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Saberi S, Askaripour M, Khaksari M, Amin Rajizadeh M, Abbas Bejeshk M, Akhbari M, Jafari E, Khoramipour K. Exercise training improves diabetic renal injury by reducing fetuin-A, oxidative stress and inflammation in type 2 diabetic rats. Heliyon 2024; 10:e27749. [PMID: 38510054 PMCID: PMC10951597 DOI: 10.1016/j.heliyon.2024.e27749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 02/26/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Background Diabetic kidney disease (DKD) stands as a primary contributor to end-stage renal disease, associated with heightened mortality in cardiovascular diseases. This study aimed to explore the impact of an eight-week high-intensity interval training (HIIT) on renal injury in diabetic rats. Methods Twenty-eight male Wistar rats were randomly allocated into four groups: healthy control (CTL), diabetic control (DC), exercise (EX), and diabetes-exercise (D + EX). Induction of diabetes in the DC and D + EX groups occurred through a two-month high-fat diet followed by a single dose of 35 mg/kg streptozotocin (STZ). Rats in the EX and D + EX groups underwent 4-10 intervals of HIIT (80-100% Vmax) over 8 weeks. Subsequently, pathological and biochemical parameters were assessed in the serum and kidney tissue of the experimental groups. Results In the DC group, diabetes led to elevated kidney damage, glomerulosclerosis, fasting blood glucose (FBG), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index, animal weight, kidney dysfunction, albuminuria, and glomerular filtration rate. Additionally, serum and kidney levels of fetuin-A increased, along with kidney levels of KIM-1. Mechanistically, diabetes induction resulted in kidney inflammation by elevating levels of tumor necrosis factor-alpha (TNF-α), transforming growth factor beta (TGF-β), and interleukin 6 (IL-6), while reducing IL-10 levels and increasing the IL-6/IL-10 ratio. Furthermore, diabetes triggered renal oxidative stress, evidenced by increased Malondialdehyde (MDA) levels and decreased levels of glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD). HIIT mitigated the adverse effects of diabetes in the D + EX group compared to the DC group. Conclusion Our findings suggest that HIIT ameliorates type 2 diabetes (T2D)-induced kidney damage by mitigating inflammation, lowering serum levels of fetuin-A, and bolstering antioxidant defenses. This study highlights the potential of HIIT as a time-efficient intervention for diabetic nephropathy.
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Affiliation(s)
- Shadan Saberi
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Majid Askaripour
- Department of Physiology, School of Medicine, Bam University of Medical Sciences, Bam, Iran
| | - Mohammad Khaksari
- Endocrinology and Metabolism Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Amin Rajizadeh
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Abbas Bejeshk
- Cardiovascular Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Akhbari
- Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran
| | - Elham Jafari
- Department of Pathology, Pathology and Stem Cell Research Center, Afzalipour Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Kayvan Khoramipour
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
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Wang J, Zhang L, Cao H, Shi X, Zhang X, Gao Z, Ikeda K, Yan T, Jia Y, Xu F. Silibinin improves L-cell mass and function through an estrogen receptor-mediated antioxidative mechanism. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 99:154022. [PMID: 35255283 DOI: 10.1016/j.phymed.2022.154022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/05/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Silibinin, a major component of milk thistle extract silymarin, promotes hypoglycemia by activating estrogen receptor (ER) α and β-mediated pathways in pancreatic β-cells. Glucagon-like peptide-1 (GLP-1) is the enteroendocrine peptide produced in L-cells, and it controls glucose homeostasis through multiple pathways. The effect of silibinin on L-cell mass and function is still unknown. PURPOSE The protective effect of silibinin on palmitate (PA)-treated intestinal L-cell line GLUTag cells and the SHRSP•Z-Leprfa/Izm-Dmcr (SP•ZF) diabetic rat model was investigated in current study. METHODS After pre-incubation with 50 μM silibinin for 4 h, GLUTag cells were treated with 0.125 mM PA. MTT, Annexin V/PI apoptosis, Hoechst 33342 staining, western blot, DCFH-DA, GLP-1 ELISA, qRT-PCR and immunofluorescence analyses were undertaken to determine ER-dependent protection of silibinin against PA-induced cellular damage. The differential protein expression of GLUTag cells under different treatments was examined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The SP•ZF diabetic rat model was chosen for in vivo study. After 4 weeks of gastric gavage with 100 or 300 mg kg-1 of silibinin, the physiological indexes of the rats were measured. Cells expressing GLP-1, 8‑hydroxy-2'-deoxyguanosine (8-OHdG), ERα, and/or ERβ in duodenum tissues were detected by immunofluorescence. RESULTS The current study showed that the GLUTag cells preincubated with silibinin activated the transcription factor nuclear erythroid-2 like factor-2 (Nrf2)-antioxidant pathway, reduced reactive oxygen species (ROS) generation, and improved cell survival and GLP-1 content, while the antioxidative effect of silibinin was blocked by the selective ERα antagonist MPP or ERβ antagonist PHTPP in GLUTag cells. Our proteomics data further revealed that ERα or β inactivation reduced glutathione peroxide and proteins associated with endocytosis and reproduction, thus at least partially reversing the protective effect of silibinin. SP•ZF rats received silibinin treatment showed increased serum GLP-1 content and improved glucose homeostasis. Furthermore, silibinin upregulated ERα and β levels and reduced the level of 8-OHdG in GLP-1-positive cells. CONCLUSIONS Our study showed that silibinin improved L-cell mass and function through an ER-mediated antioxidant pathway, and the proteomics analysis revealed for the first time the differential regulation of proteins by PA and silibinin in GLUTag cells.
