1
|
Tokarz VL, Mylvaganam S, Klip A. Palmitate-induced insulin resistance causes actin filament stiffness and GLUT4 mis-sorting without altered Akt signalling. J Cell Sci 2023; 136:jcs261300. [PMID: 37815440 DOI: 10.1242/jcs.261300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/25/2023] [Indexed: 10/11/2023] Open
Abstract
Skeletal muscle insulin resistance, a major contributor to type 2 diabetes, is linked to the consumption of saturated fats. This insulin resistance arises from failure of insulin-induced translocation of glucose transporter type 4 (GLUT4; also known as SLC2A4) to the plasma membrane to facilitate glucose uptake into muscle. The mechanisms of defective GLUT4 translocation are poorly understood, limiting development of insulin-sensitizing therapies targeting muscle glucose uptake. Although many studies have identified early insulin signalling defects and suggest that they are responsible for insulin resistance, their cause-effect has been debated. Here, we find that the saturated fat palmitate (PA) causes insulin resistance owing to failure of GLUT4 translocation in skeletal muscle myoblasts and myotubes without impairing signalling to Akt2 or AS160 (also known as TBC1D4). Instead, PA altered two basal-state events: (1) the intracellular localization of GLUT4 and its sorting towards a perinuclear storage compartment, and (2) actin filament stiffness, which prevents Rac1-dependent actin remodelling. These defects were triggered by distinct mechanisms, respectively protein palmitoylation and endoplasmic reticulum (ER) stress. Our findings highlight that saturated fats elicit muscle cell-autonomous dysregulation of the basal-state machinery required for GLUT4 translocation, which 'primes' cells for insulin resistance.
Collapse
Affiliation(s)
- Victoria L Tokarz
- Department of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Sivakami Mylvaganam
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Ontario, M5S 1A8, Canada
| | - Amira Klip
- Department of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Ontario, M5S 1A8, Canada
| |
Collapse
|
2
|
Khouri H, Ussher JR, Aguer C. Exogenous Ketone Supplementation and Ketogenic Diets for Exercise: Considering the Effect on Skeletal Muscle Metabolism. Nutrients 2023; 15:4228. [PMID: 37836512 PMCID: PMC10574738 DOI: 10.3390/nu15194228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
In recent years, ketogenic diets and ketone supplements have increased in popularity, particularly as a mechanism to improve exercise performance by modifying energetics. Since the skeletal muscle is a major metabolic and locomotory organ, it is important to take it into consideration when considering the effect of a dietary intervention, and the impact of physical activity on the body. The goal of this review is to summarize what is currently known and what still needs to be investigated concerning the relationship between ketone body metabolism and exercise, specifically in the skeletal muscle. Overall, it is clear that increased exposure to ketone bodies in combination with exercise can modify skeletal muscle metabolism, but whether this effect is beneficial or detrimental remains unclear and needs to be further interrogated before ketogenic diets or exogenous ketone supplementation can be recommended.
Collapse
Affiliation(s)
- Hannah Khouri
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Institut du Savoir Montfort, Hôpital Montfort, Ottawa, ON K1K 0T2, Canada
| | - John R Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2H5, Canada
| | - Céline Aguer
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Institut du Savoir Montfort, Hôpital Montfort, Ottawa, ON K1K 0T2, Canada
- Department of Physiology, Faculty of Medicine and Health Sciences, McGill University-Campus Outaouais, Gatineau, QC J8V 3T4, Canada
| |
Collapse
|
3
|
Zhang Y, Gao F, Gong H, Fu Y, Liu B, Qin X, Zheng Q. Intermittent fasting attenuates obesity-related atrial fibrillation via SIRT3-mediated insulin resistance mitigation. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166638. [PMID: 36657499 DOI: 10.1016/j.bbadis.2023.166638] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Atrial fibrillation (AF) is the most common tachyarrhythmia in urgent need of therapeutic optimization. Obesity engenders AF, and its pathogenesis is closely intertwined with insulin resistance (IR), but mechanism-based management is still underinvestigated. Intermittent fasting (IF) is a novel lifestyle intervention that mitigates IR, a potential AF driver, yet whether IF can prevent obesity-related AF remains elusive. Here, we aimed to evaluate the impacts of short-term IF on AF and to uncover the underlying mechanism. METHODS We subjected obese mice (high-fat diet for 8-week) to IF (alternative-day fasting for another 5-week) for AF vulnerability and substrate formation assessment, and similarly treated neonatal atrial cardiomyocytes (NRCMs) and fibroblasts (NRCFs) (palmitate, 200 μM) with IF (alternative-day short-term starvation for 8-day) for mechanism investigation. RESULTS Obese mice were prone to AF and atrial remodeling. IF reduced AF inducibility, duration, and reversed atrial remodeling including channel disturbance, left atrial dilation, cardiac hypertrophy and fibrosis in obese mice independent of weight loss. Mechanistically, IF up-regulated the SIRT3 protein level both in vivo and in vitro, and pharmacologic inhibition (3-(1H-1,2,3-Triazol-4-yl) pyridine, 50 μM) and genetic suppression of SIRT3 could attenuate the IF-mediated benefits against hypertrophy and fibrosis. Furthermore, IF activated AMPK and Akt signaling, two positive downstream targets of SIRT3, and inactivated HIF1α signaling, a negative downstream target of SIRT3 in both obese mice atria and palmitate-treated cells, while inhibition of SIRT3 reversed these effects. CONCLUSION IF prevents obesity-related AF via SIRT3-mediated IR mitigation, thus representing a feasible lifestyle intervention to improve AF management.
Collapse
Affiliation(s)
- Yudi Zhang
- The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Feng Gao
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Haoyu Gong
- The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Yuping Fu
- The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Binghua Liu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Xinghua Qin
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
| | - Qiangsun Zheng
- The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
| |
Collapse
|
4
|
Limonin mitigates cardiometabolic complications in rats with metabolic syndrome through regulation of the IRS-1/GLUT4 signalling pathway. Biomed Pharmacother 2023; 161:114448. [PMID: 36857910 DOI: 10.1016/j.biopha.2023.114448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
Limonin is a natural triterpenoid isolated from citrus fruit. In the present study, we examined the effects of limonin on cardiometabolic alterations in diet-induced metabolic syndrome. Metabolic syndrome was induced in rats by feeding them a high-fat (HF) diet plus 15% fructose in drinking water for 16 weeks. They were treated with limonin (50 or 100 mg/kg) (n = 8/group) for the final 4 weeks. Increases in body weight (BW), fasting blood glucose (FBG), serum insulin, total cholesterol (TC), blood pressure (BP), liver fat accumulation, and adipocyte hypertrophy, as well as oral glucose tolerance in rats with metabolic syndrome were alleviated by limonin treatment (p < 0.05). Limonin improved ejection fraction and left ventricular (LV) hypertrophy, and reduced angiotensin converting enzyme (ACE) activity and angiotensin II (Ang II) concentration in rats with metabolic syndrome (p < 0.05). It also reduced plasma tumour necrosis factor (TNF)-α, interleukin (IL)- 6, leptin, malonaldehyde (MDA), and superoxide generation, and increased catalase activity in rats with metabolic syndrome compared to controls (p < 0.05). Downregulation of insulin receptor substrate 1 (IRS-1) and glucose transporter type 4 (GLUT4) protein expression in epididymal fat pads and cardiac, liver, and gastrocnemius tissues was present in metabolic syndrome, and these were restored by limonin treatment (p < 0.05). In conclusion, limonin shows a potential effect in alleviating symptoms and improving cardiometabolic disorders. These beneficial effects are linked to the reduction of the renin-angiotensin system, inflammation, oxidative stress, and improvement of IRS-1/GLUT4 protein expression in the target tissue.
Collapse
|
5
|
Laiman J, Hsu YJ, Loh J, Tang WC, Chuang MC, Liu HK, Yang WS, Chen BC, Chuang LM, Chang YC, Liu YW. GSK3α phosphorylates dynamin-2 to promote GLUT4 endocytosis in muscle cells. J Cell Biol 2022; 222:213725. [PMID: 36445308 PMCID: PMC9712776 DOI: 10.1083/jcb.202102119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 08/17/2022] [Accepted: 10/31/2022] [Indexed: 12/02/2022] Open
Abstract
Insulin-stimulated translocation of glucose transporter 4 (GLUT4) to plasma membrane of skeletal muscle is critical for postprandial glucose uptake; however, whether the internalization of GLUT4 is also regulated by insulin signaling remains unclear. Here, we discover that the activity of dynamin-2 (Dyn2) in catalyzing GLUT4 endocytosis is negatively regulated by insulin signaling in muscle cells. Mechanistically, the fission activity of Dyn2 is inhibited by binding with the SH3 domain of Bin1. In the absence of insulin, GSK3α phosphorylates Dyn2 to relieve the inhibition of Bin1 and promotes endocytosis. Conversely, insulin signaling inactivates GSK3α and leads to attenuated GLUT4 internalization. Furthermore, the isoform-specific pharmacological inhibition of GSK3α significantly improves insulin sensitivity and glucose tolerance in diet-induced insulin-resistant mice. Together, we identify a new role of GSK3α in insulin-stimulated glucose disposal by regulating Dyn2-mediated GLUT4 endocytosis in muscle cells. These results highlight the isoform-specific function of GSK3α on membrane trafficking and its potential as a therapeutic target for metabolic disorders.
Collapse
Affiliation(s)
- Jessica Laiman
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yen-Jung Hsu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Julie Loh
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wei-Chun Tang
- ResearchCenter for Applied Sciences, Academia Sinica, Taipei, Taiwan
| | - Mei-Chun Chuang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hui-Kang Liu
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan,Program in the Clinical Drug Development of Herbal Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wei-Shun Yang
- Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Bi-Chang Chen
- ResearchCenter for Applied Sciences, Academia Sinica, Taipei, Taiwan
| | - Lee-Ming Chuang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan,Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yi-Cheng Chang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan,Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei, Taiwan,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan,Yi-Cheng Chang:
| | - Ya-Wen Liu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan,Correspondence to Ya-Wen Liu:
| |
Collapse
|
6
|
N-Octyl Caffeamide, a Caffeic Acid Amide Derivative, Prevents Progression of Diabetes and Hepatic Steatosis in High-Fat Diet Induced Obese Mice. Int J Mol Sci 2022; 23:ijms23168948. [PMID: 36012215 PMCID: PMC9409300 DOI: 10.3390/ijms23168948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/30/2022] Open
Abstract
The underlying pathological mechanisms of diabetes are complicated and varied in diabetic patients, which may lead to the current medications often failing to maintain glycemic control in the long term. Thus, the discovery of diverse new compounds for developing medicines to treat diabetes and its complications are urgently needed. Polyphenols are metabolites of plants and have been employed in the prevention and treatment of a variety of diseases. Caffeic acid phenethyl ester (CAPE) is a category of compounds structurally similar to polyphenols. In this study, we aimed to investigate the antidiabetic activity and potential molecular mechanisms of a novel synthetic CAPE derivative N-octyl caffeamide (36M) using high-fat (HF) diet induced obese mouse models. Our results demonstrate that 36M prevented the progression of diabetes in the HF diet fed obese mice via increasing phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and inhibiting expression of protein tyrosine phosphatase 1B (PTP1B). We also found that 36M could prevent hepatic lipid storage in the HF diet fed mice via inhibition of fatty acid synthase and lipid droplet proteins, including perilipins and Fsp27. In conclusion, 36M is a potential candidate compound that can be developed as AMPK inhibitor and PTP1B inhibitor for treating diabetes and hepatic steatosis.
Collapse
|
7
|
Zumbaugh MD, Johnson SE, Shi TH, Gerrard DE. Molecular and biochemical regulation of skeletal muscle metabolism. J Anim Sci 2022; 100:6652332. [PMID: 35908794 PMCID: PMC9339271 DOI: 10.1093/jas/skac035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/02/2022] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle hypertrophy is a culmination of catabolic and anabolic processes that are interwoven into major metabolic pathways, and as such modulation of skeletal muscle metabolism may have implications on animal growth efficiency. Muscle is composed of a heterogeneous population of muscle fibers that can be classified by metabolism (oxidative or glycolytic) and contractile speed (slow or fast). Although slow fibers (type I) rely heavily on oxidative metabolism, presumably to fuel long or continuous bouts of work, fast fibers (type IIa, IIx, and IIb) vary in their metabolic capability and can range from having a high oxidative capacity to a high glycolytic capacity. The plasticity of muscle permits continuous adaptations to changing intrinsic and extrinsic stimuli that can shift the classification of muscle fibers, which has implications on fiber size, nutrient utilization, and protein turnover rate. The purpose of this paper is to summarize the major metabolic pathways in skeletal muscle and the associated regulatory pathways.
Collapse
Affiliation(s)
- Morgan D Zumbaugh
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Sally E Johnson
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Tim H Shi
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - David E Gerrard
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| |
Collapse
|
8
|
Adnan M, Jairajpuri DS, Chaddha M, Khan MS, Yadav DK, Mohammad T, Elasbali AM, Abu Al-Soud W, Hussain Alharethi S, Hassan MI. Discovering Tuberosin and Villosol as Potent and Selective Inhibitors of AKT1 for Therapeutic Targeting of Oral Squamous Cell Carcinoma. J Pers Med 2022; 12:jpm12071083. [PMID: 35887580 PMCID: PMC9322152 DOI: 10.3390/jpm12071083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/23/2022] [Accepted: 06/27/2022] [Indexed: 11/16/2022] Open
Abstract
Oral squamous cell carcinoma (OSCC) is a major cause of death in developing countries because of high tobacco consumption. RAC-alpha serine-threonine kinase (AKT1) is considered as an attractive drug target because its prolonged activation and overexpression are associated with cancer progression and metastasis. In addition, several AKT1 inhibitors are being developed to control OSCC and other associated forms of cancers. We performed a screening of the IMPPAT (Indian Medicinal Plants, Phytochemistry and Therapeutics) database to discover promising AKT1 inhibitors which pass through various important filters such as ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, physicochemical properties, PAINS (pan-assay interference compounds) filters, PASS (prediction of activity spectra for substances) analysis, and specific interactions with AKT1. Molecules bearing admirable binding affinity and specificity towards AKT1 were selected for further analysis. Initially, we identified 30 natural compounds bearing appreciable affinity and specific interaction with AKT1. Finally, tuberosin and villosol were selected as potent and selective AKT1 inhibitors. To obtain deeper insights into binding mechanism and selectivity, we performed an all-atom molecular dynamics (MD) simulation and principal component analysis (PCA). We observed that both tuberosin and villosol strongly bind to AKT1, and their complexes were stable throughout the simulation trajectories. Our in-depth structure analysis suggested that tuberosin and villosol could be further exploited in the therapeutic targeting of OSCC and other cancers after further clinical validations.
