1
|
Ahmed K, Choi HN, Yim JE. The Impact of Taurine on Obesity-Induced Diabetes Mellitus: Mechanisms Underlying Its Effect. Endocrinol Metab (Seoul) 2023; 38:482-492. [PMID: 37846056 PMCID: PMC10613769 DOI: 10.3803/enm.2023.1776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/07/2023] [Accepted: 08/28/2023] [Indexed: 10/18/2023] Open
Abstract
This review explores the potential benefits of taurine in ameliorating the metabolic disorders of obesity and type 2 diabetes (T2D), highlighting the factors that bridge these associations. Relevant articles and studies were reviewed to conduct a comprehensive analysis of the relationship between obesity and the development of T2D and the effect of taurine on those conditions. The loss of normal β-cell function and development of T2D are associated with obesity-derived insulin resistance. The occurrence of diabetes has been linked to the low bioavailability of taurine, which plays critical roles in normal β-cell function, anti-oxidation, and anti-inflammation. The relationships among obesity, insulin resistance, β-cell dysfunction, and T2D are complex and intertwined. Taurine may play a role in ameliorating these metabolic disorders through different pathways, but further research is needed to fully understand its effects and potential as a therapeutic intervention.
Collapse
Affiliation(s)
- Kainat Ahmed
- Interdisciplinary Program in Senior Human Ecology, Changwon National University, Changwon, Korea
| | - Ha-Neul Choi
- Department of Food and Nutrition, Changwon National University, Changwon, Korea
| | - Jung-Eun Yim
- Interdisciplinary Program in Senior Human Ecology, Changwon National University, Changwon, Korea
- Department of Food and Nutrition, Changwon National University, Changwon, Korea
| |
Collapse
|
2
|
ElBanna AH, Osman AS, Hossny A, ElBanna H, Abo El-Ela FI. Dose-dependent effects of taurine against testicular damage in a streptozotocin-induced type 1 diabetes mellitus rat model. Int J Immunopathol Pharmacol 2023; 37:3946320231172745. [PMID: 37099672 PMCID: PMC10141268 DOI: 10.1177/03946320231172745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
OBJECTIVES Testicular dysfunction has been associated with chronic hyperglycemia in diabetes mellitus patients. We investigated taurine's possible mechanisms and protective effects against testicular damage using a rat model of streptozotocin-induced diabetes. METHODS Wistar rats (N = 56) were divided into seven equal groups. Untreated control rats received saline, and treated control rats received taurine 50 mg/kg orally. To induce diabetes, rats received a single dose of streptozotocin. Metformin-treated diabetic rats received metformin at a dose of 300 mg/kg. Taurine-treated groups received 10, 25, or 50 mg/kg. All treatments were provided orally once a day for 9 weeks following the streptozotocin injection. Levels of blood glucose, serum insulin, cholesterol, testicular tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1beta (IL-1β), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), and catalase (CAT) were examined. Sperm count, progressive sperm motility, and sperm abnormalities were examined. Body and relative reproductive gland weights were assessed. Histopathological examinations of the testes and epididymis were performed. RESULTS Metformin as well as taurine (in a dose-dependent manner) resulted in significant improvements in body and relative reproductive gland weights, blood glucose, serum cholesterol, and insulin levels, as well as cytokine and oxidative parameters. These findings were associated with significant improvement in sperm count, progressive sperm motility, sperm abnormalities, and histopathological lesions in the testes and epididymis. CONCLUSION Taurine can potentially improve hyperglycemia, hypercholesterolemia, and testicular damage associated with diabetes mellitus, possibly by controlling inflammation and oxidative stress.
