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Li YX, Sang YQ, Sun Y, Liu XK, Geng HF, Zha M, Wang B, Teng F, Sun HJ, Wang Y, Qiu QQ, Zang X, Wang Y, Wu TT, Jones PM, Liang J, Xu W. Pancreatic Fat is not significantly correlated with β-cell Dysfunction in Patients with new-onset Type 2 Diabetes Mellitus using quantitative Computed Tomography. Int J Med Sci 2020; 17:1673-1682. [PMID: 32714070 PMCID: PMC7378671 DOI: 10.7150/ijms.46395] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/19/2020] [Indexed: 12/14/2022] Open
Abstract
Objective: Type 2 diabetes mellitus (T2DM) is a chronic condition resulting from insulin resistance and insufficient β-cell secretion, leading to improper glycaemic regulation. Previous studies have found that excessive fat deposits in organs such as the liver and muscle can cause insulin resistance through lipotoxicity that affects β-cell function. The relationships between fat deposits in pancreatic tissue, the function of β-cells, the method of visceral fat evaluation and T2DM have been sought by researchers. This study aims to elucidate the role of pancreatic fat deposits in the development of T2DM using quantitative computed tomography (QCT), especially their effects on islet β-cell function. Methods: We examined 106 subjects at the onset of T2DM who had undergone abdominal QCT. Estimated pancreatic fat and liver fat were quantified using QCT and calculated. We analysed the correlations with Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) scores and other oral glucose tolerance test-derived parameters that reflect islet function. Furthermore, correlations of estimated pancreatic fat and liver fat with the area under the curve for insulin (AUCINS) and HOMA-IR were assessed with partial correlation analysis and demonstrated by scatter plots. Results: Associations were found between estimated liver fat and HOMA-IR, AUCINS, the modified β-cell function index (MBCI) and Homeostatic Model Assessment β (HOMA-β). However, no significant differences existed between estimated pancreas fat and those parameters. Similarly, after adjustment for sex, age and body mass index, only estimated liver fat was correlated with HOMA-IR and AUCINS. Conclusions: This study suggests no significant correlation between pancreatic fat deposition and β-cell dysfunction in the early stages of T2DM using QCT as a screening tool. The deposits of fat in the pancreas and the resulting lipotoxicity may play an important role in the late stage of islet cell function dysfunction as the course of T2DM progresses.
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Affiliation(s)
- Y X Li
- Graduate School of Bengbu Medical College, Bengbu, Anhui, China.,Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Y Q Sang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Yan Sun
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - X K Liu
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - H F Geng
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Min Zha
- Department of Endocrinology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Jiangsu, China
| | - Ben Wang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Fei Teng
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - H J Sun
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Yu Wang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Q Q Qiu
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Xiu Zang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Yun Wang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - T T Wu
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Peter M Jones
- Diabetes Research Group, Division of Diabetes & Nutritional Sciences, School of Medicine, King's College London, London, UK
| | - Jun Liang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China
| | - Wei Xu
- Graduate School of Bengbu Medical College, Bengbu, Anhui, China.,Department of Endocrinology, Xuzhou Central Hospital, Xuzhou Institute of Medical Sciences, Xuzhou Clinical School of Nanjing Medical University, Affiliated Hospital of Medical School of Southeast University, Jiangsu, China.,Diabetes Research Group, Division of Diabetes & Nutritional Sciences, School of Medicine, King's College London, London, UK
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12
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Ye R, Onodera T, Scherer PE. Lipotoxicity and β Cell Maintenance in Obesity and Type 2 Diabetes. J Endocr Soc 2019; 3:617-631. [PMID: 30834357 PMCID: PMC6391718 DOI: 10.1210/js.2018-00372] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 01/30/2019] [Indexed: 12/11/2022] Open
Abstract
Obesity and diabetes are often associated with lipotoxic conditions in multiple tissues. The insulin-producing β cells are susceptible to elevated lipid levels and the ensuing lipotoxicity. The preservation of β cell mass and function is one of the main goals of diabetes management under these metabolically stressful conditions. However, the adverse effects from the adaptive signaling pathways that β cells use to counteract lipotoxic stress have secondary negative effects in their own right. Antilipotoxic signaling cascades in β cells can contribute to their eventual failure. Such dual roles are seen for many other biological adaptive processes as well.
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Affiliation(s)
- Risheng Ye
- Department of Medical Education, Texas Tech University Health Sciences Center Paul L. Foster School of Medicine, El Paso, Texas
- Touchstone Diabetes Center, Department of Internal Medicine, the University of Texas Southwestern Medical Center, Dallas, Texas
| | - Toshiharu Onodera
- Touchstone Diabetes Center, Department of Internal Medicine, the University of Texas Southwestern Medical Center, Dallas, Texas
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, the University of Texas Southwestern Medical Center, Dallas, Texas
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13
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Matias AM, Estevam WM, Coelho PM, Haese D, Kobi JBBS, Lima-Leopoldo AP, Leopoldo AS. Differential Effects of High Sugar, High Lard or a Combination of Both on Nutritional, Hormonal and Cardiovascular Metabolic Profiles of Rodents. Nutrients 2018; 10:E1071. [PMID: 30103515 PMCID: PMC6116051 DOI: 10.3390/nu10081071] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 08/03/2018] [Accepted: 08/08/2018] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Dietary interventions in rodents can induce an excess of adipose tissue and metabolic disorders that resemble human obesity. Nevertheless, these approaches are not standardized, and the phenotypes may vary distinctly among studies. The aim of this study was to investigate the effects of different dietary interventions on nutritional, metabolic, biochemical, hormonal, and cardiovascular profiles, as well as to add to development and characterization of an experimental model of obesity. METHODS Male Wistar rats were randomized into four groups: control diet (C), high-sugar (HS), high-fat (HF), or high-sugar and high-fat (HFHS). Weekly measurements of body weight, adiposity, area under the curve (AUC) for glucose, blood pressure (BP) and serum triglycerides, total cholesterol level, and leptin were performed. RESULTS HF and HFHS models were led to obesity by increases in adipose tissue deposition and the adiposity index. All hypercaloric diets presented systolic BP increases. In addition, the AUC for glucose was greater in HF and HFHS than in C, and only the HF group presented hyperleptinemia. CONCLUSIONS HF and HFHS diet approaches promote obesity and comorbidities, and thus represent a useful tool for studying human obesity-related disorders. By contrast, the HS model did not prove to be a good model of obesity.
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Affiliation(s)
- Amanda Martins Matias
- Postgraduate Program in Nutrition and Health, Center of Health Sciences, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
| | - Wagner Müller Estevam
- Postgraduate Program in Physical Education, Center of Physical Education and Sports, Federal University of Espírito Santo (UFES), Vitória 29075-910, Espírito Santo, Brazil.
| | - Priscila Murucci Coelho
- Postgraduate Program in Nutrition and Health, Center of Health Sciences, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
| | - Douglas Haese
- University of Vila Velha, Vila Velha 29102-920, Espírito Santo, Brazil.
| | - Jéssika Butcovsky Botto Sarter Kobi
- Postgraduate Program in Nutrition and Health, Center of Health Sciences, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
| | - Ana Paula Lima-Leopoldo
- Postgraduate Program in Nutrition and Health, Center of Health Sciences, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
- Postgraduate Program in Physical Education, Center of Physical Education and Sports, Federal University of Espírito Santo (UFES), Vitória 29075-910, Espírito Santo, Brazil.
- Department of Sports, Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
| | - André Soares Leopoldo
- Postgraduate Program in Nutrition and Health, Center of Health Sciences, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
- Postgraduate Program in Physical Education, Center of Physical Education and Sports, Federal University of Espírito Santo (UFES), Vitória 29075-910, Espírito Santo, Brazil.
- Department of Sports, Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória 29075-910, Espírito Santo, Brazil.
