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Qu J, Wang Y, Wang Q. Cuproptosis: potential new direction in diabetes research and treatment. Front Endocrinol (Lausanne) 2024; 15:1344729. [PMID: 38904034 PMCID: PMC11188452 DOI: 10.3389/fendo.2024.1344729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 05/22/2024] [Indexed: 06/22/2024] Open
Abstract
Cuproptosis, a recently discovered form of cell death, stems from an overabundance of copper ions infiltrating mitochondria. These ions directly engage lipoylated proteins, prompting their oligomerization and subsequent loss of iron-sulfur clusters. This sequence induces proteotoxic stress, ultimately culminating in cell death. Type 2 diabetes, a chronic metabolic disorder resulting from a complex interplay of genetic and environmental factors, has not yet been fully understood in terms of its etiology and pathogenesis. Intricately, it is linked to various modalities of cell death, including mitochondrial autophagy, apoptosis, pyroptosis, and ferroptosis. Studies have discovered impaired copper metabolism in individuals with Type 2 diabetes, hinting at a unique role for copper homeostasis in the progression of the disease. To this end, the present research aims to delineate the potential correlation between cuproptosis and Type 2 diabetes by exhaustively reviewing the existing literature. By synthesizing relevant research on cuproptosis, the paper intends to lay the groundwork for a thorough exploration of the pathogenesis of Type 2 diabetes and the development of targeted therapeutic interventions. The ultimate objective is to facilitate a deeper understanding of Type 2 diabetes and to identify novel therapeutic strategies associated with cuproptosis.
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Affiliation(s)
| | | | - Qiuyue Wang
- Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, Liaoning, China
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2
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Wang H, Liu X, Zhou Q, Liu L, Jia Z, Qi Y, Xu F, Zhang Y. Current status and emerging trends of cardiac metabolism from the past 20 years: A bibliometric study. Heliyon 2023; 9:e21952. [PMID: 38045208 PMCID: PMC10692779 DOI: 10.1016/j.heliyon.2023.e21952] [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: 04/21/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Background Abnormal cardiac metabolism is a key factor in the development of cardiovascular diseases. Consequently, there has been considerable emphasis on researching and developing drugs that regulate metabolism. This study employed bibliometric methods to comprehensively and objectively analyze the relevant literature, offering insights into the knowledge dynamics in this field. Methods The data source for this study was the Web of Science Core Collection (WoSCC), from which the collected data were imported into bibliometric software for analysis. Results The United States was the leading contributor, accounting for 38.33 % of publications. The University of Washington and Damian J. Tyler were the most active institution and author, respectively. The American Journal of Physiology-Heart and Circulatory Physiology, Journal of Molecular and Cellular Cardiology, Cardiovascular Research, Circulation Research, and American Journal of Physiology-Endocrinology and Metabolism were highly influential journals that published numerous high-quality articles on cardiac metabolism. Common keywords in this research area included heart failure, insulin resistance, skeletal muscle, mitochondria, as well as topic words such as cardiac metabolism, fatty acid oxidation, glucose metabolism, and myocardial metabolism. Co-citation analysis has shown that research on heart failure and in vitro modeling of cardiovascular disease has gained prominence in recent years and making it a research hotspot. Conclusion Research on cardiac metabolism is steadily growing, with a specific focus on heart failure and the interplay between mitochondrial dysfunction, insulin resistance, and cardiac metabolism. An emerging trend in this field involves the enhancement of maturation in human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) through the manipulation of cardiac metabolism.
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Affiliation(s)
- Hongqin Wang
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaolin Liu
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Qingbing Zhou
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Li Liu
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Zijun Jia
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Yifei Qi
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Fengqin Xu
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Ying Zhang
- Institute of Geriatric, Xiyuan Hospital, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
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Chen KY, Liu Z, Yi J, Hui YP, Song YN, Lu JH, Chen HJ, Yang SY, Hu XY, Zhang DS, Liang GY. PDHA1 Alleviates Myocardial Ischemia-Reperfusion Injury by Improving Myocardial Insulin Resistance During Cardiopulmonary Bypass Surgery in Rats. Cardiovasc Drugs Ther 2023:10.1007/s10557-023-07501-9. [PMID: 37610688 DOI: 10.1007/s10557-023-07501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/03/2023] [Indexed: 08/24/2023]
Abstract
OBJECTIVE Cardiopulmonary bypass (CPB) is a requisite technique for thoracotomy in advanced cardiovascular surgery. However, the consequent myocardial ischemia-reperfusion injury (MIRI) is the primary culprit behind cardiac dysfunction and fatal consequences post-operation. Prior research has posited that myocardial insulin resistance (IR) plays a vital role in exacerbating the progression of MIRI. Nonetheless, the exact mechanisms underlying this phenomenon remain obscure. METHODS We constructed pyruvate dehydrogenase E1 α subunit (PDHA1) interference and overexpression rats and used ascending aorta occlusion in an in vivo model of CPB-MIRI. We devised an in vivo model of CPB-MIRI by constructing rat models with both pyruvate dehydrogenase E1α subunit (PDHA1) interference and overexpression through ascending aorta occlusion. We analyzed myocardial glucose metabolism and the degree of myocardial injury using functional monitoring, biochemical assays, and histological analysis. RESULTS We discovered a clear downregulation of glucose transporter 4 (GLUT4) protein content expression in the CPB I/R model. In particular, cardiac-specific PDHA1 interference resulted in exacerbated cardiac dysfunction, significantly increased myocardial infarction area, more pronounced myocardial edema, and markedly increased cardiomyocyte apoptosis. Notably, the opposite effect was observed with PDHA1 overexpression, leading to a mitigated cardiac dysfunction and decreased incidence of myocardial infarction post-global ischemia. Mechanistically, PDHA1 plays a crucial role in regulating the protein content expression of GLUT4 on cardiomyocytes, thereby controlling the uptake and utilization of myocardial glucose, influencing the development of myocardial insulin resistance, and ultimately modulating MIRI. CONCLUSION Overall, our study sheds new light on the pivotal role of PDHA1 in glucose metabolism and the development of myocardial insulin resistance. Our findings hold promising therapeutic potential for addressing the deleterious effects of MIRI in patients.