Collapse
Affiliation(s)
- Ahmed H ElBanna
- Michael Sayegh Faculty of Pharmacy, Aqaba University of Technology, Aqaba, Jordan
| | - Afaf S Osman
- Medical Pharmacology Department, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Amira Hossny
- Faculty of Biotechnology, MSA University, October City, Egypt
| | - Hossny ElBanna
- Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Fatma I Abo El-Ela
- Department of Pharmacology, Faculty of Veterinary Medicine, Beni-Suef University, Beni Suef, Egypt
| |
Collapse
|
3
|
Dos Reis Araujo T, Lubaczeuski C, Carneiro EM. Effects of double burden malnutrition on energetic metabolism and glycemic homeostasis: A narrative review. Life Sci 2022; 307:120883. [PMID: 35970240 DOI: 10.1016/j.lfs.2022.120883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/15/2022]
Abstract
Rapid changes in the food process led to greater consumption of ultra-processed foods which, associated with reduced physical activity, increased the number of overweight and obese individuals worldwide. However, in low and middle-income countries (LMICS) the growth of the obesity epidemic took place despite the high prevalence of undernutrition in children. This generated the coexistence of these two nutritional patterns, currently defined as double burden malnutrition (DBM). Several reports have already described the social, political, and economic aspects related to the causes and possible solutions for the control of DBM. Here, we highlight the metabolic alterations, related to fat deposition and glycemic homeostasis, described in experimental models of DBM and the differential effects of therapeutic strategies already tested. Therefore, this work aims to help the scientific community to understand how the DBM can lead to the development of obesity and type 2 diabetes through different mechanisms from traditional models of obesity and highlights the need to study these mechanisms and new therapeutic strategies to improve damages caused by DBM.
Collapse
Affiliation(s)
- Thiago Dos Reis Araujo
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Camila Lubaczeuski
- Department of Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Everardo Magalhães Carneiro
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil.
| |
Collapse
|
4
|
Huang Y, Lu J, Zhao Q, Chen J, Dong W, Lin M, Zheng H. Potential Therapeutic Mechanism of Traditional Chinese Medicine on Diabetes in Rodents: A Review from an NMR-Based Metabolomics Perspective. Molecules 2022; 27:molecules27165109. [PMID: 36014349 PMCID: PMC9414875 DOI: 10.3390/molecules27165109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Traditional Chinese medicine (TCM) has been used to treat diabetes for a long time, but its application has not been widely accepted due to unstandardized product quality and complex pharmacological mechanisms. The modernization of TCM is crucial for its further development, and in recent years the metabolomics technique has largely driven its modernization. This review focuses on the application of NMR-based metabolomics in diabetic therapy using TCM. We identified a series of metabolic pathways that altered significantly after TCM treatment, providing a better understanding of the metabolic mechanisms of TCM for diabetes care.
Collapse
Affiliation(s)
- Yinli Huang
- Department of Endocrinology, Pingyang Affiliated Hospital of Wenzhou Medical University, Wenzhou 325400, China
| | - Jiahui Lu
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Qihui Zhao
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Junli Chen
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Wei Dong
- Department of Endocrinology, Pingyang Affiliated Hospital of Wenzhou Medical University, Wenzhou 325400, China
| | - Minjie Lin
- Department of Endocrinology, Pingyang Affiliated Hospital of Wenzhou Medical University, Wenzhou 325400, China
| | - Hong Zheng
- Department of Endocrinology, Pingyang Affiliated Hospital of Wenzhou Medical University, Wenzhou 325400, China
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Correspondence:
| |
Collapse
|
5
|
Duszka K. Versatile Triad Alliance: Bile Acid, Taurine and Microbiota. Cells 2022; 11:2337. [PMID: 35954180 PMCID: PMC9367564 DOI: 10.3390/cells11152337] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/21/2022] [Accepted: 07/24/2022] [Indexed: 11/21/2022] Open
Abstract
Taurine is the most abundant free amino acid in the body, and is mainly derived from the diet, but can also be produced endogenously from cysteine. It plays multiple essential roles in the body, including development, energy production, osmoregulation, prevention of oxidative stress, and inflammation. Taurine is also crucial as a molecule used to conjugate bile acids (BAs). In the gastrointestinal tract, BAs deconjugation by enteric bacteria results in high levels of unconjugated BAs and free taurine. Depending on conjugation status and other bacterial modifications, BAs constitute a pool of related but highly diverse molecules, each with different properties concerning solubility and toxicity, capacity to activate or inhibit receptors of BAs, and direct and indirect impact on microbiota and the host, whereas free taurine has a largely protective impact on the host, serves as a source of energy for microbiota, regulates bacterial colonization and defends from pathogens. Several remarkable examples of the interaction between taurine and gut microbiota have recently been described. This review will introduce the necessary background information and lay out the latest discoveries in the interaction of the co-reliant triad of BAs, taurine, and microbiota.