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14
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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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15
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Ho N, Xu C, Thibault G. From the unfolded protein response to metabolic diseases - lipids under the spotlight. J Cell Sci 2018; 131:131/3/jcs199307. [PMID: 29439157 DOI: 10.1242/jcs.199307] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The unfolded protein response (UPR) is classically viewed as a stress response pathway to maintain protein homeostasis at the endoplasmic reticulum (ER). However, it has recently emerged that the UPR can be directly activated by lipid perturbation, independently of misfolded proteins. Comprising primarily phospholipids, sphingolipids and sterols, individual membranes can contain hundreds of distinct lipids. Even with such complexity, lipid distribution in a cell is tightly regulated by mechanisms that remain incompletely understood. It is therefore unsurprising that lipid dysregulation can be a key factor in disease development. Recent advances in analysis of lipids and their regulators have revealed remarkable mechanisms and connections to other cellular pathways including the UPR. In this Review, we summarize the current understanding in UPR transducers functioning as lipid sensors and the interplay between lipid metabolism and ER homeostasis in the context of metabolic diseases. We attempt to provide a framework consisting of a few key principles to integrate the different lines of evidence and explain this rather complicated mechanism.
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Affiliation(s)
- Nurulain Ho
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551
| | - Chengchao Xu
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142-1479, USA
| | - Guillaume Thibault
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551
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16
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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: 182] [Impact Index Per Article: 30.3] [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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17
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Sheng Q, Xiao X, Prasadan K, Chen C, Ming Y, Fusco J, Gangopadhyay NN, Ricks D, Gittes GK. Autophagy protects pancreatic beta cell mass and function in the setting of a high-fat and high-glucose diet. Sci Rep 2017; 7:16348. [PMID: 29180700 PMCID: PMC5703965 DOI: 10.1038/s41598-017-16485-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 10/09/2017] [Indexed: 12/31/2022] Open
Abstract
Autophagy is a major regulator of pancreatic beta cell homeostasis. Altered autophagic activity has been implicated in the beta cells of patients with type 2 diabetes, and in the beta cells of obese diabetic rodents. Here, we show that autophagy was induced in beta cells by either a high-fat diet or a combined high-fat and high-glucose diet, but not by high-glucose alone. However, a high-glucose intake alone did increase beta cell mass and insulin secretion moderately. Depletion of Atg7, a necessary component of the autophagy pathway, in beta cells by pancreatic intra-ductal AAV8-shAtg7 infusion in C57BL/6 mice, resulted in decreased beta cell mass, impaired glucose tolerance, defective insulin secretion, and increased apoptosis when a combined high-fat and high-glucose diet was given, seemingly due to suppression of autophagy. Taken together, our findings suggest that the autophagy pathway may act as a protective mechanism in pancreatic beta cells during a high-calorie diet.
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Affiliation(s)
- Qingfeng Sheng
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA.,Department of General Surgery, Shanghai Children's Hospital, Shanghai Jiao Tong University, No. 355, Luding Rd, Shanghai, 200062, China
| | - Xiangwei Xiao
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - Krishna Prasadan
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - Congde Chen
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - Yungching Ming
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - Joseph Fusco
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - Nupur N Gangopadhyay
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - David Ricks
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA
| | - George K Gittes
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA.
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18
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Oliva L, Aranda T, Caviola G, Fernández-Bernal A, Alemany M, Fernández-López JA, Remesar X. In rats fed high-energy diets, taste, rather than fat content, is the key factor increasing food intake: a comparison of a cafeteria and a lipid-supplemented standard diet. PeerJ 2017; 5:e3697. [PMID: 28929011 PMCID: PMC5600723 DOI: 10.7717/peerj.3697] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/26/2017] [Indexed: 11/20/2022] Open
Abstract
Background Food selection and ingestion both in humans and rodents, often is a critical factor in determining excess energy intake and its related disorders. Methods Two different concepts of high-fat diets were tested for their obesogenic effects in rats; in both cases, lipids constituted about 40% of their energy intake. The main difference with controls fed standard lab chow, was, precisely, the lipid content. Cafeteria diets (K) were self-selected diets devised to be desirable to the rats, mainly because of its diverse mix of tastes, particularly salty and sweet. This diet was compared with another, more classical high-fat (HF) diet, devised not to be as tasty as K, and prepared by supplementing standard chow pellets with fat. We also analysed the influence of sex on the effects of the diets. Results K rats grew faster because of a high lipid, sugar and protein intake, especially the males, while females showed lower weight but higher proportion of body lipid. In contrast, the weight of HF groups were not different from controls. Individual nutrient’s intake were analysed, and we found that K rats ingested large amounts of both disaccharides and salt, with scant differences of other nutrients’ proportion between the three groups. The results suggest that the key differential factor of the diet eliciting excess energy intake was the massive presence of sweet and salty tasting food. Conclusions The significant presence of sugar and salt appears as a powerful inducer of excess food intake, more effective than a simple (albeit large) increase in the diet’s lipid content. These effects appeared already after a relatively short treatment. The differential effects of sex agree with their different hedonic and obesogenic response to diet.
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Affiliation(s)
- Laia Oliva
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain
| | - Tània Aranda
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain
| | - Giada Caviola
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain
| | - Anna Fernández-Bernal
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain
| | - Marià Alemany
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain.,Institute of Biomedicine, University of Barcelona, Barcelona, Spain.,CIBER OBN, Centro de Investigaciones Biomédicas en Red, Barcelona, Spain
| | - José Antonio Fernández-López
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain.,Institute of Biomedicine, University of Barcelona, Barcelona, Spain.,CIBER OBN, Centro de Investigaciones Biomédicas en Red, Barcelona, Spain
| | - Xavier Remesar
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Faculty of Biology, Barcelona, Spain.,Institute of Biomedicine, University of Barcelona, Barcelona, Spain.,CIBER OBN, Centro de Investigaciones Biomédicas en Red, Barcelona, Spain
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19
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Seghieri M, Tricò D, Natali A. The impact of triglycerides on glucose tolerance: Lipotoxicity revisited. DIABETES & METABOLISM 2017; 43:314-322. [PMID: 28693962 DOI: 10.1016/j.diabet.2017.04.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/19/2017] [Accepted: 04/27/2017] [Indexed: 12/22/2022]
Abstract
Elevated plasma triglycerides (TGs) are early key features of conditions associated with a dysregulation in glucose metabolism and may predict the development of type 2 diabetes (T2D) over time. Although the acute ingestion of lipid, either mixed with or shortly before the meal, is neutral or slightly beneficial on glucose tolerance, a short-term increase in plasma TGs induced by either an i.v. lipid infusion or a high-fat diet produces a deterioration of glucose control. Accordingly, chronic lowering of plasma TGs by fibrates improves glucose homeostasis and may also prevent T2D. The chronic effects of the elevation of dietary lipid intake are less clear, particularly in humans, being the quality of fat probably more important than total fat intake. Although on the bases of the available experimental and clinical evidence it cannot be easily disentangled, with respect to elevated non-esterified fatty acids (NEFA) the relative contribution of elevated TGs to glucose homeostasis disregulation seems to be greater and also more plausible. In conclusion, although the association between elevated plasma TGs and impaired glucose tolerance is commonly considered not causative or merely a consequence of NEFA-mediated lipotoxicity, the available data suggest that TGs per se may directly contribute to disorders of glucose metabolism.
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Affiliation(s)
- M Seghieri
- Department of clinical and experimental medicine, laboratory of metabolism, nutrition and atherosclerosis, university of Pisa, Pisa, Italy
| | - D Tricò
- Department of clinical and experimental medicine, laboratory of metabolism, nutrition and atherosclerosis, university of Pisa, Pisa, Italy
| | - A Natali
- Department of clinical and experimental medicine, laboratory of metabolism, nutrition and atherosclerosis, university of Pisa, Pisa, Italy.
