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Dos Reis Araujo T, Alves BL, Dos Santos LMB, Gonçalves LM, Carneiro EM. Association between protein undernutrition and diabetes: Molecular implications in the reduction of insulin secretion. Rev Endocr Metab Disord 2024; 25:259-278. [PMID: 38048021 DOI: 10.1007/s11154-023-09856-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/20/2023] [Indexed: 12/05/2023]
Abstract
Undernutrition is still a recurring nutritional problem in low and middle-income countries. It is directly associated with the social and economic sphere, but it can also negatively impact the health of the population. In this sense, it is believed that undernourished individuals may be more susceptible to the development of non-communicable diseases, such as diabetes mellitus, throughout life. This hypothesis was postulated and confirmed until today by several studies that demonstrate that experimental models submitted to protein undernutrition present alterations in glycemic homeostasis linked, in part, to the reduction of insulin secretion. Therefore, understanding the changes that lead to a reduction in the secretion of this hormone is essential to prevent the development of diabetes in undernourished individuals. This narrative review aims to describe the main molecular changes already characterized in pancreatic β cells that will contribute to the reduction of insulin secretion in protein undernutrition. So, it will provide new perspectives and targets for postulation and action of therapeutic strategies to improve glycemic homeostasis during this nutritional deficiency.
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Affiliation(s)
- Thiago Dos Reis Araujo
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Bruna Lourençoni Alves
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Lohanna Monali Barreto Dos Santos
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Luciana Mateus Gonçalves
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Everardo Magalhães Carneiro
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil.
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Geng N, Gao Y, Ji Y, Niu Y, Qi C, Zhen Y, Chen J, Ren L. Geriatric nutritional risk index is correlated with islet function but not insulin resistance in elderly patients with type 2 diabetes: A retrospective study. Medicine (Baltimore) 2024; 103:e37438. [PMID: 38489692 PMCID: PMC10939577 DOI: 10.1097/md.0000000000037438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/05/2024] [Accepted: 02/08/2024] [Indexed: 03/17/2024] Open
Abstract
The geriatric nutritional risk index (GNRI) is a simple nutritional assessment tool that can predict poor prognosis in elderly subjects. The aim of this study was to evaluate the association between GNRI and both islet function and insulin sensitivity in patients with type 2 diabetes mellitus. This research carries significant implications for the integrated treatment and nutritional management of this patient population. A total of 173 patients with type 2 diabetes mellitus, aged 60 years or older, who were hospitalized in the Endocrinology Department at Hebei General Hospital from February 2018 to June 2021, were selected as the research subjects. These subjects were divided into 4 groups according to the quartile of their GNRI values: T1 (GNRI < 99.4, n = 43), T2 (99.4 ≤ GNRI < 103, n = 43), T3 (103 ≤ GNRI < 106.3, n = 43), and T4 (GNRI ≥ 106.3, n = 44). Glucose, insulin, and C-peptide concentrations were tested at 0, 30, 60, 120, and 180 minutes during a 75 g oral glucose tolerance test. The homeostasis model assessment for insulin resistance and the homeostasis model assessment for β cell function index were calculated. As the GNRI value increased, the levels of total protein, albumin, hemoglobin, alanine transaminase, aspartate aminotransferase, and 25-hydroxyvitamin D increased significantly. The area under the curve for blood glucose decreased significantly across the 4 groups, while the AUCs for insulin and C-peptide showed an overall increasing trend. β Cell function index increased significantly with the increase of GNRI; meanwhile, both the early-phase insulin secretion index and the late-phase insulin secretion index increased significantly. Although there was an increasing trend, homeostasis model assessment for insulin resistance did not change significantly among the 4 groups. This study indicates that elderly type 2 diabetes patients with higher nutritional risk have worse islet function, while insulin sensitivity is not associated with nutritional risk.
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Affiliation(s)
- Nan Geng
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Yaxue Gao
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Yuanyuan Ji
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Yingchun Niu
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Cuijuan Qi
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Yunfeng Zhen
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Jinhu Chen
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
| | - Luping Ren
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, Hebei, China
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Chege BM, Mwangi PW, Githinji CG, Bukachi F. Dietary regimens appear to possess significant effects on the development of combined antiretroviral therapy (cART)-associated metabolic syndrome. PLoS One 2024; 19:e0298752. [PMID: 38416754 PMCID: PMC10901320 DOI: 10.1371/journal.pone.0298752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/29/2024] [Indexed: 03/01/2024] Open
Abstract
INTRODUCTION This study investigated the interactions between a low protein high calorie (LPHC) diet and an integrase inhibitor-containing antiretroviral drug regimen (INI-CR)in light of evidence suggesting that the initiation of cART in patients with poor nutritional status is a predictor of mortality independent of immune status. METHODS Freshly weaned Sprague Dawley rats (120) were randomized into the standard, LPHC and normal protein high calorie (NPHC) diet groups (n = 40/group) initially for 15 weeks. Thereafter, experimental animals in each diet group were further randomized into four treatment sub-groups (n = 10/group) Control (normal saline), group 1(TDF+3TC+DTG and Tesamorelin), group 2 (TDF+3TC+DTG), and Positive control (AZT+3TC+ATV/r) with treatment and diets combined for 9 weeks. Weekly body weights, fasting blood glucose (FBG), oral glucose tolerance test (OGTT); lipid profiles, liver weights, hepatic triglycerides and adiposity were assessed at week 24. RESULTS At week 15, body weights increased between the diet group in phase 1(standard 146 ± 1.64 vs. 273.1 ± 1.56 g), (NPHC, 143.5 ± 2.40 vs. 390.2 ± 4.94 g) and (LPHC, 145.5 ± 2.28 g vs. 398.3 ± 4.89 g) (p< 0.0001). A similar increase was noted in the FBG and OGTT (p< 0.0001). In phase 2, there was an increase in FBG, OGTT, body weights, lipid profile, liver weights, hepatic triglycerides, adiposity and insulin levels in group 2 and positive control in both NPHC and LPHC diet groups (p<0.0001). Growth hormone levels were decreased in Tesamorelin-free group 2 and positive control in both NPHC and LPHC (p< 0.0001). CONCLUSIONS The obesogenic activities of the LPHC diet exceeded that of the NPHC diet and interacted with both integrase-containing and classical cART drug regimens to reproduce cART associated metabolic dysregulation. The effects were however reversed by co-administration with tesamorelin, a synthetic growth hormone releasing hormone analogue.
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Affiliation(s)
- Boniface M Chege
- School of Health Sciences, Dedan Kimathi University of Technology, Nyeri, Kenya
- Department of Human Anatomy and Medical Physiology, University of Nairobi, Nairobi, Kenya
| | - Peter W Mwangi
- Department of Human Anatomy and Medical Physiology, University of Nairobi, Nairobi, Kenya
| | - Charles G Githinji
- Department of Human Anatomy and Medical Physiology, University of Nairobi, Nairobi, Kenya
| | - Frederick Bukachi
- Department of Human Anatomy and Medical Physiology, University of Nairobi, Nairobi, Kenya
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Prates KV, Pavanello A, Gongora AB, Moreira VM, de Moraes AMP, Rigo KP, Vieira E, Mathias PCDF. Time-restricted feeding during embryonic development leads to metabolic dysfunction in adult rat offspring. Nutrition 2022; 103-104:111776. [DOI: 10.1016/j.nut.2022.111776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/24/2022]
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Gonçalves AEDSS, Rocha GZ, Marin R, Camargo RL, dos Santos A, do Carmo H, Guadagnini D, Petrucci O, Moysés ZP, Salemi VMC, Oliveira AG, Saad MJA. Pulmonary Hypertension in Obese Mice Is Accompanied by a Reduction in PPAR-γ Expression in Pulmonary Artery. Front Endocrinol (Lausanne) 2021; 12:701994. [PMID: 34552556 PMCID: PMC8450870 DOI: 10.3389/fendo.2021.701994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/16/2021] [Indexed: 11/14/2022] Open
Abstract
Obesity and insulin resistance (IR) are well-studied risk factors for systemic cardiovascular disease, but their impact on pulmonary hypertension (PH) is not well clarified. This study aims to investigate if diet-induced obesity induces PH and if peroxisome-proliferator-activated receptor (PPAR-γ) and/or endoplasmic reticulum (ER) stress are involved in this process. Mice were maintained on a high-fat diet (HFD) for 4 months, and IR and PH were confirmed. In a separate group, after 4 months of HFD, mice were treated with pioglitazone (PIO) or 4-phenylbutyric acid for the last month. The results demonstrated that HFD for at least 4 months is able to increase pulmonary artery pressure, which is maintained, and this animal model can be used to investigate the link between IR and PH, without changes in ER stress in the pulmonary artery. There was also a reduction in circulating adiponectin and in perivascular adiponectin expression in the pulmonary artery, associated with a reduction in PPAR-γ expression. Treatment with PIO improved IR and PH and reversed the lower expression of adiponectin and PPAR-γ in the pulmonary artery, highlighting this drug as potential benefit for this poorly recognized complication of obesity.
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Affiliation(s)
| | - Guilherme Zweig Rocha
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Rodrigo Marin
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Rafael Ludemann Camargo
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Andrey dos Santos
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Helison do Carmo
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Dioze Guadagnini
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Orlando Petrucci
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
| | - Zenaide Providello Moysés
- Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Vera Maria Cury Salemi
- Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | | | - Mario José Abdalla Saad
- Department of Internal Medicine, Faculty of Medicine, State University of Campinas, Campinas, Brazil
- *Correspondence: Mario José Abdalla Saad,
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Pal M, Khan J, Kumar R, Surolia A, Gupta S. Testosterone supplementation improves insulin responsiveness in HFD fed male T2DM mice and potentiates insulin signaling in the skeletal muscle and C2C12 myocyte cell line. PLoS One 2019; 14:e0224162. [PMID: 31693697 PMCID: PMC6834245 DOI: 10.1371/journal.pone.0224162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 10/07/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Type 2 Diabetes Mellitus (T2DM) is characterised by hyperglycemia due to the incidence of insulin resistance. Testosterone supplementation has been shown to have a positive co-relation with improved glycemic control in T2DM males. Clinical studies have reported that Androgen Replacement Therapy (ART) to hypogonadic males with T2DM resulted in improved glycemic control and metabolic parameters, but, these studies did not address in detail how testosterone acted on the key glucose homeostatic organs. METHOD In this study, we delineate the effect of testosterone supplementation to high-fat diet (HFD) induced T2DM in male C57BL6J mice and the effect of testosterone supplementation on the skeletal muscle insulin responsiveness. We also studied the effect of testosterone on the insulin signaling pathway proteins in C2C12 myocyte cells to validate the in vivo findings. RESULTS We found that testosterone had a potentiating effect on the skeletal muscle insulin signaling pathway to improve glycaemic control. We demonstrate that, in males, testosterone improves skeletal muscle insulin responsiveness by potentiating the PI3K-AKT pathway. The testosterone treated animals showed significant increase in the skeletal muscle Insulin Receptor (IR), p85 subunit of PI3K, P-GSK3α (Ser-21), and P-AKT (Ser-473) levels as compared to the control animals; but there was no significant change in total AKT and GSK3α. Testosterone supplementation inhibited GSK3α in the myocytes in a PI3K/AKT pathway dependent manner; on the other hand GSK3β gene expression was reduced in the skeletal muscle upon testosterone supplementation. CONCLUSION Testosterone increases insulin responsiveness by potentiating insulin signaling in the skeletal muscle cells, which is in contrast to the increased insulin resistance in the liver of testosterone treated T2DM male animals.