Collapse
Affiliation(s)
- Kalina Duszka
- Department of Nutritional Sciences, University of Vienna, 1090 Vienna, Austria
| |
Collapse
|
6
|
Bae M, Ahmed K, Yim JE. Beneficial Effects of Taurine on Metabolic Parameters in Animals and Humans. J Obes Metab Syndr 2022; 31:134-146. [PMID: 35670160 PMCID: PMC9284575 DOI: 10.7570/jomes21088] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/14/2022] [Accepted: 04/13/2022] [Indexed: 11/02/2022] Open
Abstract
Taurine (2-aminoethanesulfonic acid) is a non-essential amino acid mainly obtained through diet in humans. Despite the lack of research on the health effects of taurine in animals and humans, it is widely used as a dietary supplement. Evidence from human and animal studies indicates that taurine is involved in conjugation of bile acids and regulation of blood pressure and has anti-oxidative, anti-inflammatory, and anti-obesogenic properties. Taurine can benefit both human and non-human animal health in multiple ways. However, few interventional and epidemiological studies regarding the beneficial impacts of taurine in humans and other animals have been conducted. Here, we review the evidence from animal and human studies showing that taurine protects against dyslipidemia, obesity, hypertension, and diabetes mellitus.
Collapse
Affiliation(s)
- Minkyung Bae
- Department of Food and Nutrition, Changwon National University, Changwon, Korea.,Interdisciplinary Program in Senior Human Ecology, BK21, Changwon National University, Changwon, Korea
| | - Kainat Ahmed
- Interdisciplinary Program in Senior Human Ecology, BK21, Changwon National University, Changwon, Korea
| | - Jung-Eun Yim
- Department of Food and Nutrition, Changwon National University, Changwon, Korea.,Interdisciplinary Program in Senior Human Ecology, BK21, Changwon National University, Changwon, Korea
| |
Collapse
|
7
|
Tauroursodeoxycholic acid improves glucose tolerance and reduces adiposity in normal protein and malnourished mice fed a high-fat diet. Food Res Int 2022; 156:111331. [DOI: 10.1016/j.foodres.2022.111331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 11/19/2022]
|
8
|
De Carvalho FG, Muñoz VR, Brandao CFC, Simabuco FM, Pavan ICB, Nakandakari SCBR, Pauli JR, De Moura LP, Ropelle ER, Marchini JS, da Silva ASR, de Freitas EC. Taurine upregulates insulin signaling and mitochondrial metabolism in vitro but not in adipocytes of obese women. Nutrition 2021; 93:111430. [PMID: 34479044 DOI: 10.1016/j.nut.2021.111430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/20/2021] [Accepted: 07/18/2021] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Based on taurine's beneficial roles in metabolic diseases in rodents and obese individuals, we investigated the effects of taurine supplementation on adipose tissue using transcriptome analysis, 3T3-L1 adipocytes, and subcutaneous white adipose tissue (scWAT) of obese women. METHODS First, we applied bioinformatics analysis to evaluate the effect of the taurine synthesis pathway on the adipose tissue of several BXD mice strains. After that, using 3T3-L1 adipocytes, we investigated the effects of different taurine doses in proteins related to insulin signaling, lipid oxidation, and mitochondrial function. Finally, we evaluated the effects of taurine supplementation (3 grams, 8 wk) on the same proteins in the scWAT of obese women. RESULTS The transcriptome analysis showed that the taurine biosynthesis pathway was positively associated with insulin signaling and mitochondrial metabolism in the scWAT of BXD mice. The experiments using 3T3-L1 cells highlighted that the taurine dosage has an essential function in taurine synthesis, insulin, and mitochondrial markers. In contrast, the 8-wk taurine administration did not change the basal insulin, proteins of the taurine synthesis or insulin pathways, lipid oxidation, or mitochondrial metabolism in the scWAT of obese women. CONCLUSIONS For the first time, to our knowledge, we showed that supplementation with 3 g of taurine for 8 wk promoted no effect in the insulin signaling pathway in the scWAT of obese women. These findings bring new perspectives to investigate different taurine doses and the intervention period for human studies owing to the potential antiobesity activity of taurine.