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Affiliation(s)
- Jinyu Wang
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Luxin Zhang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Hao Cao
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China; School of Medicine, Tsinghua University, Beijing 100084, P.R. China
| | - Xinyi Shi
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Xiaorong Zhang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Zihao Gao
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Katsumi Ikeda
- School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan
| | - Tingxu Yan
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China
| | - Ying Jia
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China.
| | - Fanxing Xu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China.
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Ravichandran G, Lakshmanan DK, Arunachalam A, Thilagar S. Food obesogens as emerging metabolic disruptors; A toxicological insight. J Steroid Biochem Mol Biol 2022; 217:106042. [PMID: 34890825 DOI: 10.1016/j.jsbmb.2021.106042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 09/13/2021] [Accepted: 12/05/2021] [Indexed: 11/26/2022]
Abstract
Human food is composed of loads of chemicals derived naturally as well as unintentionally through environmental sources. Food additives added purposefully, play an important role in the palatability of foods. Most additives are synthetic whose essentiality in food processing is well-known however their health risks are not overlooked. The palatability of food should not only stimulate our eating desire alone but, also assure sufficient quality and safety. Application of food additives varies from region to region due to cultural or ethnic differences and the local food availability. There are about more than ten thousand chemicals allowed in food whereas due to weak enforcement, it becomes onerous for regulatory bodies identifying chemicals that are inadequately or not tested at all for safety. The hiking population and urbanization in many industrialized and developing countries resulted in life-style changes including culinary and eating choices. Particularly, the modern way of this globalised life demands ready-to-cook or ready-made foods, snacks, sweets, soft drinks, desserts, confectionery and so on. These sorts of food would be most uninteresting unless processed with additives. This puts food industries under demand to robustly supply foods that are either partially, fully or ultra-processed using plenty of additives. Recent research warns consuming food additives may result in serious health risks, not only for children but also for adults. Growing body of studies on food additives in various experimental animals, cell cultures, and human population suggest elevation of number of obesity and diabetes risk factors i.e. adiposity, dyslipidemia, weight gain, hyperglycaemia, insulin resistance, glucose intolerance, energy imbalance, hormonal intervention etc. Hence, it is important to identify and explore food obesogens or obesogenic food additives posing potential impact. Based on the recent toxicological findings, the review aspires to establish the association between exposure of food obesogen and metabolic disruption which may help filling knowledge gaps and distributing more knowledge, awareness and effective measures to implement treatment and preventive strategies for metabolic syndrome.
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Affiliation(s)
- Guna Ravichandran
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India
| | - Dinesh Kumar Lakshmanan
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India; Department of Biotechnology, Bannari Amman Institute of Technology, Sathyamangalam, Erode, India
| | - Abirami Arunachalam
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India
| | - Sivasudha Thilagar
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India.
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Smit SE, Manirafasha C, Marais E, Johnson R, Huisamen B. Cardioprotective Function of Green Rooibos (Aspalathus linearis) Extract Supplementation in Ex Vivo Ischemic Prediabetic Rat Hearts. PLANTA MEDICA 2022; 88:62-78. [PMID: 33285593 DOI: 10.1055/a-1239-9236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Diabetic patients develop ischemic heart disease and strokes more readily. Following an ischemic event, restoration of blood flow increases oxidative stress resulting in myocardial damage, termed ischemia/reperfusion injury. Aspalathus linearis (rooibos), rich in the antioxidant phenolic compound aspalathin, has been implicated as cardioprotective against ischemia/reperfusion injury with undefined mechanism in control rats. Primarily, the therapeutic potential of Afriplex green rooibos extract to prevent ischemia/reperfusion injury in cardiovascular disease-compromised rats was investigated. Additionally, Afriplex Green rooibos extract's cardioprotective signaling on metabolic markers and stress markers was determined using western blotting. Three hundred male Wistar rats received either 16-wk standard diet or high-caloric diet. During the final 6 wk, half received 60 mg/kg/day Afriplex green rooibos extract, containing 12.48% aspalathin. High-caloric diet increased body weight, body fat, fasting serum triglycerides, and homeostatic model assessment of insulin resistance - indicative of prediabetes. High-caloric diet rats had increased heart mass, infarct size, and decreased heart function. Afriplex green rooibos extract treatment for 6 wk lowered pre-ischemic heart rate, reduced infarct size, and improved heart function pre- and post-ischemia, without significantly affecting biometric parameters. Stabilized high-caloric diet hearts had decreased insulin independence via adenosine monophosphate activated kinase and increased inflammation (p38 mitogen-activated protein kinase), whereas Afriplex green rooibos extract treatment decreased insulin dependence (protein kinase B) and conferred anti-inflammatory effect. After 20 min ischemia, high-caloric diet hearts had upregulated ataxia-telangiectasia mutated kinase decreased insulin independence, and downregulated insulin dependence and glycogen synthase kinase 3 β inhibition. In contrast, Afriplex green rooibos extract supplementation downregulated insulin independence and inhibited extracellular signal-regulated kinase 1 and 2. During reperfusion, all protective signaling was decreased in high-caloric diet, while Afriplex green rooibos extract supplementation reduced oxidative stress (c-Jun N-terminal kinases 1 and 2) and inflammation. Taken together, Afriplex green rooibos extract supplementation for 6 wk preconditioned cardiovascular disease-compromised rat hearts against ischemia/reperfusion injury by lowering inflammation, oxidative stress, and heart rate.