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20
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Insulinotropic effects of GPR120 agonists are altered in obese diabetic and obese non-diabetic states. Clin Sci (Lond) 2016; 131:247-260. [PMID: 27980130 DOI: 10.1042/cs20160545] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptor 120 (GPR120) is a putative target for obesity and diabetes therapies. However, it remains controversial whether resident GPR120 plays a direct regulatory role in islet β-cell insulin secretion. The present study examined this issue in isolated rodent islets and rat β-cell line INS-1E, and assessed the role of GPR120 in islet insulin secretion in obese non-diabetic (OND) and diabetic states. GPR120 expression was detected in rodent islet β-cells. Docosahexaenoic acid (DHA) and synthetic GPR120 agonist GSK137647 (GSK) augmented insulin release from rat/mouse islets and INS-1E; DHA effects were partially mediated by GPR40. GPR120 knockdown and overexpression attenuated and enhanced DHA effects in INS-1E respectively. DHA and GSK improved postprandial hyperglycaemia of diabetic mice. Inhibition of calcium signalling in INS-1E reduced GPR120 activation-induced insulinotropic effects. The insulinotropic effects of DHA/GSK were amplified in OND rat islets, but diminished in diabetic rat islets. GPR120 and peroxisome proliferator-activated receptor γ (PPARγ) expression were elevated in OND islets and palmitic acid (PA)-treated INS-1E, but reduced in diabetic islets and high glucose-treated INS-1E. PPARγ activation increased GPR120 expression in rat islets and INS-1E. DHA and GSK induced protein kinase B (Akt)/extracellular signal-regulated kinase (ERK) phosphorylation in rodent islets and INS-1E, and these effects were altered in OND and diabetic states. Taken together, the present study indicates that (i) GPR120 activation has an insulinotropic influence on β-cells with the involvement of calcium signalling; (ii) GPR120 expression in β-cells and GPR120-mediated insulinotropic effects are altered in OND and diabetic states in distinct ways, and these alterations may be mediated by PPARγ.
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Owei I, Umekwe N, Wan J, Dagogo-Jack S. Plasma lipid levels predict dysglycemia in a biracial cohort of nondiabetic subjects: Potential mechanisms. Exp Biol Med (Maywood) 2016; 241:1961-1967. [PMID: 27430991 PMCID: PMC5068467 DOI: 10.1177/1535370216659946] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 06/27/2016] [Indexed: 01/04/2023] Open
Abstract
Dyslipidemia and dysglycemia are etiologically associated, but the direction, chronology, and mechanisms of the association are not fully understood. We, therefore, analyzed data from 335 healthy adults (184 black, 151 white) enrolled in the Pathobiology of Prediabetes in A Biracial Cohort study. Subjects underwent oral glucose tolerance test (OGTT) and were enrolled if they had normal fasting and 2-h plasma glucose levels. Assessments during year 1 included anthropometry, fasting lipid profile, insulin sensitivity, and insulin secretion. Thereafter, OGTT was assessed annually for 5.5 years. The primary outcome was occurrence of prediabetes (impaired fasting glucose or impaired glucose tolerance) or diabetes. During a mean follow-up of 2.62 years, 110 participants (32.8%) developed prediabetes (N = 100) or diabetes (N = 10). In multivariate logistic regression models, higher baseline low-density lipoprotein (LDL) cholesterol and triglyceride levels and lower HDL cholesterol levels significantly increased the risk of incident prediabetes. The combined relative risk (95% confidence interval [CI]) of prediabetes for participants with lower baseline HDL cholesterol (10th vs. 90th percentile), higher LDL cholesterol (90th vs. 10th percentile) and high triglycerides levels (90th vs. 10th percentile) was 4.12 (95% CI 1.61-10.56), P = 0.0032. At baseline, lipid values showed significant associations with measures of adiposity, glycemia, insulin sensitivity, and secretion. In both ethnic groups, waist circumference correlated positively with triglycerides and inversely with HDL cholesterol levels (P = 0.0004-<0.0001); fasting plasma glucose correlated positively with triglycerides and LDL cholesterol levels and inversely with HDL cholesterol levels (P = 0.006-<0.0001); insulin sensitivity correlated positively with HDL cholesterol and inversely with triglyceride levels (P < 0.0001), and insulin secretion correlated positively with triglycerides (P = 0.01) and inversely with HDL cholesterol (P < 0.0001). We conclude that a baseline lipidemic signature identifies normoglycemic individuals at high risk for future glycemic progression, via congruent associations with adiposity and glucoregulatory mechanisms. These findings suggest that early lifestyle intervention could ameliorate progressive dyslipidemia and dysglycemia.
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Affiliation(s)
- Ibiye Owei
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Nkiru Umekwe
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jim Wan
- Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Samuel Dagogo-Jack
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Marques C, Meireles M, Norberto S, Leite J, Freitas J, Pestana D, Faria A, Calhau C. High-fat diet-induced obesity Rat model: a comparison between Wistar and Sprague-Dawley Rat. Adipocyte 2016; 5:11-21. [PMID: 27144092 DOI: 10.1080/21623945.2015.1061723] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/26/2015] [Accepted: 06/04/2015] [Indexed: 02/07/2023] Open
Abstract
In the past decades, obesity and associated metabolic complications have reached epidemic proportions. For the study of these pathologies, a number of animal models have been developed. However, a direct comparison between Wistar and Sprague-Dawley (SD) Rat as models of high-fat (HF) diet-induced obesity has not been adequately evaluated so far. Wistar and SD rats were assigned for 2 experimental groups for 17 weeks: standard (St) and high-fat (HF) diet groups. To assess some of the features of the metabolic syndrome, oral glucose tolerance tests, systolic blood pressure measurements and blood biochemical analysis were performed throughout the study. The gut microbiota composition of the animals of each group was evaluated at the end of the study by real-time PCR. HF diet increased weight gain, body fat mass, mesenteric adipocyte's size, adiponectin and leptin plasma levels and decreased oral glucose tolerance in both Wistar and SD rats. However, the majority of these effects were more pronounced or earlier detected in Wistar rats. The gut microbiota of SD rats was less abundant in Bacteroides and Prevotella but richer in Bifidobacterium and Lactobacillus comparatively to the gut microbiota of Wistar rats. Nevertheless, the modulation of the gut microbiota by HF diet was similar in both strains, except for Clostridium leptum that was only reduced in Wistar rats fed with HF diet. In conclusion, both Wistar and SD Rat can be used as models of HF diet-induced obesity although the metabolic effects caused by HF diet seemed to be more pronounced in Wistar Rat. Differences in the gut microbial ecology may account for the worsened metabolic scenario observed in Wistar Rat.
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Colegrove KM, Venn-Watson S. Histomorphology of the bottlenose dolphin (Tursiops truncatus) pancreas and association of increasing islet β-cell size with chronic hypercholesterolemia. Gen Comp Endocrinol 2015; 214:17-23. [PMID: 25745813 DOI: 10.1016/j.ygcen.2015.02.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 12/12/2014] [Accepted: 02/14/2015] [Indexed: 01/09/2023]
Abstract
Bottlenose dolphins (Tursiops truncatus) can develop metabolic states mimicking prediabetes, including hyperinsulinemia, hyperlipidemia, elevated glucose, and fatty liver disease. Little is known, however, about dolphin pancreatic histomorphology. Distribution and area of islets, α, β, and δ cells were evaluated in pancreatic tissue from 22 dolphins (mean age 25.7years, range 0-51). Associations of these measurements were evaluated by sex, age, percent high glucose and lipids during the last year of life, and presence or absence of fatty liver disease and islet cell vacuolation. The most common pancreatic lesions identified were exocrine pancreas fibrosis (63.6%) and mild islet cell vacuolation (47.4%); there was no evidence of insulitis or amyloid deposition, changes commonly associated with type 2 diabetes. Dolphin islet architecture appears to be most similar to the pig, where α and β cells are localized to the central or periphery of the islet, respectively, or are well dispersed throughout the islet. Unlike pigs, large islets (greater than 10,000μm(2)) were common in dolphins, similar to that found in humans. A positive linear association was identified between dolphin age and islet area average, supporting a compensatory response similar to other species. The strongest finding in this study was a positive linear association between islet size, specifically β-cells, and percent blood samples with high cholesterol (greater than 280mg/dl, R(2)=0.57). This study is the most comprehensive assessment of the dolphin pancreas to date and may help direct future studies, including associations between chronic hypercholesterolemia and β-cell size.