Collapse
Affiliation(s)
- Flavia G De Carvalho
- School of Physical Education and Sport of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil.
| | - Vitor R Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas, Limeira, Brazil.
| | - Camila F C Brandao
- Internal Medicine Department, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, Brazil; State University of Minas Gerais, Divinopolis unit, Divinopolis, Brazil.
| | - Fernando M Simabuco
- Multidisciplinary Laboratory of Food and Health, School of Applied Sciences, University of Campinas, Limeira, Brazil.
| | - Isadora C B Pavan
- Multidisciplinary Laboratory of Food and Health, School of Applied Sciences, University of Campinas, Limeira, Brazil; Laboratory of Signaling Mechanisms, School of Pharmaceutical Sciences, University of Campinas, Campinas, Brazil.
| | | | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas, Limeira, Brazil.
| | - Leandro P De Moura
- Laboratory of Molecular Biology of Exercise, University of Campinas, Limeira, Brazil.
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas, Limeira, Brazil.
| | - Julio Sergio Marchini
- Internal Medicine Department, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, Brazil.
| | - Adelino S R da Silva
- School of Physical Education and Sport of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil.
| | - Ellen C de Freitas
- School of Physical Education and Sport of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil.
| |
Collapse
|
9
|
Zheng J, Xiao H, Duan Y, Song B, Zheng C, Guo Q, Li F, Li T. Roles of amino acid derivatives in the regulation of obesity. Food Funct 2021; 12:6214-6225. [PMID: 34105579 DOI: 10.1039/d1fo00780g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Obesity is an issue of great concern to people all over the world. It is accompanied by serious complications, leading to reduced quality of life and higher morbidity and mortality. Over the past few years, there has been an explosion in knowledge about the roles of potential therapeutic agents in obesity management. Among them, amino acid (AA) derivatives, such as taurine, glutathione (GSH), betaine, α-ketoglutarate (AKG), β-aminoisobutyric acid (BAIBA), and β-hydroxy-β-methylbutyrate (HMB), have recently gained popularity due to their beneficial effects on the promotion of weight loss and improvement in the lipid profile. The mechanisms of action of these derivatives mainly include inhibiting adipogenesis, increasing lipolysis, promoting brown/beige adipose tissue (BAT) development, and improving glucose metabolism. Therefore, this review summarizes these AA derivatives and the possible mechanisms responsible for their anti-obesity effects. Based on the current findings, these AA derivatives could be potential therapeutic agents for obesity and its related metabolic diseases.
Collapse
Affiliation(s)
- Jie Zheng
- CAS Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Baliou S, Adamaki M, Ioannou P, Pappa A, Panayiotidis MI, Christodoulou I, Spandidos DA, Kyriakopoulos AM, Zoumpourlis V. Ameliorative effect of taurine against diabetes and renal-associated disorders (Review). MEDICINE INTERNATIONAL 2021; 1:3. [PMID: 36699147 PMCID: PMC9855276 DOI: 10.3892/mi.2021.3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/25/2021] [Indexed: 01/28/2023]
Abstract
To develop novel therapeutic methods for both diabetic and renal disorders, scientists had initially focused on elucidating the molecular mechanisms of taurine in established cell lines and mouse models. Although a large amount of data have been revealed, taurine has been confirmed to be the next step of novel promising therapeutic interventions against diabetic disorders. Taurine appears to ameliorate diabetes 1-related complications in various organs through its antioxidant, anti-inflammatory and anti-hormonal actions. In type 2 diabetes, taurine has been positively implicated in glucose homeostasis, exerting potent hypoglycemic, anti-obesity, hypotensive and hypolipidemic effects. Of particular interest is that taurine provides protection against renal dysfunction, including hypertension and proteinuria, specific glomerular and tubular disorders, acute and chronic renal conditions, and diabetic nephropathy. The ameliorative effects of taurine against renal disorders are based on its osmoregulatory properties, its association with signaling pathways and its association with the renin-angiotensin-aldosterone system (RAAS). Further clinical studies are required to ensure the importance of research findings.
