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Crewe C. Energetic Stress-Induced Metabolic Regulation by Extracellular Vesicles. Compr Physiol 2023; 13:5051-5068. [PMID: 37358503 PMCID: PMC10414774 DOI: 10.1002/cphy.c230001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Recent studies have demonstrated that extracellular vesicles (EVs) serve powerful and complex functions in metabolic regulation and metabolic-associated disease, although this field of research is still in its infancy. EVs are released into the extracellular space from all cells and carry a wide range of cargo including miRNAs, mRNA, DNA, proteins, and metabolites that have robust signaling effects in receiving cells. EV production is stimulated by all major stress pathways and, as such, has a role in both restoring homeostasis during stress and perpetuating disease. In metabolic regulation, the dominant stress signal is a lack of energy due to either nutrient deficits or damaged mitochondria from nutrient excess. This stress signal is termed "energetic stress," which triggers a robust and evolutionarily conserved response that engages major cellular stress pathways, the ER unfolded protein response, the hypoxia response, the antioxidant response, and autophagy. This article proposes the model that energetic stress is the dominant stimulator of EV release with a focus on metabolically important cells such as hepatocytes, adipocytes, myocytes, and pancreatic β-cells. Furthermore, this article will discuss how the cargo in stress-stimulated EVs regulates metabolism in receiving cells in both beneficial and detrimental ways. © 2023 American Physiological Society. Compr Physiol 13:5051-5068, 2023.
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Affiliation(s)
- Clair Crewe
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, USA
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Klug L, Mähler A, Rakova N, Mai K, Schulz‐Menger J, Rahn G, Busjahn A, Jordan J, Boschmann M, Luft FC. Normobaric hypoxic conditioning in men with metabolic syndrome. Physiol Rep 2018; 6:e13949. [PMID: 30565412 PMCID: PMC6299242 DOI: 10.14814/phy2.13949] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 11/16/2018] [Indexed: 11/25/2022] Open
Abstract
The evidence that physical exercise lowers metabolic and cardiovascular risk is undisputed. Normobaric hypoxia training has been introduced to facilitate the effects of exercise. We tested the hypothesis that hypoxia training augments exercise-related effects. We randomized 23 men with metabolic-syndrome to single-blinded exercise at normoxia (FiO2 21%) or hypoxia (FiO2 15%). Six weeks endurance training on a treadmill, 3 days per week, over 60 min at 60% VO2 max was required. The study included the following: (1) metabolic phenotyping by indirect calorimetry and adipose and muscle tissue microdialysis to gain insight into effects on resting, postprandial, and exercise metabolism, (2) cardiac imaging, and (3) biopsies. Primary endpoint was the change in cardiorespiratory fitness; secondary endpoints were as follows: changes in body weight, waist circumference, blood pressure, cardiac dimensions, and adipose and muscle tissue metabolism and gene expression. Our subjects reduced waist circumference and improved several cardiovascular risk markers including blood pressure. However, these effects were similar in both training groups. Cardiac dimensions were not influenced. We focused on glucose metabolism. After an oral glucose load, adipose tissue metabolism was significantly shifted to a more lipolytic state under hypoxia, whereas muscle metabolism was similar under both conditions. Postprandial energy expenditure was significantly increased under hypoxia, whereas activity energy expenditure was improved under normoxia. Gene expression was not consistently influenced by FiO2 . Adipose tissue triglyceride lipase, leptin, and hypoxia-inducible factor-alpha expression were increased by normoxia but not hypoxia.
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Affiliation(s)
- Lars Klug
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Anja Mähler
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Natalia Rakova
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Knut Mai
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
- Department of Endocrinology & MetabolismCharite Universitätsmedizin BerlinBerlinGermany
- Clinical Research UnitBerlin Institute of Health (BIH)BerlinGermany
| | - Jeanette Schulz‐Menger
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
- DZHK (German Centre for Cardiovascular Research), partner site BerlinBerlinGermany
- Department of Cardiology and NephrologyHELIOS Klinikum Berlin BuchBerlinGermany
| | - Gabriele Rahn
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Andreas Busjahn
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Jens Jordan
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
- Present address:
Institut für Luft‐ und RaumfahrtmedizinDeutsches Zentrum für Luft‐ und Raumfahrt (DLR)KölnGermany
| | - Michael Boschmann
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
| | - Friedrich C. Luft
- Experimental & Clinical Research Center (ECRC)a joint collaboration between Max‐Delbrück Center for Molecular Medicine and Charité UniversitätsmedizinBerlinGermany
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Advanced glycation end products-induced insulin resistance involves repression of skeletal muscle GLUT4 expression. Sci Rep 2018; 8:8109. [PMID: 29802324 PMCID: PMC5970140 DOI: 10.1038/s41598-018-26482-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 05/14/2018] [Indexed: 11/08/2022] Open
Abstract
Little is known about advanced glycation end products (AGEs) participation in glucose homeostasis, a process in which skeletal muscle glucose transporter GLUT4 (Scl2a4 gene) plays a key role. This study investigated (1) the in vivo and in vitro effects of AGEs on Slc2a4/GLUT4 expression in skeletal muscle of healthy rats, and (2) the potential involvement of endoplasmic reticulum and inflammatory stress in the observed regulations. For in vivo analysis, rats were treated with advanced glycated rat albumin (AGE-albumin) for 12 weeks; for in vitro analysis, soleus muscles from normal rats were incubated with bovine AGE-albumin for 2.5 to 7.5 hours. In vivo, AGE-albumin induced whole-body insulin resistance; decreased (~30%) Slc2a4 mRNA and GLUT4 protein content; and increased (~30%) the nuclear content of nuclear factor NF-kappa-B p50 subunit (NFKB1), and cellular content of 78 kDa glucose-regulated protein (GRP78). In vitro, incubation with AGE-albumin decreased (~50%) the Slc2a4/GLUT4 content; and increased cellular content of GRP78/94, phosphorylated-IKK-alpha/beta, nuclear content of NFKB1 and RELA, and the nuclear protein binding into Slc2a4 promoter NFKB-binding site. The data reveal that AGEs impair glucose homeostasis in non-diabetic states of increased AGEs concentration; an effect that involves activation of endoplasmic reticulum- and inflammatory-stress and repression of Slc2a4/GLUT4 expression.