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Affiliation(s)
- Sybrand Engelbrecht Smit
- Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Republic of South Africa
| | - Claudine Manirafasha
- Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Republic of South Africa
| | - Erna Marais
- Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Republic of South Africa
| | - Rabia Johnson
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, Republic of South Africa
| | - Barbara Huisamen
- Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Republic of South Africa
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, Republic of South Africa
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Zhang ZH, Li J, Li J, Ma Z, Huang XJ. Veratrilla baillonii Franch Ameliorates Diabetic Liver Injury by Alleviating Insulin Resistance in Rats. Front Pharmacol 2021; 12:775563. [PMID: 34899339 PMCID: PMC8662784 DOI: 10.3389/fphar.2021.775563] [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: 09/14/2021] [Accepted: 10/27/2021] [Indexed: 11/13/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex and polygenic disorder with diverse complications. Veratrilla baillonii Franch (V. baillonii) has been applied in the intervention and treatment a diverse range of diseases, including diabetes. In this study, we revealed that water extracts of V. baillonii (WVBF) can ameliorate liver injury and insulin resistance in T2DM rat model. To elucidate the anti-diabetic mechanisms of WVBF, we performed liver transcriptome analysis that displayed WVBF treatment significantly suppressed many gene expressions involved in insulin resistance. Furthermore, functional experiments showed that WVBF treatment reduced the pathological damages of liver and pancreas, which may be regulated by Foxo1, Sirt1, G6pc, c-Met, Irs1, Akt1, Pik3r1. These results indicated that WVBF improves diabetic liver injury and insulin resistance in diabetic rats. Therefore, this study demonstrated WVBF could be used as a promising therapeutic agent for intervention and treatment of diabetes.
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Affiliation(s)
- Zhi-Hao Zhang
- College of Pharmacy, South-Central University for Nationalities, Wuhan, China
| | - Juan Li
- Key Laboratory of Environmental Health, Ministry of Education, Department of Toxicology, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Li
- College of Pharmacy, South-Central University for Nationalities, Wuhan, China
| | - Zhaowu Ma
- School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, China
| | - Xian-Ju Huang
- College of Pharmacy, South-Central University for Nationalities, Wuhan, China
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Yang J, Suo H, Song J. Protective role of mitoquinone against impaired mitochondrial homeostasis in metabolic syndrome. Crit Rev Food Sci Nutr 2020; 61:3857-3875. [PMID: 32815398 DOI: 10.1080/10408398.2020.1809344] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria control various processes in cellular metabolic homeostasis, such as adenosine triphosphate production, generation and clearance of reactive oxygen species, control of intracellular Ca2+ and apoptosis, and are thus a critical therapeutic target for metabolic syndrome (MetS). The mitochondrial targeted antioxidant mitoquinone (MitoQ) reduces mitochondrial oxidative stress, prevents impaired mitochondrial dynamics, and increases mitochondrial turnover by promoting autophagy (mitophagy) and mitochondrial biogenesis, which ultimately contribute to the attenuation of MetS conditions, including obesity, insulin resistance, hypertension and cardiovascular disease. The regulatory effect of MitoQ on mitochondrial homeostasis is mediated through AMPK and its downstream signaling pathways, including MTOR, SIRT1, Nrf2 and NF-κB. However, there are few reviews focusing on the critical role of MitoQ as a therapeutic agent in the treatment of MetS. The purpose of this review is to summarize the mitochondrial role in the pathogenesis of MetS, especially in obesity and type 2 diabetes, and discuss the effect and underlying mechanism of MitoQ on mitochondrial homeostasis in MetS.