Collapse
Affiliation(s)
- Stella Baliou
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece
| | - Maria Adamaki
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece
| | - Petros Ioannou
- Department of Internal Medicine and Infectious Diseases, University Hospital of Heraklion, 71110 Heraklion, Greece
| | - Aglaia Pappa
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, 68100 Alexandroupolis, Greece
| | - Mihalis I. Panayiotidis
- Department of Cancer Genetics, Therapeutics and Ultrastructural Pathology, The Cyprus Institute of Neurology and Genetics, 2371 Nicosia, Cyprus,Cyprus School of Molecular Medicine, 2371 Nicosia, Cyprus
| | - Ioannis Christodoulou
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, Medical School, University of Crete, 71409 Heraklion, Greece
| | | | - Vassilis Zoumpourlis
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece,Correspondence to: Dr Vassilis Zoumpourlis, Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vas. Konstantinou Avenue, 11635 Athens, Greece
| |
Collapse
|
11
|
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] [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.
Collapse
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
| |
Collapse
|
12
|
Kaneko H, Kobayashi M, Mizunoe Y, Yoshida M, Yasukawa H, Hoshino S, Itagawa R, Furuichi T, Okita N, Sudo Y, Imae M, Higami Y. Taurine is an amino acid with the ability to activate autophagy in adipocytes. Amino Acids 2018. [DOI: 10.1007/s00726-018-2550-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
13
|
Diet-induced glucose homeostasis dysregulation is enhanced by taurine supplementation in ovariectomized mice. Amino Acids 2017; 50:469-477. [PMID: 29282544 DOI: 10.1007/s00726-017-2533-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 12/19/2017] [Indexed: 01/02/2023]
Abstract
Low levels of estrogens are associated with obesity-related comorbidities. Mice with lower levels of estrogens are thereby more sensitive to the effects of a high-fat-diet (HFD) for the development of glucose intolerance and insulin resistance. Studies in vivo have demonstrated that taurine (TAU) supplementation prevents glucose and insulin resistance. Thus, we aimed to investigate the potential beneficial effects of TAU supplementation on glucose homeostasis of mice with low levels of estrogens fed with a HFD. 3-month-old female C57BL/6J mice underwent bilateral ovariectomy (OVX). After 1 week of recovery, mice were divided into 4 groups and either received: a standard chow diet (OVXC), chow diet plus drinking water enriched with 3% of TAU (OVXCT), HFD (OVXH), and HFD plus supplementation of TAU (OVXHT) for 14 weeks. Exposure to the HFD increased adiposity and plasma levels of glucose and insulin. Contrary to our prediction, the addition of TAU enhanced the deleterious effects of the HFD. Glucose and insulin tolerance tests (ipGTT and ipITT) indicated that mice maintained on the HFD + TAU had worse glucose intolerance and insulin resistance that was linked to lower insulin signaling in skeletal muscle and liver. Insulin secretion of isolated pancreatic islets of OVXH mice was higher than OVXC, and the addition of TAU associated with a HFD did not modulate insulin secretion, suggesting a failure of pancreatic β cells of OVXHT mice. These results suggest that despite the beneficial reports of TAU, it should be used cautiously in situations where the levels of estrogens are low.
Collapse
|
14
|
Sarkar P, Basak P, Ghosh S, Kundu M, Sil PC. Prophylactic role of taurine and its derivatives against diabetes mellitus and its related complications. Food Chem Toxicol 2017; 110:109-121. [PMID: 29050977 DOI: 10.1016/j.fct.2017.10.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 02/08/2023]
Abstract
Taurine is a conditionally essential amino acid present in the body in free form. Mammalian taurine is synthesized in the pancreas via the cysteine sulfinic acid pathway. Anti-oxidation and anti-inflammation are two main properties through which it exerts its therapeutic effects. Many studies have shown its excellent therapeutic potential against diabetes mellitus and related complications like diabetic neuropathy, retinopathy, nephropathy, hematological dysfunctions, reproductive dysfunctions, liver and pancreas related complications etc. Not only taurine, a number of its derivatives have also been reported to be important in ameliorating diabetic complications. The present review has been aimed to describe the importance of taurine and its derivatives against diabetic metabolic syndrome and related complications.