Collapse
Affiliation(s)
- Mohd Adnan
- Department of Biology, College of Science, University of Hail, Hail P.O. Box 2440, Saudi Arabia;
| | - Deeba Shamim Jairajpuri
- Department of Medical Biochemistry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 26671, Bahrain;
| | - Muskan Chaddha
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (M.C.); (T.M.)
| | - Mohd Shahnawaz Khan
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Dharmendra Kumar Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, Yeonsu-gu, Incheon 21924, Korea
- Correspondence: (D.K.Y.); (M.I.H.)
| | - Taj Mohammad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (M.C.); (T.M.)
| | - Abdelbaset Mohamed Elasbali
- Department of Clinical Laboratory Science, College of Applied Sciences-Qurayyat, Jouf University, Sakaka 72388, Saudi Arabia;
| | - Waleed Abu Al-Soud
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia;
- Health Sciences Research Unit, Jouf University, Sakaka 72388, Saudi Arabia
| | - Salem Hussain Alharethi
- Department of Biological Science, College of Arts and Science, Najran University, Najran 66252, Saudi Arabia;
| | - Md. Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; (M.C.); (T.M.)
- Correspondence: (D.K.Y.); (M.I.H.)
| |
Collapse
|
9
|
Ansari P, Flatt PR, Harriott P, Abdel-Wahab YHA. Insulin secretory and antidiabetic actions of Heritiera fomes bark together with isolation of active phytomolecules. PLoS One 2022; 17:e0264632. [PMID: 35239729 PMCID: PMC8893667 DOI: 10.1371/journal.pone.0264632] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 02/14/2022] [Indexed: 12/18/2022] Open
Abstract
In folklore, Heritiera fomes (H. fomes) has been extensively used in treatment of various ailments such as diabetes, cardiac and hepatic disorders. The present study aimed to elucidate the antidiabetic actions of hot water extract of H. fomes (HWHF), including effects on insulin release from BRIN BD11 cells and isolated mouse islets as well as glucose homeostasis in high-fat-fed rats. Molecular mechanisms underlying anti-diabetic activity along with isolation of active compounds were also evaluated. Non-toxic concentrations of HWHF stimulated concentration-dependent insulin release from isolated mouse islets and clonal pancreatic β-cells. The stimulatory effect was potentiated by glucose and isobutyl methylxanthine (IBMX), persisted in presence of tolbutamide or a depolarizing concentration of KCl but was attenuated by established inhibitors of insulin release such as diazoxide, verapamil, and Ca2+ chelation. HWHF caused depolarization of the β-cell membrane and increased intracellular Ca2+. The extract also enhanced glucose uptake and insulin action in 3T3-L1 differentiated adipocytes cells and significantly inhibited in a dose-dependent manner starch digestion, protein glycation, DPP-IV enzyme activity, and glucose diffusion in vitro. Oral administration of HWHF (250 mg/5ml/kg b.w.) to high-fat fed rats significantly improved glucose tolerance and plasma insulin responses and it inhibited plasma DPP-IV activity. HWHF also decreased in vivo glucose absorption and intestinal disaccharidase activity while increasing gastrointestinal motility and unabsorbed sucrose transit. Compounds were isolated from HWHF with similar molecular weights to quercitrin (C21 H20 O11) ranging from 447.9 to 449.9 Da which stimulated the insulin release in vitro and improved both glucose tolerance and plasma insulin responses in mice. In conclusion, H. fomes and its water-soluble phytochemicals such as quercitrin may exert antidiabetic actions mediated through a variety of mechanisms which might be useful as dietary adjunct in the management of type 2 diabetes.
Collapse
Affiliation(s)
- Prawej Ansari
- School of Biomedical Sciences, Ulster University, Coleraine, Co. Londonderry, Northern Ireland, United Kingdom
- Department of Pharmacy, School of Pharmacy and Public Health, Independent University, Dhaka, Bangladesh
| | - Peter R. Flatt
- School of Biomedical Sciences, Ulster University, Coleraine, Co. Londonderry, Northern Ireland, United Kingdom
| | - Patrick Harriott
- School of Biomedical Sciences, Ulster University, Coleraine, Co. Londonderry, Northern Ireland, United Kingdom
| | - Yasser H. A. Abdel-Wahab
- School of Biomedical Sciences, Ulster University, Coleraine, Co. Londonderry, Northern Ireland, United Kingdom
| |
Collapse
|
10
|
Ansari P, Azam S, Seidel V, Abdel-Wahab YHA. In vitro and in vivo antihyperglycemic activity of the ethanol extract of Heritiera fomes bark and characterization of pharmacologically active phytomolecules. J Pharm Pharmacol 2022; 74:rgac010. [PMID: 35230449 DOI: 10.1093/jpp/rgac010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/06/2022] [Indexed: 02/21/2024]
Abstract
OBJECTIVE This study aimed to demonstrate the mechanistic basis of Heritiera fomes, which has traditionally been used to treat diabetes. METHODS Clonal pancreatic β-cells and primary islets were used to measure insulin release. 3T3-L1 cells were used to analyse insulin action, and in vitro systems were used to measure further glucose-lowering activity. In vivo assessment was performed on streptozotocin (STZ)-induced type-2 diabetic rats and reversed-phase-HPLC followed by liquid chromatography mass spectrometry (LC-MS) to detect bioactive molecules. KEY FINDINGS Ethanol extract of Heritiera fomes (EEHF) significantly increased insulin release with stimulatory effects comparable to 1 µM glucagon-like peptide 1, which were somewhat reduced by diazoxide, verapamil and calcium-free conditions. Insulin release was stimulated by tolbutamide, isobutyl methylxanthine and KCl. EEHF induced membrane depolarization and increased intracellular Ca2+ levels. EEHF enhanced glucose uptake in 3T3L1 cells and decreased protein glycation. EEHF significantly inhibited postprandial hyperglycaemia following sucrose loading and inversely elevated unabsorbed sucrose concentration in the gut. It suppressed glucose absorption during in situ gut perfusion. Furthermore, EEHF improved glucose tolerance, plasma insulin and gut motility, and decreased plasma dipeptidyl peptidase IV activity. Procyanidins, epicatechin and proanthocyanidins were some of the identified bioactive constituents that may involve in β-cell actions. CONCLUSIONS This study provides some evidence to support the use of H. fomes as an antidiabetic traditional remedy.
Collapse
Affiliation(s)
- Prawej Ansari
- Department of Pharmacy, Independent University, Dhaka, Bangladesh
- School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Shofiul Azam
- Department of Biotechnology, Graduate School, Konkuk University, Chungju, Korea
| | - Veronique Seidel
- Natural Products Research Laboratory, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | | |
Collapse
|
11
|
Choi KJ, Lee JH, Park SB, Na YJ, Jung WH, Lee H, Kim KY. Development of in vitro three-dimensional drug screening system for obesity-related metabolic syndrome. J Pharmacol Sci 2022; 148:377-386. [DOI: 10.1016/j.jphs.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 10/19/2022] Open
|
12
|
Metformin and Insulin Resistance: A Review of the Underlying Mechanisms behind Changes in GLUT4-Mediated Glucose Transport. Int J Mol Sci 2022; 23:ijms23031264. [PMID: 35163187 PMCID: PMC8836112 DOI: 10.3390/ijms23031264] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
Metformin is the most commonly used treatment to increase insulin sensitivity in insulin-resistant (IR) conditions such as diabetes, prediabetes, polycystic ovary syndrome, and obesity. There is a well-documented correlation between glucose transporter 4 (GLUT4) expression and the level of IR. Therefore, the observed increase in peripheral glucose utilization after metformin treatment most likely comes from the induction of GLUT4 expression and its increased translocation to the plasma membrane. However, the mechanisms behind this effect and the critical metformin targets are still largely undefined. The present review explores the evidence for the crucial role of changes in the expression and activation of insulin signaling pathway mediators, AMPK, several GLUT4 translocation mediators, and the effect of posttranscriptional modifications based on previously published preclinical and clinical models of metformin’s mode of action in animal and human studies. Our aim is to provide a comprehensive review of the studies in this field in order to shed some light on the complex interactions between metformin action, GLUT4 expression, GLUT4 translocation, and the observed increase in peripheral insulin sensitivity.
Collapse
|
13
|
Dominant Role of PI3K p110α over p110β in Insulin and β-Adrenergic Receptor Signalling. Int J Mol Sci 2021; 22:ijms222312813. [PMID: 34884613 PMCID: PMC8657683 DOI: 10.3390/ijms222312813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/10/2021] [Accepted: 11/23/2021] [Indexed: 11/17/2022] Open
Abstract
Attribution of specific roles to the two ubiquitously expressed PI 3-kinase (PI3K) isoforms p110α and p110β in biological functions they have been implicated, such as in insulin signalling, has been challenging. While p110α has been demonstrated to be the principal isoform activated downstream of the insulin receptor, several studies have provided evidence for a role of p110β. Here we have used isoform-selective inhibitors to estimate the relative contribution of each of these isoforms in insulin signalling in adipocytes, which are a cell type with essential roles in regulation of metabolism at the systemic level. Consistent with previous genetic and pharmacological studies, we found that p110α is the principal isoform activated downstream of the insulin receptor under physiological conditions. p110α interaction with Ras enhanced the strength of p110α activation by insulin. However, this interaction did not account for the selectivity for p110α over p110β in insulin signalling. We also demonstrate that p110α is the principal isoform activated downstream of the β-adrenergic receptor (β-AR), another important signalling pathway in metabolic regulation, through a mechanism involving activation of the cAMP effector molecule EPAC1. This study offers further insights in the role of PI3K isoforms in the regulation of energy metabolism with implications for the therapeutic application of selective inhibitors of these isoforms.
Collapse
|
14
|
Indu S, Vijayalakshmi P, Selvaraj J, Rajalakshmi M. Novel Triterpenoids from Cassia fistula Stem Bark Depreciates STZ-Induced Detrimental Changes in IRS-1/Akt-Mediated Insulin Signaling Mechanisms in Type-1 Diabetic Rats. Molecules 2021; 26:6812. [PMID: 34833905 PMCID: PMC8621110 DOI: 10.3390/molecules26226812] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/05/2021] [Accepted: 11/05/2021] [Indexed: 12/03/2022] Open
Abstract
Here, we identified the mechanisms of action of antidiabetic activity of novel compounds isolated from Cassia fistula stem bark in STZ-diabetic animals. Novel triterpenoid compounds (C1, C2 and C3) were treated to STZ-administered diabetic animals at a concentration of 20mg/kg body weight orally for 60 days to assess their effects on plasma glucose, plasma insulin/C-peptide, serum lipid markers and the enzymes of carbohydrate metabolism, glucose oxidation and insulin signaling molecules. Oral administration of novel triterpenoid compounds to STZ-diabetic animals significantly decreased (p < 0.05) the plasma glucose concentration on the 7th, 15th, 30th, 45th and 60th daysin a duration-dependent manner (p < 0.05). Plasma insulin (p < 0.0001)/C-peptide (p < 0.0006), tissue glycogen (p < 0.0034), glycogen phosphorylase (p < 0.005), glucose 6-phosphatase (p < 0.0001) and lipid markers were significantly increased (p < 0.0001) in diabetic rats, whereas glucokinase (p < 0.0047), glycogen synthase (p < 0.003), glucose oxidation (p < 0.001), GLUT4 mRNA (p < 0.0463), GLUT4 protein (p < 0.0475) and the insulin-signaling molecules IR mRNA (p < 0.0195), IR protein (p < 0.0001), IRS-1 mRNA (p < 0.0478), p-IRS-1Tyr612 (p < 0.0185), Akt mRNA (p < 0.0394), p-AktSer473 (p < 0.0162), GLUT4 mRNA (p < 0.0463) and GLUT4 (p < 0.0475) were decreased in the gastrocnemius muscle. In silico analysis of C1-C3 with IRK and PPAR-γ protein coincided with in vivo findings. C1-C3 possessed promising antidiabetic activity by regulating insulin signaling mechanisms and carbohydrate metabolic enzymes.