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Affiliation(s)
- Jing Yang
- Chongqing Engineering Research Center for Processing & Storage of Distinct Agricultural Products, Chongqing Technology and Business University, Chongqing, China.,Graduate School, Chongqing Technology and Business University, Chongqing, China
| | - Huayi Suo
- College of Food Science, Southwest University, Chongqing, China
| | - Jiajia Song
- College of Food Science, Southwest University, Chongqing, China
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Packer M. Autophagy-dependent and -independent modulation of oxidative and organellar stress in the diabetic heart by glucose-lowering drugs. Cardiovasc Diabetol 2020; 19:62. [PMID: 32404204 PMCID: PMC7222526 DOI: 10.1186/s12933-020-01041-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 05/09/2020] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a lysosome-dependent intracellular degradative pathway, which mediates the cellular adaptation to nutrient and oxygen depletion as well as to oxidative and endoplasmic reticulum stress. The molecular mechanisms that stimulate autophagy include the activation of energy deprivation sensors, sirtuin-1 (SIRT1) and adenosine monophosphate-activated protein kinase (AMPK). These enzymes not only promote organellar integrity directly, but they also enhance autophagic flux, which leads to the removal of dysfunctional mitochondria and peroxisomes. Type 2 diabetes is characterized by suppression of SIRT1 and AMPK signaling as well as an impairment of autophagy; these derangements contribute to an increase in oxidative stress and the development of cardiomyopathy. Antihyperglycemic drugs that signal through insulin may further suppress autophagy and worsen heart failure. In contrast, metformin and SGLT2 inhibitors activate SIRT1 and/or AMPK and promote autophagic flux to varying degrees in cardiomyocytes, which may explain their benefits in experimental cardiomyopathy. However, metformin and SGLT2 inhibitors differ meaningfully in the molecular mechanisms that underlie their effects on the heart. Whereas metformin primarily acts as an agonist of AMPK, SGLT2 inhibitors induce a fasting-like state that is accompanied by ketogenesis, a biomarker of enhanced SIRT1 signaling. Preferential SIRT1 activation may also explain the ability of SGLT2 inhibitors to stimulate erythropoiesis and reduce uric acid (a biomarker of oxidative stress)—effects that are not seen with metformin. Changes in both hematocrit and serum urate are the most important predictors of the ability of SGLT2 inhibitors to reduce the risk of cardiovascular death and hospitalization for heart failure in large-scale trials. Metformin and SGLT2 inhibitors may also differ in their ability to mitigate diabetes-related increases in intracellular sodium concentration and its adverse effects on mitochondrial functional integrity. Differences in the actions of SGLT2 inhibitors and metformin may reflect the distinctive molecular pathways that explain differences in the cardioprotective effects of these drugs.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall Street, Dallas, TX, 75226, USA. .,Imperial College, London, UK.
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Laster J, Bonnes SL, Rocha J. Increased Use of Emulsifiers in Processed Foods and the Links to Obesity. Curr Gastroenterol Rep 2019; 21:61. [PMID: 31792622 DOI: 10.1007/s11894-019-0723-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE OF REVIEW The purpose of this review is to discuss the implications of the increased prevalence of emulsifiers in processed foods in daily consumption, the links to obesity both in mice and in vitro studies, and how those findings correlate with humans. RECENT FINDINGS There is rising interest in understanding the contributors to the obesity epidemic. One potential component recently studied has been the consumption of processed foods causing inflammatory changes leading to metabolic syndrome. This phenomenon has been shown in several mice and in vitro studies with changes in microbiome composition, elevated fasting blood glucose, hyperphagia, increased weight gain and adiposity, hepatic steatosis increased inflammatory markers, and a correlation with increased incidence of colorectal cancer. Emulsifiers are found in most foods consumed in the US population, which has increased over the years. This review focuses on understanding the initial approved safe levels of emulsifier consumption, the preceding increased use in foods with higher daily consumption than was previously tested, measuring these levels in animal models, and the positive association with obesity and metabolic syndrome. Future research will require prospectively studying emulsifier consumption more accurately along with the associated respective changes in the microbiome to determine the relationship to obesity.