Collapse
Affiliation(s)
- Poulami Sarkar
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054, India
| | - Priyanka Basak
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054, India
| | - Sumit Ghosh
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054, India
| | - Mousumi Kundu
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054, India
| | - Parames C Sil
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054, India.
| |
Collapse
|
15
|
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] [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.
Collapse
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
Collapse
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
| |
Collapse
|
16
|
Vagotomy Reduces Insulin Clearance in Obese Mice Programmed by Low-Protein Diet in the Adolescence. Neural Plast 2017; 2017:9652978. [PMID: 28951790 PMCID: PMC5603136 DOI: 10.1155/2017/9652978] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/31/2017] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to investigate the effect of subdiaphragmatic vagotomy on insulin sensitivity, secretion, and degradation in metabolic programmed mice, induced by a low-protein diet early in life, followed by exposure to a high-fat diet in adulthood. Weaned 30-day-old C57Bl/6 mice were submitted to a low-protein diet (6% protein). After 4 weeks, the mice were distributed into three groups: LP group, which continued receiving a low-protein diet; LP + HF group, which started to receive a high-fat diet; and LP + HFvag group, which underwent vagotomy and also was kept at a high-fat diet. Glucose-stimulated insulin secretion (GSIS) in isolated islets, ipGTT, ipITT, in vivo insulin clearance, and liver expression of the insulin-degrading enzyme (IDE) was accessed. Vagotomy improved glucose tolerance and reduced insulin secretion but did not alter adiposity and insulin sensitivity in the LP + HFvag, compared with the LP + HF group. Improvement in glucose tolerance was accompanied by increased insulinemia, probably due to a diminished insulin clearance, as judged by the lower C-peptide : insulin ratio, during the ipGTT. Finally, vagotomy also reduced liver IDE expression in this group. In conclusion, when submitted to vagotomy, the metabolic programmed mice showed improved glucose tolerance, associated with an increase of plasma insulin concentration as a result of insulin clearance reduction, a phenomenon probably due to diminished liver IDE expression.
Collapse
|
17
|
Branco RCS, Camargo RL, Batista TM, Vettorazzi JF, Borck PC, Dos Santos-Silva JCR, Boschero AC, Zoppi CC, Carneiro EM. Protein malnutrition blunts the increment of taurine transporter expression by a high-fat diet and impairs taurine reestablishment of insulin secretion. FASEB J 2017; 31:4078-4087. [PMID: 28572444 DOI: 10.1096/fj.201600326rrr] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 05/15/2017] [Indexed: 12/23/2022]
Abstract
Taurine (Tau) restores β-cell function in obesity; however, its action is lost in malnourished obese rodents. Here, we investigated the mechanisms involved in the lack of effects of Tau in this model. C57BL/6 mice were fed a control diet (CD) (14% protein) or a protein-restricted diet (RD) (6% protein) for 6 wk. Afterward, mice received a high-fat diet (HFD) for 8 wk [CD + HFD (CH) and RD + HFD (RH)] with or without 5% Tau supplementation after weaning on their drinking water [CH + Tau (CHT) and RH + Tau (RHT)]. The HFD increased insulin secretion through mitochondrial metabolism in CH and RH. Tau prevented all those alterations in CHT only. The expression of the taurine transporter (Tau-T), as well as Tau content in pancreatic islets, was increased in CH but had no effect on RH. Protein malnutrition programs β cells and impairs Tau-induced restoration of mitochondrial metabolism and biogenesis. This may be associated with modulation of the expression of Tau-T in pancreatic islets, which may be responsible for the absence of effect of Tau in protein-malnourished obese mice.-Branco, R. C. S., Camargo, R. L., Batista, T. M., Vettorazzi, J. F., Borck, P. C., dos Santos-Silva, J. C. R., Boschero, A. C., Zoppi, C. C., Carneiro, E. M. Protein malnutrition blunts the increment of taurine transporter expression by a high-fat diet and impairs taurine reestablishment of insulin secretion.