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Affiliation(s)
- Kathleen M Colegrove
- Zoological Pathology Program, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, LUMC, Building 101, Room 0745, Maywood, IL 60153, USA.
| | - Stephanie Venn-Watson
- Translational Medicine and Research Program, National Marine Mammal Foundation, 2240 Shelter Island Suite 200, San Diego, CA 92106, USA.
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Wauquier F, Léotoing L, Philippe C, Spilmont M, Coxam V, Wittrant Y. Pros and cons of fatty acids in bone biology. Prog Lipid Res 2015; 58:121-45. [PMID: 25835096 DOI: 10.1016/j.plipres.2015.03.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/06/2015] [Accepted: 03/23/2015] [Indexed: 12/12/2022]
Abstract
Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response.
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Affiliation(s)
- Fabien Wauquier
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Laurent Léotoing
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Claire Philippe
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Mélanie Spilmont
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Véronique Coxam
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Yohann Wittrant
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France.
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Oh YS. Mechanistic insights into pancreatic beta-cell mass regulation by glucose and free fatty acids. Anat Cell Biol 2015; 48:16-24. [PMID: 25806118 PMCID: PMC4371177 DOI: 10.5115/acb.2015.48.1.16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 02/04/2015] [Indexed: 01/14/2023] Open
Abstract
Pancreatic islets are responsible for blood glucose homeostasis. Reduced numbers of functional (insulin-secreting) beta-cells in pancreatic islets underlies diabetes. Restoration of the secretion of the proper amount of insulin is a goal. Beta-cell mass is increased by neogenesis, proliferation and cell hypertrophy, and is decreased by beta-cell death primarily through apoptosis. Many hormones and nutrients affect beta-cell mass, and glucose and free fatty acid are thought to be the most important determinants of beta-cell equilibrium. A number of molecular pathways have been implicated in beta-cell mass regulation and have been studied. This review will focus on the role of the principle metabolites, glucose and free fatty acid, and the downstream signaling pathways regulating beta-cell mass by these metabolites.
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Affiliation(s)
- Yoon Sin Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea. ; Gachon Medical Research Institute, Gil Hospital, Incheon, Korea
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Abstract
The increase in the number of patients with diabetes has become a worldwide healthcare issue, with numbers predicted to reach approximately 600 million by 2035. In Asia-Pacific region, the prevalence of type 2 diabetes has increased dramatically in recent decades, of which the major causes are believed to be modern lifestyle changes, e.g., Western dietary pattern and reduced physical activity, on their genetic basis of lower insulin secretory capacity. Particularly, in East Asian countries, the amount of fat intake has increased nearly three-fold over this half of century; dietary fat appears to be the major culprit of type 2 diabetes pandemic in East Asia. However, convincing evidence has not yet been provided as to whether high-fat diet causes type 2 diabetes in epidemiological cohort studies. Here, we summarize clinical studies regarding fat intake and type 2 diabetes, and animal studies on high-fat diet-induced diabetes including our recent works on the novel mouse lines (selectively bred diet-induced glucose intolerance-prone [SDG-P] and -resistant [SDG-R]) to address the etiology of high-fat diet-induced diabetes. These epidemiological and experimental findings would provide further insight into the etiology of type 2 diabetes under the modern nutritional environment, namely in the context of increased fat intake.
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Affiliation(s)
- Mototsugu Nagao
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603 Japan
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27
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Jiang H, Feng J, Du Z, Zhen H, Lin M, Jia S, Li T, Huang X, Ostenson CG, Chen Z. Oral administration of soybean peptide Vglycin normalizes fasting glucose and restores impaired pancreatic function in Type 2 diabetic Wistar rats. J Nutr Biochem 2014; 25:954-63. [PMID: 24985367 DOI: 10.1016/j.jnutbio.2014.04.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 03/31/2014] [Accepted: 04/17/2014] [Indexed: 12/18/2022]
Abstract
Vglycin, a natural 37-residue polypeptide isolated from pea seeds in which six half-cysteine residues are embedded in three pairs of disulfide bonds, is resistant to digestive enzymes and has antidiabetic potential. To investigate the pharmacological activity of Vglycin in vivo and to examine the mechanisms involved, the therapeutic effect of Vglycin in diabetic rats was examined. Diabetes was induced in Wistar rats by high-fat diet and multiple streptozotocin intraperitoneal injections. Diabetic rats were treated daily with Vglycin for 4 weeks. Body weight, food intake, fasting plasma glucose and insulin levels were assayed weekly. Glucose and insulin tolerance tests were conducted on Day 29. Subsequently, levels of p-Akt in the liver and pancreas and cleaved PARP, Pdx-1 and insulin in the pancreas were detected by immunoblotting. The morphology of the pancreas and the insulin expression in the pancreas were analyzed by hematoxylin-eosin staining and immunohistochemistry, respectively. Furthermore, human liver-derived cell lines were used to explore the in vitro effects of Vglycin on insulin sensitivity and glucose uptake. Chronic treatment with Vglycin normalized fasting glucose levels in diabetic rats. The improvement in glucose homeostasis and the increased insulin sensitivity mediated by restored insulin signaling likely contributed to decreased food intake and reduced body weight. Vglycin protected pancreatic cells from damage by streptozotocin. Although insulin synthesis and secretion in impaired β-cell were not significantly elevated, islets morphology was improved in the Vglycin-treated groups. These results suggest that Vglycin could be useful in Type 2 diabetes for restoring impaired insulin signaling, glucose tolerance and pancreatic function.
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Affiliation(s)
- Hua Jiang
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Wuhan, P.R. China
| | - Jueping Feng
- Department of Oncology, Wuhan Pu-Ai Hospital, Tong ji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Zhongxia Du
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Wuhan, P.R. China
| | - Hui Zhen
- Department of Clinical Laboratory, the Second Staff Hospital of Wuhan Iron and Steel (Group) Corporation, Wuhan, P.R. China
| | - Mei Lin
- Department of Oncology, Wuhan Pu-Ai Hospital, Tong ji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Shaohui Jia
- College of Health Science, Wuhan Sports University, Wuhan, P.R. China
| | - Tao Li
- Department of narcotics control, Chongqing Police College, Chongqing City, P.R. China
| | - Xinyuan Huang
- College of Life Science and Technology, Hubei Engineering University, Xiaogan, P.R. China
| | | | - Zhengwang Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Wuhan, P.R. China.