Collapse
MESH Headings
- Animals
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- C-Peptide/blood
- Cassia/chemistry
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/metabolism
- Glucokinase/metabolism
- Glucose-6-Phosphatase/metabolism
- Hypoglycemic Agents/chemistry
- Hypoglycemic Agents/isolation & purification
- Hypoglycemic Agents/pharmacology
- Insulin/blood
- Insulin/metabolism
- Insulin Receptor Substrate Proteins/metabolism
- Lipid Metabolism/drug effects
- Male
- Molecular Docking Simulation
- Molecular Structure
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- PPAR gamma/metabolism
- Plant Bark/chemistry
- Plants, Medicinal/chemistry
- Potassium Channels, Inwardly Rectifying/metabolism
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Signal Transduction/drug effects
- Triterpenes/chemistry
- Triterpenes/isolation & purification
- Triterpenes/pharmacology
Collapse
Affiliation(s)
- Sabapathy Indu
- DBT-BIF Centre, PG & Research Department of Biotechnology & Bioinformatics, Holy Cross College (Autonomous), Bharathidasan University, Trichy 620002, Tamil Nadu, India; (S.I.); (P.V.)
| | - Periyasamy Vijayalakshmi
- DBT-BIF Centre, PG & Research Department of Biotechnology & Bioinformatics, Holy Cross College (Autonomous), Bharathidasan University, Trichy 620002, Tamil Nadu, India; (S.I.); (P.V.)
| | - Jayaraman Selvaraj
- Department of Biochemistry, Saveetha Institute of Medical and Technical Sciences, Saveetha Dental College and Hospitals, Saveetha University, Chennai 600020, Tamil Nadu, India;
| | - Manikkam Rajalakshmi
- DBT-BIF Centre, PG & Research Department of Biotechnology & Bioinformatics, Holy Cross College (Autonomous), Bharathidasan University, Trichy 620002, Tamil Nadu, India; (S.I.); (P.V.)
| |
Collapse
|
15
|
Song X, Dong H, Zang Z, Wu W, Zhu W, Zhang H, Guan Y. Kudzu Resistant Starch: An Effective Regulator of Type 2 Diabetes Mellitus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:4448048. [PMID: 34691353 PMCID: PMC8528595 DOI: 10.1155/2021/4448048] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/30/2021] [Accepted: 09/16/2021] [Indexed: 12/23/2022]
Abstract
Kudzu is a traditional medicinal dietary supplement, and recent research has shown its significant benefits in the prevention/treatment of type 2 diabetes mellitus (T2DM). Starch is one of the main substances in Kudzu that contribute decisively to the treatment of T2DM. However, the underlying mechanism of the hypoglycemic activity is not clear. In this study, the effect of Kudzu resistant starch supplementation on the insulin resistance, gut physical barrier, and gut microbiota was investigated in T2DM mice. The result showed that Kudzu resistant starch could significantly decrease the value of fasting blood glucose and the levels of total cholesterol, total triglyceride, and high-density lipoprotein, as well as low-density lipoprotein, in the blood of T2DM mice. The insulin signaling sensitivity in liver tissue was analyzed; the result indicated that intake of different doses of Kudzu resistant starch can help restore the expression of IRS-1, p-PI3K, p-Akt, and Glut4 and thus enhance the efficiency of insulin synthesis. Furthermore, the intestinal microorganism changes before and after ingestion of Kudzu resistant starch were also analyzed; the result revealed that supplementation of KRS helps to alleviate and improve the dysbiosis of the gut microbiota caused by T2DM. These results validated that Kudzu resistant starch could improve the glucose sensitivity of T2DM mice by modulating IRS-1/PI3K/AKT/Glut4 signaling transduction. Kudzu resistant starch can be used as a promising prebiotic, and it also has beneficial effects on the gut microbiota structure of T2DM mice.
Collapse
Affiliation(s)
- Xinqi Song
- Key Laboratory of Modern Preparation of Traditional Chinese Medicines, Ministry of Education, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Huanhuan Dong
- School of Pharmacy, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Zhenzhong Zang
- Key Laboratory of Modern Preparation of Traditional Chinese Medicines, Ministry of Education, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Wenting Wu
- School of Pharmacy, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Weifeng Zhu
- Key Laboratory of Modern Preparation of Traditional Chinese Medicines, Ministry of Education, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Hua Zhang
- School of Pharmacy, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| | - Yongmei Guan
- Key Laboratory of Modern Preparation of Traditional Chinese Medicines, Ministry of Education, Jiangxi University of Chinese Medicine, 330004 Nanchang, China
| |
Collapse
|
16
|
Ahmed HMS, Mohamed SG, Ibrahim WS, Rezk AM, Mahmoud AAA, Mahmoud MF, Ibrahim IAAEH. Acute and chronic metabolic effects of carvedilol in high-fructose, high-fat diet-fed mice: implication of β-arrestin2 pathway. Can J Physiol Pharmacol 2021; 100:68-77. [PMID: 34570983 DOI: 10.1139/cjpp-2021-0299] [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: 11/22/2022]
Abstract
We aimed to investigate the acute and chronic effects of carvedilol on insulin resistance in high-fructose, high-fat diet (HFrHFD) - fed mice and the implication of the β-arrestin2 pathway. The acute effect of carvedilol (10 mg/kg, i.p.) on glucose tolerance and hepatic lipid signaling in normal and insulin resistant mice was investigated. Then, the chronic effect of carvedilol on insulin resistance and dyslipidemia in HFrHFD-fed mice was examined. Changes in β-arrestin2 and its downstream signals in liver, skeletal muscle, and adipose tissue were measured. This involved measuring phosphatidylinositol 4,5-bisphosphate (PIP2) and diacylglycerol (DAG) levels and protein kinase B (AKT) activity. Carvedilol acutely reduced fasting blood glucose levels in both normal and insulin resistant mice without significantly affecting the glucose tolerance. These acute effects were associated with increased hepatic PIP2 but decreased hepatic DAG levels. Chronic administration of carvedilol significantly ameliorated insulin resistance and dyslipidemia in HFrHFD-fed mice. These chronic effects were associated with increased β-arrestin2, PIP2, and AKT activity levels but decreased DAG levels in the classical insulin target tissues. In conclusion, carvedilol acutely maintains glucose homeostasis and chronically ameliorates insulin resistance and dyslipidemia in HFrHFD-fed mice. The insulin sensitizing effects of carvedilol are highly correlated with the upregulation of β-arrestin2 pathway.
Collapse
Affiliation(s)
- Hoda M S Ahmed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt.,Medical Supply Chain, Abo-Hammad Health Administration, Ministry of Health, Egypt
| | - Samar G Mohamed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt.,Department of Toxic and Narcotic Drugs, Forensic Medicine, Cairo Laboratory, Medicolegal Organization, Ministry of Justice, Cairo, Egypt
| | - Wael S Ibrahim
- Department of Pharmacology and Toxicology, School of Pharmacy, Badr University in Cairo (BUC), Cairo, Egypt
| | - Asmaa M Rezk
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt.,Department of Pharmacy, Benha University Hospitals, Benha, Egypt
| | - Amr A A Mahmoud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt
| | - Mona F Mahmoud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt
| | - Islam A A E-H Ibrahim
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Egypt
| |
Collapse
|
17
|
Świderska E, Strycharz J, Wróblewski A, Czarny P, Szemraj J, Drzewoski J, Śliwińska A. Chronic and Intermittent Hyperglycemia Modulates Expression of Key Molecules of PI3K/AKT Pathway in Differentiating Human Visceral Adipocytes. Int J Mol Sci 2021; 22:ijms22147712. [PMID: 34299331 PMCID: PMC8304829 DOI: 10.3390/ijms22147712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Due to its prominence in the regulation of metabolism and inflammation, adipose tissue is a major target to investigate alterations in insulin action. This hormone activates PI3K/AKT pathway which is essential for glucose homeostasis, cell differentiation, and proliferation in insulin-sensitive tissues, like adipose tissue. The aim of this work was to evaluate the impact of chronic and intermittent high glucose on the expression of biomolecules of insulin signaling pathway during the differentiation and maturation of human visceral preadipocytes. Methods: Human visceral preadipocytes (HPA-V) cells were treated with high glucose (30 mM)during the proliferation and/or differentiation and/or maturation stage. The level of mRNA (by Real-Time PCR) and protein (by Elisa tests) expression of IRS1, PI3K, PTEN, AKT2, and GLUT4 was examined after each culture stage. Furthermore, we investigated whether miR-29a-3p, miR-143-3p, miR-152-3p, miR-186-5p, miR-370-3p, and miR-374b-5p may affect the expression of biomolecules of the insulin signaling pathway. Results: Both chronic and intermittent hyperglycemia affects insulin signaling in visceral pre/adipocytes by upregulation of analyzed PI3K/AKT pathway molecules. Both mRNA and protein expression level is more dependent on stage-specific events than the length of the period of high glucose exposure. What is more, miRs expression changes seem to be involved in PI3K/AKT expression regulation in response to hyperglycemic stimulation.
Collapse
Affiliation(s)
- Ewa Świderska
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (J.S.); (A.W.); (P.C.); (J.S.)
- Correspondence: ; Tel.: +48-693-843-960
| | - Justyna Strycharz
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (J.S.); (A.W.); (P.C.); (J.S.)
| | - Adam Wróblewski
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (J.S.); (A.W.); (P.C.); (J.S.)
| | - Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (J.S.); (A.W.); (P.C.); (J.S.)
| | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (J.S.); (A.W.); (P.C.); (J.S.)
| | - Józef Drzewoski
- Central Hospital of Medical University, 92-213 Lodz, Poland;
| | - Agnieszka Śliwińska
- Department of Nucleic Acids Biochemistry, Medical University of Lodz, 92-213 Lodz, Poland;
| |
Collapse
|
18
|
Wang CC, Chen HJ, Chan DC, Chiu CY, Liu SH, Lan KC. Low-Dose Acrolein, an Endogenous and Exogenous Toxic Molecule, Inhibits Glucose Transport via an Inhibition of Akt-Regulated GLUT4 Signaling in Skeletal Muscle Cells. Int J Mol Sci 2021; 22:ijms22137228. [PMID: 34281282 PMCID: PMC8268984 DOI: 10.3390/ijms22137228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 01/28/2023] Open
Abstract
Urinary acrolein adduct levels have been reported to be increased in both habitual smokers and type-2 diabetic patients. The impairment of glucose transport in skeletal muscles is a major factor responsible for glucose uptake reduction in type-2 diabetic patients. The effect of acrolein on glucose metabolism in skeletal muscle remains unclear. Here, we investigated whether acrolein affects muscular glucose metabolism in vitro and glucose tolerance in vivo. Exposure of mice to acrolein (2.5 and 5 mg/kg/day) for 4 weeks substantially increased fasting blood glucose and impaired glucose tolerance. The glucose transporter-4 (GLUT4) protein expression was significantly decreased in soleus muscles of acrolein-treated mice. The glucose uptake was significantly decreased in differentiated C2C12 myotubes treated with a non-cytotoxic dose of acrolein (1 μM) for 24 and 72 h. Acrolein (0.5–2 μM) also significantly decreased the GLUT4 expression in myotubes. Acrolein suppressed the phosphorylation of glucose metabolic signals IRS1, Akt, mTOR, p70S6K, and GSK3α/β. Over-expression of constitutive activation of Akt reversed the inhibitory effects of acrolein on GLUT4 protein expression and glucose uptake in myotubes. These results suggest that acrolein at doses relevant to human exposure dysregulates glucose metabolism in skeletal muscle cells and impairs glucose tolerance in mice.
Collapse
Affiliation(s)
- Ching-Chia Wang
- Department of Pediatrics, College of Medicine, National Taiwan University & Hospital, Taipei 100, Taiwan;
| | - Huang-Jen Chen
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
| | - Ding-Cheng Chan
- Department of Geriatrics and Gerontology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
| | - Chen-Yuan Chiu
- Center of Consultation, Center for Drug Evaluation, Taipei 115, Taiwan;
| | - Shing-Hwa Liu
- Department of Pediatrics, College of Medicine, National Taiwan University & Hospital, Taipei 100, Taiwan;
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan
- Correspondence: (S.-H.L.); (K.-C.L.)
| | - Kuo-Cheng Lan
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
- Correspondence: (S.-H.L.); (K.-C.L.)
| |
Collapse
|
19
|
Association of nod-like receptor pyrin domain containing 3 (rs10754558) and protein kinase C zeta (rs2503706) gene polymorphisms with the risk of type 2 diabetes mellitus in Indian population. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
20
|
Ahmad K, Shaikh S, Lee EJ, Lee YH, Choi I. Consequences of Dicarbonyl Stress on Skeletal Muscle Proteins in Type 2 Diabetes. Curr Protein Pept Sci 2021; 21:878-889. [PMID: 31746292 DOI: 10.2174/1389203720666191119100759] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/27/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Skeletal muscle is the largest organ in the body and constitutes almost 40% of body mass. It is also the primary site of insulin-mediated glucose uptake, and skeletal muscle insulin resistance, that is, diminished response to insulin, is characteristic of Type 2 diabetes (T2DM). One of the foremost reasons posited to explain the etiology of T2DM involves the modification of proteins by dicarbonyl stress due to an unbalanced metabolism and accumulations of dicarbonyl metabolites. The elevated concentration of dicarbonyl metabolites (i.e., glyoxal, methylglyoxal, 3-deoxyglucosone) leads to DNA and protein modifications, causing cell/tissue dysfunctions in several metabolic diseases such as T2DM and other age-associated diseases. In this review, we recapitulated reported effects of dicarbonyl stress on skeletal muscle and associated extracellular proteins with emphasis on the impact of T2DM on skeletal muscle and provided a brief introduction to the prevention/inhibition of dicarbonyl stress.
Collapse
Affiliation(s)
- Khurshid Ahmad
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea
| | - Sibhghatulla Shaikh
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea
| | - Eun Ju Lee
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea
| | - Yong-Ho Lee
- Department of Biomedical Sciences, Daegu Catholic University, Gyeongsan, 38430, Korea
| | - Inho Choi
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea
| |
Collapse
|
21
|
Autoregulation of insulin receptor signaling through MFGE8 and the αvβ5 integrin. Proc Natl Acad Sci U S A 2021; 118:2102171118. [PMID: 33903257 DOI: 10.1073/pnas.2102171118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The role of integrins, in particular αv integrins, in regulating insulin resistance is incompletely understood. We have previously shown that the αvβ5 integrin ligand milk fat globule epidermal growth factor like 8 (MFGE8) regulates cellular uptake of fatty acids. In this work, we evaluated the impact of MFGE8 on glucose homeostasis. We show that acute blockade of the MFGE8/β5 pathway enhances while acute augmentation dampens insulin-stimulated glucose uptake. Moreover, we find that insulin itself induces cell-surface enrichment of MFGE8 in skeletal muscle, which then promotes interaction between the αvβ5 integrin and the insulin receptor leading to dampening of skeletal-muscle insulin receptor signaling. Blockade of the MFGE8/β5 pathway also enhances hepatic insulin sensitivity. Our work identifies an autoregulatory mechanism by which insulin-stimulated signaling through its cognate receptor is terminated through up-regulation of MFGE8 and its consequent interaction with the αvβ5 integrin, thereby establishing a pathway that can potentially be targeted to improve insulin sensitivity.