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Kupr B, Schnyder S, Handschin C. Role of Nuclear Receptors in Exercise-Induced Muscle Adaptations. Cold Spring Harb Perspect Med 2017; 7:a029835. [PMID: 28242783 PMCID: PMC5453380 DOI: 10.1101/cshperspect.a029835] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Skeletal muscle is not only one of the largest, but also one of the most dynamic organs. For example, plasticity elicited by endurance or resistance exercise entails complex transcriptional programs that are still poorly understood. Various signaling pathways are engaged in the contracting muscle fiber and collectively culminate in the modulation of the activity of numerous transcription factors (TFs) and coregulators. Because exercise confers many benefits for the prevention and treatment of a wide variety of pathologies, pharmacological activation of signaling pathways and TFs is an attractive avenue to elicit therapeutic effects. Members of the nuclear receptor (NR) superfamily are of particular interest owing to the presence of well-defined DNA- and ligand-binding domains. In this review, we summarize the current understanding of the involvement of NRs in muscle biology and exercise adaptation.
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Affiliation(s)
- Barbara Kupr
- Biozentrum, University of Basel, Basel 4056, Switzerland
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Schaun MI, Marschner RA, Peres TR, Markoski MM, Lehnen AM. Aerobic training prior to myocardial infarction increases cardiac GLUT4 and partially preserves heart function in spontaneously hypertensive rats. Appl Physiol Nutr Metab 2017; 42:334-337. [DOI: 10.1139/apnm-2016-0439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We assessed cardiac function (echocardiographic) and glucose transporter 4 (GLUT4) expression (Western blot) in response to 10 weeks of aerobic training (treadmill) prior to acute myocardial infarction (AMI) by ligation of the left coronary artery in spontaneously hypertensive rats. Animals were allocated to sedentary+sham, sedentary+AMI, training+sham, and training+AMI. Aerobic training prior to AMI partially preserves heart function. AMI and/or aerobic training increased GLUT4 expression. However, those animals trained prior to AMI showed a greater increase in GLUT4 in cardiomyocytes.
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Affiliation(s)
- Maximiliano Isoppo Schaun
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre, RS, 90620-001, Brazil
| | - Rafael Aguiar Marschner
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre, RS, 90620-001, Brazil
| | - Thiago Rodrigues Peres
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre, RS, 90620-001, Brazil
| | - Melissa Medeiros Markoski
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre, RS, 90620-001, Brazil
| | - Alexandre Machado Lehnen
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre, RS, 90620-001, Brazil
- Faculdade Sogipa de Educação Física, Porto Alegre, Rio Grande do Sul, 90550-003, Brazil
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Esteves JV, Enguita FJ, Machado UF. MicroRNAs-Mediated Regulation of Skeletal Muscle GLUT4 Expression and Translocation in Insulin Resistance. J Diabetes Res 2017; 2017:7267910. [PMID: 28428964 PMCID: PMC5385897 DOI: 10.1155/2017/7267910] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 01/12/2023] Open
Abstract
The solute carrier family 2 facilitated glucose transporter member 4 (GLUT4) plays a key role in the insulin-induced glucose uptake by muscle and adipose tissues. In prediabetes and diabetes, GLUT4 expression/translocation has been detected as reduced, participating in mechanisms that impair glycemic control. Recently, a class of short endogenous noncoding RNAs named microRNAs (miRNAs) has been increasingly described as involved in the posttranscriptional epigenetic regulation of gene expression. The present review focuses on miRNAs potentially involved in the expression of GLUT4 expression, and proteins related to GLUT4 and translocation in skeletal muscle, seeking to correlate them with insulin resistance and diabetes. So far, miR-21a-5p, miR-29a-3p, miR-29c-3p, miR-93-5p, miR-106b-5p, miR-133a-3p, miR-133b-3p, miR-222-3p, and miR-223-3p have been reported to directly and/or indirectly regulate the GLUT4 expression; and their expression is altered under diabetes-related conditions. Besides, some miRNAs that have been linked to the expression of proteins involved in GLUT4 translocation machinery in muscle could also impact glucose uptake. That makes these miRNAs promising targets for preventive and/or therapeutic approaches, which could improve glycemic control, thus deserving future new investigations.