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Affiliation(s)
- Madhuraka Pal
- Molecular Science Laboratory, National Institute of Immunology, New Delhi, India
| | - Jasim Khan
- Molecular Toxicology Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India
| | - Ravi Kumar
- Molecular Science Laboratory, National Institute of Immunology, New Delhi, India
| | - Avadhesha Surolia
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sarika Gupta
- Molecular Science Laboratory, National Institute of Immunology, New Delhi, India
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Yagi T, Toyoshima Y, Tokita R, Taguchi Y, Okamoto Y, Takahashi SI, Kato H, Minami S. Low-protein diet enhances adiponectin secretion in rats. Biosci Biotechnol Biochem 2019; 83:1774-1781. [PMID: 31130066 DOI: 10.1080/09168451.2019.1621153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Previous studies including ours have shown that a low-protein diet up-regulates insulin signaling in the liver and muscle and induces fatty liver in rats. Adiponectin is known as an insulin-sensitizing adipocytokine. We, therefore, examined the effect of a low-protein diet on the adiponectin levels in rats. The low-protein diet significantly increased serum adiponectin level. However, mRNA and protein levels of adiponectin in white adipose tissue (WAT) were not changed by the low-protein diet. Since it is known that oligomerization is important to control serum adiponectin level, we examined the population of adiponectin oligomeric forms in WAT and found that low-protein diet did not change it. Despite these events, the amount of its secretion was significantly increased in the adipocytes isolated from WAT of low-protein diet-fed rats. These results indicate that a low-protein diet enhances adiponectin secretion, which is not due to the increased intracellular amount and oligomerization of adiponectin.
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Affiliation(s)
- Takashi Yagi
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan
| | - Yuka Toyoshima
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan
| | - Reiko Tokita
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan
| | - Yusuke Taguchi
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan
| | - Yoshihisa Okamoto
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan.,b Department of Medicine, Japan Community Health Care Organization Hodogaya Central Hospital , Yokohama , Kanagawa , Japan
| | - Shin-Ichiro Takahashi
- c Department of Animal Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo , Japan
| | - Hisanori Kato
- d Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo , Japan
| | - Shiro Minami
- a Department of Bioregulation, Institute for Advanced Medical Sciences, Nippon Medical School , Nakahara-ku, Kawasaki , Kanagawa , Japan
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Marin L, Silva HBF, Damin G, Ignacio-Souza LM, Reis SRDL, de Oliveira CAM, Ribeiro RA, Reis MADB, Latorraca MQ, Ferreira F, Arantes VC. Nutritional recovery from a low-protein diet during pregnancy does not restore the kinetics of insulin secretion and Ca 2+ or alterations in the cAMP/PKA and PLC/PKC pathways in islets from adult rats. Appl Physiol Nutr Metab 2019; 43:1257-1267. [PMID: 29758169 DOI: 10.1139/apnm-2017-0629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the insulin release induced by glucose, the Ca2+ oscillatory pattern, and the cyclic AMP (cAMP)/protein kinase A (PKA) and phospholipase C (PLC)/protein kinase C (PKC) pathways in islets from adult rats that were reared under diets with 17% protein (C) or 6% protein (LP) during gestation, suckling, and after weaning and in rats receiving diets with 6% protein during gestation and 17% protein after birth (R). First-phase glucose-induced insulin secretion was reduced in LP and R islets, and the second phase was partially restored in the R group. Glucose stimulation did not modify intracellular Ca2+ concentration, but it reduced the Ca2+ oscillatory frequency in the R group compared with the C group. Intracellular cAMP concentration was higher and PKA-Cα expression was lower in the R and LP groups compared with the C group. The PKCα content in islets from R rats was lower than that in C and LP rats. Thus, nutritional recovery from a low-protein diet during fetal life did not repair the kinetics of insulin release, impaired Ca2+ handling, and altered the cAMP/PKA and PLC/PKC pathways.
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Affiliation(s)
- Leonardo Marin
- a Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá-MT, 78060-900, Brazil
| | | | - Gabriela Damin
- a Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá-MT, 78060-900, Brazil
| | | | | | | | - Rosane Aparecida Ribeiro
- d Universidade Federal do Rio de Janeiro, Núcleo em Ecologia e desenvolvimento socioambiental, Rio de Janeiro-RJ, 21941-901, Brazil
| | | | | | - Fabiano Ferreira
- e Departamento de Fisiologia e Farmacologia da Universidade Federal de Pernambuco, Recife-PE, 50670-901, Brazil
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Branco RCS, Camargo RL, Batista TM, Vettorazzi JF, Lubaczeuski C, Bomfim LHM, Silveira LR, Boschero AC, Zoppi CC, Carneiro EM. Protein malnutrition mitigates the effects of a high-fat diet on glucose homeostasis in mice. J Cell Physiol 2018; 234:6313-6323. [PMID: 30317568 DOI: 10.1002/jcp.27361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/17/2018] [Indexed: 12/25/2022]
Abstract
Nutrient malnutrition, during the early stages of development, may facilitate the onset of metabolic diseases later in life. However, the consequences of nutritional insults, such as a high-fat diet (HFD) after protein restriction, are still controversial. We assessed overall glucose homeostasis and molecular markers of mitochondrial function in the gastrocnemius muscle of protein-restricted mice fed an HFD until early adulthood. Male C57BL/6 mice were fed a control (14% protein-control diet) or a protein-restricted (6% protein-restricted diet) diet for 6 weeks. Afterward, mice received an HFD or not for 8 weeks (mice fed a control diet and HFD [CH] and mice fed a protein-restricted diet and HFD [RH]). RH mice showed lower weight gain and fat accumulation and did not show an increase in fasting plasma glucose and insulin levels compared with CH mice. RH mice showed higher energy expenditure, increased citrate synthase, peroxisome-proliferator-activated receptor gamma coactivator 1-alpha protein content, and higher levels of malate and α-ketoglutarate compared with CH mice. Moreover, RH mice showed increased AMPc-dependent kinase and acetyl coenzyme-A (CoA) carboxylase phosphorylation, lower intramuscular triacylglycerol content, and similar malonyl-CoA levels. In conclusion, protein undernourishment after weaning does not potentiate fat accumulation and insulin resistance in adult young mice fed an HFD. This outcome seems to be associated with increased skeletal muscle mitochondrial oxidative capacity and reduced lipids accumulation.
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Affiliation(s)
- Renato Chaves Souto Branco
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Rafael Ludemann Camargo
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Thiago Martins Batista
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Jean Franciesco Vettorazzi
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Camila Lubaczeuski
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Lucas Henrique Montes Bomfim
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Leonardo Reis Silveira
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Antônio Carlos Boschero
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cláudio Cesar Zoppi
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Everardo Magalhães Carneiro
- Department of Structural and Functional Biology, Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Abstract
The main forms of childhood malnutrition occur predominantly in children <5 years of age living in low-income and middle-income countries and include stunting, wasting and kwashiorkor, of which severe wasting and kwashiorkor are commonly referred to as severe acute malnutrition. Here, we use the term 'severe malnutrition' to describe these conditions to better reflect the contributions of chronic poverty, poor living conditions with pervasive deficits in sanitation and hygiene, a high prevalence of infectious diseases and environmental insults, food insecurity, poor maternal and fetal nutritional status and suboptimal nutritional intake in infancy and early childhood. Children with severe malnutrition have an increased risk of serious illness and death, primarily from acute infectious diseases. International growth standards are used for the diagnosis of severe malnutrition and provide therapeutic end points. The early detection of severe wasting and kwashiorkor and outpatient therapy for these conditions using ready-to-use therapeutic foods form the cornerstone of modern therapy, and only a small percentage of children require inpatient care. However, the normalization of physiological and metabolic functions in children with malnutrition is challenging, and children remain at high risk of relapse and death. Further research is urgently needed to improve our understanding of the pathophysiology of severe malnutrition, especially the mechanisms causing kwashiorkor, and to develop new interventions for prevention and treatment.
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Affiliation(s)
- Zulfiqar A Bhutta
- Centre for Global Child Health, Hospital for Sick Children, Peter Gilgan Centre for Research &Learning, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Center of Excellence in Women and Child Health, Aga Khan University, Karachi, Pakistan
| | - James A Berkley
- Clinical Research Department, KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
- The Childhood Acute Illness &Nutrition (CHAIN) Network, Nairobi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Robert H J Bandsma
- Centre for Global Child Health, Hospital for Sick Children, Peter Gilgan Centre for Research &Learning, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- The Childhood Acute Illness &Nutrition (CHAIN) Network, Nairobi, Kenya
- Department of Biomedical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Marko Kerac
- Department of Population Health, London School of Hygiene &Tropical Medicine, London, UK
| | - Indi Trehan
- Lao Friends Hospital for Children, Luang Prabang, Laos
- Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Paediatrics and Child Health, University of Malawi, Blantyre, Malawi
| | - André Briend
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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Borck PC, Batista TM, Vettorazzi JF, Camargo RL, Boschero AC, Vieira E, Carneiro EM. Protein malnutrition after weaning disrupts peripheral clock and daily insulin secretion in mice. J Nutr Biochem 2017; 50:54-65. [PMID: 29032081 DOI: 10.1016/j.jnutbio.2017.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 07/13/2017] [Accepted: 08/28/2017] [Indexed: 12/22/2022]
Abstract
Changes in nutritional state may alter circadian rhythms through alterations in expression of clock genes. Protein deficiency has a profound effect on body metabolism, but the effect of this nutrient restriction after weaning on biological clock has not been explored. Thus, this study aims to investigate whether the protein restriction affects the daily oscillation in the behavior and metabolic rhythms, as well as expression of clock genes in peripheral tissues. Male C57BL/6 J mice, after weaning, were fed a normal-protein (NP) diet or a low-protein (LP) diet for 8 weeks. Mice fed an LP diet did not show difference in locomotor activity and energy expenditure, but the food intake was increased, with parallel increased expression of the orexigenic neuropeptide Npy and disruption of the anorexigenic Pomc oscillatory pattern in the hypothalamus. LP mice showed disruption in the daily rhythmic patterns of plasma glucose, triglycerides and insulin. Also, the rhythmic expression of clock genes in peripheral tissues and pancreatic islets was altered in LP mice. In pancreatic islets, the disruption of clock genes was followed by impairment of daily glucose-stimulated insulin secretion and the expression of genes involved in exocytosis. Pharmacological activation of REV-ERBα could not restore the insulin secretion in LP mice. The present study demonstrates that protein restriction, leading to development of malnutrition, alters the peripheral clock and metabolic outputs, suggesting that this nutrient provides important entraining cues to regulate the daily fluctuation of biological clock.