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Affiliation(s)
- Kai-Yuan Chen
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Zhou Liu
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Jing Yi
- Department of Anesthesiology, Affiliated Hospital of Guizhou Medical University, Guiyang, 550001, Guizhou Province, China
| | - Yong-Peng Hui
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Ying-Nan Song
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Jun-Hou Lu
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Hong-Jin Chen
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China
| | - Si-Yuan Yang
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China
| | - Xuan-Yi Hu
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China
| | - Deng-Shen Zhang
- Department of Cardiovascular Surgery, the Affiliated Hospital of Zunyi Medical University, Zunyi, 563009, Guizhou Province, China
| | - Gui-You Liang
- Department of Cardiovascular Surgery, the Affiliated Hospital of Guizhou Medical University, Beijing Road, Yunyan District, Guiyang, 550001, Guizhou Province, China.
- Translational Medicine Research Center, Guizhou Medical University, Guiyang, 550025, Guizhou Province, China.
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Yoo C, Kim J, Kyun S, Hashimoto T, Tomi H, Lim K. Synergic effect of exogenous lactate and caffeine on fat oxidation and hepatic glycogen concentration in resting rats. Phys Act Nutr 2022; 26:5-13. [PMID: 36775646 PMCID: PMC9925112 DOI: 10.20463/pan.2022.0019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/08/2022] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Although several physiological roles of lactate have been revealed in the last decades, its effects on energy metabolism and substrate oxidation remain unknown. Therefore, we investigated the effects of lactate on the energy metabolism of resting rats. METHODS Male rats were divided into control (Con; distilled water), caffeine (Caf; 10 mg/kg), L-lactate (Lac; 2 g/kg), and lactate-plus-caffeine (Lac+Caf; 2 g/ kg + 10 mg) groups. Following oral administration of supplements, resting energy expenditure (study 1), biochemical blood parameters, and mRNA expression involved in energy metabolism in the soleus muscle were measured at different time points within 120 minutes of administration (study 2). Moreover, glycogen level and Pyruvate dehydrogenase (PDH) activity were measured. RESULTS Groups did not differ in total energy expenditure throughout the 6 hour post-treatment evaluation. Within the first 4 hours, the Lac and Lac+Caf groups showed higher fat oxidation rates than the Con group (p<0.05). Lactate treatment decreased blood free fatty acid levels (p<0.05) and increased the mRNA expression of fatty acid translocase (FAT/CD36) (p<0.05) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) (p<0.05) in the skeletal muscle. Hepatic glycogen level in the Lac+Caf group was significantly increased (p<0.05). Moreover, after 30 and 120 minutes, PDH activity was significantly higher in lactate-supplemented groups compared to Con group (p<0.05). CONCLUSION Our findings showed that Lac+Caf enhanced fat metabolism in the whole body and skeletal muscle while increasing hepatic glycogen concentration and PDH activity. This indicates Lac+Caf can be used as a potential post-workout supplement.