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Affiliation(s)
- João Victor Esteves
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Francisco Javier Enguita
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
- *Ubiratan Fabres Machado:
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Gerlinger-Romero F, Yonamine CY, Junior DCP, Esteves JVD, Machado UF. Dysregulation between TRIM63/FBXO32 expression and soleus muscle wasting in diabetic rats: potential role of miR-1-3p, -29a/b-3p, and -133a/b-3p. Mol Cell Biochem 2016; 427:187-199. [PMID: 28000044 DOI: 10.1007/s11010-016-2910-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 12/03/2016] [Indexed: 11/28/2022]
Abstract
Diabetes mellitus (DM) induces a variable degree of muscle sarcopenia, which may be related to protein degradation and to the expression of both E3 ubiquitin ligases and some specific microRNAs (miRNAs). The present study investigated the effect of diabetes and acute muscle contraction upon the TRIM63 and FBXO32 expression as well as the potential involvement of some miRNAs. Diabetes was induced by streptozotocin and studied after 30 days. Soleus muscles were harvested, stimulated to contract in vitro for twitch tension analysis (0.5 Hz), 30 min later for tetanic analysis (100 Hz), and 30 min later were frozen. TRIM63 and FBXO32 proteins were quantified by western blotting; Trim63 mRNA, Fbxo32 mRNA, miR-1-3p, miR-29a-3p, miR-29b-3p, miR-133a-3p, and miR-133b-3p were quantified by qPCR. Diabetes induced sarcopenia by decreasing (P < 0.05) muscle weight/tibia length index, maximum tetanic contraction and relaxation rates, and absolute twitch and tetanic forces (P < 0.05). Diabetes decreased (P < 0.05) the Trim63 and Fbxo32 mRNAs (30%) and respective proteins (60%), and increased (P < 0.01) the miR-29b-3p (2.5-fold). In muscle from diabetic rats, acute contractile stimulus increased TRIM63 protein, miR-1-3p, miR-29a-3p, and miR-133a/b-3p, but decreased miR-29b-3p (P < 0.05). Independent of the metabolic condition, after muscle contraction, both TRIM63 and FBXO32 proteins correlated significantly with miR-1-3p, miR-29a/b-3p, and miR-133a/b-3p. All diabetes-induced regulations were reversed by insulin treatment. Concluding, the results depict that muscle wasting in long-term insulinopenic condition may not be accompanied by increased proteolysis, pointing out the protein synthesis as an important modulator of muscle sarcopenia in DM.
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Affiliation(s)
- Frederico Gerlinger-Romero
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
| | - Caio Yogi Yonamine
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Danilo Correa Pinto Junior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - João Victor DelConti Esteves
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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Sousa LMMDC, Silva RDS, Fonseca VUD, Leandro RM, Di Vincenzo TS, Alves-Wagner AB, Machado UF, Papa PDC. Is the canine corpus luteum an insulin-sensitive tissue? J Endocrinol 2016; 231:223-233. [PMID: 27679426 DOI: 10.1530/joe-16-0173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 09/27/2016] [Indexed: 01/08/2023]
Abstract
This study aimed to determine in the canine corpus luteum throughout the dioestrus (1) the influence of insulin on glucose uptake; (2) the regulation of genes potentially involved; and (3) the influence of hypoxia on glucose transporter expression and steroidogenesis, after treatment with cobalt chloride (CoCl2). Glucose uptake by luteal cells increased 2.7 folds (P < 0.05) in response to insulin; a phenomenon related to increased expression of glucose transporter (GLUT) 4 and phosphorylation of protein kinase B (AKT). The gene expression of insulin receptor and SLC2A4 (codifier of GLUT4) genes after insulin stimulation increased on day 20 post ovulation (p.o.) and declined on day 40 p.o. (P < 0.05). Regarding potentially involved molecular mechanisms, the nuclear factor kappa B gene RELA was upregulated on days 30/40 p.o., when SLC2A4 mRNA was low, and the interleukin 6 (IL6) gene was upregulated in the first half of dioestrus, when SLC2A4 mRNA was high. CoCl2 in luteal cell cultures increased the hypoxia-inducible factor HIF1A/HIF1A and the SLC2A4/GLUT4 expression, and decreased progesterone (P4) production and hydroxyl-delta-5-steroid dehydrogenase 3 beta (HSD3B) mRNA expression (P < 0.05). This study shows that the canine luteal cells are responsive to insulin, which stimulates glucose uptake in AKT/GLUT4-mediated pathway; that may be related to local activity of RELA and IL6. Besides, the study reveals that luteal cells under hypoxia activate HIF1A-modulating luteal function and insulin-stimulated glucose uptake. These data indicate that insulin regulates luteal cells' glucose disposal, participating in the maintenance and functionality of the corpus luteum.