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MESH Headings
- Adipose Tissue, White/metabolism
- Animals
- Biological Clocks
- CLOCK Proteins/genetics
- CLOCK Proteins/metabolism
- Diet, Protein-Restricted/adverse effects
- Gene Expression Regulation, Developmental/drug effects
- Glycine/analogs & derivatives
- Glycine/pharmacology
- Hypothalamus/metabolism
- Insulin/genetics
- Insulin/metabolism
- Insulin Secretion
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/metabolism
- Isoquinolines/pharmacology
- Liver/metabolism
- Male
- Mice, Inbred C57BL
- Muscle, Skeletal/metabolism
- Neurons/metabolism
- Neuropeptide Y/genetics
- Neuropeptide Y/metabolism
- Nuclear Receptor Subfamily 1, Group D, Member 1/agonists
- Nuclear Receptor Subfamily 1, Group D, Member 1/antagonists & inhibitors
- Nuclear Receptor Subfamily 1, Group D, Member 1/metabolism
- Organ Specificity
- Pro-Opiomelanocortin/genetics
- Pro-Opiomelanocortin/metabolism
- Protein Deficiency/etiology
- Protein Deficiency/physiopathology
- Random Allocation
- Thiophenes/pharmacology
- Weaning
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Affiliation(s)
- Patricia Cristine Borck
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
| | - Thiago Martins Batista
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
| | - Jean Franciesco Vettorazzi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
| | - Rafael Ludemann Camargo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
| | - Antonio Carlos Boschero
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
| | - Elaine Vieira
- Postgraduate Program on Physical Education, Universidade Católica de Brasília-UCB, Brasília, DF, Brazil.
| | - Everardo Magalhães Carneiro
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil
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12
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Ozaki Y, Saito K, Nakazawa K, Konishi M, Itoh N, Hakuno F, Takahashi S, Kato H, Takenaka A. Rapid increase in fibroblast growth factor 21 in protein malnutrition and its impact on growth and lipid metabolism. Br J Nutr 2015; 114:1410-8. [PMID: 26330054 DOI: 10.1017/S0007114515002846] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Protein malnutrition promotes hepatic steatosis, decreases insulin-like growth factor (IGF)-I production and retards growth. To identify new molecules involved in such changes, we conducted DNA microarray analysis on liver samples from rats fed an isoenergetic low-protein diet for 8 h. We identified the fibroblast growth factor 21 gene (Fgf21) as one of the most strongly up-regulated genes under conditions of acute protein malnutrition (P<0·05, false-discovery rate<0·001). In addition, amino acid deprivation increased Fgf21 mRNA levels in rat liver-derived RL-34 cells (P<0·01). These results suggested that amino acid limitation directly increases Fgf21 expression. FGF21 is a polypeptide hormone that regulates glucose and lipid metabolism. FGF21 also promotes a growth hormone-resistance state and suppresses IGF-I in transgenic mice. Therefore, to determine further whether Fgf21 up-regulation causes hepatic steatosis and growth retardation after IGF-I decrease in protein malnutrition, we fed an isoenergetic low-protein diet to Fgf21-knockout (KO) mice. Fgf21-KO did not rescue growth retardation and reduced plasma IGF-I concentration in these mice. Fgf21-KO mice showed greater epididymal white adipose tissue weight and increased hepatic TAG and cholesterol levels under protein malnutrition conditions (P<0·05). Overall, the results showed that protein deprivation directly increased Fgf21 expression. However, growth retardation and decreased IGF-I were not mediated by increased FGF21 expression in protein malnutrition. Furthermore, FGF21 up-regulation rather appears to have a protective effect against obesity and hepatic steatosis in protein-malnourished animals.
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13
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Bandsma RHJ, Ackerley C, Koulajian K, Zhang L, van Zutphen T, van Dijk TH, Xiao C, Giacca A, Lewis GF. A low-protein diet combined with low-dose endotoxin leads to changes in glucose homeostasis in weanling rats. Am J Physiol Endocrinol Metab 2015; 309:E466-73. [PMID: 26152763 DOI: 10.1152/ajpendo.00090.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 07/01/2015] [Indexed: 12/23/2022]
Abstract
Severe malnutrition is a leading cause of global childhood mortality, and infection and hypoglycemia or hyperglycemia are commonly present. The etiology behind the changes in glucose homeostasis is poorly understood. Here, we generated an animal model of severe malnutrition with and without low-grade inflammation to investigate the effects on glucose homeostasis. Immediately after weaning, rats were fed diets containing 5 [low-protein diet (LP)] or 20% protein [control diet (CTRL)], with or without repeated low-dose intraperitoneal lipopolysaccharide (LPS; 2 mg/kg), to mimic inflammation resulting from infections. After 4 wk on the diets, hyperglycemic clamps or euglycemic hyperinsulinemic clamps were performed with infusion of [U-(13)C6]glucose and [2-(13)C]glycerol to assess insulin secretion, action, and hepatic glucose metabolism. In separate studies, pancreatic islets were isolated for further analyses of insulin secretion and islet morphometry. Glucose clearance was reduced significantly by LP feeding alone (16%) and by LP feeding with LPS administration (43.8%) compared with control during the hyperglycemic clamps. This was associated with a strongly reduced insulin secretion in LP-fed rats in vivo as well as ex vivo in islets but signficantly enhanced whole body insulin sensitivity. Gluconeogenesis rates were unaffected by LP feeding, but glycogenolysis was higher after LP feeding. A protein-deficient diet in young rats leads to a susceptibility to low-dose endotoxin-induced impairment in glucose clearance with a decrease in the islet insulin secretory pathway. A protein-deficient diet is associated with enhanced peripheral insulin sensitivity but impaired insulin-mediated suppression of hepatic glycogenolysis.
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Affiliation(s)
- Robert H J Bandsma
- Division of Gastroenterology, Hepatology, and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada; Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;
| | - Cameron Ackerley
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Khajag Koulajian
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Ling Zhang
- Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Tim van Zutphen
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Changting Xiao
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Adria Giacca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Gary F Lewis
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
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14
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da Silva Lippo BR, Batista TM, de Rezende LF, Cappelli AP, Camargo RL, Branco RCS, Barbosa Sampaio HC, Protzek AOP, Wanderley MI, Arantes VC, Corat MAF, Carneiro EM, Udrisar DP, Wanderley AG, Ferreira F. Low-protein diet disrupts the crosstalk between the PKA and PKC signaling pathways in isolated pancreatic islets. J Nutr Biochem 2015; 26:556-62. [DOI: 10.1016/j.jnutbio.2014.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/26/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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15
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Rezende LF, Camargo RL, Branco RC, Cappelli AP, Boschero AC, Carneiro EM. Reduced insulin clearance and lower insulin-degrading enzyme expression in the liver might contribute to the thrifty phenotype of protein-restricted mice. Br J Nutr 2014; 112:900-7. [PMID: 25036874 DOI: 10.1017/S0007114514001238] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nutrient restriction during the early stages of life usually leads to alterations in glucose homeostasis, mainly insulin secretion and sensitivity, increasing the risk of metabolic disorders in adulthood. Despite growing evidence regarding the importance of insulin clearance during glucose homeostasis in health and disease, no information exists about this process in malnourished animals. Thus, in the present study, we aimed to determine the effect of a nutrient-restricted diet on insulin clearance using a model in which 30-d-old C57BL/6 mice were exposed to a protein-restricted diet for 14 weeks. After this period, we evaluated many metabolic variables and extracted pancreatic islet, liver, gastrocnemius muscle (GCK) and white adipose tissue samples from the control (normal-protein diet) and restricted (low-protein diet, LP) mice. Insulin concentrations were determined using RIA and protein expression and phosphorylation by Western blot analysis. The LP mice exhibited lower body weight, glycaemia, and insulinaemia, increased glucose tolerance and altered insulin dynamics after the glucose challenge. The improved glucose tolerance could partially be explained by an increase in insulin sensitivity through the phosphorylation of the insulin receptor/protein kinase B and AMP-activated protein kinase/acetyl-CoA carboxylase in the liver, whereas the changes in insulin dynamics could be attributed to reduced insulin secretion coupled with reduced insulin clearance and lower insulin-degrading enzyme (IDE) expression in the liver and GCK. In summary, protein-restricted mice not only produce and secrete less insulin, but also remove and degrade less insulin. This phenomenon has the double benefit of sparing insulin while prolonging and potentiating its effects, probably due to the lower expression of IDE in the liver, possibly with long-term consequences.