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Affiliation(s)
| | - Sara L Bonnes
- Internal Medicine, Mayo Clinic Rochester, Rochester, MN, USA
| | - Jason Rocha
- University of Texas Health at San Antonio, San Antonio, TX, USA
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Ramírez-Vélez R, García-Hermoso A, Hackney AC, Izquierdo M. Effects of exercise training on Fetuin-a in obese, type 2 diabetes and cardiovascular disease in adults and elderly: a systematic review and Meta-analysis. Lipids Health Dis 2019; 18:23. [PMID: 30670052 PMCID: PMC6343360 DOI: 10.1186/s12944-019-0962-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 01/06/2019] [Indexed: 12/18/2022] Open
Abstract
Background Elevated levels of fetuin-A are associated with increased risks of metabolic syndrome, type 2 diabetes and nonalcoholic fatty liver disease. This meta-analysis investigated whether exercise interventions can reduce fetuin-A in adults. Methods We searched clinical trials that objectively assessed fetuin-A and included study arms with exercise intervention. The pre-intervention and post-intervention data were used for meta-analysis. The effect sizes were calculated as standardized mean differences or changes in fetuin-A and expressed as Hedges’ g using random-effects models. Results The overall Hedges’ g for fetuin-A in all included interventions was − 0.640 (95%CI − 1.129 to − 0.151; n = 9), but this effect was not observed in obese (g = − 0.096; 95%CI, − 0.328 to 0.135) and type 2 diabetes/dysglycemia (g = − 0.56; 95%CI, − 1.348 to 0.236) individuals. Additionally, the random-effects meta-regression analysis showed that there was not a greater decrease in fetuin-A in individuals who achieved greater body mass index reductions (regression coefficient = 0.065; 95%CI, − 0.185 to 0.315). Conclusion Supervised exercise is associated with reductions in fetuin-A levels in adults and elderly. However, the results of the present meta-analysis should be interpreted with caution because of the variety of type of exercises and individual obesity related-disorders involve. Therefore, additional high-quality randomized controlled trials describing the effect of supervised exercise interventions on fetuin-A in adults are still needed. Electronic supplementary material The online version of this article (10.1186/s12944-019-0962-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robinson Ramírez-Vélez
- Centro de Estudios para la Medición de la Actividad Física CEMA, Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 111221, Colombia.
| | - Antonio García-Hermoso
- Laboratorio de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, USACH, 7500618, Santiago, Chile
| | - Anthony C Hackney
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Mikel Izquierdo
- Department of Health Sciences, Public University of Navarre, CIBERFES (CB16/10/00315), Pamplona, Navarre, Spain
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Park SS, Lee YJ, Song S, Kim B, Kang H, Oh S, Kim E. Lactobacillus acidophilus NS1 attenuates diet-induced obesity and fatty liver. J Endocrinol 2018; 237:87-100. [PMID: 29507043 DOI: 10.1530/joe-17-0592] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 03/05/2018] [Indexed: 12/25/2022]
Abstract
Obesity is a major threat to public health, and it is strongly associated with insulin resistance and fatty liver disease. Here, we demonstrated that administration of Lactobacillus acidophilus NS1 (LNS1) significantly reduced obesity and hepatic lipid accumulation, with a concomitant improvement in insulin sensitivity, in high-fat diet (HFD)-fed mice. Furthermore, administration of LNS1 inhibited the effect of HFD feeding on the SREBP-1c and PPARα signaling pathways and reduced lipogenesis with an increase in fatty acid oxidation in ex vivo livers from HFD-fed mice. These LNS1 effects were confirmed in HepG2 cells and ex vivo livers by treatment with LNS1 culture supernatant (LNS1-CS). Interestingly, AMPK phosphorylation and activity in the liver of HFD-fed mice were increased by administration of LNS1. Consistently, chemical inhibition of AMPK with compound C, a specific inhibitor of AMPK, dramatically reduced the effect of LNS1-CS on lipid metabolism in HepG2 cells and ex vivo livers by modulating the SREBP-1c and PPARα signaling pathways. Furthermore, administration of LNS1 to HFD-fed mice significantly improved insulin resistance and increased Akt phosphorylation in the liver, white adipose tissue and skeletal muscle. Together, these data suggest that LNS1 may prevent diet-induced obesity and related metabolic disorders by improving lipid metabolism and insulin sensitivity through an AMPK→SREBP-1c/PPARα signaling pathway.