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Affiliation(s)
- Choongsung Yoo
- Department of Kinesiology and Sport management, Texas A&M University, College Station, Texas 77845, United States of America
| | - Jisu Kim
- Physical Activity & Performance Institute, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Sunghwan Kyun
- Department of Physical Education, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Takeshi Hashimoto
- Faculty of Sport & Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan
| | - Hironori Tomi
- Center for Regional Sustainability and Innovation Kochi University, B-200 Mononobe, Nankoku, Kochi 682035, Japan
| | - Kiwon Lim
- Physical Activity & Performance Institute, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea,Department of Physical Education, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea,Corresponding author : Kiwon Lim, Ph. D. Laboratory of Exercise Nutrition, Department of Physical Education, Konkuk University 120, Neungdong-ro, Gwangin-gu, Seoul 143-701, Republic of Korea. Tel: +82-2-450-3827 Fax: +82-2-452-6027 E-mail:
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Navarro CDC, Francisco A, Figueira TR, Ronchi JA, Oliveira HCF, Vercesi AE, Castilho RF. Dichloroacetate reactivates pyruvate-supported peroxide removal by liver mitochondria and prevents NAFLD aggravation in NAD(P) + transhydrogenase-null mice consuming a high-fat diet. Eur J Pharmacol 2022; 917:174750. [PMID: 35032488 DOI: 10.1016/j.ejphar.2022.174750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/14/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022]
Abstract
The mechanisms by which a high-fat diet (HFD) promotes non-alcoholic fatty liver disease (NAFLD) appear to involve liver mitochondrial dysfunction and redox imbalance. The functional loss of the enzyme NAD(P)+ transhydrogenase, a main source of mitochondrial NADPH, results in impaired mitochondrial peroxide removal, pyruvate dehydrogenase inhibition by phosphorylation, and progression of NAFLD in HFD-fed mice. The present study aimed to investigate whether pharmacological reactivation of pyruvate dehydrogenase by dichloroacetate attenuates the mitochondrial redox dysfunction and the development of NAFLD in NAD(P)+ transhydrogenase-null (Nnt-/-) mice fed an HFD (60% of total calories from fat). For this purpose, Nnt-/- mice and their congenic controls (Nnt+/+) were fed chow or an HFD for 20 weeks and received sodium dichloroacetate or NaCl in the final 12 weeks via drinking water. The results showed that HFD reduced the ability of isolated liver mitochondria from Nnt-/- mice to remove peroxide, which was prevented by the dichloroacetate treatment. HFD-fed mice of both Nnt genotypes exhibited increased body and liver mass, as well as a higher content of hepatic triglycerides, but dichloroacetate treatment attenuated these abnormalities only in Nnt-/- mice. Notably, dichloroacetate treatment decreased liver pyruvate dehydrogenase phosphorylation levels and prevented the aggravation of NAFLD in HFD-fed Nnt-/- mice. Conversely, dichloroacetate treatment elicited moderate hepatocyte ballooning in chow-fed mice, suggesting potentially toxic effects. We conclude that the protection against HFD-induced NAFLD by dichloroacetate is associated with its role in reactivating pyruvate dehydrogenase and reestablishing the pyruvate-supported liver mitochondrial capacity to handle peroxide in Nnt-/- mice.
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Affiliation(s)
- Claudia D C Navarro
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil.
| | - Annelise Francisco
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil
| | - Tiago R Figueira
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil; School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, 14040-907, Brazil
| | - Juliana A Ronchi
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil
| | - Helena C F Oliveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-862, Brazil
| | - Anibal E Vercesi
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil
| | - Roger F Castilho
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, 13083-888, Brazil.
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Mendez DA, Ortiz RM. Thyroid hormones and the potential for regulating glucose metabolism in cardiomyocytes during insulin resistance and T2DM. Physiol Rep 2021; 9:e14858. [PMID: 34405550 PMCID: PMC8371345 DOI: 10.14814/phy2.14858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/30/2022] Open
Abstract
In order for the heart to maintain its continuous mechanical work and provide the systolic movement to uphold coronary blood flow, substantial synthesis of adenosine triphosphate (ATP) is required. Under normal conditions cardiac tissue utilizes roughly 70% fatty acids (FA), and 30% glucose for the production of ATP; however, during impaired metabolic conditions like insulin resistance and diabetes glucose metabolism is dysregulated and FA account for 99% of energy production. One of the major consequences of a shift in FA metabolism in cardiac tissue is an increase in reactive oxygen species (ROS) and lipotoxicity, which ultimately lead to mitochondrial dysfunction. Thyroid hormones (TH) have direct effects on cardiac function and glucose metabolism during impaired metabolic conditions suggesting that TH may improve glucose metabolism in an insulin resistant condition. None-classical TH signaling in the heart has shown to phosphorylate protein kinase B (Akt) and increase activity of phosphoinositide-3-kinase (PI3K), which are critical mediators in the insulin-stimulated glucose uptake pathway. Studies on peripheral tissues such as skeletal muscle and adipocytes have demonstrated TH treatment improved glucose intolerance in a diabetic model and increased insulin-regulated glucose transporter (GLUT4) mRNA levels. GLUT4 is a downstream target of thyroid response element (TRE), which demonstrates that THs regulate glucose via GLUT4. Elevated 3,5,3'-triiodothyronine (T3) increased glucose oxidation rate and decreased the glycolytic intermediate, fructose 6-phosphate (F6P) in cardiomyocytes, in addition to increasing mitochondrial biogenesis and pyruvate transport across the mitochondrial membrane. These findings along with a few other studies on T3 treatment in cardiac tissue suggest TH may improve glucose metabolism in an insulin resistant model and ameliorate the effects of diabetes and metabolic syndrome. This review highlights the potential benefits of exogenous TH on ameliorating metabolic dysfunction in the heart.