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16
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Pereira MP, Buzelle SL, Batistela E, Doneda DL, de França SA, dos Santos MP, Andrade CM, Garófalo MA, do C. Kettelhut I, Navegantes LC, Chaves VE, Bertolini GL, Kawashita NH. High glucose uptake in growing rats adapted to a low-protein, high-carbohydrate diet determines low fasting glycemia even with high hepatic gluconeogenesis. Can J Physiol Pharmacol 2014; 92:460-6. [DOI: 10.1139/cjpp-2013-0346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The our objective was to investigate the adaptations induced by a low-protein, high-carbohydrate (LPHC) diet in growing rats, which by comparison with the rats fed a control (C) diet at displayed lower fasting glycemia and similar fasting insulinemia, despite impairment in insulin signaling in adipose tissues. In the insulin tolerance test the LPHC rats showed higher rates of glucose disappearance (30%) and higher tolerance to overload of glucose than C rats. The glucose uptake by the soleus muscle, evaluated in vivo by administration of 2-deoxy-[14C]glucose, increased by 81%. The phosphoenolpyruvate carboxykinase content and the incorporation of [1-14C]pyruvate into glucose was also higher in the slices of liver from the LPHC rats than in those from C rats. The LPHC rats showed increases in l-lactate as well as in other gluconeogenic precursors in the blood. These rats also had a higher hepatic production of glucose, evaluated by in situ perfusion. The data obtained indicate that the main substrates for gluconeogenesis in the LPHC rats are l-lactate and glycerol. Thus, we concluded that the fasting glycemia in the LPHC animals was maintained mainly by increases in the hepatic gluconeogenesis from glycerol and l-lactate, compensating, at least in part, for the higher glucose uptake by the tissues.
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Affiliation(s)
- Mayara P. Pereira
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Samyra L. Buzelle
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Emanuele Batistela
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Diego L. Doneda
- Department of Basic Sciences in Health, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Suélem A. de França
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Maísa P. dos Santos
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Cláudia M.B. Andrade
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Maria A.R. Garófalo
- Departments of Physiology and Biochemistry-Immunology, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Isis do C. Kettelhut
- Departments of Physiology and Biochemistry-Immunology, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luiz C.C. Navegantes
- Departments of Physiology and Biochemistry-Immunology, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Valéria E. Chaves
- Laboratory of Physiology and Pharmacology, Federal University of São João Del Rei, Divinópolis, Minas Gerais, Brazil
| | - Gisele L. Bertolini
- Department of Basic Sciences in Health, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Nair H. Kawashita
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
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17
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Vettorazzi JF, Ribeiro RA, Santos-Silva JC, Borck PC, Batista TM, Nardelli TR, Boschero AC, Carneiro EM. Taurine supplementation increases K(ATP) channel protein content, improving Ca2+ handling and insulin secretion in islets from malnourished mice fed on a high-fat diet. Amino Acids 2014; 46:2123-36. [PMID: 24866813 DOI: 10.1007/s00726-014-1763-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 05/08/2014] [Indexed: 12/21/2022]
Abstract
Pancreatic β-cells are highly sensitive to suboptimal or excess nutrients, as occurs in protein-malnutrition and obesity. Taurine (Tau) improves insulin secretion in response to nutrients and depolarizing agents. Here, we assessed the expression and function of Cav and KATP channels in islets from malnourished mice fed on a high-fat diet (HFD) and supplemented with Tau. Weaned mice received a normal (C) or a low-protein diet (R) for 6 weeks. Half of each group were fed a HFD for 8 weeks without (CH, RH) or with 5% Tau since weaning (CHT, RHT). Isolated islets from R mice showed lower insulin release with glucose and depolarizing stimuli. In CH islets, insulin secretion was increased and this was associated with enhanced KATP inhibition and Cav activity. RH islets secreted less insulin at high K(+) concentration and showed enhanced KATP activity. Tau supplementation normalized K(+)-induced secretion and enhanced glucose-induced Ca(2+) influx in RHT islets. R islets presented lower Ca(2+) influx in response to tolbutamide, and higher protein content and activity of the Kir6.2 subunit of the KATP. Tau increased the protein content of the α1.2 subunit of the Cav channels and the SNARE proteins SNAP-25 and Synt-1 in CHT islets, whereas in RHT, Kir6.2 and Synt-1 proteins were increased. In conclusion, impaired islet function in R islets is related to higher content and activity of the KATP channels. Tau treatment enhanced RHT islet secretory capacity by improving the protein expression and inhibition of the KATP channels and enhancing Synt-1 islet content.
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Affiliation(s)
- Jean F Vettorazzi
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
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18
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Ozaki Y, Takeda T, Akanishi N, Hakuno F, Toyoshima Y, Takahashi SI, Takenaka A. Insulin injection restored increased insulin receptor substrate (IRS)-2 protein during short-term protein restriction but did not affect reduced insulin-like growth factor (IGF)-I mRNA or increased triglyceride accumulation in the liver of rats. Biosci Biotechnol Biochem 2014; 78:130-8. [DOI: 10.1080/09168451.2014.877825] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
Dietary protein restriction reduces insulin-like growth factor (IGF)-I synthesis and impairs growth. Moreover, insulin secretion is impaired and hepatic insulin signaling is activated presumably through upregulation of insulin receptor substrate (IRS)-2, which can stimulate lipogenesis thereby resulting in steatosis. In order to determine whether impaired insulin secretion is the primary cause of these changes, we injected insulin into protein-restricted rats and compensated for the reduction in insulin secretion for 1 and 7 d. Insulin infusion did not overcome the reduction in liver IGF-I mRNA nor the hepatic triglyceride accumulation. In contrast, it clearly suppressed the upregulation of hepatic IRS-2 on day 1, but not on day 7. Furthermore, insulin elimination increased IRS-2 in H4IIE-C3 cells. In summary, we found that reduced insulin secretion during protein restriction directly increased hepatic IRS-2 as a rapid response on day 1, while additional mechanisms contributed to the upregulation of IRS-2 on day 7.
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Affiliation(s)
- Yori Ozaki
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Japan
| | - Tomoya Takeda
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Japan
| | - Narumi Akanishi
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Fumihiko Hakuno
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuka Toyoshima
- Department of Bioregulation, Nippon Medical School, Kawasaki, Japan
| | - Shin-Ichiro Takahashi
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Asako Takenaka
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Japan
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Toyoshima Y, Tokita R, Taguchi Y, Akiyama-Akanishi N, Takenaka A, Kato H, Chida K, Hakuno F, Minami S, Takahashi SI. Tissue-specific effects of protein malnutrition on insulin signaling pathway and lipid accumulation in growing rats. Endocr J 2014; 61:499-512. [PMID: 24621780 DOI: 10.1507/endocrj.ej13-0514] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Our previous studies have revealed that protein malnutrition enhances insulin signaling in rat liver and muscle in response to a bolus insulin injection. However, it has not been established whether protein malnutrition up-regulates insulin signaling under physiological conditions, such as feeding. Here, we studied the effects of protein malnutrition on insulin signaling after feeding in rat liver, muscle and white adipose tissue (WAT). Six-week-old rats were fed a 15% casein diet (15C) or a calorie-matched 5% casein diet (5C) for 8 h/day during 14 days. On the 15th day, blood and tissues were collected at various time points after feeding. Feeding-induced insulin secretion was reduced in 5C-fed rats compared to 15C-fed rats. The 5C-feeding suppressed immediate activation of insulin receptor after feeding in the liver, muscle, and WAT. However, 5C-feeding constantly increased tyrosine phosphorylation of insulin receptor substrate (IRS)-2 and threonine phosphorylation of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) in the liver during the examined periods, corresponding to the changes of their amounts. In skeletal muscle, 5C-feeding did not appreciably alter insulin signaling. In WAT, 5C-feeding decreased tyrosine phosphorylation of IRS-1 compared to 15C-feeding. Furthermore, hepatic triglyceride content was increased and feeding-induced acetyl-CoA carboxylase 1 gene expression was enhanced in 5C-fed rats. The 5C-feeding decreased insulin-dependent glucose uptake in adipocytes. These results suggest that enhanced insulin signaling through increased IRS-2 and 4E-BP1 levels in the liver and repressed insulin signaling through decreased IRS-1 levels in WAT contribute to the preferential hepatic lipid accumulation under protein malnutrition.
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Affiliation(s)
- Yuka Toyoshima
- Department of Bioregulation, Nippon Medical School, Kawasaki 211-8533, Japan
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20
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Batista TM, da Silva PMR, Amaral AG, Ribeiro RA, Boschero AC, Carneiro EM. Taurine Supplementation Restores Insulin Secretion and Reduces ER Stress Markers in Protein-Malnourished Mice. Advances in Experimental Medicine and Biology 2013. [DOI: 10.1007/978-1-4614-6093-0_14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Batista TM, Ribeiro RA, da Silva PMR, Camargo RL, Lollo PCB, Boschero AC, Carneiro EM. Taurine supplementation improves liver glucose control in normal protein and malnourished mice fed a high-fat diet. Mol Nutr Food Res 2012; 57:423-34. [DOI: 10.1002/mnfr.201200345] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 10/11/2012] [Accepted: 10/23/2012] [Indexed: 01/05/2023]
Affiliation(s)
- Thiago M. Batista
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
| | - Rosane A. Ribeiro
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
- Núcleo em Ecologia e Desenvolvimento Sócio-Ambiental de Macaé (NUPEM); Universidade Federal do Rio de Janeiro (UFRJ); Macaé RJ Brazil
| | - Priscilla M. R. da Silva
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
| | - Rafael L. Camargo
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
| | - Pablo C. B. Lollo
- Departamento de Alimentos e Nutrição, Faculdade de Engenharia de Alimentos; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
| | - Antonio C. Boschero
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
| | - Everardo M. Carneiro
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia; Universidade Estadual de Campinas (UNICAMP); Campinas SP Brazil
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22
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Yang J, Dolinger M, Ritaccio G, Mazurkiewicz J, Conti D, Zhu X, Huang Y. Leucine stimulates insulin secretion via down-regulation of surface expression of adrenergic α2A receptor through the mTOR (mammalian target of rapamycin) pathway: implication in new-onset diabetes in renal transplantation. J Biol Chem 2012; 287:24795-806. [PMID: 22645144 DOI: 10.1074/jbc.m112.344259] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The amino acid leucine is a potent secretagogue, capable of inducing insulin secretion. It also plays an important role in the regulation of mTOR activity, therefore, providing impetus to investigate if a leucine-sensing mechanism in the mTOR pathway is involved in insulin secretion. We found that leucine-induced insulin secretion was inhibited by both the mTOR inhibitor rapamycin as well as the adrenergic α2 receptor agonist clonidine. We also demonstrated that leucine down-regulated the surface expression of adrenergic α2A receptor via activation of the mTOR pathway. The leucine stimulatory effect on insulin secretion was attenuated in diabetic Goto-Kakizaki rats that overexpress adrenergic α2A receptors, confirming the role of leucine in insulin secretion. Thus, our data demonstrate that leucine regulates insulin secretion by modulating adrenergic α2 receptors through the mTOR pathway. The role of the mTOR pathway in metabolic homeostasis led us to a second important finding in this study; retrospective analysis of clinical data showed that co-administration of rapamycin and clonidine was associated with an increased incidence of new-onset diabetes in renal transplantation patients over those receiving rapamycin alone. We believe that inhibition of mTOR by rapamycin along with activation of adrenergic α2 receptors by clonidine represents a double-hit to pancreatic islets that synergistically disturbs glucose homeostasis. This new insight may have important implications for the clinical management of renal transplant patients.