Collapse
Affiliation(s)
- Renato Chaves Souto Branco
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Rafael Ludemann Camargo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Thiago Martins Batista
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Jean Franciesco Vettorazzi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Patrícia Cristine Borck
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | | | - Antonio Carlos Boschero
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cláudio Cesar Zoppi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Everardo Magalhães Carneiro
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| |
Collapse
|
18
|
Acute Exercise Improves Insulin Clearance and Increases the Expression of Insulin-Degrading Enzyme in the Liver and Skeletal Muscle of Swiss Mice. PLoS One 2016; 11:e0160239. [PMID: 27467214 PMCID: PMC4965115 DOI: 10.1371/journal.pone.0160239] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/15/2016] [Indexed: 11/19/2022] Open
Abstract
The effects of exercise on insulin clearance and IDE expression are not yet fully elucidated. Here, we have explored the effect of acute exercise on insulin clearance and IDE expression in lean mice. Male Swiss mice were subjected to a single bout of exercise on a speed/angle controlled treadmill for 3-h at approximately 60-70% of maximum oxygen consumption. As expected, acute exercise reduced glycemia and insulinemia, and increased insulin tolerance. The activity of AMPK-ACC, but not of IR-Akt, pathway was increased in the liver and skeletal muscle of trained mice. In an apparent contrast to the reduced insulinemia, glucose-stimulated insulin secretion was increased in isolated islets of these mice. However, insulin clearance was increased after acute exercise and was accompanied by increased expression of the insulin-degrading enzyme (IDE), in the liver and skeletal muscle. Finally, C2C12, but not HEPG2 cells, incubated at different concentrations of 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) for 3-h, showed increased expression of IDE. In conclusion, acute exercise increases insulin clearance, probably due to an augmentation of IDE expression in the liver and skeletal muscle. The elevated IDE expression, in the skeletal muscle, seems to be mediated by activation of AMPK-ACC pathway, in response to exercise. We believe that the increase in the IDE expression, comprise a safety measure to maintain glycemia at or close to physiological levels, turning physical exercise more effective and safe.
Collapse
|
19
|
Ogino M, Ichimura M, Nakano N, Minami A, Kitagishi Y, Matsuda S. Roles of PTEN with DNA Repair in Parkinson's Disease. Int J Mol Sci 2016; 17:ijms17060954. [PMID: 27314344 PMCID: PMC4926487 DOI: 10.3390/ijms17060954] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/27/2016] [Accepted: 06/09/2016] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress is considered to play key roles in aging and pathogenesis of many neurodegenerative diseases such as Parkinson’s disease, which could bring DNA damage by cells. The DNA damage may lead to the cell apoptosis, which could contribute to the degeneration of neuronal tissues. Recent evidence suggests that PTEN (phosphatase and tensin homolog on chromosome 10) may be involved in the pathophysiology of the neurodegenerative disorders. Since PTEN expression appears to be one dominant determinant of the neuronal cell death, PTEN should be a potential molecular target of novel therapeutic strategies against Parkinson’s disease. In addition, defects in DNA damage response and DNA repair are often associated with modulation of hormone signaling pathways. Especially, many observations imply a role for estrogen in a regulation of the DNA repair action. In the present review, we have attempted to summarize the function of DNA repair molecules at a viewpoint of the PTEN signaling pathway and the hormone related functional modulation of cells, providing a broad interpretation on the molecular mechanisms for treatment of Parkinson’s disease. Particular attention will be paid to the mechanisms proposed to explain the health effects of food ingredients against Parkinson’s disease related to reduce oxidative stress for an efficient therapeutic intervention.
Collapse
Affiliation(s)
- Mako Ogino
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Mayuko Ichimura
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Noriko Nakano
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Akari Minami
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Yasuko Kitagishi
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Satoru Matsuda
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| |
Collapse
|
20
|
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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/26/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
|
21
|
Taurine Supplementation Leads to a Disruption in Energy Homeostasis in Menopausal Obese Mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 803:735-48. [DOI: 10.1007/978-3-319-15126-7_59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
22
|
Camargo RL, Branco RCS, de Rezende LF, Vettorazzi JF, Borck PC, Boschero AC, Carneiro EM. The Effect of Taurine Supplementation on Glucose Homeostasis: The Role of Insulin-Degrading Enzyme. TAURINE 9 2015; 803:715-24. [DOI: 10.1007/978-3-319-15126-7_57] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
23
|
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] [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.
Collapse
|