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Affiliation(s)
| | - Renata Dos Santos Silva
- Department of SurgerySchool of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Vanessa Uemura da Fonseca
- Department of SurgerySchool of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Rafael Magdanelo Leandro
- Department of SurgerySchool of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Thiago Senna Di Vincenzo
- Department of SurgerySchool of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Ana Bárbara Alves-Wagner
- Department of Physiology and BiophysicsInstitute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and BiophysicsInstitute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Paula de Carvalho Papa
- Department of SurgerySchool of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
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Controlled Heat Stress Promotes Myofibrillogenesis during Myogenesis. PLoS One 2016; 11:e0166294. [PMID: 27824934 PMCID: PMC5100975 DOI: 10.1371/journal.pone.0166294] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 10/26/2016] [Indexed: 11/24/2022] Open
Abstract
Hyperthermia therapy has recently emerged as a clinical modality used to finely tune heat stress inside the human body for various biomedical applications. Nevertheless, little is known regarding the optimal timing or temperature of heat stress that is needed to achieve favorable results following hyperthermia therapy for muscle regeneration purposes. The regeneration of skeletal muscle after injury is a highly complex and coordinated process that involves a multitude of cellular mechanisms. The main objective of this study was to characterize the effects of hyperthermal therapy on the overall behavior of myoblasts during myogenic differentiation. Various cellular processes, including myogenesis, myofibrillogenesis, hypertrophy/atrophy, and mitochondrial biogenesis, were studied using systematic cellular, morphological, and pathway-focused high-throughput gene expression profiling analyses. We found that C2C12 myoblasts exhibited distinctive time and temperature-dependence in biosynthesis and regulatory events during myogenic differentiation. Specifically, we for the first time observed that moderate hyperthermia at 39°C favored the growth of sarcomere in myofibrils at the late stage of myogenesis, showing universal up-regulation of characteristic myofibril proteins. Characteristic myofibrillogenesis genes, including heavy polypeptide 1 myosin, heavy polypeptide 2 myosin, alpha 1 actin, nebulin and titin, were all significantly upregulated (p<0.01) after C2C12 cells differentiated at 39°C over 5 days compared with the control cells cultured at 37°C. Furthermore, moderate hyperthermia enhanced myogenic differentiation, with nucleus densities per myotube showing 2.2-fold, 1.9-fold and 1.6-fold increases when C2C12 cells underwent myogenic differentiation at 39°C over 24 hours, 48 hours and 72 hours, respectively, as compared to the myotubes that were not exposed to heat stress. Yet, atrophy genes were sensitive even to moderate hyperthermia, indicating that strictly controlled heat stress is required to minimize the development of atrophy in myotubes. In addition, mitochondrial biogenesis was enhanced following thermal induction of myoblasts, suggesting a subsequent shift toward anabolic demand requirements for energy production. This study offers a new perspective to understand and utilize the time and temperature-sensitive effects of hyperthermal therapy on muscle regeneration.
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Dantas WS, Marcondes JAM, Shinjo SK, Perandini LA, Zambelli VO, Neves WD, Barcellos CRG, Rocha MP, Yance VDRV, Pereira RTDS, Murai IH, Pinto ALDS, Roschel H, Gualano B. GLUT4 translocation is not impaired after acute exercise in skeletal muscle of women with obesity and polycystic ovary syndrome. Obesity (Silver Spring) 2015; 23:2207-15. [PMID: 26373822 DOI: 10.1002/oby.21217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to examine the effects of acute exercise on insulin signaling in skeletal muscle of women with polycystic ovary syndrome (PCOS) and controls (CTRL). METHODS Fifteen women with obesity and PCOS and 12 body mass index-matched CTRL participated in this study. Subjects performed a 40-min single bout of exercise. Muscle biopsies were performed before and 60 min after exercise. Selected proteins were assessed by Western blotting. RESULTS CTRL, but not PCOS, showed a significant increase in PI3-k p85 and AS160 Thr 642 after a single bout of exercise (P = 0.018 and P = 0.018, respectively). Only PCOS showed an increase in Akt Thr 308 and AMPK phosphorylation after exercise (P = 0.018 and P = 0.018, respectively). Total GLUT4 expression was comparable between groups (P > 0.05). GLUT4 translocation tended to be significantly higher in both groups after exercise (PCOS: P = 0.093; CTRL: P = 0.091), with no significant difference between them (P > 0.05). CONCLUSIONS A single bout of exercise elicited similar GLUT4 translocation in skeletal muscle of PCOS and CTRL, despite a slightly differential pattern of protein phosphorylation. The absence of impairment in GLUT4 translocation suggests that PCOS patients with obesity and insulin resistance may benefit from exercise training.