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Affiliation(s)
- Jun Yang
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York 12208, USA
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da Silva PMR, Batista TM, Ribeiro RA, Zoppi CC, Boschero AC, Carneiro EM. Decreased insulin secretion in islets from protein malnourished rats is associated with impaired glutamate dehydrogenase function: effect of leucine supplementation. Metabolism 2012; 61:721-32. [PMID: 22078937 DOI: 10.1016/j.metabol.2011.09.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 08/27/2011] [Accepted: 09/27/2011] [Indexed: 02/06/2023]
Abstract
We herein studied the role of glutamate dehydrogenase (GDH), in response to leucine (LEU) supplementation, upon insulin secretion of malnourished rats. Weaned male Wistar rats were fed normal-protein (17%) or low-protein diet (6%, LP) for 8 weeks. Half of the rats of each group were supplemented with LEU (1.5%) in the drinking water for the following 4 weeks. Gene and protein expressions, static insulin secretion, and cytoplasmic Ca(2+) oscillations were measured. Glutamate dehydrogenase messenger RNA was 58% lower in LP islets, and LEU supplementation augmented it in 28%. The LP islets secreted less insulin when exposed to 20 mmol/L LEU, 20 mmol/L LEU + 2 mmol/L glutamine (with or without 5 mmol/L aminooxyacetic acid, a branched chain aminotransferase inhibitor, or 20 μmol/L epigallocatechin gallate, a GDH inhibitor), 20 mmol/L α-ketoisocaproate, glutamine + 20 mmol/L β-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid (a GDH activator), and 22.2 mmol/L glucose. Leucine supplementation augmented insulin secretion to levels found in normal-protein islets in all the above conditions, an effect that was blunted when islets were incubated with epigallocatechin gallate. The glutamine + β-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid-induced increased [Ca(2+)](i) and oscillations were higher than those for LP islets. Leucine supplementation normalized these parameters in LP islets. Impaired GDH function was associated with lower insulin release in LP islets, and LEU supplementation normalized insulin secretion via restoration of GDH function. In addition, GDH may contribute to insulin secretion through ameliorations of Ca(2+) handling in LP islets.
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Affiliation(s)
- Priscilla Muniz Ribeiro da Silva
- Department of Anatomy, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas,PO Box 6109, CEP 13083-970 Campinas, SP, Brazil
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Marroquí L, Batista TM, Gonzalez A, Vieira E, Rafacho A, Colleta SJ, Taboga SR, Boschero AC, Nadal A, Carneiro EM, Quesada I. Functional and structural adaptations in the pancreatic α-cell and changes in glucagon signaling during protein malnutrition. Endocrinology 2012; 153:1663-72. [PMID: 22334714 DOI: 10.1210/en.2011-1623] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chronic malnutrition leads to multiple changes in β-cell function and peripheral insulin actions to adapt glucose homeostasis to these restricted conditions. However, despite glucose homeostasis also depends on glucagon effects, the role of α-cells in malnutrition is largely unknown. Here, we studied α-cell function and hepatic glucagon signaling in mice fed with low-protein (LP) or normal-protein diet for 8 wk after weaning. Using confocal microscopy, we found that inhibition of Ca²⁺ signaling by glucose was impaired in α-cells of LP mice. Consistent with these findings, the ability of glucose to inhibit glucagon release in isolated islets was also diminished in LP mice. This altered secretion was not related with changes in either glucagon gene expression or glucagon content. A morphometric analysis showed that α-cell mass was significantly increased in malnourished animals, aspect that was probably related with their enhanced plasma glucagon levels. When we analyzed the hepatic function, we observed that the phosphorylation of protein kinase A and cAMP response-binding element protein in response to fasting or exogenous glucagon was impaired in LP mice. Additionally, the up-regulated gene expression in response to fasting observed in the hepatic glucagon receptor as well as several key hepatic enzymes, such as peroxisome proliferator-activated receptor γ, glucose-6-phosphatase, and phosphoenolpyruvate carboxykinase, was altered in malnourished animals. Finally, liver glycogen mobilization in response to fasting and the ability of exogenous glucagon to raise plasma glucose levels were lower in LP mice. Therefore, chronic protein malnutrition leads to several alterations in both the α-cell function and hepatic glucagon signaling.
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Affiliation(s)
- Laura Marroquí
- Instituto de Bioingeniería, Universidad Miguel Hernández, 03202 Elche, Spain
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Batista TM, Ribeiro RA, Amaral AG, de Oliveira CA, Boschero AC, Carneiro EM. Taurine supplementation restores glucose and carbachol-induced insulin secretion in islets from low-protein diet rats: involvement of Ach-M3R, Synt 1 and SNAP-25 proteins. J Nutr Biochem 2012; 23:306-12. [DOI: 10.1016/j.jnutbio.2010.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 11/21/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
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de Oliveira CAM, Latorraca MQ, de Mello MAR, Carneiro EM. Mechanisms of insulin secretion in malnutrition: modulation by amino acids in rodent models. Amino Acids 2010; 40:1027-34. [DOI: 10.1007/s00726-010-0716-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 07/26/2010] [Indexed: 11/27/2022]
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Soriano S, Gonzalez A, Marroquí L, Tudurí E, Vieira E, Amaral AG, Batista TM, Rafacho A, Boschero AC, Nadal A, Carneiro EM, Quesada I. Reduced insulin secretion in protein malnourished mice is associated with multiple changes in the beta-cell stimulus-secretion coupling. Endocrinology 2010; 151:3543-54. [PMID: 20555033 DOI: 10.1210/en.2010-0008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanism by which protein malnutrition impairs glucose-stimulated insulin secretion in the pancreatic beta-cell is not completely known but may be related to alterations in the signaling events involved in insulin release. Here, we aimed to study the stimulus-secretion coupling of beta-cells from mice fed with low-protein (LP) diet or normal-protein (NP) diet for 8 wk after weaning. Patch-clamp measurements in isolated cells showed that beta-cells from LP mice had a resting membrane potential that was more hyperpolarized than controls. Additionally, depolarization and generation of action potentials in response to stimulatory glucose concentrations were also impaired in beta-cells of LP mice. All these alterations in the LP group were most likely attributed to higher ATP-dependent K(+) (K(ATP)) channel activity in resting conditions and lower efficiency of glucose to induce the closure of these channels. Moreover, a Western blot analysis revealed higher protein levels of the sulphonylurea receptor of the K(ATP) channel in islets of LP mice. Because beta-cell Ca(2+) signals depend on electrical activity, intracellular Ca(2+) oscillations were measured by fluorescence microscopy in intact islets, indicating a lower response to glucose in the LP group. Finally, cell-to-cell synchrony of Ca(2+) signals was analyzed by confocal microscopy. Islets from LP mice exhibited a decreased level of coupling among beta-cells, which was probably due to the low expression levels of connexin 36. Therefore, low-protein diet leads to several alterations in the stimulus-secretion coupling of pancreatic beta-cells that might explain the diminished insulin secretion in response to glucose in this malnutrition state.
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Affiliation(s)
- Sergi Soriano
- Instituto de Bioingeniería and CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Universidad Miguel Hernández, 03202 Elche, Spain.
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Filiputti E, Rafacho A, Araújo EP, Silveira LR, Trevisan A, Batista TM, Curi R, Velloso LA, Quesada I, Boschero AC, Carneiro EM. Augmentation of insulin secretion by leucine supplementation in malnourished rats: possible involvement of the phosphatidylinositol 3-phosphate kinase/mammalian target protein of rapamycin pathway. Metabolism 2010; 59:635-44. [PMID: 19913855 DOI: 10.1016/j.metabol.2009.09.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 01/01/2023]
Abstract
A regimen of low-protein diet induces a reduction of pancreatic islet function that is associated with development of metabolic disorders including diabetes and obesity afterward. In the present study, the influence of leucine supplementation on metabolic parameters, insulin secretion to glucose and to amino acids, as well as the levels of proteins that participate in the phosphatidylinositol 3-phosphate kinase (PI3K) pathway was investigated in malnourished rats. Four groups were fed with different diets for 12 weeks: a normal protein diet (17%) without (NP) or with leucine supplementation (NPL) or a low (6%)-protein diet without (LP) or with leucine supplementation (LPL). Leucine was given in the drinking water during the last 4 weeks. As indicated by the intraperitoneal glucose tolerance test, LPL rats exhibited increased glucose tolerance as compared with NPL group. Both NPL and LPL rats had higher circulating insulin levels than controls. The LPL rats also showed increased insulin secretion by pancreatic islets in response to glucose or arginine compared with those observed in islets from LP animals. Glucose oxidation was significantly reduced in NPL, LP, and LPL isolated islets as compared with NP; but no alteration was observed for leucine and glutamate oxidation among the 4 groups. Western blotting analysis demonstrated increased PI3K and mammalian target protein of rapamycin protein contents in LPL compared with LP islets. A significant increase in insulin-induced insulin receptor substrate 1-associated PI3K activation was also observed in LPL compared with LP islets. These findings indicate that leucine supplementation can augment islet function in malnourished rats and that activation of the PI3K/mammalian target protein of rapamycin pathway may play a role in this process.