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Affiliation(s)
- Sung-Soo Park
- Department of Biological SciencesCollege of Natural Sciences, Chonnam National University, Gwangju, South Korea
| | - Yeon-Joo Lee
- Department of Biological SciencesCollege of Natural Sciences, Chonnam National University, Gwangju, South Korea
| | - Sooyeon Song
- Division of Animal ScienceCollege of Agriculture & Life Science, Chonnam National University, Gwangju, South Korea
| | - Boyong Kim
- Gwangju CenterKorea Basic Science Institute, Gwangju, South Korea
| | - Hyuno Kang
- Gwangju CenterKorea Basic Science Institute, Gwangju, South Korea
| | - Sejong Oh
- Division of Animal ScienceCollege of Agriculture & Life Science, Chonnam National University, Gwangju, South Korea
| | - Eungseok Kim
- Department of Biological SciencesCollege of Natural Sciences, Chonnam National University, Gwangju, South Korea
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Shi H, Munk A, Nielsen TS, Daughtry MR, Larsson L, Li S, Høyer KF, Geisler HW, Sulek K, Kjøbsted R, Fisher T, Andersen MM, Shen Z, Hansen UK, England EM, Cheng Z, Højlund K, Wojtaszewski JFP, Yang X, Hulver MW, Helm RF, Treebak JT, Gerrard DE. Skeletal muscle O-GlcNAc transferase is important for muscle energy homeostasis and whole-body insulin sensitivity. Mol Metab 2018. [PMID: 29525407 PMCID: PMC6001359 DOI: 10.1016/j.molmet.2018.02.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Objective Given that cellular O-GlcNAcylation levels are thought to be real-time measures of cellular nutrient status and dysregulated O-GlcNAc signaling is associated with insulin resistance, we evaluated the role of O-GlcNAc transferase (OGT), the enzyme that mediates O-GlcNAcylation, in skeletal muscle. Methods We assessed O-GlcNAcylation levels in skeletal muscle from obese, type 2 diabetic people, and we characterized muscle-specific OGT knockout (mKO) mice in metabolic cages and measured energy expenditure and substrate utilization pattern using indirect calorimetry. Whole body insulin sensitivity was assessed using the hyperinsulinemic euglycemic clamp technique and tissue-specific glucose uptake was subsequently evaluated. Tissues were used for histology, qPCR, Western blot, co-immunoprecipitation, and chromatin immunoprecipitation analyses. Results We found elevated levels of O-GlcNAc-modified proteins in obese, type 2 diabetic people compared with well-matched obese and lean controls. Muscle-specific OGT knockout mice were lean, and whole body energy expenditure and insulin sensitivity were increased in these mice, consistent with enhanced glucose uptake and elevated glycolytic enzyme activities in skeletal muscle. Moreover, enhanced glucose uptake was also observed in white adipose tissue that was browner than that of WT mice. Interestingly, mKO mice had elevated mRNA levels of Il15 in skeletal muscle and increased circulating IL-15 levels. We found that OGT in muscle mediates transcriptional repression of Il15 by O-GlcNAcylating Enhancer of Zeste Homolog 2 (EZH2). Conclusions Elevated muscle O-GlcNAc levels paralleled insulin resistance and type 2 diabetes in humans. Moreover, OGT-mediated signaling is necessary for proper skeletal muscle metabolism and whole-body energy homeostasis, and our data highlight O-GlcNAcylation as a potential target for ameliorating metabolic disorders. Type 2 diabetic humans have elevated O-GlcNAc levels in skeletal muscle. Knockout of OGT in muscle elevates whole body insulin sensitivity. Knockout of OGT in muscle increases resistance to diet-induced obesity. Muscle-specific OGT knockout mice have elevated plasma IL-15 levels. OGT in muscle controls Il15 expression by O-GlcNAcylation and inhibition of EZH2.
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Affiliation(s)
- Hao Shi
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Alexander Munk
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Thomas S Nielsen
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Morgan R Daughtry
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Louise Larsson
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Shize Li
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Kasper F Høyer
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, DK8000, Denmark
| | - Hannah W Geisler
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Karolina Sulek
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, DK2100, Denmark
| | - Taylor Fisher
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Marianne M Andersen
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Zhengxing Shen
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Ulrik K Hansen
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark
| | - Eric M England
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Zhiyong Cheng
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Kurt Højlund
- Department of Endocrinology, Odense University Hospital, Odense, Denmark; Section of Molecular Diabetes and Metabolism, Institute of Molecular Medicine and Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, DK2100, Denmark
| | - Xiaoyong Yang
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Matthew W Hulver
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; The Virginia Tech Metabolic Phenotyping Core, Blacksburg, VA 24061, USA
| | - Richard F Helm
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Jonas T Treebak
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK2200, Denmark.
| | - David E Gerrard
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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12
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Liang Y, Yuan W, Zhu W, Zhu J, Lin Q, Zou X, Deng C, Fu Y, Zheng X, Yang M, Wu S, Yu X, Shan Z. Macrophage migration inhibitory factor promotes expression of GLUT4 glucose transporter through MEF2 and Zac1 in cardiomyocytes. Metabolism 2015; 64:1682-93. [PMID: 26455966 DOI: 10.1016/j.metabol.2015.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 08/20/2015] [Accepted: 09/08/2015] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Evidence shows that both macrophage migration inhibitory factor (MIF) and GLUT4 glucose transporter are involved in diabetic cardiomyopathy (DCM), but it remains largely unknown whether and how MIF regulates GLUT4 expression in cardiomyocytes. The present study aims to investigate the mechanism underlying the modulation of GLUT4 by MIF in cardiomyocytes. MATERIAL AND METHODS Activations of AKT and AMPK signaling, and expressions of MIF, GLUT4 and the candidate GLUT4 regulation associated transcription factors in the diabetic mouse myocardium were determined. The screened transcription factors mediating MIF-promoted GLUT4 expression were verified by RNA interference (RNAi) and electrophoretic mobility shift assay (EMSA), respectively. RESULTS MIF was increased, but GLUT4 was decreased in the diabetic mouse myocardium. MIF could enhance glucose uptake and up-regulate GLUT4 expression in NMVCs. Expressions of transcription factor MEF2A, -2C, -2D and Zac1 were significantly up-regulated in MIF-treated neonatal mouse ventricular cardiomyocytes (NMVCs), and markedly reduced in the diabetic myocardium. Knockdown of MEF2A, -2C, -2D and Zac1 could significantly inhibit glucose uptake and GLUT4 expression in cardiomyocytes. Moreover, EMSA results revealed that transcriptional activities of MEF2 and Zac1 were significantly increased in MIF-treated NMVCs. AMPK signaling was activated in MIF-stimulated NMVCs, and AMPK activator AICAR could enhance MEF2A, -2C, -2D, Zac1 and GLUT4 expression. Additionally, MIF effects were inhibited by an AMPK inhibitor compound C and siRNA targeting MIF receptor CD74, suggesting the involvement of CD74-dependent AMPK activation. CONCLUSIONS Transcription factor MEF2 and Zac1 mediate MIF-induced GLUT4 expression through CD74-dependent AMPK activation in cardiomyocytes.