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Affiliation(s)
- Wagner Silva Dantas
- School of Physical Education and Sport, Department of Biodynamic of Human Movement, University of Sao Paulo, Brazil
| | | | | | | | | | - Willian Das Neves
- School of Physical Education and Sport, Department of Biodynamic of Human Movement, University of Sao Paulo, Brazil
| | | | | | | | | | - Igor Hisashi Murai
- School of Physical Education and Sport, Department of Biodynamic of Human Movement, University of Sao Paulo, Brazil
| | - Ana Lucia De Sá Pinto
- Rheumatology Division, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Hamilton Roschel
- School of Physical Education and Sport, Department of Biodynamic of Human Movement, University of Sao Paulo, Brazil
- Rheumatology Division, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Bruno Gualano
- School of Physical Education and Sport, Department of Biodynamic of Human Movement, University of Sao Paulo, Brazil
- Rheumatology Division, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
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Oliveira-Batista RD, Silva A, Passos KMRD, Nogueira RMB, Seraphim PM. Six-week anaerobic training improves proteolytic profile of diabetic rats. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2015; 59:400-6. [PMID: 26421672 DOI: 10.1590/2359-3997000000114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To evaluate the effect of six-week anaerobic training on the mRNA expression of genes related to proteolysis Ubb (Ubiquitin), E2-14kDa, Trim63 (MuRF1 protein) and Nfkb1 in the skeletal muscle of diabetic rats. MATERIALS AND METHODS Four groups were established: DE (DiabetesExercised), DS (Diabetes Sedentary), CE (Control Exercised) and CS (Control Sedentary). The training consisted of 3 sets of 12 jumps in the liquid mean with load equivalent to 50% of BW for 6 weeks. Euthanasia occurred under ip anesthesia, and blood, adipose tissue and skeletal muscles were collected. Gene expression was quantified by RT-PCR in the gastrocnemius muscle. ANOVA one-way was used for comparison among groups, with post-hoc (Tukey) when necessary, considering p < 0.05. RESULTS We observed reduction in the body weight and adipose tissue in the diabetic groups. The muscle mass was reduced in DS, which could be reversed by training (DE). Although DS and DE have presented similar body weight, the training protocol in DE promoted reduction in the adipose tissue, and increase of muscle mass. Anaerobic training was efficient to reduce glycaemia only in the diabetic animals until 6 hours after the end of training. The Trim63 gene expression was increased in DS; decreased Ubb gene level was observed in trained rats (CE and DE) compared to sedentary (CS and DS), and DE presented the lowest level of E2-14kDa gene expression. CONCLUSION Six-week anaerobic training promoted muscle mass gain, improved glycemic control, and exerted inhibitory effect on the proteolysis of gastrocnemius muscle of diabetic rats.
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Affiliation(s)
- Rogério de Oliveira-Batista
- Departamento de Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista, Presidente Prudente, SP, Brasil
| | - Angelita Silva
- Departamento de Medicina Veterinária, Universidade do Oeste Paulista, Presidente Prudente, SP, Brasil
| | | | | | - Patricia Monteiro Seraphim
- Departamento de Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista, Presidente Prudente, SP, Brasil
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Woolcott OO, Ader M, Bergman RN. Glucose homeostasis during short-term and prolonged exposure to high altitudes. Endocr Rev 2015; 36:149-73. [PMID: 25675133 PMCID: PMC4399271 DOI: 10.1210/er.2014-1063] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis.
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Affiliation(s)
- Orison O Woolcott
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048
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Lehnen TE, Lehnen AM, Tavares AMV, Belló-Klein A, Markoski MM, Machado UF, Schaan B. Atorvastatin administered before myocardial infarction in rats improves contractility irrespective of metabolic changes. Clin Exp Pharmacol Physiol 2014; 41:986-94. [DOI: 10.1111/1440-1681.12313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Tatiana Ederich Lehnen
- Postgraduate Program in Endocrinology; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
- Endocrine Division; Hospital de Clínicas de Porto Alegre; Porto Alegre Rio Grande do Sul Brazil
- Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - Alexandre Machado Lehnen
- Postgraduate Program in Endocrinology; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
- Endocrine Division; Hospital de Clínicas de Porto Alegre; Porto Alegre Rio Grande do Sul Brazil
- Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - Angela Maria Vicente Tavares
- Laboratory of Cardiovascular Physiology; Institute of Basic Health Sciences; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - Adriane Belló-Klein
- Laboratory of Cardiovascular Physiology; Institute of Basic Health Sciences; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - Melissa Medeiros Markoski
- Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - Beatriz Schaan
- Postgraduate Program in Endocrinology; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