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Affiliation(s)
- Eliane Filiputti
- Department of Anatomy, Cell Biology and Physiology and Biophysics, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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Zoppi CC, Silveira LR, Oliveira CAM, Boschero AC, Curi R, Carneiro EM. Insulin release, peripheral insulin resistance and muscle function in protein malnutrition: a role of tricarboxylic acid cycle anaplerosis. Br J Nutr 2010; 103:1237-50. [DOI: 10.1017/s0007114509993060] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pancreatic β-cells and skeletal muscle act in a synergic way in the control of systemic glucose homeostasis. Several pyruvate-dependent and -independent shuttles enhance tricarboxylic acid cycle intermediate (TACI) anaplerosis and increase β-cell ATP:ADP ratio, triggering insulin exocytotic mechanisms. In addition, mitochondrial TACI cataplerosis gives rise to the so-called metabolic coupling factors, which are also related to insulin release. Peripheral insulin resistance seems to be related to skeletal muscle fatty acid (FA) accumulation and oxidation imbalance. In this sense, exercise has been shown to enhance skeletal muscle TACI anaplerosis, increasing FA oxidation and by this manner restores insulin sensitivity. Protein malnutrition reduces β-cell insulin synthesis, release and peripheral sensitivity. Despite little available data concerning mitochondrial metabolism under protein malnutrition, evidence points towards reduced β-cell and skeletal muscle mitochondrial capacity. The observed decrease in insulin synthesis and release may reflect reduced anaplerotic and cataplerotic capacity. Furthermore, insulin release is tightly coupled to ATP:ADP rise which in turn is related to TACI anaplerosis. The effect of protein malnutrition upon peripheral insulin resistance is time-dependent and directly related to FA oxidation capacity. In contrast to β-cells, TACI anaplerosis and cataplerosis pathways in skeletal muscle seem to control FA oxidation and regulate insulin resistance.
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Rafacho A, Giozzet V, Boschero A, Abrantes J, Cestari T, Carneiro E, Bosqueiro J. Reduced pancreatic β-cell mass is associated with decreased FoxO1 and Erk1/2 protein phosphorylation in low-protein malnourished rats. Braz J Med Biol Res 2009; 42:935-41. [DOI: 10.1590/s0100-879x2009001000010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 08/10/2009] [Indexed: 02/01/2023] Open
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Cheim LMG, Oliveira EA, Arantes VC, Veloso RV, Reis MAB, Gomes-da-Silva MHG, Carneiro EM, Boschero AC, Latorraca MQ. Effect of nutritional recovery with soybean flour diet on body composition, energy balance and serum leptin concentration in adult rats. Nutr Metab (Lond) 2009; 6:34. [PMID: 19703309 PMCID: PMC2748074 DOI: 10.1186/1743-7075-6-34] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Accepted: 08/24/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malnutrition in early life is associated with obesity in adulthood and soybean products may have a beneficial effect on its prevention and treatment. This study evaluated body composition, serum leptin and energy balance in adult rats subjected to protein restriction during the intrauterine stage and lactation and recovering on a soybean flour diet. METHODS Five groups of the Wistar strain of albino rats were used: CC, offspring born to and suckled by mothers fed a control diet and fed the same diet after weaning; CS, offspring born to and suckled by mothers fed a control diet and fed a soybean diet with 17% protein after weaning; LL, offspring of mothers fed a low protein diet and fed the same diet after weaning; LC, offspring of mothers fed a low protein diet, but fed a control diet after weaning; LS, offspring of mothers fed a low protein diet, but fed a soybean diet with 17% protein after weaning. Food intake, body, perirenal and retroperitoneal adipose tissue were measured in grams. Leptin was quantified using the Enzyme Linked Immuno Sorbent Assay (ELISA) and insulin by radioimmunoassay (RIA). Carcass composition was determined by chemical methods and energy expenditure was calculated by the difference between energy intake and carcass energy gain. Data were tested by analysis of variance (ANOVA). RESULTS The LC and LS groups had higher energetic intake concerning body weight, lower energy expenditure, proportion of fat carcass and fat pads than CC and CS groups. The LS group showed reduced body weight gain and lower energy efficiency, which was reflected in less energy gain as protein and the proportion of carcass protein, and lower energy gain as lipid than in the LC groups, although both groups had eaten the same amount of diet and showed equal energy expenditure. Serum leptin did not differ among groups and was unrelated to food or energy intake and energy expenditure. Serum insulin was higher in the LS than in the LC group. CONCLUSION Protein restriction during intrauterine life and lactation periods did not provoke obesity in adulthood. Nutritional recovery with soybean diet decreased the body weight at the expense of lower energy efficiency with repercussion on lean mass.
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Affiliation(s)
- Loanda Maria G Cheim
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brasil.
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Egwim E. Hypoglycemic Potencies of Crude Ethanolic Extracts of Cashew Roots and Unripe Pawpaw Fruits in Guinea Pigs and Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/j157v05n01_04] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chamson-Reig A, Thyssen SM, Hill DJ, Arany E. Exposure of the pregnant rat to low protein diet causes impaired glucose homeostasis in the young adult offspring by different mechanisms in males and females. Exp Biol Med (Maywood) 2009; 234:1425-36. [PMID: 19657071 DOI: 10.3181/0902-rm-69] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The understanding of the mechanisms by which gender dimorphisms are involved in the modulation of insulin sensitivity and glucose tolerance can be crucial to unravel the development of type 2 diabetes. Rats treated with a low protein diet (LP, 8% protein content) during pregnancy and lactation have a reduced beta-cell mass at birth and a reduced insulin secretion at weaning. In this study we examined the effect of LP diet on glucose homeostasis from birth to adulthood when offspring previously exposed to LP were subsequently switched to control diet (C, 20% protein content) at weaning. The LP group had a reduced body weight after weaning compared to the C-fed rats, although their food intake was not significantly different. Furthermore, LP males had a significant increase in visceral adiposity relative to their body weight (P < 0.05). Intraperitoneal glucose tolerance test (IGTT) showed that glucose clearance was unchanged until 130 days of age when LP-fed females showed elevated blood glucose compared to C, despite similar plasma insulin levels. Females also demonstrated a significant reduction in mean pancreatic islet number, individual islet size and beta cell mass. However, no differences in IGTT or islet morphometry were observed in LP males, although basal insulin levels were twofold higher. Akt phosphorylation in response to insulin was reduced in adipose and skeletal muscle of adult rats following exposure to LP diet in early life when compared to control-fed animals, but this was only apparent in males. Plasma testosterone levels were also reduced in males at 130 days age. These data suggest that the development of impaired glucose homeostasis in offspring of LP-fed rats is likely to occur by different mechanisms in males and females.
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Affiliation(s)
- Astrid Chamson-Reig
- Lawson Health Research Institute, St. Joseph's Health Care, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada.
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Giozzet VAG, Rafacho A, Boschero AC, Carneiro EM, Bosqueiro JR. Dexamethasone treatment in vivo counteracts the functional pancreatic islet alterations caused by malnourishment in rats. Metabolism 2008; 57:617-24. [PMID: 18442623 DOI: 10.1016/j.metabol.2007.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 12/05/2007] [Indexed: 11/24/2022]
Abstract
The effects of dexamethasone (Dex) on the metabolic parameters, peripheral insulin, and glucose sensitivity in vivo as well as on islet function ex vivo of rats submitted to low-protein diet were analyzed. Dexamethasone (1.0 mg/kg body weight) was administered intraperitoneally daily to adult Wistar rats fed on a normal-protein diet or low-protein diet (LPD) for 5 days, whereas control rats fed on a normal-protein diet or low-protein diet (LP) received saline alone. At the end of the experimental period, LP rats showed a significant reduction in serum insulin, total serum protein, and serum albumin levels compared with rats fed on a normal-protein diet (P<.05). All these parameters tended to be normalized in LPD rats (P<.05); furthermore, these rats exhibited increased serum glucose and nonesterified fatty acid levels compared with LP rats (P<.05). Rats submitted to the low-protein diet demonstrated normal peripheral glucose sensitivity and improved peripheral insulin sensitivity, which was reversed by Dex treatment. A reduced area of islets from LP rats was partially recovered in LPD rats (P<.05). At 16.7 mmol/L glucose, insulin secretion from LPD islets was also partially recovered and was significantly higher than that from LP islets (P<.05). In conclusion, induction of insulin resistance by Dex treatment reverses most of the metabolic alterations in rats submitted to a low-protein diet. In addition, several islet functions were also improved by Dex, confirming the plasticity of pancreatic islets in adverse conditions.
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Affiliation(s)
- Vanessa A G Giozzet
- Department of Physiology and Biophysics, Institute of Biology, State University of Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil
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Filiputti E, Ferreira F, Souza KL, Stoppiglia LF, Arantes VC, Boschero AC, Carneiro EM. Impaired insulin secretion and decreased expression of the nutritionally responsive ribosomal kinase protein S6K-1 in pancreatic islets from malnourished rats. Life Sci 2008; 82:542-8. [DOI: 10.1016/j.lfs.2007.12.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 09/25/2007] [Accepted: 12/15/2007] [Indexed: 11/21/2022]
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de Barros Reis MA, Arantes VC, Cunha DA, Latorraca MQ, Toyama MH, Carneiro EM, Boschero AC. Increased L-CPT-1 activity and altered gene expression in pancreatic islets of malnourished adult rats: a possible relationship between elevated free fatty acid levels and impaired insulin secretion. J Nutr Biochem 2007; 19:85-90. [PMID: 17531461 DOI: 10.1016/j.jnutbio.2007.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 12/29/2006] [Accepted: 01/11/2007] [Indexed: 10/23/2022]
Abstract
Intrauterine growth restriction is associated with chronically elevated levels of serum fatty acids and reduced glucose-stimulated insulin secretion. Lipid metabolism in pancreatic beta cells is critical for the regulation of insulin secretion, and the chronic exposure to fatty acids results in higher palmitate oxidation rates and an altered insulin response to glucose. Using a rat model of isocaloric protein restriction, we examined whether pre- and postnatal protein malnutrition influences the properties of pancreatic islet carnitine palmitoyltransferase-1 (liver isoform, L-CPT-1), a rate-limiting enzyme that regulates fatty acid oxidation in mitochondria. The activity of L-CPT-1 in pancreatic islets increased in the low protein (LP), although the L-CPT-1 mRNA levels were unaffected by malnutrition. The susceptibility of enzyme to inhibition by malonyl-CoA was unaltered and the content of malonyl-CoA was reduced in LP cells. Because the mitochondrial oxidation of fatty acids is related to the altered expression of a number of genes encoding proteins involved in insulin secretion, the levels of expression of insulin and GLUT-2 mRNA were assessed. A reduced expression of both genes was observed in malnourished rats. These results provide further evidence that increased L-CPT-1 activity and changes in gene expression in pancreatic islets may be involved in the reduced insulin secretion seen in malnourished rats.