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Affiliation(s)
- Dora A. Mendez
- Department of Molecular & Cell BiologySchool of Natural SciencesUniversity of CaliforniaMercedCAUSA
| | - Rudy M. Ortiz
- Department of Molecular & Cell BiologySchool of Natural SciencesUniversity of CaliforniaMercedCAUSA
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7
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Schmoll D, Ziegler N, Viollet B, Foretz M, Even PC, Azzout-Marniche D, Nygaard Madsen A, Illemann M, Mandrup K, Feigh M, Czech J, Glombik H, Olsen JA, Hennerici W, Steinmeyer K, Elvert R, Castañeda TR, Kannt A. Activation of Adenosine Monophosphate-Activated Protein Kinase Reduces the Onset of Diet-Induced Hepatocellular Carcinoma in Mice. Hepatol Commun 2020; 4:1056-1072. [PMID: 32626837 PMCID: PMC7327225 DOI: 10.1002/hep4.1508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 12/19/2022] Open
Abstract
The worldwide obesity and type 2 diabetes epidemics have led to an increase in nonalcoholic fatty liver disease (NAFLD). NAFLD covers a spectrum of hepatic pathologies ranging from simple steatosis to nonalcoholic steatohepatitis, characterized by fibrosis and hepatic inflammation. Nonalcoholic steatohepatitis predisposes to the onset of hepatocellular carcinoma (HCC). Here, we characterized the effect of a pharmacological activator of the intracellular energy sensor adenosine monophosphate–activated protein kinase (AMPK) on NAFLD progression in a mouse model. The compound stimulated fat oxidation by activating AMPK in both liver and skeletal muscle, as revealed by indirect calorimetry. This translated into an ameliorated hepatic steatosis and reduced fibrosis progression in mice fed a diet high in fat, cholesterol, and fructose for 20 weeks. Feeding mice this diet for 80 weeks caused the onset of HCC. The administration of the AMPK activator for 12 weeks significantly reduced tumor incidence and size. Conclusion: Pharmacological activation of AMPK reduces NAFLD progression to HCC in preclinical models.
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Affiliation(s)
| | | | - Benoit Viollet
- Université de Paris Institut Cochin CNRS UMR 8104 INSERM U1016 Paris France
| | - Marc Foretz
- Université de Paris Institut Cochin CNRS UMR 8104 INSERM U1016 Paris France
| | - Patrick C Even
- UMR Nutrition Physiology and Ingestive Behavior AgroParisTech INRA Université Paris-Saclay Paris France
| | - Dalila Azzout-Marniche
- UMR Nutrition Physiology and Ingestive Behavior AgroParisTech INRA Université Paris-Saclay Paris France
| | | | | | | | | | | | | | | | | | | | | | | | - Aimo Kannt
- Sanofi R&D Frankfurt Germany.,Institute of Experimental Pharmacology Medical Faculty Mannheim University of Heidelberg Mannheim Germany.,Fraunhofer IME Translational Medicine and Pharmacology Frankfurt Germany
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Karwi QG, Uddin GM, Ho KL, Lopaschuk GD. Loss of Metabolic Flexibility in the Failing Heart. Front Cardiovasc Med 2018; 5:68. [PMID: 29928647 PMCID: PMC5997788 DOI: 10.3389/fcvm.2018.00068] [Citation(s) in RCA: 246] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/18/2018] [Indexed: 12/15/2022] Open
Abstract
To maintain its high energy demand the heart is equipped with a highly complex and efficient enzymatic machinery that orchestrates ATP production using multiple energy substrates, namely fatty acids, carbohydrates (glucose and lactate), ketones and amino acids. The contribution of these individual substrates to ATP production can dramatically change, depending on such variables as substrate availability, hormonal status and energy demand. This "metabolic flexibility" is a remarkable virtue of the heart, which allows utilization of different energy substrates at different rates to maintain contractile function. In heart failure, cardiac function is reduced, which is accompanied by discernible energy metabolism perturbations and impaired metabolic flexibility. While it is generally agreed that overall mitochondrial ATP production is impaired in the failing heart, there is less consensus as to what actual switches in energy substrate preference occur. The failing heart shift toward a greater reliance on glycolysis and ketone body oxidation as a source of energy, with a decrease in the contribution of glucose oxidation to mitochondrial oxidative metabolism. The heart also becomes insulin resistant. However, there is less consensus as to what happens to fatty acid oxidation in heart failure. While it is generally believed that fatty acid oxidation decreases, a number of clinical and experimental studies suggest that fatty acid oxidation is either not changed or is increased in heart failure. Of importance, is that any metabolic shift that does occur has the potential to aggravate cardiac dysfunction and the progression of the heart failure. An increasing body of evidence shows that increasing cardiac ATP production and/or modulating cardiac energy substrate preference positively correlates with heart function and can lead to better outcomes. This includes increasing glucose and ketone oxidation and decreasing fatty acid oxidation. In this review we present the physiology of the energy metabolism pathways in the heart and the changes that occur in these pathways in heart failure. We also look at the interventions which are aimed at manipulating the myocardial metabolic pathways toward more efficient substrate utilization which will eventually improve cardiac performance.
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Affiliation(s)
| | | | | | - Gary D. Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
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An R, Tang Z, Li Y, Li T, Xu Q, Zhen J, Huang F, Yang J, Chen C, Wu Z, Li M, Sun J, Zhang X, Chen J, Wu L, Zhao S, Qingyan J, Zhu W, Yin Y, Sun Z. Activation of Pyruvate Dehydrogenase by Sodium Dichloroacetate Shifts Metabolic Consumption from Amino Acids to Glucose in IPEC-J2 Cells and Intestinal Bacteria in Pigs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:3793-3800. [PMID: 29471628 DOI: 10.1021/acs.jafc.7b05800] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The extensive metabolism of amino acids (AA) as fuel is an important reason for the low use efficiency of protein in pigs. In this study, we investigated whether regulation of the pyruvate dehydrogenase kinase (PDK)/pyruvate dehydrogenase alpha 1 (PDHA1) pathway affected AA consumption by porcine intestinal epithelial (IPEC-J2) cells and intestinal bacteria in pigs. The effects of knockdown of PDHA1 and PDK1 with small interfering RNA (siRNA) on nutrient consumption by IPEC-J2 cells were evaluated. IPEC-J2 cells were then cultured with sodium dichloroacetate (DCA) to quantify AA and glucose consumption and nutrient oxidative metabolism. The results showed that knockdown of PDHA1 using siRNA decreased glucose consumption but increased total AA (TAA) and glutamate (Glu) consumption by IPEC-J2 cells ( P < 0.05). Opposite effects were observed using siRNA targeting PDK1 ( P < 0.05). Additionally, culturing IPEC-J2 cells in the presence of 5 mM DCA markedly increased the phosphorylation of PDHA1 and PDH phosphatase 1, but inhibited PDK1 phosphorylation ( P < 0.05). DCA treatment also reduced TAA and Glu consumption and increased glucose depletion ( P < 0.05). These results indicated that PDH was the regulatory target for shifting from AA metabolism to glucose metabolism and that culturing cells with DCA decreased the consumption of AAs by increasing the depletion of glucose through PDH activation.