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Affiliation(s)
- Yeyou Liang
- Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, China.
| | - Weiwei Yuan
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Wensi Zhu
- Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, China.
| | - Jiening Zhu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Qiuxiong Lin
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xiao Zou
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Chunyu Deng
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Yongheng Fu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xilong Zheng
- The Libin Cardiovascular Institute of AB, Department of Biochemistry & Molecular Biology, Cumming School of Medicine, The University of Calgary, Calgary, Canada.
| | - Min Yang
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Shulin Wu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xiyong Yu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Zhixin Shan
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
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13
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Exercise Pills: At the Starting Line. Trends Pharmacol Sci 2015; 36:906-917. [PMID: 26439443 DOI: 10.1016/j.tips.2015.08.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/26/2015] [Accepted: 08/26/2015] [Indexed: 12/11/2022]
Abstract
Sedentary lifestyles, limited physical exercise, and prolonged inactivity undoubtedly increase chronic diseases, including obesity, type 2 diabetes, and cardiovascular diseases. It is widely acknowledged that exercise induces a number of physiological adaptations that have beneficial effects in the prevention and treatment of these chronic metabolic diseases. Unfortunately, exercise compliance is extremely low and often not possible. The development of exercise science and molecular techniques has increased our understanding of the molecular pathways responsive to exercise. Knowledge of these molecular targets has led to the development of chemical interventions that can mimic the beneficial effects of exercise without requiring actual muscle activity. This review focuses on the concept of 'exercise pills' and how they mimic the effects produced by physical exercise including oxidative fiber-type transformation, mitochondrial biogenesis, increased fat oxidation, angiogenesis, and improvement of exercise capacity. We also review candidate exercise pills, and contrast the beneficial effects and molecular mechanisms between physical exercise and exercise pills.
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Louden ED, Luzzo KM, Jimenez PT, Chi T, Chi M, Moley KH. TallyHO obese female mice experience poor reproductive outcomes and abnormal blastocyst metabolism that is reversed by metformin. Reprod Fertil Dev 2015; 27:31-9. [PMID: 25472042 DOI: 10.1071/rd14339] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Obese women experience worse reproductive outcomes than normal weight women, specifically infertility, pregnancy loss, fetal malformations and developmental delay of offspring. The aim of the present study was to use a genetic mouse model of obesity to recapitulate the human reproductive phenotype and further examine potential mechanisms and therapies. New inbred, polygenic Type 2 diabetic TallyHO mice and age-matched control C57BL/6 mice were superovulated to obtain morula or blastocyst stage embryos that were cultured in human tubal fluid (HTF) medium. Deoxyglucose uptake was determined for individual insulin-stimulated blastocysts. Apoptosis was detected by confocal microscopy using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) assay and Topro-3 nuclear dye. Embryos were scored for TUNEL-positive as a percentage of total nuclei. AMP-activated protein kinase (AMPK) activation, tumour necrosis factor (TNF)-α expression and adiponectin expression were analysed by western immunoblot and confocal immunofluorescent microscopy. Lipid accumulation was assayed by BODIPY. Comparisons were made between TallyHO morulae cultured to blastocyst embryos in either HTF medium or HTF medium with 25 μg mL(-1) metformin. TallyHO mice developed whole body abnormal insulin tolerance, had decreased litter sizes and increased non-esterified fatty acid levels. Blastocysts from TallyHO mice exhibited increased apoptosis, decreased insulin sensitivity and decreased AMPK. A possible cause for the insulin resistance and abnormal AMPK phosphorylation was the increased TNF-α expression and lipid accumulation, as detected by BODIPY, in TallyHO blastocysts and decreased adiponectin. Culturing TallyHO morulae with the AMPK activator metformin led to a reversal of all the abnormal findings, including increased AMPK phosphorylation, improved insulin-stimulated glucose uptake and normalisation of lipid accumulation. Women with obesity and insulin resistance experience poor pregnancy outcomes. Previously we have shown in mouse models of insulin resistance that AMPK activity is decreased and that activators of AMPK reverse poor embryo outcomes. Here, we show for the first time using a genetically altered obese model, not a diet-induced model, that metformin reverses many of the adverse effects of obesity at the level of the blastocyst. Expanding on this we determine that activation of AMPK via metformin reduces lipid droplet accumulation, presumably by eliminating the inhibitory effects of TNF-α, resulting in normalisation of fatty acid oxidation and HADH2 (hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase (trifunctional protein), alpha subunit) activity. Metformin exposure in vitro was able to partially reverse these effects, at the level of the blastocyst, and may thus be effective in preventing the adverse effects of obesity on pregnancy and reproductive outcomes.