Collapse
|
22
|
Abstract
As the principal tissue for insulin-stimulated glucose disposal, skeletal muscle is a primary driver of whole-body glycemic control. Skeletal muscle also uniquely responds to muscle contraction or exercise with increased sensitivity to subsequent insulin stimulation. Insulin's dominating control of glucose metabolism is orchestrated by complex and highly regulated signaling cascades that elicit diverse and unique effects on skeletal muscle. We discuss the discoveries that have led to our current understanding of how insulin promotes glucose uptake in muscle. We also touch upon insulin access to muscle, and insulin signaling toward glycogen, lipid, and protein metabolism. We draw from human and rodent studies in vivo, isolated muscle preparations, and muscle cell cultures to home in on the molecular, biophysical, and structural elements mediating these responses. Finally, we offer some perspective on molecular defects that potentially underlie the failure of muscle to take up glucose efficiently during obesity and type 2 diabetes.
Collapse
|
23
|
Nakitto AMS, Muyonga JH, Byaruhanga YB, Wagner AE. Solanum anguivi Lam. Fruits: Their Potential Effects on Type 2 Diabetes Mellitus. Molecules 2021; 26:2044. [PMID: 33918509 PMCID: PMC8038283 DOI: 10.3390/molecules26072044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 12/27/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder of glucose homeostasis associated with a status of insulin resistance, impaired insulin signaling, β-cell dysfunction, impaired glucose and lipid metabolism, sub-clinical inflammation, and increased oxidative stress. Consuming fruits and vegetables rich in phytochemicals with potential antidiabetic effects may prevent T2DM and/or support a conservative T2DM treatment while being safer and more affordable for people from low-income countries. Solanum anguivi Lam. fruits (SALF) have been suggested to exhibit antidiabetic properties, potentially due to the presence of various phytochemicals, including saponins, phenolics, alkaloids, ascorbic acid, and flavonoids. For the saponin fraction, antidiabetic effects have already been reported. However, it remains unclear whether this is also true for the other phytochemicals present in SALF. This review article covers information on glucose homeostasis, T2DM pathogenesis, and also the potential antidiabetic effects of phytochemicals present in SALF, including their potential mechanisms of action.
Collapse
Affiliation(s)
- Aisha Musaazi Sebunya Nakitto
- Department of Food Technology and Nutrition, School of Food Technology Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062 Kampala, Uganda or (A.M.S.N.); (J.H.M.); (Y.B.B.)
- Institute of Nutritional Sciences, Justus-Liebig University, Wilhelmstrasse 20, 35392 Giessen, Germany
| | - John H. Muyonga
- Department of Food Technology and Nutrition, School of Food Technology Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062 Kampala, Uganda or (A.M.S.N.); (J.H.M.); (Y.B.B.)
| | - Yusuf Byenkya Byaruhanga
- Department of Food Technology and Nutrition, School of Food Technology Nutrition and Bioengineering, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062 Kampala, Uganda or (A.M.S.N.); (J.H.M.); (Y.B.B.)
| | - Anika E. Wagner
- Institute of Nutritional Sciences, Justus-Liebig University, Wilhelmstrasse 20, 35392 Giessen, Germany
| |
Collapse
|
24
|
Jung SR, Park SY, Koh JH, Kim JY. Lithium enhances exercise-induced glycogen breakdown and insulin-induced AKT activation to facilitate glucose uptake in rodent skeletal muscle. Pflugers Arch 2021; 473:673-682. [PMID: 33660027 PMCID: PMC8049887 DOI: 10.1007/s00424-021-02543-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Abstract
The purpose of this study was to investigate the effect of lithium on glucose disposal in a high-fat diet-induced type 2 diabetes mellitus (T2DM) and streptozotocin-induced type 1 diabetes mellitus (T1DM) animal model along with low-volume exercise and low-dose insulin. Lithium decreased body weight, fasting plasma glucose, and insulin levels when to treat with low-volume exercise training; however, there were no adaptive responses like an increase in GLUT4 content and translocation factor levels. We discovered that lithium enhanced glucose uptake by acute low-volume exercise-induced glycogen breakdown, which was facilitated by the dephosphorylation of serine 473-AKT (Ser473-AKT) and serine 9-GSK3β. In streptozotocin-induced T1DM mice, Li/low-dose insulin facilitates glucose uptake through increase the level of exocyst complex component 7 (Exoc7) and Ser473-AKT. Thus, lithium enhances acute exercise-induced glycogen breakdown and insulin-induced AKT activation and could serve as a candidate therapeutic target to regulate glucose level of DM patients.
Collapse
Affiliation(s)
- Su-Ryun Jung
- College of Pharmacy, Keimyung University, Daegu, Republic of Korea
| | - Sol-Yi Park
- Department of Physiology, College of Medicine, Yeungnam University, Gyeongsan, Republic of Korea
| | - Jin-Ho Koh
- Department of Physiology, College of Medicine, Yeungnam University, Gyeongsan, Republic of Korea.
| | - Jong-Yeon Kim
- Department of Physiology, College of Medicine, Yeungnam University, Gyeongsan, Republic of Korea.
| |
Collapse
|
25
|
Norris D, Yang P, Shin SY, Kearney AL, Kim HJ, Geddes T, Senior AM, Fazakerley DJ, Nguyen LK, James DE, Burchfield JG. Signaling Heterogeneity is Defined by Pathway Architecture and Intercellular Variability in Protein Expression. iScience 2021; 24:102118. [PMID: 33659881 PMCID: PMC7892930 DOI: 10.1016/j.isci.2021.102118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/07/2021] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Insulin's activation of PI3K/Akt signaling, stimulates glucose uptake by enhancing delivery of GLUT4 to the cell surface. Here we examined the origins of intercellular heterogeneity in insulin signaling. Akt activation alone accounted for ~25% of the variance in GLUT4, indicating that additional sources of variance exist. The Akt and GLUT4 responses were highly reproducible within the same cell, suggesting the variance is between cells (extrinsic) and not within cells (intrinsic). Generalized mechanistic models (supported by experimental observations) demonstrated that the correlation between the steady-state levels of two measured signaling processes decreases with increasing distance from each other and that intercellular variation in protein expression (as an example of extrinsic variance) is sufficient to account for the variance in and between Akt and GLUT4. Thus, the response of a population to insulin signaling is underpinned by considerable single-cell heterogeneity that is largely driven by variance in gene/protein expression between cells. Insulin signaling is heterogeneous between cells in the same population The temporal response of signaling components within a cell is highly reproducible Upstream responses (Akt) can only partially predict downstream response (GLUT4) Protein expression variance is a driver of intercellular signaling heterogeneity
Collapse
Affiliation(s)
- Dougall Norris
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Pengyi Yang
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Mathematics and Statistics, The University of Sydney, Sydney, NSW 2006, Australia.,Computational Systems Biology Group, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW 2145, Australia
| | - Sung-Young Shin
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, VIC 3800, Australia.,Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Alison L Kearney
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Hani Jieun Kim
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Mathematics and Statistics, The University of Sydney, Sydney, NSW 2006, Australia.,Computational Systems Biology Group, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW 2145, Australia
| | - Thomas Geddes
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Mathematics and Statistics, The University of Sydney, Sydney, NSW 2006, Australia.,Computational Systems Biology Group, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW 2145, Australia
| | - Alistair M Senior
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Daniel J Fazakerley
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia
| | - Lan K Nguyen
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, VIC 3800, Australia.,Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - David E James
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia.,Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia
| | - James G Burchfield
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
26
|
Vieira RFL, Muñoz VR, Junqueira RL, de Oliveira F, Gaspar RC, Nakandakari SCBR, Costa SDO, Torsoni MA, da Silva ASR, Cintra DE, de Moura LP, Ropelle ER, Zaghloul I, Mekary RA, Pauli JR. Time-restricted feeding combined with aerobic exercise training can prevent weight gain and improve metabolic disorders in mice fed a high-fat diet. J Physiol 2021; 600:797-813. [PMID: 33450053 DOI: 10.1113/jp280820] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 01/08/2021] [Indexed: 01/02/2023] Open
Abstract
KEY POINTS Time-restricted feeding (TRF, in which energy intake is restricted to 8 h/day during the dark phase) alone or combined with aerobic exercise (AE) training can prevent weight gain and metabolic disorders in Swiss mice fed a high-fat diet. The benefits of TRF combined with AE are associated with improved hepatic metabolism and decreased hepatic lipid accumulation. TRF combined with AE training increased fatty acid oxidation and decreased expression of lipogenic and gluconeogenic genes in the liver of young male Swiss mice. TRF combined with AE training attenuated the detrimental effects of high-fat diet feeding on the insulin signalling pathway in the liver. ABSTRACT Time-restricted feeding (TRF) or physical exercise have been shown to be efficient in the prevention and treatment of metabolic disorders; however, the additive effects of TRF combined with aerobic exercise (AE) training on liver metabolism have not been widely explored. In this study TRF (8 h in the active phase) and TRF combined with AE (TRF+Exe) were compared in male Swiss mice fed a high-fat diet, with evaluation of the effects on insulin sensitivity and expression of hepatic genes involved in fatty acid oxidation, lipogenesis and gluconeogenesis. As in previous reports, we show that TRF alone (eating only between zeitgeber time 16 and 0) was sufficient to reduce weight and adiposity gain, increase fatty acid oxidation and decrease lipogenesis genes in the liver. In addition, we show that mice of the TRF+Exe group showed additional adaptations such as increased oxygen consumption ( V ̇ O 2 ), carbon dioxide production ( V ̇ C O 2 ) and production of ketone bodies (β-hydroxybutyrate). Also, TRF+Exe attenuated the negative effects of high-fat diet feeding on the insulin signalling pathway (insulin receptor, insulin receptor substrate, Akt), and led to increased fatty acid oxidation (Ppara, Cpt1a) and decreased gluconeogenic (Fbp1, Pck1, Pgc1a) and lipogenic (Srebp1c, Cd36) gene expression in the liver. These molecular results were accompanied by increased glucose metabolism, lower serum triglycerides and reduced hepatic lipid content in the TRF+Exe group. The data presented in this study show that TRF alone has benefits but TRF+Exe has additive benefits and can mitigate the harmful effects of consuming a high-fat diet on body adiposity, liver metabolism and glycaemic homeostasis in young male Swiss mice.
Collapse
Affiliation(s)
- Renan Fudoli Lins Vieira
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Lima Junqueira
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Fellipe de Oliveira
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | | | - Suleyma de Oliveira Costa
- Laboratory of Metabolism Disorders, Faculty of Applied Sciences, State University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Marcio Alberto Torsoni
- Laboratory of Metabolism Disorders, Faculty of Applied Sciences, State University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, São Paulo, Brazil
| | - Adelino S R da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, and Postgraduate Program in Physical Education and Sport, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Dennys Esper Cintra
- Laboratory of Nutritional Genomics (LabGeN), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, São Paulo, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, São Paulo, Brazil
| | - Iman Zaghloul
- Massachusetts College of Pharmacy and Health Sciences (MCPHS), Boston, MA, USA
| | - Rania A Mekary
- Massachusetts College of Pharmacy and Health Sciences (MCPHS), Boston, MA, USA.,Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, São Paulo, Brazil
| |
Collapse
|
27
|
Chuang WT, Yen CC, Huang CS, Chen HW, Lii CK. Benzyl Isothiocyanate Ameliorates High-Fat Diet-Induced Hyperglycemia by Enhancing Nrf2-Dependent Antioxidant Defense-Mediated IRS-1/AKT/TBC1D1 Signaling and GLUT4 Expression in Skeletal Muscle. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:15228-15238. [PMID: 33301311 DOI: 10.1021/acs.jafc.0c06269] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Obesity caused lipotoxicity, which results in insulin resistance. We studied whether benzyl isothiocyanate (BITC) improved insulin resistance in muscle. BITC was studied in vivo in mice fed a high-fat diet (HFD) and in vitro in C2C12 myotubes treated with palmitic acid (PA). In C2C12 cells, BITC mitigated PA inhibition of glucose uptake and phosphorylation of IRS-1, AKT, and TBC1D1 in response to insulin. BITC upregulated the expression of HO-1, GSTP, and GCLM mRNA and protein as well as GSH contents, which suppressed oxidative damage. Knockdown of Nrf2 abrogated BITC enhancement of antioxidant defense and subsequently reversed BITC protection against PA-induced insulin resistance. Moreover, BITC upregulated the expression of GLUT4, PPARγ, and C/EBPα. In HFD-fed mice, plasma total cholesterol, nonesterified fatty acid, and glucose levels and HOMA-IR were dose-dependently decreased with 0.05 or 0.1% BITC administration. In gastrocnemius muscle, compared with the HFD group, BITC increased the phosphorylation of AKT and TBC1D1, GSH contents, and the expression of antioxidant enzymes as well as GLUT4. These results indicate that BITC ameliorates obesity-induced hyperglycemia by enhancing insulin sensitivity in muscle. This is partly attributed to its inhibition of lipotoxicity-induced oxidative insult and upregulation of GLUT4 expression.