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Affiliation(s)
- Rui An
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Zhiru Tang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Yunxia Li
- Institute of Animal Nutrition , Sichuan Agricultural University , Chengdu 611130 , People's Republic of China
| | - Tiejun Li
- Institute of Subtropical Agriculture, The Chinese Academy of Sciences , Changsha 410125 , People's Republic of China
| | - Qingqing Xu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Jifu Zhen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Feiru Huang
- College of Animal Science and Technology , Huazhong Agricultural University , Wuhan 430070 , People's Republic of China
| | - Jing Yang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Cheng Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Zhaoliang Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Mao Li
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Jiajing Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Xiangxin Zhang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Jinchao Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Liuting Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
| | - Shengjun Zhao
- School of Animal Science and Nutritional Engineering , Wuhan Polytechnic University , Wuhan 430023 , People's Republic of China
| | - Jiang Qingyan
- College of Animal Science and Technology , Huanan Agricultural University , Guangzhou 510642 , People's Republic of China
| | - Weiyun Zhu
- College of Animal Science and Technology , Nanjing Agricultural University , Nanjing 210095 , People's Republic of China
| | - Yulong Yin
- Institute of Subtropical Agriculture, The Chinese Academy of Sciences , Changsha 410125 , People's Republic of China
| | - Zhihong Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , People's Republic of China
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Vadvalkar SS, Matsuzaki S, Eyster CA, Giorgione JR, Bockus LB, Kinter CS, Kinter M, Humphries KM. Decreased Mitochondrial Pyruvate Transport Activity in the Diabetic Heart: ROLE OF MITOCHONDRIAL PYRUVATE CARRIER 2 (MPC2) ACETYLATION. J Biol Chem 2017; 292:4423-4433. [PMID: 28154187 DOI: 10.1074/jbc.m116.753509] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 01/30/2017] [Indexed: 11/06/2022] Open
Abstract
Alterations in mitochondrial function contribute to diabetic cardiomyopathy. We have previously shown that heart mitochondrial proteins are hyperacetylated in OVE26 mice, a transgenic model of type 1 diabetes. However, the universality of this modification and its functional consequences are not well established. In this study, we demonstrate that Akita type 1 diabetic mice exhibit hyperacetylation. Functionally, isolated Akita heart mitochondria have significantly impaired maximal (state 3) respiration with physiological pyruvate (0.1 mm) but not with 1.0 mm pyruvate. In contrast, pyruvate dehydrogenase activity is significantly decreased regardless of the pyruvate concentration. We found that there is a 70% decrease in the rate of pyruvate transport in Akita heart mitochondria but no decrease in the mitochondrial pyruvate carriers 1 and 2 (MPC1 and MPC2). The potential role of hyperacetylation in mediating this impaired pyruvate uptake was examined. The treatment of control mitochondria with the acetylating agent acetic anhydride inhibits pyruvate uptake and pyruvate-supported respiration in a similar manner to the pyruvate transport inhibitor α-cyano-4-hydroxycinnamate. A mass spectrometry selective reactive monitoring assay was developed and used to determine that acetylation of lysines 19 and 26 of MPC2 is enhanced in Akita heart mitochondria. Expression of a double acetylation mimic of MPC2 (K19Q/K26Q) in H9c2 cells was sufficient to decrease the maximal cellular oxygen consumption rate. This study supports the conclusion that deficient pyruvate transport activity, mediated in part by acetylation of MPC2, is a contributor to metabolic inflexibility in the diabetic heart.
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Affiliation(s)
- Shraddha S Vadvalkar
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Satoshi Matsuzaki
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Craig A Eyster
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Jennifer R Giorgione
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Lee B Bockus
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and.,the Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Caroline S Kinter
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Michael Kinter
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and
| | - Kenneth M Humphries
- From the Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104 and .,the Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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11
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Fukushima A, Lopaschuk GD. Cardiac fatty acid oxidation in heart failure associated with obesity and diabetes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1525-34. [PMID: 26996746 DOI: 10.1016/j.bbalip.2016.03.020] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 12/01/2022]
Abstract
Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
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Affiliation(s)
- Arata Fukushima
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Gary D Lopaschuk
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada.