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Affiliation(s)
- Erica D Louden
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
| | - Kerri M Luzzo
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
| | - Patricia T Jimenez
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
| | - Tiffany Chi
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
| | - Maggie Chi
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
| | - Kelle H Moley
- Department of Obstetrics and Gynecology, Washington University School of Medicine, 425 S. Euclid Ave, Campus Box 8064, St Louis, MO 63110, USA
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15
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Rao Y, Liu H, Gao L, Yu H, Tan JH, Ou TM, Huang SL, Gu LQ, Ye JM, Huang ZS. Discovery of natural alkaloid bouchardatine as a novel inhibitor of adipogenesis/lipogenesis in 3T3-L1 adipocytes. Bioorg Med Chem 2015; 23:4719-4727. [DOI: 10.1016/j.bmc.2015.05.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 10/23/2022]
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16
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Trepanowski JF, Mey J, Varady KA. Fetuin-A: a novel link between obesity and related complications. Int J Obes (Lond) 2014; 39:734-41. [PMID: 25468829 DOI: 10.1038/ijo.2014.203] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/04/2014] [Accepted: 11/02/2014] [Indexed: 12/13/2022]
Abstract
Fetuin-A (FetA) is a 64-kDa glycoprotein that is secreted from both the liver and adipose tissue. Circulating FetA is elevated in obesity and related disorders including type 2 diabetes mellitus, nonalcoholic fatty liver disease and the metabolic syndrome; and a FetA-related parameter, caliciprotein particle, is highly relevant to vascular calcification in overweight/obese patients with chronic kidney disease. FetA level is also associated with impaired insulin sensitivity and glucose tolerance. Accumulating evidence suggests that elevated FetA level causes impaired glycemic control, as FetA has been implicated in impairment of insulin receptor signaling, toll-like receptor 4 activation, macrophage migration and polarization, adipocyte dysfunction, hepatocyte triacylglycerol accumulation and liver inflammation and fibrosis. Weight loss, aerobic exercise, metformin and pioglitazone have each been shown to be effective for reducing FetA level.
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Affiliation(s)
- J F Trepanowski
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - J Mey
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - K A Varady
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
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Valentine RJ, Coughlan KA, Ruderman NB, Saha AK. Insulin inhibits AMPK activity and phosphorylates AMPK Ser⁴⁸⁵/⁴⁹¹ through Akt in hepatocytes, myotubes and incubated rat skeletal muscle. Arch Biochem Biophys 2014; 562:62-9. [PMID: 25172224 DOI: 10.1016/j.abb.2014.08.013] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 01/16/2023]
Abstract
Recent studies have highlighted the importance of an inhibitory phosphorylation site, Ser(485/491), on the α-subunit of AMP-activated protein kinase (AMPK); however, little is known about the regulation of this site in liver and skeletal muscle. We examined whether the inhibitory effects of insulin on AMPK activity may be mediated through the phosphorylation of this inhibitory Ser(485/491) site in hepatocytes, myotubes and incubated skeletal muscle. HepG2 and C2C12 cells were stimulated with or without insulin for 15-min. Similarly, rat extensor digitorum longus (EDL) muscles were treated +/- insulin for 10-min. Insulin significantly increased Ser(485/491) p-AMPK under all conditions, resulting in a subsequent reduction in AMPK activity, ranging from 40% to 70%, despite no change in p-AMPK Thr(172). Akt inhibition both attenuated the increase in Ser(485/491) p-AMPK caused by insulin, and prevented the decrease in AMPK activity. Similarly, the growth factor IGF-1 stimulated Ser(485/491) AMPK phosphorylation, and this too was blunted by inhibition of Akt. Inhibition of the mTOR pathway with rapamycin, however, had no effect on insulin-stimulated Ser(485/491) p-AMPK. These data suggest that insulin and IGF-1 diminish AMPK activity in hepatocytes and muscle, most likely through Akt activation and the inhibitory phosphorylation of Ser(485/491) on its α-subunit.
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Affiliation(s)
- Rudy J Valentine
- Endocrinology, Diabetes, and Nutrition Section, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Kimberly A Coughlan
- Endocrinology, Diabetes, and Nutrition Section, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Neil B Ruderman
- Endocrinology, Diabetes, and Nutrition Section, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Asish K Saha
- Endocrinology, Diabetes, and Nutrition Section, Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
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