Collapse
Affiliation(s)
- Wei-Ting Chuang
- Department of Nutrition, China Medical University, 40402 Taichung, Taiwan
| | - Chih-Ching Yen
- Department of Respiratory Therapy, China Medical University, 40402 Taichung, Taiwan
- Department of Internal Medicine, China Medical University Hospital, 40447 Taichung, Taiwan
| | - Chin-Shiu Huang
- Department of Health and Nutrition Biotechnology, Asia University, 41354 Taichung, Taiwan
| | - Haw-Wen Chen
- Department of Nutrition, China Medical University, 40402 Taichung, Taiwan
| | - Chong-Kuei Lii
- Department of Nutrition, China Medical University, 40402 Taichung, Taiwan
- Department of Health and Nutrition Biotechnology, Asia University, 41354 Taichung, Taiwan
| |
Collapse
|
28
|
Ancu O, Mickute M, Guess ND, Hurren NM, Burd NA, Mackenzie RW. Does high dietary protein intake contribute to the increased risk of developing prediabetes and type 2 diabetes? Appl Physiol Nutr Metab 2020; 46:1-9. [PMID: 32755490 DOI: 10.1139/apnm-2020-0396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin resistance is a complex metabolic disorder implicated in the development of many chronic diseases. While it is generally accepted that body mass loss should be the primary approach for the management of insulin resistance-related disorders in overweight and obese individuals, there is no consensus among researchers regarding optimal protein intake during dietary restriction. Recently, it has been suggested that increased plasma branched-chain amino acids concentrations are associated with the development of insulin resistance and type 2 diabetes. The exact mechanism by which excessive amino acid availability may contribute to insulin resistance has not been fully investigated. However, it has been hypothesised that mammalian target of rapamycin (mTOR) complex 1 hyperactivation in the presence of amino acid overload contributes to reduced insulin-stimulated glucose uptake because of insulin receptor substrate (IRS) degradation and reduced Akt-AS160 activity. In addition, the long-term effects of high-protein diets on insulin sensitivity during both weight-stable and weight-loss conditions require more research. This review focusses on the effects of high-protein diets on insulin sensitivity and discusses the potential mechanisms by which dietary amino acids can affect insulin signalling. Novelty: Excess amino acids may over-activate mTOR, resulting in desensitisation of IRS-1 and reduced insulin-mediated glucose uptake.
Collapse
Affiliation(s)
- Oana Ancu
- Department of Life Sciences, University of Roehampton, London SW15 4DJ, UK
| | - Monika Mickute
- Diabetes Research Centre, University of Leicester and the NIHR Leicester Biomedical Research Centre, Leicester, LE17RH, UK
| | - Nicola D Guess
- Department of Nutritional Sciences, King's College London, London, WC2R2LS, UK
| | - Nicholas M Hurren
- Department of Life Sciences, University of Roehampton, London SW15 4DJ, UK
| | - Nicholas A Burd
- Division of Nutritional Sciences, University of Illinois, Urbana, IL 61820, USA
| | | |
Collapse
|
29
|
Chen CC, Lii CK, Lin YH, Shie PH, Yang YC, Huang CS, Chen HW. Andrographis paniculata Improves Insulin Resistance in High-Fat Diet-Induced Obese Mice and TNFα-Treated 3T3-L1 Adipocytes. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2020; 48:1073-1090. [DOI: 10.1142/s0192415x20500524] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Pro-inflammatory cytokines interfere with blood glucose homeostasis, which leads to hyperglycemia. Andrographis paniculata (AP) has been shown to possess anti-inflammatory activity and to reduce blood glucose levels in diabetes. The two major bioactive diterpenoids in AP, andrographolide (AND) and 14-deoxy-11,12-didehydroandrographolide (deAND), have potent anti-inflammatory activity. We studied whether APE (an ethanolic extract of AP), AND, and deAND could improve a high-fat diet (HFD)-induced hyperglycemia in vivo and TNF[Formula: see text]-induced impairment of insulin signaling in vitro. Male C57BL/6JNarl mice were fed a normal diet (ND) or the HFD, and the fatty mice were treated with APE, deAND, or AND for 16 weeks. 3T3-L1 cells were used to study the underlying mechanisms by which APE, deAND, or AND attenuated TNF[Formula: see text]-induced insulin resistance. The HFD significantly induced obesity, hyperglycemia, insulin resistance, and inflammation, whereas APE and deAND significantly ameliorated HFD-induced obesity, hyperglycemia, insulin resistance, and TNF[Formula: see text] production. The HFD significantly impaired insulin signaling by decreasing the protein expression of p-IRS1 tyr632 and p-AKT ser473, as well as the membrane translocation of GLUT4 in response to insulin stimulation in epididymal adipose tissue. HFD-impaired the membrane translocation of GLUT4 was significantly reversed by deAND and APE. In addition, deAND and APE markedly reversed the detrimental effect of TNF[Formula: see text] on the insulin signaling pathway and glucose uptake in 3T3-L1 cells. Despite no significant positive effect on p-AS160, a trend for recovery by deAND and APE was observed. These results suggest that deAND and APE protect against HFD-induced insulin resistance by ameliorating inflammation-driven impairment of insulin sensitivity.
Collapse
Affiliation(s)
- Chih-Chieh Chen
- Department of Nutrition, China Medical University, Taichung, Taiwan
| | - Chong-Kuei Lii
- Department of Nutrition, China Medical University, Taichung, Taiwan
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan
| | - Yi-Hsueh Lin
- Department of Nutrition, China Medical University, Taichung, Taiwan
| | - Pei-Hsin Shie
- Department of Nutrition, China Medical University, Taichung, Taiwan
| | - Ya-Chen Yang
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan
| | - Chin-Shiu Huang
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan
| | - Haw-Wen Chen
- Department of Nutrition, China Medical University, Taichung, Taiwan
| |
Collapse
|
30
|
Jacobs AJ, Roskam AL, Hummel FM, Ronan PJ, Gorres-Martens BK. Exercise improves high-fat diet- and ovariectomy-induced insulin resistance in rats with altered hepatic fat regulation. Curr Res Physiol 2020; 3:11-19. [PMID: 34746816 PMCID: PMC8562195 DOI: 10.1016/j.crphys.2020.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/21/2020] [Accepted: 06/09/2020] [Indexed: 12/28/2022] Open
Abstract
A high-fat diet (HFD) and loss of endogenous estrogens increases the risk for type 2 diabetes (T2D) and insulin resistance. Although exercise is known to prevent and manage insulin resistance, the cellular mechanisms remain largely unknown, especially in the context of a combined HFD and endogenous estrogen loss via ovariectomy (OVX). This study uses female Wistar rats to assess the effect of diet, endogenous estrogens, an exercise on insulin resistance, serum hormones, hepatic AMPK, hepatic regulators of fat metabolism, and expression of signaling molecules of the brain reward pathway. The combination of the HFD/OVX increased the homeostatic model assessment of insulin resistance (HOMA-IR), the glucose-insulin (G-I) index, and the serum adiponectin and leptin values, and exercise decreased these factors. The combination of the HFD/OVX decreased hepatic pAMPK, and exercise restored hepatic pAMPK, an important regulator of fat and glucose metabolism. Furthermore, consumption of the HFD by rats with intact ovaries (and endogenous estrogens) did not result in these drastic changes compared to intact rats fed a standard diet, suggesting that the presence of estrogens provides whole body benefits. Additionally, the HFD decreased the hepatic protein expression of acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS), two proteins involved in de novo lipid synthesis and increased the hepatic protein expression of lipoprotein lipase (LPL), a protein involved in fat storage. Finally, exercise increased mRNA expression of the dopamine D2 receptor and tyrosine hydroxylase in the dopaminergic neuron cell body region of the ventral tegmental area, which is a key component of the brain reward pathway. Overall, this study demonstrates that exercise prevents insulin resistance even when a HFD is combined with OVX, despite hepatic changes in ACC, FAS, and LPL.
Collapse
Affiliation(s)
| | - Adam L Roskam
- Chemistry Department, Mount Marty College, Yankton, SD, USA
| | - Faith M Hummel
- Biology Department, Black Hills State University, Spearfish, SD, USA
| | - Patrick J Ronan
- Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, USA.,Department of Psychiatry and Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, USA
| | | |
Collapse
|
31
|
Rathaur P, SR KJ. Metabolism and Pharmacokinetics of Phytochemicals in the Human Body. Curr Drug Metab 2020; 20:1085-1102. [DOI: 10.2174/1389200221666200103090757] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/27/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022]
Abstract
Background:Phytochemicals are obtained from various plants and used for the treatment of diseases as both traditional and modern medicines. Poor bioavailability of phytochemicals is a major concern in applying phytochemicals as a therapeutic agent. It is, therefore, necessary to understand the metabolism and pharmacokinetics of phytochemicals for its implication as a therapeutic agent.Methods:Articles on the metabolism of phytochemicals from the PubMed database. The articles were classified into the digestion, absorption, metabolism, excretion, toxicity, and bioavailability of phytochemicals and the effect of gut microbiota on the metabolism of phytochemicals.Results:The metabolism of each phytochemical is largely dependent on the individual's digestive ability, membrane transporters, metabolizing enzymes and gut microbiota. Further, the form of the phytochemical and genetic make-up of the individual greatly influences the metabolism of phytochemicals.Conclusion:The metabolism of phytochemicals is mostly depended on the form of phytochemicals and individualspecific variations in the metabolism of phytochemicals. Understanding the metabolism and pharmacokinetics of phytochemicals might help in applying plant-based medicines for the treatment of various diseases.
Collapse
Affiliation(s)
- Pooja Rathaur
- Department of Life Science, School of Sciences, Gujarat University, Ahmedabad, India
| | - Kaid Johar SR
- Department of Zoology, Biomedical Technology and Human Genetics, School of Sciences, Gujarat University, Ahmedabad, India
| |
Collapse
|
32
|
Zhang N, Liu X, Zhuang L, Liu X, Zhao H, Shan Y, Liu Z, Li F, Wang Y, Fang J. Berberine decreases insulin resistance in a PCOS rats by improving GLUT4: Dual regulation of the PI3K/AKT and MAPK pathways. Regul Toxicol Pharmacol 2020; 110:104544. [DOI: 10.1016/j.yrtph.2019.104544] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/26/2019] [Accepted: 11/24/2019] [Indexed: 02/09/2023]
|
33
|
Yang HW, Son M, Choi J, Oh S, Jeon YJ, Byun K, Ryu B. Effect of Ishophloroglucin A, A Component of Ishige okamurae, on Glucose Homeostasis in the Pancreas and Muscle of High Fat Diet-Fed Mice. Mar Drugs 2019; 17:E608. [PMID: 31731426 PMCID: PMC6891760 DOI: 10.3390/md17110608] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 10/16/2019] [Accepted: 10/21/2019] [Indexed: 12/24/2022] Open
Abstract
Ishophloroglucin A (IPA), a component of Ishige okamurae (IO), was previously evaluated to standardize the antidiabetic potency of IO. However, the potential of IPA as a functional food for diabetes prevention has not yet been evaluated. Here, we investigated if 1.35 mg/kg IPA, which is the equivalent content of IPA in 75 mg/kg IO, improved glucose homeostasis in high-fat diet (HFD)-induced diabetes after 12 weeks of treatment. IPA significantly ameliorated glucose intolerance, reducing fasting glucose levels as well as 2 h glucose levels in HFD mice. In addition, IPA exerted a protective effect on the pancreatic function in HFD mice via pancreatic β-cells and C-peptide. The level of glucose transporter 4 (GLUT4) in the muscles of HFD mice was stimulated by IPA intake. Our results suggested that IPA, which is a component of IO, can improve glucose homeostasis via GLUT4 in the muscles of HFD mice. IO may be used as a functional food for the prevention of diabetes.
Collapse
Affiliation(s)
- Hye-Won Yang
- Department of Marine Life Science, School of Marine Biomedical Sciences, Jeju National University, 1 Ara 1-dong, Jejudaehak-ro, Jeju 63243, Korea; (H.-W.Y.); (Y.-J.J.)
| | - Myeongjoo Son
- Department of Anatomy & Cell Biology, Gachon University College of Medicine, Incheon 21936, Korea; (M.S.); (J.C.)
- Functional Cellular Networks Laboratory, College of Medicine, Department of Medicine, Graduate School and Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea;
| | - Junwon Choi
- Department of Anatomy & Cell Biology, Gachon University College of Medicine, Incheon 21936, Korea; (M.S.); (J.C.)
- Functional Cellular Networks Laboratory, College of Medicine, Department of Medicine, Graduate School and Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea;
| | - Seyeon Oh
- Functional Cellular Networks Laboratory, College of Medicine, Department of Medicine, Graduate School and Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea;
| | - You-Jin Jeon
- Department of Marine Life Science, School of Marine Biomedical Sciences, Jeju National University, 1 Ara 1-dong, Jejudaehak-ro, Jeju 63243, Korea; (H.-W.Y.); (Y.-J.J.)
- Marine Science Institute, Jeju National University, Jeju 63333, Korea
| | - Kyunghee Byun
- Department of Anatomy & Cell Biology, Gachon University College of Medicine, Incheon 21936, Korea; (M.S.); (J.C.)
- Functional Cellular Networks Laboratory, College of Medicine, Department of Medicine, Graduate School and Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea;
| | - BoMi Ryu
- Department of Marine Life Science, School of Marine Biomedical Sciences, Jeju National University, 1 Ara 1-dong, Jejudaehak-ro, Jeju 63243, Korea; (H.-W.Y.); (Y.-J.J.)
- Marine Science Institute, Jeju National University, Jeju 63333, Korea
| |
Collapse
|
34
|
Ovariectomy and obesity have equal impact in causing mitochondrial dysfunction and impaired skeletal muscle contraction in rats. Menopause 2019; 25:1448-1458. [PMID: 29994976 DOI: 10.1097/gme.0000000000001149] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Previous studies have demonstrated that either an obese-insulin resistance condition or a condition involving loss of estrogen impaired skeletal muscle function as indicated by a decrease in muscle contraction. The differing effects of combined estrogen deficiency over obese-insulin resistance on skeletal muscle function have, however, not yet been determined. Our hypothesis was that estrogen deficiency aggravates skeletal muscle dysfunction in obese-insulin resistant rats, via increased muscle oxidative stress and mitochondrial dysfunction. METHODS Twenty-four female Wistar rats were divided into 2 groups and animals in each group were fed either a normal diet (ND) or a high-fat diet (HFD) for 24 weeks. At week 13, rats in each group were subdivided into 2 subgroups: sham-operated or ovariectomized (n = 6/subgroup). At the end of the experimental period the contraction of the gastrocnemius muscles was tested before the rats were sacrificed. Skeletal muscle was removed to assess oxidative stress and mitochondrial function. RESULTS We found that an obese-insulin resistant condition was observed in sham-operated HFD-fed rats, ovariectomized ND-fed rats, and ovariectomized HFD-fed rats. Skeletal muscle contractile function (peak-force ratio [g/g]; 25.40 ± 2.03 [ovariectomized ND-fed rats], 22.44 ± 0.85 [sham-operated HFD-fed rats] and 25.06 ± 0.61 [ovariectomized HFD-fed rats]), skeletal muscle mitochondrial function, and oxidative stress were equally significantly impaired in all 3 groups, when compared with those of sham-operated ND-fed rats (31.12 ± 1.88 g/g [NDS]; P < 0.05). Surprisingly, loss of estrogen did not aggravate these dysfunctions of skeletal muscles in HFD-fed rats. CONCLUSIONS These findings suggest that skeletal muscle dysfunction may occur due to increased muscle oxidative stress and mitochondrial dysfunction as a result of ovariectomy and obese-insulin resistance. Loss of estrogen, however, did not aggravate these impairments in the muscle of rats with obese-insulin resistant condition.