- Endocrine Division; Hospital de Clínicas de Porto Alegre; Porto Alegre Rio Grande do Sul Brazil
- Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
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Moraes PA, Yonamine CY, Pinto Junior DC, Esteves JVD, Machado UF, Mori RC. Insulin acutely triggers transcription of Slc2a4 gene: participation of the AT-rich, E-box and NFKB-binding sites. Life Sci 2014; 114:36-44. [PMID: 25123536 DOI: 10.1016/j.lfs.2014.07.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 11/16/2022]
Abstract
AIMS The insulin-sensitive glucose transporter protein GLUT4 (solute carrier family 2 member 4 (Slc2a4) gene) plays a key role in glycemic homeostasis. Decreased GLUT4 expression is a current feature in insulin resistant conditions such as diabetes, and the restoration of GLUT4 content improves glycemic control. This study investigated the effect of insulin upon Slc2a4/GLUT4 expression, focusing on the AT-rich element, E-box and nuclear factor NF-kappa-B (NFKB) site. MAIN METHODS Rat soleus muscles were incubated during 180 min with insulin, added or not with wortmannin (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma isoform (PI3K)-inhibitor), ML9 (serine/threonine protein kinase (AKT) inhibitor) and tumor necrosis factor (TNF, GLUT4 repressor), and processed for analysis of GLUT4 protein (Western blotting); Slc2a4, myocyte enhancer factor 2a/d (Mef2a/d), hypoxia inducible factor 1a (Hif1a), myogenic differentiation 1 (Myod1) and nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (Nfkb1) messenger ribonucleic acids (mRNAs) (polymerase chain reaction (PCR)); and AT-rich- (myocyte-specific enhancer factor 2 (MEF2)-binding site), E-box- (hypoxia inducible factor 1 alpha (HIF1A)- and myoblast determination protein 1 (MYOD1)-binding site), and NFKB-binding activity (electrophoretic mobility assay). KEY FINDINGS Insulin increased Slc2a4 mRNA expression (140%) and nuclear proteins binding to AT-rich and E-box elements (~90%), all effects were prevented by wortmannin and ML9. Insulin also increased Mef2a/d and Myod1 mRNA expression, suggesting the participation of these transcriptional factors in the Slc2a4 enhancing effect. Conversely, insulin decreased Nfkb1 mRNA expression and protein binding to the NFKB-site (~50%). Furthermore, TNF-induced inhibition of GLUT4 expression (~40%) was prevented by insulin in an NFKB-binding repressing mechanism. GLUT4 protein paralleled the Slc2a4 mRNA regulations. SIGNIFICANCE Insulin enhances the Slc2a4/GLUT4 expression in the skeletal muscle by activating AT-rich and E-box elements, in a PI3K/AKT-dependent mechanism, and repressing NFKB-site activity as well. These results unravel how post-prandial increase of insulin may guarantee GLUT4 expression, and how the insulin signaling impairment can participate in insulin resistance-induced repression of GLUT4.
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Affiliation(s)
- Paulo Alexandre Moraes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Caio Yogi Yonamine
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Danilo Correa Pinto Junior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - João Victor DelConti Esteves
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Rosana Cristina Mori
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
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Liu Y, Nie H, Zhang K, Ma D, Yang G, Zheng Z, Liu K, Yu B, Zhai C, Yang S. A feedback regulatory loop between HIF-1α and miR-21 in response to hypoxia in cardiomyocytes. FEBS Lett 2014; 588:3137-46. [PMID: 24983504 DOI: 10.1016/j.febslet.2014.05.067] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 05/21/2014] [Indexed: 12/12/2022]
Abstract
Accumulating evidence suggests that hypoxia-inducible factor 1α (HIF-1α) regulates numerous miRNAs and is crucial for cellular response to hypoxia. However, the relationship between HIF-1α and miR-21 in hypoxic cardiomyocytes is little known. We found that hypoxia induced HIF-1α and miR-21 expression. HIF-1α knockdown increased cell apoptosis and reduced miR-21 expression. Furthermore, we found that HIF-1α transcriptionally enhanced miR-21 promoter activity by binding to its promoter, which required the recruitment of CBP/p300. In addition, we found that miR-21 inhibition increased cell apoptosis and reduced HIF-1α expression, and modulated the PTEN/Akt pathway. Our results indicate that HIF-1α-miR-21 feedback contributes to the adaptation of cardiomyocytes to hypoxia, and has potential as therapeutic target for myocardial ischemia.
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Affiliation(s)
- Yang Liu
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China
| | - Honggang Nie
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China
| | - Kuikui Zhang
- Department of Cardiology, The First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 150086, China
| | - Dan Ma
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China
| | - Guang Yang
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Zhilei Zheng
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Kai Liu
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China
| | - Bo Yu
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China
| | - Changlin Zhai
- Department of Cardiology, The First Affiliated Hospital of Jiaxing University, Jiaxing 314000, China.
| | - Shuang Yang
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150086, China.