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Mizukami H, Inaba W, Takahashi K, Inoue K, Sawanobori K, Yagihashi S. Augmented reduction of islet β-cell mass in Goto-Kakizaki rats fed high-fat diet and its suppression by pitavastatin treatment. J Diabetes Investig 2014; 3:235-44. [PMID: 24843571 PMCID: PMC4014944 DOI: 10.1111/j.2040-1124.2011.00173.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aims/Introduction: High fat diet (HFD) is known to be a risk for development of type 2 diabetes. It is unclear, however, how it affects the glucose tolerance or the islet structure in type 2 diabetes. The aim of this study is: (i) to examine the effects of HFD on the islet in GK rats, non‐obese type 2 diabetic model; and (ii) to explore if pitavastatin treatment influences the change. Materials and Methods: To see the effects of HFD on islet changes in type 2 diabetes, 4‐week old male GK and Wistar rats were fed HFD for 16 weeks and subjected to glucose tolerance tests and pathological studies of the islet. The effects of pitavastatin (3 mg/kg/day for 16 weeks, oral), one of the lipophilc statins, were also examined in both GK and Wistrar rats fed with or without HFD. Results: The HFD induced hyperlipidemia and aggravated glucose intolerance in both GK and Wistar rats. Pitavastatin treatment did not influence the glucose tolerance in HFD‐fed animals. HFD caused an increase in hepatic lipid contents in all the animals, which was partially suppressed by pitavastatin treatment. GK rats showed reduced β‐cell mass, and fibrosis and macrophage migration in the islets. HFD feeding in GK rats augmented these changes which were associated with enhanced expression of 8‐hydroxydeoxyguanosine and an increase in apoptotic cells. Pitavastatin treatment improved the HFD‐induced islet pathology, and pancreatic insulin contents paralleled the structural changes. Conclusions: HFD feeding worsened the islet pathology in GK rats which was suppressed by pitavastatin treatment. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00173.x, 2011)
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Affiliation(s)
- Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki
| | - Wataru Inaba
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki
| | - Kazunori Takahashi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki
| | - Keisuke Inoue
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company Ltd., Higashimurayama, Tokyo, Japan
| | - Kimio Sawanobori
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company Ltd., Higashimurayama, Tokyo, Japan
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki
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Meidute Abaraviciene S, Muhammed SJ, Amisten S, Lundquist I, Salehi A. GPR40 protein levels are crucial to the regulation of stimulated hormone secretion in pancreatic islets. Lessons from spontaneous obesity-prone and non-obese type 2 diabetes in rats. Mol Cell Endocrinol 2013; 381:150-9. [PMID: 23911664 DOI: 10.1016/j.mce.2013.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/27/2013] [Accepted: 07/22/2013] [Indexed: 12/21/2022]
Abstract
The role of islet GPR40 protein in the pathogenesis of diabetes is unclear. We explored the influence of GPR40 protein levels on hormone secretion in islets from two rat models of spontaneous type 2 diabetes displaying either hyperlipidaemia or hyperglycaemia. GPR40 expression was analysed by confocal microscopy, Western blot and qPCR in islets from preobese Zucker (fa/fa) rats, diabetic Goto-Kakizaki (GK) rats, and controls. Confocal microscopy of control islets showed expression of GPR40 protein in insulin, glucagon and somatostatin cells. GPR40 expression was strongly increased in islets of hyperlipidaemic fa/fa rats and coincided with a concentration-related increase in palmitate-induced release of insulin and glucagon and its inhibition of somatostatin release. Conversely, hyperglycaemic GK islets displayed an extremely faint expression of GPR40 as did high-glucose-cultured control islets. This was reflected in abolished palmitate-induced hormone response in GK islets and high-glucose-cultured control islets. The palmitate antagonist rosiglitazone promoted reappearance of GPR40 in high-glucose-cultured islets and served as partial agonist in glucose-stimulated insulin release. GPR40 protein is abundantly expressed in pancreatic islets and modulates stimulated hormone secretion. Mild hyperlipidaemia in obesity-prone diabetes creates increased GPR40 expression and increased risk for an exaggerated palmitate-induced insulin response and lipotoxicity, a metabolic situation suitable for GPR40 antagonist treatment. Chronic hyperglycaemia creates abrogated GPR40 expression and downregulated insulin release, a metabolic situation suitable for GPR40 agonist treatment to avoid glucotoxicity. GPR40 protein is interactively modulated by both free fatty acids and glucose and is a promising target for pharmacotherapy in different variants of type 2 diabetes.
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Affiliation(s)
- Sandra Meidute Abaraviciene
- Department of Clinical Science, SUS, Division of Islet Cell Physiology, University of Lund, Sweden; Department of Stem Cell Biology, State Research Institute Centre of Innovative Vilnius, Lithuania
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Huang EY, Leone VA, Devkota S, Wang Y, Brady MJ, Chang EB. Composition of dietary fat source shapes gut microbiota architecture and alters host inflammatory mediators in mouse adipose tissue. JPEN J Parenter Enteral Nutr 2013; 37:746-54. [PMID: 23639897 DOI: 10.1177/0148607113486931] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Growing evidence shows that dietary factors can dramatically alter the gut microbiome in ways that contribute to metabolic disturbance and progression of obesity. In this regard, mesenteric adipose tissue has been implicated in mediating these processes through the elaboration of proinflammatory adipokines. In this study, we examined the relationship of these events by determining the effects of dietary fat content and source on gut microbiota, as well as the effects on adipokine profiles of mesenteric and peripheral adipocytes. METHODS Adult male C57Bl/6 mice were fed milk fat-based, lard-based (saturated fatty acid sources), or safflower oil (polyunsaturated fatty acid)-based high-fat diets for 4 weeks. Body mass and food consumption were measured. Stool 16S ribosomal RNA (rRNA) was isolated and analyzed via terminal restriction fragment length polymorphism as well as variable V3-4 sequence tags via next-generation sequencing. Mesenteric and gonadal adipose samples were analyzed for both lipogenic and inflammatory mediators via quantitative real-time polymerase chain reaction. RESULTS High-fat feedings caused more weight gain with concomitant increases in caloric consumption relative to low-fat diets. In addition, each of the high-fat diets induced dramatic and specific 16S rRNA phylogenic profiles that were associated with different inflammatory and lipogenic mediator profiles of mesenteric and gonadal fat depots. CONCLUSIONS Our findings support the notion that dietary fat composition can both reshape the gut microbiota and alter host adipose tissue inflammatory/lipogenic profiles. They also demonstrate the interdependency of dietary fat source, commensal gut microbiota, and inflammatory profile of mesenteric fat that can collectively affect the host metabolic state.
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31
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Wu L, Li X, Zhu H, Xu P, Gao X. A prescribed Chinese herbal medicine improves glucose profile and ameliorates oxidative stress in Goto-Kakisaki rats fed with high fat diet. PLoS One 2013; 8:e60262. [PMID: 23565214 PMCID: PMC3614962 DOI: 10.1371/journal.pone.0060262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 02/24/2013] [Indexed: 12/03/2022] Open
Abstract
Oxidative stress (OS) plays a role in hyperglycemia induced islet β cell dysfunction, however, studies on classic anti-oxidants didn’t show positive results in treating diabetes. We previously demonstrated that the prescribed Chinese herbal medicine preparation “Qing Huo Yi Hao” (QHYH) improved endothelial function in type 2 diabetic patients. QHYH protected endothelial cells from high glucose-induced damages by scavenging superoxide anion and reducing production of reactive oxygen species. Its active component protected C2C12 myotubes against palmitate-induced oxidative damage and mitochondrial dysfunction. In the present study, we investigated whether QHYH protected islet β cell function exacerbated by high fat diet (HFD) in hyperglycemic GK rats. 4-week-old male rats were randomly divided into high HFD feeding group (n = 20) and chow diet feeding group (n = 10). Each gram of HFD contained 4.8 kcal of energy, 52% of which from fat. Rats on HFD were further divided into 2 groups given either QHYH (3 ml/Kg/d) or saline through gastric tube. After intervention, serum glucose concentrations were monitored; IPGTTs were performed without anesthesia on 5 fasting rats randomly chosen from each group on week 4 and 16. Serum malondialdehyde (MDA) concentrations and activities of serum antioxidant enzymes were measured on week 4 and 16. Islet β cell mass and OS marker staining was done by immunohistochemistry on week 16. QHYH prevented the exacerbation of hyperglycemia in HFD feeding GK rats for 12 weeks. On week 16, it improved the exacerbated glucose tolerance and prevented the further loss of islet β cell mass induced by HFD. QHYH markedly decreased serum MDA concentration, increased serum catalase (CAT) and SOD activities on week 4. However, no differences of serum glucose concentration or OS were observed on week 16. We concluded that QHYH decreased hyperglycemia exacerbated by HFD in GK rats by improving β cell function partly via its antioxidant effect.