Collapse
|
35
|
Adipocytes initiate an adipose-cerebral-peripheral sympathetic reflex to induce insulin resistance during high-fat feeding. Clin Sci (Lond) 2019; 133:1883-1899. [PMID: 31477624 DOI: 10.1042/cs20190412] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/06/2019] [Accepted: 09/02/2019] [Indexed: 01/22/2023]
Abstract
The underlying mechanism by which amassing of white adipose tissue in obesity regulates sympathetic nerve system (SNS) drive to the tissues responsible for glucose disposal, and causes insulin resistance (IR), remains unknown. We tested the hypothesis that high-fat (HF) feeding increases afferent impulses from white adipose tissue that reflexively elevate efferent nerve activity to skeletal muscle (SM) and adipose tissue to impair their local glucose uptake. We also investigated how salt-intake can enhance IR. HF-fed rats received a normal salt (0.4%) or high salt (4%) diet for 3 weeks. High-salt intake in HF fed rats decreased insulin-stimulated 2-deoxyglucose uptake by over 30% in white adipose tissue and SM, exacerbated inflammation, and impaired their insulin signaling and glucose transporter 4 (Glut4) trafficking. Dietary salt in HF fed rats also increased the activity of the adipose-cerebral-muscle renin-angiotensin system (RAS) axes, SNS, and reactive oxygen species (ROS). Insulin sensitivity was reduced by 32% in HF rats during high-salt intake, but was improved by over 62% by interruption of central RAS and SNS drive, and by over 45% by denervation or deafferentation of epididymal fat (all P<0.05). Our study suggest that a HF diet engages a sympathetic reflex from the white adipose tissue that activates adipose-cerebral-muscle RAS/ROS axes and coordinates a reduction in peripheral glucose uptake. These are all enhanced by salt-loading. These findings provide new insight into the role of a reflex initiated in adipose tissue in the regulation of glucose homeostasis during HF feeding that could lead to new therapeutic approaches to IR.
Collapse
|
36
|
Gorres-Martens BK, Field TJ, Schmidt ER, Munger KA. Exercise prevents HFD- and OVX-induced type 2 diabetes risk factors by decreasing fat storage and improving fuel utilization. Physiol Rep 2019; 6:e13783. [PMID: 29981201 PMCID: PMC6035332 DOI: 10.14814/phy2.13783] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 11/24/2022] Open
Abstract
Previous studies suggest that the loss of estrogens increase one's risk for type 2 diabetes (T2D), and combining the loss of estrogens with a high-fat diet (HFD) poses an even greater risk for T2D. The extent to which exercise can ameliorate the deleterious effects of estrogen loss combined with a HFD and the molecular mechanisms accounting for the whole body changes is currently unknown. Therefore, we fed female Wistar rats a standard diet or a HFD for 10 weeks. The rats fed the HFD were either ovariectomized (OVX) or their ovaries remained intact. A subset of the HFD/OVX rats also underwent exercise training on a motor-driven treadmill. Exercise significantly reduced the total body weight gain, periuterine white adipose tissue (WAT) weight, hyperglycemia, and hyperinsulinemia. Additionally, the ability to store fat, as measured by lipoprotein lipase (LPL) in the WAT, was increased in the HFD/OVX group; however, exercise reduced the LPL levels. Furthermore, the combination of the HFD with OVX decreased the WAT citrate synthase protein level, which was increased with exercise. These data suggest that even during the combined HFD/OVX physiological state, exercise can decrease several risk factors associated with T2D, decrease fat storage, and increase fuel utilization.
Collapse
Affiliation(s)
| | - Tyler J Field
- Exercise and Sport Sciences Department, Augustana University, Sioux Falls, South Dakota
| | - Emma R Schmidt
- Exercise and Sport Sciences Department, Augustana University, Sioux Falls, South Dakota
| | - Karen A Munger
- Research & Development, Sioux Falls VA Health Care System, Sioux Falls, South Dakota
| |
Collapse
|
37
|
Jaiswal N, Gavin MG, Quinn WJ, Luongo TS, Gelfer RG, Baur JA, Titchenell PM. The role of skeletal muscle Akt in the regulation of muscle mass and glucose homeostasis. Mol Metab 2019; 28:1-13. [PMID: 31444134 PMCID: PMC6822261 DOI: 10.1016/j.molmet.2019.08.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/29/2019] [Accepted: 08/01/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Skeletal muscle insulin signaling is a major determinant of muscle growth and glucose homeostasis. Protein kinase B/Akt plays a prominent role in mediating many of the metabolic effects of insulin. Mice and humans harboring systemic loss-of-function mutations in Akt2, the most abundant Akt isoform in metabolic tissues, are glucose intolerant and insulin resistant. Since the skeletal muscle accounts for a significant amount of postprandial glucose disposal, a popular hypothesis in the diabetes field suggests that a reduction in Akt, specifically in skeletal muscle, leads to systemic glucose intolerance and insulin resistance. Despite this common belief, the specific role of skeletal muscle Akt in muscle growth and insulin sensitivity remains undefined. METHODS We generated multiple mouse models of skeletal muscle Akt deficiency to evaluate the role of muscle Akt signaling in vivo. The effects of these genetic perturbations on muscle mass, glucose homeostasis and insulin sensitivity were assessed using both in vivo and ex vivo assays. RESULTS Surprisingly, mice lacking Akt2 alone in skeletal muscle displayed normal skeletal muscle insulin signaling, glucose tolerance, and insulin sensitivity despite a dramatic reduction in phosphorylated Akt. In contrast, deletion of both Akt isoforms (M-AktDKO) prevented downstream signaling and resulted in muscle atrophy. Despite the absence of Akt signaling, in vivo and ex vivo insulin-stimulated glucose uptake were normal in M-AktDKO mice. Similar effects on insulin sensitivity were observed in mice with prolonged deletion (4 weeks) of both skeletal muscle Akt isoforms selectively in adulthood. Conversely, short term deletion (2 weeks) of skeletal muscle specific Akt in adult muscles impaired insulin tolerance paralleling the effect observed by acute pharmacological inhibition of Akt in vitro. Mechanistically, chronic ablation of Akt induced mitochondrial dysfunction and activation of AMPK, which was required for insulin-stimulated glucose uptake in the absence of Akt. CONCLUSIONS Together, these data indicate that chronic reduction in Akt activity alone in skeletal muscle is not sufficient to induce insulin resistance or prevent glucose uptake in all conditions. Therefore, since insulin-stimulated glucose disposal in skeletal muscle is markedly impaired in insulin-resistant states, we hypothesize that alterations in signaling molecules in addition to skeletal muscle Akt are necessary to perturb glucose tolerance and insulin sensitivity in vivo.
Collapse
Affiliation(s)
- N Jaiswal
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - M G Gavin
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - W J Quinn
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - T S Luongo
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - R G Gelfer
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - J A Baur
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - P M Titchenell
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
38
|
Grice BA, Barton KJ, Covert JD, Kreilach AM, Tackett L, Brozinick JT, Elmendorf JS. Excess membrane cholesterol is an early contributing reversible aspect of skeletal muscle insulin resistance in C57BL/6NJ mice fed a Western-style high-fat diet. Am J Physiol Endocrinol Metab 2019; 317:E362-E373. [PMID: 31237447 PMCID: PMC6732462 DOI: 10.1152/ajpendo.00396.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Skeletal muscle insulin resistance manifests shortly after high-fat feeding, yet mechanisms are not known. Here we set out to determine whether excess skeletal muscle membrane cholesterol and cytoskeletal derangement known to compromise glucose transporter (GLUT)4 regulation occurs early after high-fat feeding. We fed 6-wk-old male C57BL/6NJ mice either a low-fat (LF, 10% kcal) or a high-fat (HF, 45% kcal) diet for 1 wk. This HF feeding challenge was associated with an increase, albeit slight, in body mass, glucose intolerance, and hyperinsulinemia. Liver analyses did not reveal signs of hepatic insulin resistance; however, skeletal muscle immunoblots of triad-enriched regions containing transverse tubule membrane showed a marked loss of stimulated GLUT4 recruitment. An increase in cholesterol was also found in these fractions from HF-fed mice. These derangements were associated with a marked loss of cortical filamentous actin (F-actin) that is essential for GLUT4 regulation and known to be compromised by increases in membrane cholesterol. Both the withdrawal of the HF diet and two subcutaneous injections of the cholesterol-lowering agent methyl-β-cyclodextrin at 3 and 6 days during the 1-wk HF feeding intervention completely mitigated cholesterol accumulation, cortical F-actin loss, and GLUT4 dysregulation. Moreover, these beneficial membrane/cytoskeletal changes occurred concomitant with a full restoration of metabolic responses. These results identify skeletal muscle membrane cholesterol accumulation as an early, reversible, feature of insulin resistance and suggest cortical F-actin loss as an early derangement of skeletal muscle insulin resistance.
Collapse
Affiliation(s)
- Brian A Grice
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kelly J Barton
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jacob D Covert
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Alec M Kreilach
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Lixuan Tackett
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Joseph T Brozinick
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Eli Lilly and Company, Indianapolis, Indiana
| | - Jeffrey S Elmendorf
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| |
Collapse
|
39
|
Gu Z, Mu H, Shen H, Deng K, Liu D, Yang M, Zhang Y, Zhang W, Mai K. High level of dietary soybean oil affects the glucose and lipid metabolism in large yellow croaker Larimichthys crocea through the insulin-mediated PI3K/AKT signaling pathway. Comp Biochem Physiol B Biochem Mol Biol 2019; 231:34-41. [PMID: 30772486 DOI: 10.1016/j.cbpb.2018.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 12/06/2018] [Indexed: 12/17/2022]
Abstract
The present study was conducted to investigate the metabolic responses of glucose and lipid in large yellow croaker Larimichthys crocea (initial weight, 36.80 ± 0.39 g) to high level of dietary soybean oil. Three isonitrogenous (46% crude protein) and isolipidic (13% crude lipid) experimental diets were designed, with 100% fish oil (FO), 50% fish oil and 50% soybean oil (FS) and 100% soybean oil (SO), respectively. After a 12-week growth trial, the results showed that compared with FO group, contents n-6 PUFAs increased while the n-3 PUFAs decreased significantly both in liver and muscle in FS and SO groups. Concentrations of blood glucose, leptin, free fatty acid and total triglyceride reached the highest values in SO group, while blood insulin showed no significant difference among all groups. The gene expressions of insulin receptor substrate-2, glucose-6-phosphatase, phosphoenolpyruvate carboxykinase, fatty acid synthetase, and lipoprotein lipase increased, and the insulin receptor substrate-1, phosphotidylinsositol-3-kinase (PI3K), hexokinase, glycogen synthetase and glucose transporter 2 in liver decreased significantly in SO group. Meanwhile, the phosphorylation of protein kinase B (AKT) also decreased significantly in this group. These results suggested that high level of dietary soybean oil depressed PI3K/AKT signaling pathway, and then affected glucose and lipid metabolism by glycolysis, gluconeogenesis, glucose transportation, glycogenesis and lipogenesis.
Collapse
Affiliation(s)
- Zhixiang Gu
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Hua Mu
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Haohao Shen
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Kangyu Deng
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Dong Liu
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Mengxi Yang
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Yue Zhang
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Wenbing Zhang
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Wen Hai Road, Qingdao 266237, China.
| | - Kangsen Mai
- The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture), Fisheries College, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Wen Hai Road, Qingdao 266237, China
| |
Collapse
|
40
|
MicroRNAs as Regulators of Insulin Signaling: Research Updates and Potential Therapeutic Perspectives in Type 2 Diabetes. Int J Mol Sci 2018; 19:ijms19123705. [PMID: 30469501 PMCID: PMC6321520 DOI: 10.3390/ijms19123705] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/08/2018] [Accepted: 11/17/2018] [Indexed: 12/21/2022] Open
Abstract
The insulin signaling pathway is composed of a large number of molecules that positively or negatively modulate insulin specific signal transduction following its binding to the cognate receptor. Given the importance of the final effects of insulin signal transduction, it is conceivable that many regulators are needed in order to tightly control the metabolic or proliferative functional outputs. MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression through their specific binding within the 3′UTR sequence of messenger RNA (mRNA), thus causing mRNA decoy or translational inhibition. In the last decade, miRNAs have been addressed as pivotal cellular rheostats which control many fundamental signaling pathways, including insulin signal transduction. Several studies demonstrated that multiple alterations of miRNAs expression or function are relevant for the development of insulin resistance in type 2 diabetes (T2D); such alterations have been highlighted in multiple insulin target organs including liver, muscles, and adipose tissue. Indirectly, miRNAs have been identified as modulators of inflammation-derived insulin resistance, by controlling/tuning the activity of innate immune cells in insulin target tissues. Here, we review main findings on miRNA functions as modulators of insulin signaling in physiologic- or in T2D insulin resistance- status. Additionally, we report the latest hypotheses of prospective therapies involving miRNAs as potential targets for future drugs in T2D.