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12
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Abstract
Type 2 diabetes mellitus escalates the risk of heart failure partly via its ability to induce a cardiomyopathic state that is independent of coronary artery disease and hypertension. Although the pathogenesis of diabetic cardiomyopathy has yet to be fully elucidated, aberrations in cardiac substrate metabolism and energetics are thought to be key drivers. These aberrations include excessive fatty acid utilisation and storage, suppressed glucose oxidation and impaired mitochondrial oxidative phosphorylation. An appreciation of how these abnormalities arise and synergise to promote adverse cardiac remodelling is critical to their effective amelioration. This review focuses on disturbances in myocardial fuel (fatty acids and glucose) flux and energetics in type 2 diabetes, how these disturbances relate to the development of diabetic cardiomyopathy and the potential therapeutic agents that could be used to correct them.
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Affiliation(s)
- Nelson Amaral
- British Heart Foundation Centre of Excellence, Cardiovascular Division, King's College London, London, UK
| | - Darlington O Okonko
- British Heart Foundation Centre of Excellence, Cardiovascular Division, King's College London, London, UK
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13
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Broz AK, Tovar-Méndez A, Mooney BP, Johnston ML, Miernyk JA, Randall DD. A novel regulatory mechanism based upon a dynamic core structure for the mitochondrial pyruvate dehydrogenase complex? Mitochondrion 2014; 19 Pt B:144-53. [DOI: 10.1016/j.mito.2014.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 05/06/2014] [Accepted: 05/12/2014] [Indexed: 12/11/2022]
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14
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Bayeva M, Sawicki KT, Ardehali H. Taking diabetes to heart--deregulation of myocardial lipid metabolism in diabetic cardiomyopathy. J Am Heart Assoc 2013; 2:e000433. [PMID: 24275630 PMCID: PMC3886738 DOI: 10.1161/jaha.113.000433] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marina Bayeva
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL
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15
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Luong KVQ, Nguyen LTH. The impact of thiamine treatment in the diabetes mellitus. J Clin Med Res 2012; 4:153-60. [PMID: 22719800 PMCID: PMC3376872 DOI: 10.4021/jocmr890w] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2012] [Indexed: 01/19/2023] Open
Abstract
Thiamine acts as a coenzyme for transketolase (Tk) and for the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase complexes, enzymes which play a fundamental role for intracellular glucose metabolism. The relationship between thiamine and diabetes mellitus (DM) has been reported in the literature. Thiamine levels and thiamine-dependent enzyme activities have been reduced in DM. Genetic studies provide opportunity to link the relationship between thiamine and DM (such as Tk, SLC19A2 gene, transcription factor Sp1, α-1-antitrypsin, and p53). Thiamine and its derivatives have been demonstrated to prevent the activation of the biochemical pathways (increased flux through the polyol pathway, formation of advanced glycation end-products, activation of protein kinase C, and increased flux through the hexosamine biosynthesis pathway) induced by hyperglycemia in DM.Thiamine definitively has a role in the diabetic endothelial vascular diseases (micro and macroangiopathy), lipid profile, retinopathy, nephropathy, cardiopathy, and neuropathy.
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Choi CS, Ghoshal P, Srinivasan M, Kim S, Cline G, Patel MS. Liver-Specific Pyruvate Dehydrogenase Complex Deficiency Upregulates Lipogenesis in Adipose Tissue and Improves Peripheral Insulin Sensitivity. Lipids 2010; 45:987-95. [DOI: 10.1007/s11745-010-3470-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/25/2010] [Indexed: 10/19/2022]
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17
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Ekberg NR, Brismar K, Malmstedt J, Hedblad MA, Adamson U, Ungerstedt U, Wisniewski N. Analyte flux at a biomaterial-tissue interface over time: implications for sensors for type 1 and 2 diabetes mellitus. J Diabetes Sci Technol 2010; 4:1063-72. [PMID: 20920426 PMCID: PMC2956810 DOI: 10.1177/193229681000400505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The very presence of an implanted sensor (a foreign body) causes changes in the adjacent tissue that may alter the analytes being sensed. The objective of this study was to investigate changes in glucose availability and local tissue metabolism at the sensor-tissue interface in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). METHOD Microdialysis was used to model implanted sensors. Capillary glucose and subcutaneous (sc) microdialysate analytes were monitored in five T1DM and five T2DM patients. Analytes included glucose, glycolysis metabolites (lactate, pyruvate), a lipolysis metabolite (glycerol), and a protein degradation byproduct (urea). On eight consecutive days, four measurements were taken during a period of steady state blood glucose. RESULTS Microdialysate glucose and microdialysate-to-blood-glucose ratio increased over the first several days in all patients. Although glucose recovery eventually stabilized, the lactate levels continued to rise. These trends were explained by local inflammatory and microvascular changes observed in histological analysis of biopsy samples. Urea concentrations mirrored glucose trends. Urea is neither produced nor consumed in sc tissue, and so the initially increasing urea trend is explained by increased local capillary presence during the inflammatory process. Pyruvate in T2DM microdialysate was significantly higher than in T1DM, an observation that is possibly explained by mitochondrial dysfunction in T2DM. Glycerol in T2DM microdialysate (but not in T1DM) was higher than in healthy volunteers, which is likely explained by sc insulin resistance (insulin is a potent antilipolytic hormone). Urea was also higher in microdialysate of patients with diabetes mellitus compared to healthy volunteers. Urea is a byproduct of protein degradation, which is known to be inhibited by insulin. Therefore, insulin deficiency or resistance may explain the higher urea levels. To our knowledge, this is the first histological evaluation of a human tissue biopsy containing an implanted glucose monitoring device. CONCLUSIONS Monitoring metabolic changes at a material-tissue interface combined with biopsy histology helped to formulate an understanding of physiological changes adjacent to implanted glucose sensors. Microdialysate glucose trends were similar over 1-week in T1DM and T2DM; however, differences in other analytes indicated wound healing and metabolic activities in the two patient groups differ. We propose explanations for the specific observed differences based on differential insulin insufficiency/resistance and mitochondrial dysfunction in T1DM versus T2DM.