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Latorraca MQ, Carneiro EM, Boschero AC, Mello MAR. Protein deficiency during pregnancy and lactation impairs glucose-induced insulin secretion but increases the sensitivity to insulin in weaned rats. Br J Nutr 1998; 80:291-7. [DOI: 10.1017/s0007114598001342] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We studied glucose homeostasis in rat pups from dams fed on a normal-protein (170 g/kg) (NP) diet or a diet containing 60 g protein/kg (LP) during fetal life and the suckling period. At birth, total serum protein, serum albumin and serum insulin levels were similar in both groups. However, body weight and serum glucose levels in LP rats were lower than those in NP rats. At the end of the suckling period (28 d of age), total serum protein, serum albumin and serum insulin were significantly lower and the liver glycogen and serum free fatty acid levels were significantly higher in LP rats compared with NP rats. Although the fasting serum glucose level was similar in both groups, the area under the blood glucose concentration curve after a glucose load was higher for NP rats (859 (sem 58) mmol/l per 120 min for NP rats v. 607 (sem 52) mmol/l per 120 min for LP rats; P < 0.005). The mean post-glucose increase in insulin was higher for NP rats (30 (sem 4.7) nmol/l per 120 min for NP rats v. 17 (sem 3.9) nmol/l per 120 min for LP rats; P < 0.05). The glucose disappearance rate for NP rats (0.7 (sem 0.1) %/min) was lower than that for LP rats (1.6 (sem 0.2)%/min; P < 0.001). Insulin secretion from isolated islets (1 h incubation) in response to 16.7mmol glucose/l was augmented 14-fold in NP rats but only 2.6-fold in LP rats compared with the respective basal secretion (2.8 mmol/l; P < 0.001). These results indicate that in vivo as well as in vitro insulin secretion in pups from dams maintained on a LP diet is reduced. This defect may be counteracted by an increase in the sensitivity of target tissues to insulin.
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Arantes VC, Reis MAB, Latorraca MQ, Ferreira F, Stoppiglia LF, Carneiro EM, Boschero AC. Palmitic acid increase levels of pancreatic duodenal homeobox-1 and p38/stress-activated protein kinase in islets from rats maintained on a low protein diet. Br J Nutr 2007; 96:1006-12. [PMID: 17181874 DOI: 10.1017/bjn20061950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A severe reduction in insulin release in response to glucose is consistently noticed in protein-deprived rats and is attributed partly to the chronic exposure to elevated levels of NEFA. Since the pancreatic and duodenal transcription factor homeobox 1 (PDX-1) is important for the maintenance of beta-cell physiology, and since PDX-1 expression is altered in the islets of rats fed a low protein (LP) diet and that rats show high NEFA levels, we assessed PDX-1 and insulin mRNA expression, as well as PDX-1 and p38/stress activated protein kinase 2 (SAPK2) protein expression, in islets from young rats fed low (6%) or normal (17%; control) protein diets and maintained for 48 h in culture medium containing 5.6 mmol/l glucose, with or without 0.6 mmol/l palmitic acid. We also measured glucose-induced insulin secretion and glucose metabolism. Insulin secretion by isolated islets in response to 16.7 mmol/l glucose was reduced in LP compared with control rats. In the presence of NEFA, there was an increase in insulin secretion in both groups. At 2.8 mmol/l glucose, the metabolism of this sugar was reduced in LP islets, regardless of the presence of this fatty acid. However, when challenged with 16.7 mmol/l glucose, LP and control islets showed a severe reduction in glucose oxidation in the presence of NEFA. The PDX-1 and insulin mRNA were significantly higher when NEFA was added to the culture medium in both groups of islets. The effect of palmitic acid on PDX-1 and p38/SAPK2 protein levels was similar in LP and control islets, but the increase was much more evident in LP islets. These results demonstrate the complex interrelationship between nutrients in the control of insulin release and support the view that fatty acids play an important role in glucose homeostasis by affecting molecular mechanisms and stimulus/secretion coupling pathways.
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Affiliation(s)
- Vanessa C Arantes
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
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Hayirli A. The role of exogenous insulin in the complex of hepatic lipidosis and ketosis associated with insulin resistance phenomenon in postpartum dairy cattle. Vet Res Commun 2007; 30:749-74. [PMID: 17004039 DOI: 10.1007/s11259-006-3320-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2005] [Indexed: 11/27/2022]
Abstract
As a result of a marked decline in dry matter intake (DMI) prior to parturition and a slow rate of increase in DMI relative to milk production after parturition, dairy cattle experience a negative energy balance. Changes in nutritional and metabolic status during the periparturient period predispose dairy cattle to develop hepatic lipidosis and ketosis. The metabolic profile during early lactation includes low concentrations of serum insulin, plasma glucose, and liver glycogen and high concentrations of serum glucagon, adrenaline, growth hormone, plasma beta-hydroxybutyrate and non-esterified fatty acids, and liver triglyceride. Moreover, during late gestation and early lactation, flow of nutrients to fetus and mammary tissues are accorded a high degree of metabolic priority. This priority coincides with lowered responsiveness and sensitivity of extrahepatic tissues to insulin, which presumably plays a key role in development of hepatic lipidosis and ketosis. Hepatic lipidosis and ketosis compromise production, immune function, and fertility. Cows with hepatic lipidosis and ketosis have low tissue responsiveness to insulin owing to ketoacidosis. Insulin has numerous roles in metabolism of carbohydrates, lipids and proteins. Insulin is an anabolic hormone and acts to preserve nutrients as well as being a potent feed intake regulator. In addition to the major replacement therapy to alleviate severity of negative energy balance, administration of insulin with concomitant delivery of dextrose increases efficiency of treatment for hepatic lipidosis and ketosis. However, data on use of insulin to prevent these lipid-related metabolic disorders are limited and it should be investigated.
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Affiliation(s)
- A Hayirli
- Department of Animal Nutrition and Nutritional Disorders, School of Veterinary Medicine, Atatürk University, Erzurum 25700, Turkey.
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Frank JW, Escobar J, Suryawan A, Nguyen HV, Kimball SR, Jefferson LS, Davis TA. Dietary protein and lactose increase translation initiation factor activation and tissue protein synthesis in neonatal pigs. Am J Physiol Endocrinol Metab 2006; 290:E225-33. [PMID: 16144813 DOI: 10.1152/ajpendo.00351.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein synthesis and eukaryotic initiation factor (eIF) activation are increased in muscle and liver of pigs parenterally infused with amino acids and insulin. To examine the effects of enteral protein and carbohydrate on protein synthesis, pigs (n = 42, 1.7 kg body wt) were fed isocaloric milk diets containing three levels of protein (5, 15, and 25 g x kg body wt(-1) x day(-1)) and two levels of lactose (low = 11 and high = 23 g x kg body wt(-1) x day(-1)) from 1 to 6 days of age. On day 7, pigs were gavage fed after 4-h food deprivation, and tissue protein synthesis rates and biomarkers of mRNA translation were assessed. Piglet growth and protein synthesis rates in muscle and liver increased with dietary protein and plateaued at 15 g x kg body wt(-1) x day(-1) (P < 0.001). Growth tended to be greater in high-lactose-fed pigs (P = 0.07). Plasma insulin was lowest in pigs fed 5 g x kg body wt(-1) x day(-1) protein (P < 0.0001). Plasma branched-chain amino acids increased as protein intake increased (P < 0.0001). Muscle (P < 0.001) and liver (P < or = 0.001) ribosomal protein S6 kinase-1 and eIF4E-binding protein phosphorylation increased with protein intake and plateaued at 15 g x kg body wt(-1) x day(-1). The results indicate that growth and protein synthesis rates in neonatal pigs are influenced by dietary protein and lactose intake and might be mediated by plasma amino acids and insulin levels. However, feeding protein well above the piglet's requirement does not further stimulate the activation of translation initiation or protein synthesis in skeletal muscle and liver.
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Affiliation(s)
- Jason W Frank
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates St., Houston, TX 77030, USA
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Delghingaro-Augusto V, Ferreira F, Bordin S, do Amaral MEC, Toyama MH, Boschero AC, Carneiro EM. A low protein diet alters gene expression in rat pancreatic islets. J Nutr 2004; 134:321-7. [PMID: 14747667 DOI: 10.1093/jn/134.2.321] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Insulin secretion is regulated mainly by circulating nutrients, particularly glucose, and is also modulated by hormonal and neuronal inputs. Nutritional alterations during fetal and early postnatal periods, induced by either low protein or energy-restricted diets, produce beta-cell dysfunction. As a consequence, insulin secretion in response to different secretagogues is reduced, as is the number of beta-cells and the size and vascularization of islets. In this study, we used a cDNA macroarray technique and RT-PCR to assess the pattern of gene expression in pancreatic islets from rats fed isocaloric low (6 g/100 g, LP) and normal (17 g/100 g, NP) protein diets, after weaning. Thirty-two genes related to metabolism, neurotransmitter receptors, protein trafficking and targeting, intracellular kinase network members and hormones had altered expression (up- or down-regulated). RT-PCR confirmed the macroarray results for five selected genes, i.e., clusterin, secretogranin II precursor, eukaryotic translation initiation factor 2, phospholipase A(2) and glucose transporter. Thus, cDNA macroarray analysis revealed significant changes in the gene expression pattern in rats fed a low protein diet after weaning. The range of proteins affected indicated that numerous mechanisms are involved in the intracellular alterations in the endocrine pancreas, including impaired glucose-induced insulin secretion.
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Affiliation(s)
- Viviane Delghingaro-Augusto
- Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
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Abstract
The alteration of pancreatic endocrine and exocrine secretory responses induced by secretagogues and neural input was investigated in post-weaning growth-retarded (GR) piglets. Blood and pancreatic juice were collected from these animals (6-8-weeks old). Plasma insulin and pancreatic digestive enzymes induced by nutrients, drugs and vagal stimulation were measured biochemically. The pancreas was inspected by immunohistochemical analysis. In GR piglets, the plasma glucose and insulin concentrations at the resting state were very low, and the secretory response was also markedly reduced, with maximum inhibition of 90% by glucose administration and 83% by arginine administration. The insulin secretion was not increased by 2-deoxy-D-glucose administration in GR piglets. The pancreatic juice secretions induced by vagal stimulation and secretagogues in GR piglets were not different from those induced in the control piglets. However, amylase activity in the pancreatic juice and in the pancreas was significantly decreased in GR piglets, although trypsin and chymotrypsin activities were not different. In the immunohistochemical analysis, the numbers of islets and the staining degree for insulin antibody also declined in the pancreases of GR piglets. These results indicated the reduction of insulin and amylase secretions from the pancreas in GR piglets, suggesting that a dysfunction of pancreatic endocrine and exocrine secretion during growth after weaning may be an important factor in the induction of growth retardation in piglets.
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Affiliation(s)
- E Harada
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori, Japan.