Collapse
|
41
|
Dehghani R, Rahmani F, Rezaei N. MicroRNA in Alzheimer's disease revisited: implications for major neuropathological mechanisms. Rev Neurosci 2018; 29:161-182. [PMID: 28941357 DOI: 10.1515/revneuro-2017-0042] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 07/09/2017] [Indexed: 12/28/2022]
Abstract
Pathology of Alzheimer's disease (AD) goes far beyond neurotoxicity resulting from extracellular deposition of amyloid β (Aβ) plaques. Aberrant cleavage of amyloid precursor protein and accumulation of Aβ in the form of the plaque or neurofibrillary tangles are the known primary culprits of AD pathogenesis and target for various regulatory mechanisms. Hyper-phosphorylation of tau, a major component of neurofibrillary tangles, precipitates its aggregation and prevents its clearance. Lipid particles, apolipoproteins and lipoprotein receptors can act in favor or against Aβ and tau accumulation by altering neural membrane characteristics or dynamics of transport across the blood-brain barrier. Lipids also alter the oxidative/anti-oxidative milieu of the central nervous system (CNS). Irregular cell cycle regulation, mitochondrial stress and apoptosis, which follow both, are also implicated in AD-related neuronal loss. Dysfunction in synaptic transmission and loss of neural plasticity contribute to AD. Neuroinflammation is a final trail for many of the pathologic mechanisms while playing an active role in initiation of AD pathology. Alterations in the expression of microRNAs (miRNAs) in AD and their relevance to AD pathology have long been a focus of interest. Herein we focused on the precise pathomechanisms of AD in which miRNAs were implicated. We performed literature search through PubMed and Scopus using the search term: ('Alzheimer Disease') OR ('Alzheimer's Disease') AND ('microRNAs' OR 'miRNA' OR 'MiR') to reach for relevant articles. We show how a limited number of common dysregulated pathways and abnormal mechanisms are affected by various types of miRNAs in AD brain.
Collapse
Affiliation(s)
- Reihaneh Dehghani
- Molecular Immunology Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran 1419783151, Iran
| | - Farzaneh Rahmani
- Students Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran
| | - Nima Rezaei
- Molecular Immunology Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran 1419783151, Iran
| |
Collapse
|
42
|
Petersen MC, Shulman GI. Mechanisms of Insulin Action and Insulin Resistance. Physiol Rev 2018; 98:2133-2223. [PMID: 30067154 PMCID: PMC6170977 DOI: 10.1152/physrev.00063.2017] [Citation(s) in RCA: 1324] [Impact Index Per Article: 220.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022] Open
Abstract
The 1921 discovery of insulin was a Big Bang from which a vast and expanding universe of research into insulin action and resistance has issued. In the intervening century, some discoveries have matured, coalescing into solid and fertile ground for clinical application; others remain incompletely investigated and scientifically controversial. Here, we attempt to synthesize this work to guide further mechanistic investigation and to inform the development of novel therapies for type 2 diabetes (T2D). The rational development of such therapies necessitates detailed knowledge of one of the key pathophysiological processes involved in T2D: insulin resistance. Understanding insulin resistance, in turn, requires knowledge of normal insulin action. In this review, both the physiology of insulin action and the pathophysiology of insulin resistance are described, focusing on three key insulin target tissues: skeletal muscle, liver, and white adipose tissue. We aim to develop an integrated physiological perspective, placing the intricate signaling effectors that carry out the cell-autonomous response to insulin in the context of the tissue-specific functions that generate the coordinated organismal response. First, in section II, the effectors and effects of direct, cell-autonomous insulin action in muscle, liver, and white adipose tissue are reviewed, beginning at the insulin receptor and working downstream. Section III considers the critical and underappreciated role of tissue crosstalk in whole body insulin action, especially the essential interaction between adipose lipolysis and hepatic gluconeogenesis. The pathophysiology of insulin resistance is then described in section IV. Special attention is given to which signaling pathways and functions become insulin resistant in the setting of chronic overnutrition, and an alternative explanation for the phenomenon of ‟selective hepatic insulin resistanceˮ is presented. Sections V, VI, and VII critically examine the evidence for and against several putative mediators of insulin resistance. Section V reviews work linking the bioactive lipids diacylglycerol, ceramide, and acylcarnitine to insulin resistance; section VI considers the impact of nutrient stresses in the endoplasmic reticulum and mitochondria on insulin resistance; and section VII discusses non-cell autonomous factors proposed to induce insulin resistance, including inflammatory mediators, branched-chain amino acids, adipokines, and hepatokines. Finally, in section VIII, we propose an integrated model of insulin resistance that links these mediators to final common pathways of metabolite-driven gluconeogenesis and ectopic lipid accumulation.
Collapse
Affiliation(s)
- Max C Petersen
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
| |
Collapse
|
43
|
Wang Y, Wen L, Zhou S, Zhang Y, Wang XH, He YY, Davie A, Broadbent S. Effects of four weeks intermittent hypoxia intervention on glucose homeostasis, insulin sensitivity, GLUT4 translocation, insulin receptor phosphorylation, and Akt activity in skeletal muscle of obese mice with type 2 diabetes. PLoS One 2018; 13:e0203551. [PMID: 30199540 PMCID: PMC6130870 DOI: 10.1371/journal.pone.0203551] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/22/2018] [Indexed: 01/03/2023] Open
Abstract
AIMS The aims of this study were to determine the effects of four weeks of intermittent exposure to a moderate hypoxia environment (15% oxygen), and compare with the effects of exercise in normoxia or hypoxia, on glucose homeostasis, insulin sensitivity, GLUT4 translocation, insulin receptor phosphorylation, Akt-dependent GSK3 phosphorylation and Akt activity in skeletal muscle of obese mice with type 2 diabetes. METHODS C57BL/6J mice that developed type 2 diabetes with a high-fat-diet (55% fat) (fasting blood glucose, FBG = 13.9 ± 0.69 (SD) mmol/L) were randomly allocated into diabetic control (DC), rest in hypoxia (DH), exercise in normoxia (DE), and exercise in hypoxia (DHE) groups (n = 7, each), together with a normal-diet (4% fat) control group (NC, FBG = 9.1 ± 1.11 (SD) mmol/L). The exercise groups ran on a treadmill at intensities of 75-90% VO2max. The interventions were applied one hour per day, six days per week for four weeks. Venous blood samples were analysed for FBG, insulin (FBI) and insulin sensitivity (QUICKI) pre and post the intervention period. The quadriceps muscle samples were collected 72 hours post the last intervention session for analysis of GLUT4 translocation, insulin receptor phosphorylation, Akt expression and phosphorylated GSK3 fusion protein by western blot. Akt activity was determined by the ratio of the phosphorylated GSK3 fusion protein to the total Akt protein. RESULTS The FBG of the DH, DE and DHE groups returned to normal level (FBG = 9.4 ± 1.50, 8.86 ± 0.94 and 9.0 ± 1.13 (SD) mmol/L for DH, DE and DHE respectively, P < 0.05), with improved insulin sensitivity compared to DC (P < 0.05), after the four weeks treatment, while the NC and DC showed no significant changes, as analysed by general linear model with repeated measures. All three interventions resulted in a significant increase of GLUT4 translocation to cell membrane compared to the DC group (P < 0.05). The DE and DH showed a similar level of insulin receptor phosphorylation compared with NC that was significantly lower than the DC (P < 0.05) post intervention. The DH and DHE groups showed a significantly higher Akt activity compared to the DE, DC and NC (P < 0.05) post intervention, as analysed by one-way ANOVA. CONCLUSIONS This study produced new evidence that intermittent exposure to mild hypoxia (0.15 FiO2) for four weeks resulted in normalisation of FBG, improvement in whole body insulin sensitivity, and a significant increase of GLUT4 translocation in the skeletal muscle, that were similar to the effects of exercise intervention during the same time period, in mice with diet-induced type 2 diabetes. However, exercise in hypoxia for four weeks did not have additive effects on these responses. The outcomes of the research may contribute to the development of effective, alternative and complementary interventions for management of hyperglycaemia and type 2 diabetes, particularly for individuals with limitations in participation of physical activity.
Collapse
Affiliation(s)
- Yun Wang
- School of Health and Human Sciences, Southern Cross University, Lismore, Australia
| | - Li Wen
- Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sport, Tianjin, China
| | - Shi Zhou
- School of Health and Human Sciences, Southern Cross University, Lismore, Australia
| | - Yong Zhang
- Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sport, Tianjin, China
| | - Xin-Hao Wang
- Department of Health and Exercise Science, Tianjin University of Sport, Tianjin, China
| | - You-Yu He
- Department of Health and Exercise Science, Tianjin University of Sport, Tianjin, China
| | - Allan Davie
- School of Health and Human Sciences, Southern Cross University, Lismore, Australia
| | - Suzanne Broadbent
- School of Health and Human Sciences, Southern Cross University, Lismore, Australia
| |
Collapse
|
44
|
Rasool S, Geetha T, Broderick TL, Babu JR. High Fat With High Sucrose Diet Leads to Obesity and Induces Myodegeneration. Front Physiol 2018; 9:1054. [PMID: 30258366 PMCID: PMC6143817 DOI: 10.3389/fphys.2018.01054] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 07/16/2018] [Indexed: 12/21/2022] Open
Abstract
Skeletal muscle utilizes both free fatty acids (FFAs) and glucose that circulate in the blood stream. When blood glucose levels acutely increase, insulin stimulates muscle glucose uptake, oxidation, and glycogen synthesis. Under these conditions, skeletal muscle preferentially oxidizes glucose while the oxidation of fatty acids (FAs) oxidation is reciprocally decreased. In metabolic disorders associated with insulin resistance, such as diabetes and obesity, both glucose uptake, and utilization muscle are significantly reduced causing FA oxidation to provide the majority of ATP for metabolic processes and contraction. Although the causes of this metabolic inflexibility or disrupted "glucose-fatty acid cycle" are largely unknown, a diet high in fat and sugar (HFS) may be a contributing factor. This metabolic inflexibility observed in models of obesity or with HFS feeding is detrimental because high rates of FA oxidation in skeletal muscle can lead to the buildup of toxic metabolites of fat metabolism and the accumulation of pro-inflammatory cytokines, which further exacerbate the insulin resistance. Further, HFS leads to skeletal muscle atrophy with a decrease in myofibrillar proteins and phenotypically characterized by loss of muscle mass and strength. Overactivation of ubiquitin proteasome pathway, oxidative stress, myonuclear apoptosis, and mitochondrial dysfunction are some of the mechanisms involved in muscle atrophy induced by obesity or in mice fed with HFS. In this review, we will discuss how HFS diet negatively impacts the various physiological and metabolic mechanisms in skeletal muscle.
Collapse
Affiliation(s)
- Suhail Rasool
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
| | - Thangiah Geetha
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
| | - Tom L Broderick
- Laboratory of Diabetes and Exercise Metabolism, Department of Physiology, Midwestern University, Glendale, AZ, United States
| | - Jeganathan R Babu
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
| |
Collapse
|
45
|
Muñoz VR, Gaspar RC, Crisol BM, Formigari GP, Sant'Ana MR, Botezelli JD, Gaspar RS, da Silva ASR, Cintra DE, de Moura LP, Ropelle ER, Pauli JR. Physical exercise reduces pyruvate carboxylase (PCB) and contributes to hyperglycemia reduction in obese mice. J Physiol Sci 2018; 68:493-501. [PMID: 28710665 PMCID: PMC10717866 DOI: 10.1007/s12576-017-0559-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/25/2017] [Indexed: 01/07/2023]
Abstract
The present study evaluated the effects of exercise training on pyruvate carboxylase protein (PCB) levels in hepatic tissue and glucose homeostasis control in obese mice. Swiss mice were distributed into three groups: control mice (CTL), fed a standard rodent chow; diet-induced obesity (DIO), fed an obesity-inducing diet; and a third group, which also received an obesity-inducing diet, but was subjected to an exercise training protocol (DIO + EXE). Protocol training was carried out for 1 h/d, 5 d/wk, for 8 weeks, performed at an intensity of 60% of exhaustion velocity. An insulin tolerance test (ITT) was performed in the last experimental week. Twenty-four hours after the last physical exercise session, the animals were euthanized and the liver was harvested for molecular analysis. Firstly, DIO mice showed increased epididymal fat and serum glucose and these results were accompanied by increased PCB and decreased p-Akt in hepatic tissue. On the other hand, physical exercise was able to increase the performance of the mice and attenuate PCB levels and hyperglycemia in DIO + EXE mice. The above findings show that physical exercise seems to be able to regulate hyperglycemia in obese mice, suggesting the participation of PCB, which was enhanced in the obese condition and attenuated after a treadmill running protocol. This is the first study to be aimed at the role of exercise training in hepatic PCB levels, which may be a novel mechanism that can collaborate to reduce the development of hyperglycemia and type 2 diabetes in DIO mice.
Collapse
Affiliation(s)
- Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Barbara Moreira Crisol
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | | | - Marcella Ramos Sant'Ana
- Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - José Diego Botezelli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rodrigo Stellzer Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Adelino S R da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Dennys Esper Cintra
- Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- OCRC-Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- OCRC-Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- CEPECE-Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- OCRC-Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- CEPECE-Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.