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Affiliation(s)
- Neda Rajamand Ekberg
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
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18
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Kohda Y, Umeki M, Kono T, Terasaki F, Matsumura H, Tanaka T. Thiamine ameliorates diabetes-induced inhibition of pyruvate dehydrogenase (PDH) in rat heart mitochondria: investigating the discrepancy between PDH activity and PDH E1alpha phosphorylation in cardiac fibroblasts exposed to high glucose. J Pharmacol Sci 2010; 113:343-52. [PMID: 20644337 DOI: 10.1254/jphs.09359fp] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The activity of pyruvate dehydrogenase (PDH) is reduced in diabetic patients. Phosphorylation of the PDH E1alpha subunit by PDH kinase contributes to the suppression of PDH activity. PDH requires thiamine as a coenzyme. We investigated the exact mechanism of diabetes-induced PDH inhibition, and the effect of thiamine in both in vivo and in vitro experiments. Treatment of rats with thiamine significantly, although partially, recovered streptozotocin (STZ)-induced reductions in mitochondrial PDH activity. Nevertheless, we found that PDH E1alpha phosphorylation in the thiamine-treated STZ group was perfectly diminished to the same level as that in the control group. STZ treatment significantly caused enhancements of the expression of O-glycosylated protein in the rat hearts, which was decreased by thiamine repletion. Next, the rat cardiac fibroblasts (RCFs) were cultured in the presence of high glucose levels. Thiamine dramatically recovered high glucose-induced PDH inhibition. High glucose loads did not alter the phosphorylated PDH E1alpha. PDH inhibition in RCFs was not accompanied by an increase in the PDH E1alpha phosphorylation. The O-glycosylated protein was markedly increased in RCFs exposed to high glucose, which was inhibited by thiamine. These results suggest that thiamine ameliorates diabetes-induced PDH inhibition by suppressing the increased expression of the O-glycosylated protein. The O-glycosylation of PDH E1alpha may be involved in the regulation of the PDH activity.
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Affiliation(s)
- Yuka Kohda
- Laboratory of Pharmacotherapy, Osaka University of Pharmaceutical Sciences, Takatsuki, Japan.
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Yunoki K, Renaguli M, Kinoshita M, Matsuyama H, Mawatari S, Fujino T, Kodama Y, Sugiyama M, Ohnishi M. Dietary sphingolipids ameliorate disorders of lipid metabolism in Zucker fatty rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:7030-7035. [PMID: 20443604 DOI: 10.1021/jf100722f] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Dietary sphingolipids (SL) inhibit colon carcinogenesis, reduce serum cholesterol, and improve skin barrier function and are considered to be "functional lipids". For comparative determination of the effects of SL with different chemical compositions on lipid metabolism and its related hepatic gene expression, Zucker fatty rats were fed pure sphingomyelin (SM) of animal origin and glucosylceramide (GC) of plant origin. After 45 days, the SM and GC diets led to significant reductions in hepatic lipid and plasma non-HDL cholesterol. Both SM and GC diets decreased plasma insulin levels, whereas only the GC diet increased the plasma adiponectin level. Hepatic gene expression analysis revealed increased expression of adiponectin receptor 2 (Adipor2), peroxisome proliferator-activated receptor alpha (PPARalpha), and pyruvate dehydrogenase kinase 4 (Pdk4). However, expression of stearoyl CoA desaturase (Scd1) was significantly decreased. These results suggest that dietary SL, even of different origins and chemical compositions, may prevent fatty liver and hypercholesterolemia through improvement of adiponectin signaling and consequent increases in insulin sensitivity.
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Affiliation(s)
- Keita Yunoki
- Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
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20
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Yi X, Xu L, Kim K, Kim HS, Maeda N. Genetic reduction of lipoic acid synthase expression modestly increases atherosclerosis in male, but not in female, apolipoprotein E-deficient mice. Atherosclerosis 2010; 211:424-30. [PMID: 20347443 DOI: 10.1016/j.atherosclerosis.2010.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 03/02/2010] [Accepted: 03/03/2010] [Indexed: 01/18/2023]
Abstract
OBJECTIVES To evaluate the effects of a genetic reduction of Lias gene expression on atherosclerosis development. METHODS AND RESULTS Heterozygous knockout mice for the lipoid acid synthase gene (Lias(+/-)) were crossed with apolipoprotein E-deficient (ApoE(-/-)) mice, and the plaque size in aortic sinuses of Lias(+/-)ApoE(-/-)mice was evaluated at 6 months of age. Lesions at the aortic sinus in Lias(+/-)ApoE(-/-) males were significantly larger (1.5x) than those in Lias(+/+) ApoE(-/-) littermate males. The lesion size was inversely correlated with an increased erythrocyte reduced glutathione/oxidized glutathione (GSH/GSSH) ratio, a systemic index of body redox balance. Lias(+/-)ApoE(-/-)males also had significantly increased plasma cholesterol and reduced pyruvate dehydrogenase complex activity in the liver. Significant reductions in the expression of genes for antioxidant enzymes, including superoxide dismutase 1 (SOD1) and SOD2, were observed in aortas of Lias(+/-)ApoE(-/-)males. Female Lias(+/-)ApoE(-/-)also exhibited changes in these parameters, parallel to those observed in males. However, the Lias gene effects for the majority of these factors, including atherosclerotic lesion size, were not significant in females. CONCLUSIONS Our data provide evidence that Lias deficiency enhances atherosclerosis in male mice, at least in part due to reduced antioxidant capacity. The notable absence of such effects in females leaves open the possibility of a gender-specific protection mechanism.