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16
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Zanquetta MM, Alves-Wagner AB, Mori RC, Campello RS, Machado UF. Recovery of insulin sensitivity and Slc2a4 mRNA expression depend on T3 hormone during refeeding. Metabolism 2014; 63:328-34. [PMID: 24361184 DOI: 10.1016/j.metabol.2013.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 10/08/2013] [Accepted: 11/03/2013] [Indexed: 01/06/2023]
Abstract
OBJECTIVE GLUT4 protein, encoded by the Slc2a4 gene, plays a key role in muscle glucose uptake, and its expression decreases in muscles under insulin resistance. Slc2a4/GLUT4 decreases with fasting and rapidly increases with refeeding and the same occurs to plasma glucose, amino acids, insulin and T3. Thus, they might be potential regulators of the Slc2a4 gene, which makes them promising targets for strategies to improve GLUT4 expression. Herein, we investigate the role of metabolic-hormonal parameters triggered by refeeding upon the Slc2a4 expression. MATERIALS/METHODS Plasma glucose/insulin/T3, and gastrocnemius Slc2a4 mRNA contents were measured in rats studied at the end of 48-h fasting, and subsequently at: i) 2-4h after spontaneous refeeding; ii) 2-4h after T3 injection, without refeeding; and iii) 0.5-2h after intravenous infusion of insulin, insulin+glucose and insulin+amino acids, without refeeding. RESULTS Refeeding increased plasma glucose/insulin/T3 and muscle Slc2a4 mRNA, reverting insulin resistance. Post-fasting infusions surprisingly induced a further Slc2a4 mRNA decrease (~20%, P<0.05 vs. fasting), but T3 injection induced a ~2-fold increase in Slc2a4 mRNA, 2-4h later (P<0.001). Moreover, T3 increased glycemia and insulinemia to the 2h-refed rats levels, suggesting that T3 elevation is a key factor to the mechanisms of metabolic balance during refeeding. CONCLUSIONS Refeeding induces a rapid increase in muscle Slc2a4 expression, not associated with increased plasma glucose, insulin or amino acids, but highly correlated to increased plasma T3 concentration. This result points out T3 hormone as a powerful Slc2a4 enhancer, an effect that may be acutely explored in situations of insulin resistance.
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Affiliation(s)
- Melissa Moreira Zanquetta
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05088-900, Brazil
| | - Ana Barbara Alves-Wagner
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05088-900, Brazil
| | - Rosana Cristina Mori
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05088-900, Brazil.
| | - Raquel Saldanha Campello
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05088-900, Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05088-900, Brazil
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Mechanisms regulating GLUT4 transcription in skeletal muscle cells are highly conserved across vertebrates. PLoS One 2013; 8:e80628. [PMID: 24260440 PMCID: PMC3832493 DOI: 10.1371/journal.pone.0080628] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 10/03/2013] [Indexed: 12/30/2022] Open
Abstract
The glucose transporter 4 (GLUT4) plays a key role in glucose uptake in insulin target tissues. This transporter has been extensively studied in many species in terms of its function, expression and cellular traffic and complex mechanisms are involved in its regulation at many different levels. However, studies investigating the transcription of the GLUT4 gene and its regulation are scarce. In this study, we have identified the GLUT4 gene in a teleost fish, the Fugu (Takifugu rubripes), and have cloned and characterized a functional promoter of this gene for the first time in a non-mammalian vertebrate. In silico analysis of the Fugu GLUT4 promoter identified potential binding sites for transcription factors such as SP1, C/EBP, MEF2, KLF, SREBP-1c and GC-boxes, as well as a CpG island, but failed to identify a TATA box. In vitro analysis revealed three transcription start sites, with the main residing 307 bp upstream of the ATG codon. Deletion analysis determined that the core promoter was located between nucleotides -132/+94. By transfecting a variety of 5´deletion constructs into L6 muscle cells we have determined that Fugu GLUT4 promoter transcription is regulated by insulin, PG-J2, a PPARγ agonist, and electrical pulse stimulation. Furthermore, our results suggest the implication of motifs such as PPARγ/RXR and HIF-1α in the regulation of Fugu GLUT4 promoter activity by PPARγ and contractile activity, respectively. These data suggest that the characteristics and regulation of the GLUT4 promoter have been remarkably conserved during the evolution from fish to mammals, further evidencing the important role of GLUT4 in metabolic regulation in vertebrates.
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Furuya DT, Neri EA, Poletto AC, Anhê GF, Freitas HS, Campello RS, Rebouças NA, Machado UF. Identification of nuclear factor-κB sites in the Slc2a4 gene promoter. Mol Cell Endocrinol 2013; 370:87-95. [PMID: 23462193 DOI: 10.1016/j.mce.2013.01.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/26/2012] [Accepted: 01/22/2013] [Indexed: 11/15/2022]
Abstract
Glucose transporter GLUT4 protein, codified by Slc2a4 gene plays a key role in glycemic homeostasis. Insulin resistance, as in obesity, has been associated to inflammatory state, in which decreased GLUT4 is a feature. Inflammatory NF-κB transcriptional factor has been proposed as a repressor of Slc2a4; although, the binding site(s) in Slc2a4 promoter and the direct repressor effect have never been reported yet. A motif-based sequence analysis of mouse Slc2a4 promoter revealed two putative κB sites located inside -83/-62 and -134/-113 bp. Eletrophoretic mobility assay showed that p50 and p65 NF-κB subunits bind to both putative κB sites. Chromatin immunoprecipitation assay using genomic DNA from adipocytes confirmed p50- and p65-binding to Slc2a4 promoter. Moreover, transfection experiments revealed that NF-κB binds to the -134/-113bp region of the mouse Slc2a4 gene promoter, inhibiting the Slc2a4 gene transcription. The current findings demonstrate the existence of two κB sites in Slc2a4 gene promote, and that NF-κB has a direct repressor effect upon the Slc2a4 gene, providing an important link between insulin resistance and inflammation.