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Ferreira F, Barbosa HCL, Stoppiglia LF, Delghingaro-Augusto V, Pereira EA, Boschero AC, Carneiro EM. Decreased insulin secretion in islets from rats fed a low protein diet is associated with a reduced PKAalpha expression. J Nutr 2004; 134:63-7. [PMID: 14704294 DOI: 10.1093/jn/134.1.63] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A low protein diet has been shown to affect the amount and activity of several enzymes and to decrease insulin secretion by islets isolated from rats fed such a diet. To understand the mechanisms involved in this phenomenon, we investigated the effects of forskolin, a stimulator of adenylyl cyclase, on insulin secretion by pancreatic islets from rats fed a normal (17%; NP) or low (6%; LP) protein diet for 8 wk. Isolated islets were incubated for 1 h in Krebs-bicarbonate solution containing 8.3 mmol glucose/L, with or without 10 micromol forskolin/L. The forskolin-induced insulin secretion was higher in islets from NP rats than in those from LP rats (P<0.05). Western blotting revealed that the amount of the alpha catalytic subunit of protein kinase A (PKAalpha) was 35% lower in islets from LP rats than in islets from NP rats (P<0.05). Moreover, PKAalpha mRNA expression was reduced by 30% in islets from LP rats (P<0.05). Our results indicated a possible relationship between a low protein diet and a reduction in PKAalpha expression. These alterations in PKAalpha may be responsible in part for the decreased insulin secretion by islets from rats fed a low protein diet.
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Affiliation(s)
- Fabiano Ferreira
- Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
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Ferreira F, Filiputti E, Arantes VC, Stoppiglia LF, Araújo EP, Delghingaro-Augusto V, Latorraca MQ, Toyama MH, Boschero AC, Carneiro EM. Decreased cholinergic stimulation of insulin secretion by islets from rats fed a low protein diet is associated with reduced protein kinase calpha expression. J Nutr 2003; 133:695-9. [PMID: 12612139 DOI: 10.1093/jn/133.3.695] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Undernutrition has been shown to affect the autonomic nervous system, leading to permanent alterations in insulin secretion. To understand these interactions better, we investigated the effects of carbamylcholine (CCh) and phorbol 12-myristate 13-acetate (PMA) on insulin secretion in pancreatic islets from rats fed a normal (17%; NP) or low (6%; LP) protein diet for 8 wk. Isolated islets were incubated for 1 h in Krebs-bicarbonate solution containing 8.3 mmol glucose/L, with or without PMA (400 nmol/L) and CCh. Increasing concentrations of CCh (0.1-1000 micro mol/L) dose dependently increased insulin secretion by islets from both groups of rats. However, insulin secretion by islets from rats fed the NP diet was significantly higher than that of rats fed the LP diet, and the dose-response curve to CCh was shifted to the right in islets from rats fed LP with a 50% effective concentration (EC(50)) of 2.15 +/- 0.7 and 4.64 +/- 0.1 micro mol CCh/L in islets of rats fed NP and LP diets, respectively (P < 0.05). PMA-induced insulin secretion was higher in islets of rats fed NP compared with those fed LP. Western blotting revealed that the protein kinase (PK)Calpha and phospholipase (PL)Cbeta(1) contents of islets of rats fed LP were 30% lower than those of islets of rats fed NP (P < 0.05). In addition, PKCalpha mRNA expression was reduced by 50% in islets from rats fed LP. In conclusion, a reduced expression of PKCalpha and PLCbeta(1) may be involved in the decreased insulin secretion by islets from LP rats after stimulation with CCh and PMA.
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Affiliation(s)
- Fabiano Ferreira
- Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), SP, Brasil
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Arantes VC, Teixeira VPA, Reis MAB, Latorraca MQ, Leite AR, Carneiro EM, Yamada AT, Boschero AC. Expression of PDX-1 is reduced in pancreatic islets from pups of rat dams fed a low protein diet during gestation and lactation. J Nutr 2002; 132:3030-5. [PMID: 12368391 DOI: 10.1093/jn/131.10.3030] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Intrauterine and early postnatal malnutrition has profound consequences on fetal and postnatal development in both humans and animals. In addition, low birth weight has been reported to be associated with impaired insulin secretion, insulin resistance and diminished area of pancreatic islets. Because the transcription factor pancreatic and duodenal homeobox 1 (PDX-1) is important for the maintenance of B-cell physiology, PDX-1 expression and islet area were assessed in neonatal rats of dams fed low (6%) or normal (17%) protein diets during pregnancy. PDX-1 protein and mRNA levels, as well as insulin secretion and islet area, were measured after 28 d of life in normal, low protein and recovered rats whose dams consumed a normal protein diet after delivery. Insulin secretion by isolated islets in response to 2.8 and 16.7 mmol glucose/L was reduced in 28-d-old low protein rats compared with the control (P < 0.05). At birth and after 28 d of life, the islet area and PDX-1 protein expression were also reduced (P < 0.05). In contrast, PDX-1 mRNA levels in islets from 28-d-old low protein rats were not different from control rats. PDX-1 protein expression in pancreatic islets, the area of islets and insulin secretion were restored in recovered rats, whereas PDX-1 mRNA levels were higher than in normal rats (P < 0.05). These results suggest a link among diminished PDX-1 protein expression, a reduction in islet area and impaired insulin secretion in low protein rats. The reintroduction of a normal diet early in life restored islet area and cell physiology.
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Affiliation(s)
- Vanessa C Arantes
- Departamento de Fisiologia e Biofísica e., Instituto de Biologia, Universidade Estadual de Campinas, SP, Brasil
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Abstract
Pancreatic islets were isolated from rats that had been nursed by dams fed with a control or an 8.7% protein diet during the first 12 d of the lactation period. Glucose-induced insulin secretion from islets in the 8.7% protein group was reduced 50%. The islet insulin and DNA content were similar, whereas the pancreatic insulin content was reduced by 30 % in the rats fed 8.7 % protein. In order to elucidate the mechanism responsible for the attenuation of insulin secretion, measurements were performed of the activity of several islet enzymes that had previously been supposed to be involved in the coupling of glucose stimulation to insulin secretion. Islet glucose oxidation was unaffected, but glucose-stimulated hydrolysis of phosphatidylinositol was reduced by one-third in the islets of rats fed 8.7% protein. The activity of mitochondrial glycerophosphate dehydrogenase was similar in islets of rats fed the 8.7% protein diet and those fed the control diet. The activity of Ca-independent phospholipase A2 was increased fourfold in the islets of rats fed 8.7% protein. It is concluded that impairment of glucose-induced insulin secretion in rats fed a low-protein diet may be caused by attenuation of islet phosphatidylinositol hydrolysis, and it is tentatively suggested that the increased activity of Ca-independent phospholipase A2 in islets of rats fed a low-protein diet may participate in the stimulation of apoptosis.
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Affiliation(s)
- Francisco B Barbosa
- Department of Medical Biochemistry and Genetics, The Panum Institute, University of Copenhagen, Denmark
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Galdino R, de Souza Almeida CC, Luciano E, de Mello MAR. Protein malnutrition does not impair glucose metabolism adaptations to exercise-training. Nutr Res 2000. [DOI: 10.1016/s0271-5317(00)00144-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Altered insulin secretion and sensitivity have been observed in Mg-deficient animals. However, the effects of Mg deficiency and supplementation on intracellular signaling events triggered by insulin are unknown. Therefore, we studied the early steps of insulin action in muscle and liver of rats fed Mg-deficient (DF-6, DF-11) or control (CO-6, CO-11) diets for 6 or 11 wk, respectively, and Mg-deficient or control diets for 6 wk, followed by Mg supplementation for 5 wk (SDF and SCO groups, respectively). There were no differences in the glucose disappearance rate (K(itt)) or insulin signaling between CO-6 and DF-6 rats. Between the two groups of rats fed for 11 wk, the DF-11 group had a significantly greater K(itt). SDF and SCO rats had K(itt) that did not differ from CO-11 rats, but that were significantly lower than in DF-11 rats. In the latter rats, insulin receptor and insulin receptor substrate-1 protein and phosphorylation levels were elevated in liver and there was a greater association between the insulin receptor substrate-1 and p85 subunit of phosphatidyl-inositol 3-kinase compared with CO-11 rats. There were no differences in the early steps of insulin action in SDF and control rats. These results suggest that the normal insulin sensitivity maintained by Mg supplementation and the increased insulin sensitivity produced by a long period of Mg deprivation may result, at least in part, from alterations in or maintenance of the early molecular steps of insulin action in hepatic tissue.
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Affiliation(s)
- M A Reis
- Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
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Latorraca MQ, Reis MA, Carneiro EM, Mello MA, Velloso LA, Saad MJ, Boschero AC. Protein deficiency and nutritional recovery modulate insulin secretion and the early steps of insulin action in rats. J Nutr 1998; 128:1643-9. [PMID: 9772130 DOI: 10.1093/jn/128.10.1643] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Maternal malnutrition was shown to affect early growth and leads to permanent alterations in insulin secretion and sensitivity of offspring. In addition, epidemiological studies showed an association between low birth weight and glucose intolerance in adult life. To understand these interactions better, we investigated the insulin secretion by isolated islets and the early events related to insulin action in the hind-limb muscle of adult rats fed a diet of 17% protein (control) or 6% protein [low (LP) protein] during fetal life, suckling and after weaning, and in rats receiving 6% protein during fetal life and suckling followed by a 17% protein diet after weaning (recovered). The basal and maximal insulin secretion by islets from rats fed LP diet and the basal release by islets from recovered rats were significantly lower than that of control rats. The dose-response curves to glucose of islets from LP and recovered groups were shifted to the right compared to control islets, with the half-maximal response (EC50) occurring at 16.9 +/- 1.3, 12.4 +/- 0.5 and 8.4 +/- 0.1 mmol/L, respectively. The levels of insulin receptor, as well as insulin receptor substrate-1 and phosphorylation and the association between insulin receptor substrate-1 and phosphatidylinositol 3-kinase were greater in rats fed a LP diet than in control rats. In recovered rats, these variables were not significantly different from those of the other two groups. These results suggest that glucose homeostasis is maintained in LP and recovered rats by an increased sensitivity to insulin as a result of alterations in the early steps of the insulin signal transduction pathway.
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Affiliation(s)
- M Q Latorraca
- Departamento de Fisiologia e Biofisica, Instituto de Biologia, Universidade Estadual de Campinas, UNICAMP, Campinas, São Paulo 13083-970, Brasil
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