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Affiliation(s)
- Xianwen Yi
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC 27599-7525, USA.
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Kiilerich K, Gudmundsson M, Birk JB, Lundby C, Taudorf S, Plomgaard P, Saltin B, Pedersen PA, Wojtaszewski JFP, Pilegaard H. Low muscle glycogen and elevated plasma free fatty acid modify but do not prevent exercise-induced PDH activation in human skeletal muscle. Diabetes 2010; 59:26-32. [PMID: 19833896 PMCID: PMC2797931 DOI: 10.2337/db09-1032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To test the hypothesis that free fatty acid (FFA) and muscle glycogen modify exercise-induced regulation of PDH (pyruvate dehydrogenase) in human skeletal muscle through regulation of PDK4 expression. RESEARCH DESIGN AND METHODS On two occasions, healthy male subjects lowered (by exercise) muscle glycogen in one leg (LOW) relative to the contra-lateral leg (CON) the day before the experimental day. On the experimental days, plasma FFA was ensured normal or remained elevated by consuming breakfast rich (low FFA) or poor (high FFA) in carbohydrate, 2 h before performing 20 min of two-legged knee extensor exercise. Vastus lateralis biopsies were obtained before and after exercise. RESULTS PDK4 protein content was approximately 2.2- and approximately 1.5-fold higher in LOW than CON leg in high FFA and low FFA, respectively, and the PDK4 protein content in the CON leg was approximately twofold higher in high FFA than in low FFA. In all conditions, exercise increased PDHa (PDH in the active form) activity, resulting in similar levels in LOW leg in both trials and CON leg in high FFA, but higher level in CON leg in low FFA. PDHa activity was closely associated with the PDH-E1alpha phosphorylation level. CONCLUSIONS Muscle glycogen and plasma FFA attenuate exercise-induced PDH regulation in human skeletal muscle in a nonadditive manner. This might be through regulation of PDK4 expression. The activation of PDH by exercise independent of changes in muscle glycogen or plasma FFA suggests that exercise overrules FFA-mediated inhibition of PDH (i.e., carbohydrate oxidation), and this may thus be one mechanism behind the health-promoting effects of exercise.
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Affiliation(s)
- Kristian Kiilerich
- Copenhagen Muscle Research Centre, University of Copenhagen, Copenhagen, Denmark.
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Hoy AJ, Brandon AE, Turner N, Watt MJ, Bruce CR, Cooney GJ, Kraegen EW. Lipid and insulin infusion-induced skeletal muscle insulin resistance is likely due to metabolic feedback and not changes in IRS-1, Akt, or AS160 phosphorylation. Am J Physiol Endocrinol Metab 2009; 297:E67-75. [PMID: 19366875 PMCID: PMC2711668 DOI: 10.1152/ajpendo.90945.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes is characterized by hyperlipidemia, hyperinsulinemia, and insulin resistance. The aim of this study was to investigate whether acute hyperlipidemia-induced insulin resistance in the presence of hyperinsulinemia was due to defective insulin signaling. Hyperinsulinemia (approximately 300 mU/l) with hyperlipidemia or glycerol (control) was produced in cannulated male Wistar rats for 0.5, 1 h, 3 h, or 5 h. The glucose infusion rate required to maintain euglycemia was significantly reduced by 3 h with lipid infusion and was further reduced after 5 h of infusion, with no difference in plasma insulin levels, indicating development of insulin resistance. Consistent with this finding, in vivo skeletal muscle glucose uptake (31%, P < 0.05) and glycogen synthesis rate (38%, P < 0.02) were significantly reduced after 5 h compared with 3 h of lipid infusion. Despite the development of insulin resistance, there was no difference in the phosphorylation state of multiple insulin-signaling intermediates or muscle diacylglyceride and ceramide content over the same time course. However, there was an increase in cumulative exposure to long-chain acyl-CoA (70%) with lipid infusion. Interestingly, although muscle pyruvate dehydrogenase kinase 4 protein content was decreased in hyperinsulinemic glycerol-infused rats, this decrease was blunted in muscle from hyperinsulinemic lipid-infused rats. Decreased pyruvate dehydrogenase complex activity was also observed in lipid- and insulin-infused animals (43%). Overall, these results suggest that acute reductions in muscle glucose metabolism in rats with hyperlipidemia and hyperinsulinemia are more likely a result of substrate competition than a significant early defect in insulin action or signaling.
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Affiliation(s)
- Andrew J Hoy
- Diabetes and Obesity Research Program, Garvan Institute of Medical Research, Darlinghurst, University of New South Wales, Sydney, New South Wales, Australia.
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