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Affiliation(s)
- Lin Wu
- Department of Geriatrics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiang Li
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Hongguang Zhu
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ping Xu
- Shanghai Laboratory Animal Center, Chinese Academy of Science, Shanghai, China
| | - Xin Gao
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
- * E-mail:
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Sustained delivery of IL-1Ra from PF127-gel reduces hyperglycemia in diabetic GK-rats. PLoS One 2013; 8:e55925. [PMID: 23409091 PMCID: PMC3568082 DOI: 10.1371/journal.pone.0055925] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 01/03/2013] [Indexed: 12/13/2022] Open
Abstract
Interleukin-1beta (IL-1β) is a major cause for induction of various inflammatory mechanisms that are decisively involved to provoke pathogenesis of type 2 diabetes mellitus (T2DM). Interleukin-1 receptor antagonist (IL-1Ra) a naturally occurring anti-inflammatory antagonist of IL-1β has been recently approved for treatment of T2DM but due to its short half-life, higher doses and frequent dosing intervals are required. Pluronic F-127 (PF127) has previously shown to prolong the release of various proteinous drugs and their serum half-lives. Subsequently, in our previous work, we developed a new dosage form of IL-1Ra using PF127 and investigated its in-vitro and in-vivo effects. Here in present work, we have extended this approach using diabetic Goto-kakizaki (GK) rats. We administered IL-1Ra loaded in PF127 gel subcutaneously for one month into GK rats. IL-1Ra loaded in PF127 gel exhibited a sustained and prolonged hypoglycemic effects on treated animals. Intraperitoneal glucose tolerance test (IPGTT) results showed that IL-1Ra loaded in PF127 gel increased glucose tolerance along with increased insulin sensitivity and β-cell’s secretory function in treated rats. Moreover, significant reduction in pro-insulin/insulin ratio, lipid profiles and interleukin 6 (IL-6) were also observed. Immunohistochemical analysis showed slight macrophages infiltration in pancreatic islets. Histochemical analysis revealed no PF127-induced alteration in the normal physiology of skin and kidney of treated animals. Hence, we concluded that IL-1Ra loaded in PF127 gel has potential to exhibit broad spectrum anti-inflammatory effects alleviating the symptoms of T2DM.
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Interleukin-1 receptor antagonist improves normoglycemia and insulin sensitivity in diabetic Goto-Kakizaki-rats. Eur J Pharmacol 2013; 701:87-95. [DOI: 10.1016/j.ejphar.2013.01.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/17/2012] [Accepted: 01/09/2013] [Indexed: 02/07/2023]
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Gerbaix M, Metz L, Mac-Way F, Lavet C, Guillet C, Walrand S, Masgrau A, Linossier MT, Vico L, Courteix D. Impact of an obesogenic diet program on bone densitometry, micro architecture and metabolism in male rat. Lipids Health Dis 2012; 11:91. [PMID: 22781503 PMCID: PMC3439365 DOI: 10.1186/1476-511x-11-91] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/10/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The relationships between fat mass and bone tissue are complex and not fully elucidated. A high-fat/high-sucrose diet has been shown to induce harmful effects on bone micro architecture and bone biomechanics of rat. When such diet leads to obesity, it may induce an improvement of biomechanical bone parameters in rodent.Here, we examined the impact of a high-fat/high-sucrose diet on the body composition and its resulting effects on bone density and structure in male rats. Forty three Wistar rats aged 7 months were split into 3 groups: 1 sacrificed before diet (BD, n = 14); 1 subjected to 16 weeks of high-fat/high-sucrose diet (HF/HS, n = 14); 1 subjected to standard diet (Control, n = 15). Abdominal circumference and insulin sensitivity were measured and visceral fat mass was weighed. The bone mineral density (BMD) was analyzed at the whole body and tibia by densitometry. Microcomputed tomography and histomorphometric analysis were performed at L2 vertebrae and tibia to study the trabecular and cortical bone structures and the bone cell activities. Osteocalcin and CTX levels were performed to assess the relative balance of the bone formation and resorption. Differences between groups have been tested with an ANOVA with subsequent Scheffe post-hoc test. An ANCOVA with global mass and global fat as covariates was used to determine the potential implication of the resulting mechanical loading on bone. RESULTS The HF/HS group had higher body mass, fat masses and abdominal circumference and developed an impaired glucose tolerance (p < 0.001). Whole body bone mass (p < 0.001) and BMD (p < 0.05) were higher in HF/HS group vs. Control group. The trabecular thickness at vertebrae and the cortical porosity of tibia were improved (p < 0.05) in HF/HS group. Bone formation was predominant in HF/HS group while an unbalance bone favoring bone resorption was observed in the controls. The HF/HS and Control groups had higher total and abdominal fat masses and altered bone parameters vs. BD group. CONCLUSIONS The HF/HS diet had induced obesity and impaired glucose tolerance. These changes resulted in an improvement of quantitative, qualitative and metabolic bone parameters. The fat mass increase partly explained these observations.
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Affiliation(s)
- Maude Gerbaix
- Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques, Clermont Université, Université Blaise Pascal, EA 3533, BP 80026, F-63171, Aubière Cedex, France.
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Oktavianthi S, Trimarsanto H, Febinia CA, Suastika K, Saraswati MR, Dwipayana P, Arindrarto W, Sudoyo H, Malik SG. Uncoupling protein 2 gene polymorphisms are associated with obesity. Cardiovasc Diabetol 2012; 11:41. [PMID: 22533685 PMCID: PMC3412711 DOI: 10.1186/1475-2840-11-41] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 04/25/2012] [Indexed: 11/10/2022] Open
Abstract
Background Uncoupling protein 2 (UCP2) gene polymorphisms have been reported as genetic risk factors for obesity and type 2 diabetes mellitus (T2DM). We examined the association of commonly observed UCP2 G(−866)A (rs659366) and Ala55Val (C > T) (rs660339) single nucleotide polymorphisms (SNPs) with obesity, high fasting plasma glucose, and serum lipids in a Balinese population. Methods A total of 603 participants (278 urban and 325 rural subjects) were recruited from Bali Island, Indonesia. Fasting plasma glucose (FPG), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) were measured. Obesity was determined based on WHO classifications for adult Asians. Participants were genotyped for G(−866)A and Ala55Val polymorphisms of the UCP2 gene. Results Obesity prevalence was higher in urban subjects (51%) as compared to rural subjects (23%). The genotype, minor allele (MAF), and heterozygosity frequencies were similar between urban and rural subjects for both SNPs. All genotype frequencies were in Hardy-Weinberg equilibrium. A combined analysis of genotypes and environment revealed that the urban subjects carrying the A/A genotype of the G(−866)A SNP have higher BMI than the rural subjects with the same genotype. Since the two SNPs showed strong linkage disequilibrium (D’ = 0.946, r2 = 0.657), a haplotype analysis was performed. We found that the AT haplotype was associated with high BMI only when the urban environment was taken into account. Conclusions We have demonstrated the importance of environmental settings in studying the influence of the common UCP2 gene polymorphisms in the development of obesity in a Balinese population.
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Affiliation(s)
- Sukma Oktavianthi
- Eijkman Institute for Molecular Biology, Jl, Diponegoro 69, Jakarta, Indonesia
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Mediation of glucolipotoxicity in INS-1 rat insulinoma cells by small heterodimer partner interacting leucine zipper protein (SMILE). Biochem Biophys Res Commun 2012; 419:768-73. [PMID: 22387546 DOI: 10.1016/j.bbrc.2012.02.098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 02/16/2012] [Indexed: 12/25/2022]
Abstract
Sustained elevations of glucose and free fatty acid concentration have deleterious effects on pancreatic beta cell function. One of the hallmarks of such glucolipotoxicity is a reduction in insulin gene expression, resulting from decreased insulin promoter activity. Sterol regulatory element binding protein-1c (SREBP-1c), a lipogenic transcription factor, is related to the development of beta cell dysfunction caused by elevated concentrations of glucose and free fatty acid. Small heterodimer partner (SHP) interacting leucine zipper protein (SMILE), also known as Zhangfei, is a novel protein which interacts with SHP that mediates glucotoxicity in INS-1 rat insulinoma cells. Treatment of INS-1 cells with high concentrations of glucose and palmitate increased SREBP-1c and SMILE expression, and decreased insulin gene expression. Adenovirus-mediated overexpression of SREBP-1c in INS-1 cells induced SMILE expression. Moreover, adenovirus-mediated overexpression of SMILE (Ad-SMILE) in INS-1 cells impaired glucose-stimulated insulin secretion as well as insulin gene expression. Ad-SMILE overexpression also inhibited the expression of beta-cell enriched transcription factors including pancreatic duodenal homeobox factor-1, beta cell E box transactivator 2 and RIPE3b1/MafA, in INS-1 cells. Finally, in COS-1 cells, expression of SMILE inhibited the insulin promoter activity induced by these same beta-cell enriched transcription factors. These results collectively suggest that SMILE plays an important role in the development of beta cell dysfunction induced by glucolipotoxicity.