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Affiliation(s)
- D T Furuya
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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19
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Girgis CM, Cheng K, Scott CH, Gunton JE. Novel links between HIFs, type 2 diabetes, and metabolic syndrome. Trends Endocrinol Metab 2012; 23:372-80. [PMID: 22766319 DOI: 10.1016/j.tem.2012.05.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/03/2012] [Accepted: 05/05/2012] [Indexed: 12/25/2022]
Abstract
Hypoxia inducible factors (HIFs) are master-regulators of cellular responses to hypoxia, and thus are crucial for survival. HIFs also play a role in regulating cellular processes in β-cells, liver, muscle, and adipose tissue, have effects on the regulation of weight, and play a role in type 2 diabetes (T2D). Indeed, in people with T2D the HIF pathway is dyregulated in major metabolic tissues involved in the pathogenesis of diabetes. This review covers the contrasting, complementary and conflicting effects of decreasing and increasing HIFs in various tissues, and shows that a delicate balance exists between HIF levels and optimal metabolic function. We propose that increasing the activity of HIFs might be a potential therapeutic strategy for treating T2D.
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Affiliation(s)
- Christian M Girgis
- Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia
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20
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de Leon EB, Bortoluzzi A, Rucatti A, Nunes RB, Saur L, Rodrigues M, Oliveira U, Alves-Wagner AB, Xavier LL, Machado UF, Schaan BD, Dall'Ago P. Neuromuscular electrical stimulation improves GLUT-4 and morphological characteristics of skeletal muscle in rats with heart failure. Acta Physiol (Oxf) 2011; 201:265-73. [PMID: 20698833 DOI: 10.1111/j.1748-1716.2010.02176.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM Changes in skeletal muscle morphology and metabolism are associated with limited functional capacity in heart failure, which can be attenuated by neuromuscular electrical stimulation (ES). The purpose of the present study was to analyse the effects of ES upon GLUT-4 protein content, fibre structure and vessel density of the skeletal muscle in a rat model of HF subsequent to myocardial infarction. METHODS Forty-four male Wistar rats were assigned to one of four groups: sham (S), sham submitted to ES (S+ES), heart failure (HF) and heart failure submitted to ES (HF+ES). The rats in the ES groups were submitted to ES of the left leg during 20 days (2.5 kHz, once a day, 30 min, duty cycle 50%- 15 s contraction/15 s rest). After this period, the left tibialis anterior muscle was collected from all the rats for analysis. RESULTS HF+ES rats showed lower values of lung congestion when compared with HF rats (P = 0.0001). Although muscle weight was lower in HF rats than in the S group, thus indicating hypotrophy, 20 days of ES led to their recovery (P < 0.0001). In both groups submitted to ES, there was an increase in muscle vessel density (P < 0.04). Additionally, heart failure determined a 49% reduction in GLUT-4 protein content (P < 0.03), which was recovered by ES (P < 0.01). CONCLUSION In heart failure, ES improves morphological changes and raises GLUT-4 content in skeletal muscle.
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Affiliation(s)
- E B de Leon
- Laboratório de Fisiologia, UFCSPA, Rio Grande do Sul, Brazil
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Del Duca D, Wong G, Trieu P, Rodaros D, Kouremenos A, Tadevosyan A, Vaniotis G, Villeneuve LR, Tchervenkov CI, Nattel S, Allen BG, Hébert TE, Rohlicek CV. Association of neonatal hypoxia with lasting changes in left ventricular gene expression: an animal model. J Thorac Cardiovasc Surg 2009; 138:538-46, 546.e1. [PMID: 19698832 DOI: 10.1016/j.jtcvs.2009.04.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 04/01/2009] [Accepted: 04/27/2009] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Innovations in pediatric cardiovascular surgery have resulted in significant improvements in survival for children with congenital heart disease. In adults with such disease, however, surgical morbidity and mortality remain significant. We hypothesized that hypoxemia in early life causes lasting changes in gene expression in the developing heart and that such changes may persist into later life, affecting the physiology of the adult myocardium. METHODS Microarray expression analyses were performed with left ventricular tissue from 10- and 90-day-old rats exposed to hypoxia (inspired oxygen fraction 0.12) for the first 10 days after birth then subsequently reared in ambient air and with tissue from age-matched rats reared entirely in ambient air. Changes in expression of selected genes were confirmed with real-time reverse transcriptase polymerase chain reaction. Left ventricular cardiomyocytes were isolated from adult animals in both groups, and cellular morphology and viability were compared. RESULTS Microarray analyses revealed significant changes in 1945 and 422 genes in neonates and adults, respectively. Changes in genes associated with adaptive vascular remodeling and energy homeostasis, as well as regulation of apoptosis, were confirmed by real-time reverse transcriptase polymerase chain reaction. The viability of cardiomyocytes isolated from hypoxic animals was significantly lower than in those from control animals (36.7% +/- 13.3% vs 85.0% +/- 2.9%, P = .024). CONCLUSIONS Neonatal hypoxia is associated with significant changes in left ventricular gene expression in both neonatal and adult rats. This may have physiologic implications for the adult myocardium.
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Affiliation(s)
- Danny Del Duca
- Division of Cardiovascular Surgery, Montréal Children's Hospital-McGill University Health Centre, Montréal, Québec, Canada
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