- OCRC-Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
- CEPECE-Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.
| |
Collapse
|
46
|
Raun SH, Ali M, Kjøbsted R, Møller LLV, Federspiel MA, Richter EA, Jensen TE, Sylow L. Rac1 muscle knockout exacerbates the detrimental effect of high-fat diet on insulin-stimulated muscle glucose uptake independently of Akt. J Physiol 2018; 596:2283-2299. [PMID: 29749029 DOI: 10.1113/jp275602] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/19/2018] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS The actin cytoskeleton regulating GTPase, Rac1, is a novel player in insulin-stimulated glucose uptake in muscle in vivo. High-fat diet (HFD) exacerbates muscle insulin resistance in Rac1 muscle knockout (mKO) mice. Muscle Rac1 KO protects against HFD-induced insulin resistance in fat tissue indicating tissue cross-talk. A fatty diet markedly reduces insulin clearance in mice. ABSTRACT Insulin resistance and perturbations in glucose metabolism underpin common lifestyle diseases such as type 2 diabetes and obesity. Insulin resistance in muscle is characterized by compromised activity of the GTPase, Ras-related C3 Botulinum toxin substrate 1 (Rac1), yet the role of Rac1 in insulin-stimulated glucose uptake in vivo and diet-induced insulin resistance is unknown. Inducible muscle-specific Rac1 knockout (Rac1 mKO) and wild type (WT) littermate mice were either fed a chow or a 60% high-fat diet (HFD). Insulin-stimulated 2-deoxy-glucose uptake, intracellular signalling, protein expression, substrate utilization, and glucose and insulin tolerance were assessed. In chow-fed mice, in vivo insulin-stimulated glucose uptake was reduced in triceps, soleus and gastrocnemius muscles from Rac1 mKO mice. HFD-induced whole body insulin resistance was exacerbated by the lack of muscle Rac1 and glucose uptake was reduced in all muscles, except for soleus. Muscle Akt (also known as protein kinase B) signalling was unaffected by diet or genotype. In adipose tissue, Rac1 mKO mice were protected from HFD-induced insulin resistance (with respect to both glucose uptake and phosphorylated-Akt), rendering their whole body glucose tolerance comparable to WT mice on HFD. Our findings show that lack of Rac1 exacerbates HFD-induced insulin resistance in skeletal muscle. Whole body glucose tolerance, however, was largely unaffected in Rac1 mKO mice, likely due to improved insulin-stimulated glucose uptake in adipose tissue. We conclude that lack of Rac1 in the context of obesity is detrimental to insulin-stimulated muscle glucose uptake in muscle independently of Akt signalling.
Collapse
Affiliation(s)
- Steffen H Raun
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Mona Ali
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Rasmus Kjøbsted
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Lisbeth L V Møller
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Morten A Federspiel
- Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Thomas E Jensen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| | - Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen, 2100, Denmark
| |
Collapse
|
47
|
Liu CW, Tsai HC, Huang CC, Tsai CY, Su YB, Lin MW, Lee KC, Hsieh YC, Li TH, Huang SF, Yang YY, Hou MC, Lin HC, Lee FY, Lee SD. Effects and mechanisms of caffeine to improve immunological and metabolic abnormalities in diet-induced obese rats. Am J Physiol Endocrinol Metab 2018; 314:E433-E447. [PMID: 29118012 DOI: 10.1152/ajpendo.00094.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In obesity, there are no effective therapies for parallel immune and metabolic abnormalities, including systemic/tissue insulin-resistance/inflammation, adiposity and hepatic steatosis. Caffeine has anti-inflammation, antihepatic steatosis, and anti-insulin resistance effects. In this study, we evaluated the effects and molecular mechanisms of 6 wk of caffeine treatment (HFD-caf) on immunological and metabolic abnormalities of high-fat diet (HFD)-induced obese rats. Compared with HFD vehicle (HFD-V) rats, in HFD-caf rats the suppressed circulating immune cell inflammatory [TNFα, MCP-1, IL-6, intercellular adhesion molecule 1 (ICAM-1), and nitrite] profiles were accompanied by decreased liver, white adipose tissue (WAT), and muscle macrophages and their intracellular cytokine levels. Metabolically, the increase in metabolic rates reduced lipid accumulation in various tissues, resulting in reduced adiposity, lower fat mass, decreased body weight, amelioration of hepatic steatosis, and improved systemic/muscle insulin resistance. Further mechanistic approaches revealed an upregulation of tissue lipogenic [(SREBP1c, fatty acid synthase, acetyl-CoA carboxylase)/insulin-sensitizing (GLUT4 and p-IRS1)] markers in HFD-caf rats. Significantly, ex vivo experiments revealed that the cytokine release by the cocultured peripheral blood mononuclear cell (monocyte) and WAT (adipocyte), which are known to stimulate macrophage migration and hepatocyte lipogenesis, were lower in HFD-V groups than HFD-caf groups. Caffeine treatment simultaneously ameliorates immune and metabolic pathogenic signals present in tissue to normalize immunolgical and metabolic abnormalities found in HFD-induced obese rats.
Collapse
Affiliation(s)
- Chih-Wei Liu
- Division of Allergy, Immunology and Rheumatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Hung-Cheng Tsai
- Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Chia-Chang Huang
- Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Chang-Youh Tsai
- Division of Allergy, Immunology and Rheumatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Yen-Bo Su
- Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Ming-Wei Lin
- Division of Preventive Medicine, Institute of Public Health, National Yang-Ming University, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Kuei-Chuan Lee
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Yun-Cheng Hsieh
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Tzu-Hao Li
- Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
- Chia-Yi Branch of Taichung Veterans General Hospital, Chiayi, Taiwan
| | - Shiang-Fen Huang
- Division of Infection, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Ying-Ying Yang
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Ming-Chih Hou
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Han-Chieh Lin
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Fa-Yauh Lee
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
| | - Shou-Dong Lee
- Department of Medicine, National Yang-Ming University School, Taipei, Taiwan
- Cheng Hsin General Hospital, Taipei, Taiwan
| |
Collapse
|
48
|
Lu H, Bogdanovic E, Yu Z, Cho C, Liu L, Ho K, Guo J, Yeung LSN, Lehmann R, Hundal HS, Giacca A, Fantus IG. Combined Hyperglycemia- and Hyperinsulinemia-Induced Insulin Resistance in Adipocytes Is Associated With Dual Signaling Defects Mediated by PKC-ζ. Endocrinology 2018; 159:1658-1677. [PMID: 29370351 PMCID: PMC5939637 DOI: 10.1210/en.2017-00312] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 01/03/2018] [Indexed: 12/27/2022]
Abstract
A hyperglycemic and hyperinsulinemic environment characteristic of type 2 diabetes causes insulin resistance. In adipocytes, defects in both insulin sensitivity and maximum response of glucose transport have been demonstrated. To investigate the molecular mechanisms, freshly isolated rat adipocytes were incubated in control (5.6 mM glucose, no insulin) and high glucose (20 mM)/high insulin (100 nM) (HG/HI) for 18 hours to induce insulin resistance. Insulin-resistant adipocytes manifested decreased sensitivity of glucose uptake associated with defects in insulin receptor substrate (IRS)-1 Tyr phosphorylation, association of p85 subunit of phosphatidylinositol-3-kinase, Akt Ser473 and Thr308 phosphorylation, accompanied by impaired glucose transporter 4 translocation. In contrast, protein kinase C (PKC)-ζ activity was augmented by chronic HG/HI. Inhibition of PKC-ζ with a specific cell-permeable peptide reversed the signaling defects and insulin sensitivity of glucose uptake. Transfection of dominant-negative, kinase-inactive PKC-ζ blocked insulin resistance, whereas constitutively active PKC-ζ recapitulated the defects. The HG/HI incubation was associated with stimulation of IRS-1 Ser318 and Akt Thr34 phosphorylation, targets of PKC-ζ. Transfection of IRS-1 S318A and Akt T34A each partially corrected insulin signaling, whereas combined transfection of both completely normalized insulin signaling. In vivo hyperglycemia/hyperinsulinemia in rats for 48 hours similarly resulted in activation of PKC-ζ and increased phosphorylation of IRS-1 Ser318 and Akt Thr34. These data indicate that impairment of insulin signaling by chronic HG/HI is mediated by dual defects at IRS-1 and Akt mediated by PKC-ζ.
Collapse
Affiliation(s)
- Huogen Lu
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Elena Bogdanovic
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Zhiwen Yu
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Charles Cho
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Lijiang Liu
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Karen Ho
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - June Guo
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Lucy S N Yeung
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Reiner Lehmann
- Department of Internal Medicine IV, Endocrinology, Metabolism, Pathobiochemistry and Clinical Chemistry, University Hospital Tuebingen, Tuebingen, Germany
| | - Harinder S Hundal
- Division of Molecular Physiology Unit, Faculty of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Adria Giacca
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - I George Fantus
- Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
- Correspondence: I. George Fantus, MD, Departments of Medicine and Physiology, Mount Sinai Hospital, Joseph and Wolfe Lebovic Building, 60 Murray Street, 5th Floor, Room 5028, Toronto, Ontario M5T 3L9, Canada. E-mail:
| |
Collapse
|
49
|
Naufahu J, Elliott B, Markiv A, Dunning-Foreman P, McGrady M, Howard D, Watt P, Mackenzie RWA. High-Intensity Exercise Decreases IP6K1 Muscle Content and Improves Insulin Sensitivity (SI2*) in Glucose-Intolerant Individuals. J Clin Endocrinol Metab 2018; 103:1479-1490. [PMID: 29300979 DOI: 10.1210/jc.2017-02019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022]
Abstract
CONTEXT Insulin resistance (IR) in skeletal muscle contributes to whole body hyperglycemia and the secondary complications associated with type 2 diabetes. Inositol hexakisphosphate kinase-1 (IP6K1) may inhibit insulin-stimulated glucose transport in this tissue type. OBJECTIVE Muscle and plasma IP6K1 were correlated with two-compartment models of glucose control in insulin-resistant hyperinsulinemic individuals. Muscle IP6K1 was also compared after two different exercise trials. DESIGN Nine prediabetic [hemoglobin A1c; 6.1% (0.2%)] patients were recruited to take part in a resting control, a continuous exercise (90% of lactate threshold), and a high-intensity exercise trial (6 30-second sprints). Muscle biopsies were drawn before and after each 60-minute trial. A labeled ([6,62H2]glucose) intravenous glucose tolerance test was performed immediately after the second muscle sample. RESULTS Fasting muscle IP6K1 content did not correlate with insulin sensitivity (SI2*) (P = 0.961). High-intensity exercise reduced IP6K1 muscle protein and messenger RNA expression (P = 0.001). There was no effect on protein IP6K1 content after continuous exercise. Akt308 phosphorylation of was significantly greater after high-intensity exercise. Intermittent exercise reduced hepatic glucose production after the same trial. The same intervention also increased SI2*, and this effect was significantly greater compared with the effect of continuous exercise improvements. Our in vitro experiment demonstrated that the chemical inhibition of IP6K1 increased insulin signaling in C2C12 myotubes. CONCLUSIONS The in vivo and in vitro approaches used in the current study suggest that a decrease in muscle IP6K1 may be linked to whole body increases in SI2*. In addition, high-intensity exercise reduces hepatic glucose production in insulin-resistant individuals.
Collapse
Affiliation(s)
- Jane Naufahu
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Bradley Elliott
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Anatoliy Markiv
- Biosciences Education, King's College London, London, United Kingdom
| | - Petra Dunning-Foreman
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Maggie McGrady
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - David Howard
- Department of Oncology, Charing Cross Hospital, Imperial NHS Trust Hospitals, London, United Kingdom
| | - Peter Watt
- Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | | |
Collapse
|
50
|
Silvestri E, Cioffi F, De Matteis R, Senese R, de Lange P, Coppola M, Salzano AM, Scaloni A, Ceccarelli M, Goglia F, Lanni A, Moreno M, Lombardi A. 3,5-Diiodo-L-Thyronine Affects Structural and Metabolic Features of Skeletal Muscle Mitochondria in High-Fat-Diet Fed Rats Producing a Co-adaptation to the Glycolytic Fiber Phenotype. Front Physiol 2018; 9:194. [PMID: 29593557 PMCID: PMC5854997 DOI: 10.3389/fphys.2018.00194] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/23/2018] [Indexed: 11/22/2022] Open
Abstract
Hyperlipidemic state-associated perturbations in the network of factors controlling mitochondrial functions, i. e., morphogenesis machinery and metabolic sensor proteins, produce metabolic inflexibility, insulin resistance and reduced oxidative capacity in skeletal muscle. Moreover, intramyocellular lipid (IMCL) accumulation leads to tissue damage and inflammation. The administration of the naturally occurring metabolite 3,5-diiodo-L-thyronine (T2) with thyromimetic actions to high fat diet (HFD)-fed rats exerts a systemic hypolipidemic effect, which produces a lack of IMCL accumulation, a shift toward glycolytic fibers and amelioration of insulin sensitivity in gastrocnemius muscle. In this study, an integrated approach combining large-scale expression profile and functional analyses was used to characterize the response of skeletal muscle mitochondria to T2 during a HFD regimen. Long-term T2 administration to HDF rats induced a glycolytic phenotype of gastrocnemius muscle as well as an adaptation of mitochondria to the fiber type, with a decreased representation of enzymes involved in mitochondrial oxidative metabolism. At the same time, T2 stimulated the activity of individual respiratory complex I, IV, and V. Moreover, T2 prevented the HFD-associated increase in the expression of peroxisome proliferative activated receptor γ coactivator-1α and dynamin-1-like protein as well as mitochondrial morphological aberrations, favoring the appearance of tubular and tethered organelles in the intermyofibrillar regions. Remarkably, T2 reverted the HDF-associated expression pattern of proinflammatory factors, such as p65 subunit of NF-kB, and increased the fiber-specific immunoreactivity of adipose differentiation–related protein in lipid droplets. All together, these results further support a role of T2 in counteracting in vivo some of the HFD-induced impairment in structural/metabolic features of skeletal muscle by impacting the mitochondrial phenotype.
Collapse
Affiliation(s)
- Elena Silvestri
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Federica Cioffi
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Rita De Matteis
- Department of Biomolecular Sciences, Urbino University, Urbino, Italy
| | - Rosalba Senese
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania, Caserta, Italy
| | - Pieter de Lange
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania, Caserta, Italy
| | - Maria Coppola
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Anna M Salzano
- Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, Naples, Italy
| | - Andrea Scaloni
- Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, Naples, Italy
| | - Michele Ceccarelli
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Fernando Goglia
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Antonia Lanni
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania, Caserta, Italy
| | - Maria Moreno
- Department of Science and Technologies, University of Sannio, Benevento, Italy
| | - Assunta Lombardi
- Department of Biology, University of Naples Federico II, Naples, Italy
| |
Collapse
|