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37
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Akash MSH, Shen Q, Rehman K, Chen S. Interleukin-1 receptor antagonist: a new therapy for type 2 diabetes mellitus. J Pharm Sci 2012; 101:1647-58. [PMID: 22271340 DOI: 10.1002/jps.23057] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Revised: 12/27/2011] [Accepted: 01/04/2011] [Indexed: 02/06/2023]
Abstract
Various complex mechanisms and their multifactorial pathways decisively provoke low-grade local and systemic inflammation in β-cells of pancreatic islets and peripheral tissues to induce β-cells' dysfunction and apoptosis, insulin resistance, and ultimately, overt type 2 diabetes mellitus (T2DM). Conventional antidiabetic agents are being less popular, as they have some potential adverse effects. Currently, many anti-inflammatory therapeutic modalities are being investigated to abate the infuriating effects of inducers of T2DM and among them, interleukin-1 receptor antagonist (IL-1Ra) is the only one that has been approved by US Food and Drug Administration. We have compared IL-1Ra with other anti-inflammatory agents and conventional antidiabetic agents. Although, IL-1Ra has broad-spectrum anti-inflammatory activities, it also has some limitations due to its short half-life. To overcome the problem of short half-life of IL-1Ra, recently, we fused IL-1Ra in recombinant human serum albumin and expressed it in Pichia pastoris. Its bioactivity was also checked by IL-1-induced A375.S2 apoptotic cells. Furthermore, we have also formulated IL-1Ra with Pluronic F-127-based thermosensitive gel and investigated its in vitro characteristics to prolong its therapeutic effects. Further studies are required to investigate its therapeutic effects against diabetes and diabetes-associated complications.
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Affiliation(s)
- Muhammad Sajid Hamid Akash
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang Province 310058, China
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Tarabra E, Pelengaris S, Khan M. A simple matter of life and death-the trials of postnatal Beta-cell mass regulation. Int J Endocrinol 2012; 2012:516718. [PMID: 22577380 PMCID: PMC3346985 DOI: 10.1155/2012/516718] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/31/2011] [Indexed: 12/17/2022] Open
Abstract
Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.
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Affiliation(s)
- Elena Tarabra
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
- *Elena Tarabra:
| | - Stella Pelengaris
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Michael Khan
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
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Portha B, Giroix MH, Tourrel-Cuzin C, Le-Stunff H, Movassat J. The GK rat: a prototype for the study of non-overweight type 2 diabetes. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2012; 933:125-59. [PMID: 22893405 DOI: 10.1007/978-1-62703-068-7_9] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Type 2 diabetes mellitus (T2D) arises when the endocrine pancreas fails to secrete sufficient insulin to cope with the metabolic demand because of β-cell secretory dysfunction and/or decreased β-cell mass. Defining the nature of the pancreatic islet defects present in T2D has been difficult, in part because human islets are inaccessible for direct study. This review is aimed to illustrate to what extent the Goto Kakizaki rat, one of the best characterized animal models of spontaneous T2D, has proved to be a valuable tool offering sufficient commonalities to study this aspect. A comprehensive compendium of the multiple functional GK abnormalities so far identified is proposed in this perspective, together with their time-course and interactions. A special focus is given toward the pathogenesis of defective β-cell number and function in the GK model. It is proposed that the development of T2D in the GK model results from the complex interaction of multiple events: (1) several susceptibility loci containing genes responsible for some diabetic traits; (2) gestational metabolic impairment inducing an epigenetic programming of the offspring pancreas and the major insulin target tissues; and (3) environmentally induced loss of β-cell differentiation due to chronic exposure to hyperglycemia/hyperlipidemia, inflammation, and oxidative stress.
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Affiliation(s)
- Bernard Portha
- Laboratoire B2PE (Biologie et Pathologie du Pancréas Endocrine), Unité BFA (Biologie Fonctionnelle et Adaptive), Université Paris-Diderot, CNRS EAC 4413, Paris, France.
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Atorvastatin exerts its anti-atherosclerotic effects by targeting the receptor for advanced glycation end products. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1130-7. [PMID: 21651980 DOI: 10.1016/j.bbadis.2011.05.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 05/12/2011] [Accepted: 05/19/2011] [Indexed: 12/25/2022]
Abstract
Recent studies demonstrated the beneficial role of atorvastatin in reducing the risk of cardiovascular morbidity and mortality in patients with diabetes mellitus and/or metabolic syndrome. To investigate the mechanisms underlying the anti-atheroscleroic action of atorvastatin, we examined the expression of the receptor for advanced glycation end products (RAGE) and its downstream target gene, monocyte chemoattractant protein-1 (MCP-1) using real-time PCR. In in vitro studies, exposure to high glucose or AGE induced oxidative stress and activation of the AGE/RAGE system in human umbilical vein endothelial cells. Treatment of the cells with atorvastatin significantly released the oxidative stress by restoring the levels of glutathione and inhibited the RAGE upregulation. In diabetic Goto Kakisaki (GK) rats fed with a high-fat diet for 12weeks, RAGE and MCP-1 were upregulated in the aortas, and there was a significant correlation between RAGE and MCP-1 mRNA abundance (r=0.482, P=0.031). Treatment with atorvastatin (20mg/kg qd) significantly downregulated the expression of RAGE and MCP-1. These data thus demonstrate a novel "pleiotropic" activity of atorvastatin in reducing the risk of cardiovascular diseases by targeting RAGE expression.
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Ahmad Mali Z, Goyal A, Lal Sharma P. Mustard Oil Based High Fat Diet is Associated with Decreased Body Weight Gain, Less Adiposity and Improved Glucose and Lipid Homeostasis in Wistar Rats. ACTA ACUST UNITED AC 2011. [DOI: 10.3923/ajcn.2011.43.52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Guri AJ, Bassaganya-Riera J. Systemic effects of white adipose tissue dysregulation and obesity-related inflammation. Obesity (Silver Spring) 2011; 19:689-700. [PMID: 20930712 DOI: 10.1038/oby.2010.230] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Amir J Guri
- Nutritional Immunology and Molecular Medicine Laboratory, CyberInfrastructure Division, Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
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Ardestani A, Sauter NS, Paroni F, Dharmadhikari G, Cho JH, Lupi R, Marchetti P, Oberholzer J, Conte JK, Maedler K. Neutralizing interleukin-1beta (IL-1beta) induces beta-cell survival by maintaining PDX1 protein nuclear localization. J Biol Chem 2011; 286:17144-55. [PMID: 21393239 DOI: 10.1074/jbc.m110.210526] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The transcription factor PDX1 plays a critical role during β-cell development and in glucose-induced insulin gene transcription in adult β-cells. Acute glucose exposure leads to translocalization of PDX1 to the nucleoplasm, whereas under conditions of oxidative stress, PDX1 shuttles from the nucleus to the cytosol. Here we show that cytosolic PDX1 expression correlated with β-cell failure in diabetes. In isolated islets from patients with type 2 diabetes and from diabetic mice, we found opposite regulation of insulin and PDX1 mRNA; insulin was decreased in diabetes, but PDX1 was increased. This suggests that elevated PDX1 mRNA levels may be insufficient to regulate insulin. In diabetic islets, PDX1 protein was localized in the cytosol, whereas in non-diabetic controls, PDX1 was in the nucleus. In contrast, overexpression of either IL-1 receptor antagonist or shuttling-deficient PDX1 restored β-cell survival and function and PDX1 nuclear localization. Our results show that nuclear localization of PDX1 is essential for a functional β-cell and provides a novel mechanism of the protective effect of IL-1 receptor antagonist on β-cell survival and function.
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Affiliation(s)
- Amin Ardestani
- Islet Biology Laboratory, Centre for Biomolecular Interactions Bremen 28355, University of Bremen, Leobener Strasse NW2, Rm. B2080, 28359 Bremen, Germany
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Morrison FS, Johnstone KA, Harries LW. Physiological effects of Type 2 diabetes on mRNA processing and gene expression. Expert Rev Endocrinol Metab 2011; 6:255-267. [PMID: 30290446 DOI: 10.1586/eem.10.76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Characteristics of Type 2 diabetes include both high blood glucose (hyperglycemia) and raised cholesterol and triglycerides (hyperlipidemia). Several studies have now shown that both hyperglycemia and hyperlipidemia can alter gene expression by disrupting physiological mechanisms of gene regulation, including alternative mRNA splicing, epigenetic gene regulation and miRNA-mediated regulation of gene expression. These processes may also be influenced by intracellular oxidative stress, which is increased in diabetes and in response to hyperglycemia and hyperlipidemia. Many pathways relevant to diabetes are affected by altered gene expression, including lipid and glucose metabolism and oxidative phosphorylation. This article considers how hyperglycemia and hyperlipidemia can alter gene expression in diabetes, which could potentially contribute to the worsening of the diabetic phenotype and diabetic complications.
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Affiliation(s)
- Faer S Morrison
- a Institute of Biomedical and Clinical Science, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, EX2 5DW, UK
| | - Karen A Johnstone
- a Institute of Biomedical and Clinical Science, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, EX2 5DW, UK
| | - Lorna W Harries
- a Institute of Biomedical and Clinical Science, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, EX2 5DW, UK
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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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46
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Basic techniques for pancreatic research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010. [PMID: 20700840 DOI: 10.1007/978-90-481-9060-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Umpierrez GE, Smiley D, Robalino G, Peng L, Gosmanov AR, Kitabchi AE. Lack of lipotoxicity effect on {beta}-cell dysfunction in ketosis-prone type 2 diabetes. Diabetes Care 2010; 33:626-31. [PMID: 20028938 PMCID: PMC2827521 DOI: 10.2337/dc09-1369] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Over half of newly diagnosed obese African Americans with diabetic ketoacidosis (DKA) discontinue insulin therapy and go through a period of near-normoglycemia remission. This subtype of diabetes is known as ketosis-prone type 2 diabetes (KPDM). RESEARCH DESIGN AND METHODS To investigate the role of lipotoxicity on beta-cell function, eight obese African Americans with KPDM, eight obese subjects with type 2 diabetes with severe hyperglycemia without ketosis (ketosis-resistant type 2 diabetes), and nine nondiabetic obese control subjects underwent intravenous infusion of 20% intralipid at 40 ml/h for 48 h. beta-Cell function was assessed by changes in insulin and C-peptide concentration during infusions and by changes in acute insulin response to arginine stimulation (AIR(arg)) before and after lipid infusion. RESULTS The mean time to discontinue insulin therapy was 11.0 +/- 8.0 weeks in KPDM and 9.6 +/- 2.2 weeks in ketosis-resistant type 2 diabetes (P = NS). At remission, KPDM and ketosis-resistant type 2 diabetes had similar glucose (94 +/- 14 vs. 109 +/- 20 mg/dl), A1C (5.7 +/- 0.4 vs. 6.3 +/- 1.1%), and baseline AIR(arg) response (34.8 +/- 30 vs. 64 +/- 69 microU/ml). P = NS despite a fourfold increase in free fatty acid (FFA) levels (0.4 +/- 0.3 to 1.8 +/- 1.1 mmol/l, P < 0.01) during the 48-h intralipid infusion; the response to AIR(arg) stimulation, as well as changes in insulin and C-peptide levels, were similar among obese patients with KPDM, patients with ketosis-resistant type 2 diabetes, and nondiabetic control subjects. CONCLUSIONS Near-normoglycemia remission in obese African American patients with KPDM and ketosis-resistant type 2 diabetes is associated with a remarkable recovery in basal and stimulated insulin secretion. A high FFA level by intralipid infusion for 48 h was not associated with beta-cell decompensation (lipotoxicity) in KPDM patients.
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48
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Giroix MH, Louchami K, Carpentier YA, Sener A, Malaisse WJ. Fatty acid pattern of pancreatic islet lipids in Goto-Kakizaki rats. Endocrine 2010; 37:173-9. [PMID: 20963567 DOI: 10.1007/s12020-009-9286-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 11/09/2009] [Indexed: 11/25/2022]
Abstract
Perturbations of fatty acid content and pattern were recently documented in epididymal and parametrial lipids, as well as plasma, liver, spleen, and brain phospholipids and triglycerides of Goto-Kakizaki rats (GK). This study extends such an investigation to pancreatic islets from both control and GK rats. Groups of 5,500-14,560 islets were obtained from either control or GK rats (n = 3 in each case) and examined for their lipid fatty acid content. In the islet triglycerides, the major difference between control and GK rats, i.e., a higher C18:2ω6 content in GK rats, was similar to that found in liver triglycerides. In the islet phospholipids, however, a number of differences between control and GK rats, concerning saturated, monodesaturated, and long-chain polyunsaturated ω3 and ω6 fatty acids, were often not similar to those found in liver phospholipids. The present study reveals a number of anomalies in the fatty acid pattern of islet phospholipids in GK rats, often differing from those encountered in liver phospholipids. Such a tissue specificity was borne out by the finding that, even in control animals, the situation found in islet phospholipids differed from that recorded in liver phospholipids.
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Affiliation(s)
- Marie-Hélène Giroix
- Laboratory of Biology and Pathology of Endocrine Pancreas, Unit of Functional and Adaptative Biology, Université Paris-Diderot/CNRS, Paris, France
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Portha B, Lacraz G, Chavey A, Figeac F, Fradet M, Tourrel-Cuzin C, Homo-Delarche F, Giroix MH, Bailbé D, Gangnerau MN, Movassat J. Islet structure and function in the GK rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:479-500. [PMID: 20217511 DOI: 10.1007/978-90-481-3271-3_21] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Type 2 diabetes mellitus (T2D) arises when the endocrine pancreas fails to secrete sufficient insulin to cope with the metabolic demand because of beta-cell secretory dysfunction and/or decreased beta-cell mass. Defining the nature of the pancreatic islet defects present in T2D has been difficult, in part because human islets are inaccessible for direct study. This review is aimed to illustrate to what extent the Goto-Kakizaki rat, one of the best characterized animal models of spontaneous T2D, has proved to be a valuable tool offering sufficient commonalities to study this aspect. A comprehensive compendium of the multiple functional GK islet abnormalities so far identified is proposed in this perspective. The pathogenesis of defective beta-cell number and function in the GK model is also discussed. It is proposed that the development of T2D in the GK model results from the complex interaction of multiple events: (i) several susceptibility loci containing genes responsible for some diabetic traits (distinct loci encoding impairment of beta-cell metabolism and insulin exocytosis, but no quantitative trait locus for decreased beta-cell mass); (ii) gestational metabolic impairment inducing an epigenetic programming of the offspring pancreas (decreased beta-cell neogenesis and proliferation) transmitted over generations; and (iii) loss of beta-cell differentiation related to chronic exposure to hyperglycaemia/hyperlipidaemia, islet inflammation, islet oxidative stress, islet fibrosis and perturbed islet vasculature.
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Affiliation(s)
- Bernard Portha
- Laboratoire B2PE, Unité BFA, Université Paris-Diderot et CNRS EAC4413, F - 75205 Paris Cedex13, France.
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Hyperinsulinism and diabetes: genetic dissection of beta cell metabolism-excitation coupling in mice. Cell Metab 2009; 10:442-53. [PMID: 19945402 PMCID: PMC3245718 DOI: 10.1016/j.cmet.2009.10.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 10/13/2009] [Accepted: 10/27/2009] [Indexed: 12/24/2022]
Abstract
The role of metabolism-excitation coupling in insulin secretion has long been apparent, but in recent years, in parallel with studies of human hyperinsulinism and diabetes, genetic manipulation of proteins involved in glucose transport, metabolism, and excitability in mice has brought the central importance of this pathway into sharp relief. We focus on these animal studies and how they provide important insights into not only metabolic and electrical regulation of insulin secretion, but also downstream consequences of alterations in this pathway and the etiology and treatment of insulin-secretion diseases in humans.
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