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Carrillo ED, Hernández DI, Clara MV, Lezama I, García MC, Sánchez JA. Exercise increases MEF2A abundance in rat cardiac muscle by downregulating microRNA-223-5p. Sci Rep 2023; 13:14481. [PMID: 37660209 PMCID: PMC10475133 DOI: 10.1038/s41598-023-41696-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/30/2023] [Indexed: 09/04/2023] Open
Abstract
Exercise plays an important role in cardiac health and enhances the transport of glucose in cardiac muscle by increasing the glucose transporter-4 (GLUT4) content at the cell membrane. The GLUT4 gene is a target of myocyte enhancer transcription factor 2A (MEF2A). Several transcription factors are regulated by microRNAs (miRs), small non-coding RNAs that control gene expression at the posttranscriptional level. In this study we tested the hypothesis that exercise regulates the expression of miR-223 and that MEF2A is a direct target of miR-223. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot experiments showed that GLUT4 gene expression and protein abundance increased by 30 and 23%, respectively, in the microsomal fraction immediately after exercise, and had returned to control levels after 18 h. In contrast, the increase in GLUT4 in the membrane fraction was delayed. Exercise also increased the protein abundance of transcription factors involved in GLUT4 expression. Immediately after exercise, the protein abundance of MEF2A, nuclear respiratory factor 1 (NRF1), and forkhead box O1 (FOXO1) increased by 18, 30, and 40%, respectively. qRT-PCR experiments showed that miR-223-3p and miR-223-5p expression decreased immediately after exercise by 60 and 30%, respectively, and luciferase assays indicated that MEF2A is a target of the 5p strand of miR-223. Overexpression of miR-223-5p in H9c2 cells decreased the protein abundance of MEF2A. Our results suggest that the exercise-induced increase in GLUT4 content in cardiac muscle is partly due to the posttranscriptional increase in MEF2A protein abundance caused by the decrease in miR-223-5p expression. The exercise-induced decrease in miR-223-3p expression likely contributes to the increases in NRF1 and FOXO1 abundance and GLUT4 content.
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Affiliation(s)
- Elba D Carrillo
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico
| | - Dulce I Hernández
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico
| | - Maikel Valle Clara
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico
| | - Ivonne Lezama
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico
| | - María C García
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico
| | - Jorge A Sánchez
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, CP 07360, Mexico City, Mexico.
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2
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Chang YC, Chan MH, Yang YF, Li CH, Hsiao M. Glucose transporter 4: Insulin response mastermind, glycolysis catalyst and treatment direction for cancer progression. Cancer Lett 2023; 563:216179. [PMID: 37061122 DOI: 10.1016/j.canlet.2023.216179] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/27/2023] [Accepted: 04/07/2023] [Indexed: 04/17/2023]
Abstract
The glucose transporter family (GLUT) consists of fourteen members. It is responsible for glucose homeostasis and glucose transport from the extracellular space to the cell cytoplasm to further cascade catalysis. GLUT proteins are encoded by the solute carrier family 2 (SLC2) genes and are members of the major facilitator superfamily of membrane transporters. Moreover, different GLUTs also have their transporter kinetics and distribution, so each GLUT member has its uniqueness and importance to play essential roles in human physiology. Evidence from many studies in the field of diabetes showed that GLUT4 travels between the plasma membrane and intracellular vesicles (GLUT4-storage vesicles, GSVs) and that the PI3K/Akt pathway regulates this activity in an insulin-dependent manner or by the AMPK pathway in response to muscle contraction. Moreover, some published results also pointed out that GLUT4 mediates insulin-dependent glucose uptake. Thus, dysfunction of GLUT4 can induce insulin resistance, metabolic reprogramming in diverse chronic diseases, inflammation, and cancer. In addition to the relationship between GLUT4 and insulin response, recent studies also referred to the potential upstream transcription factors that can bind to the promoter region of GLUT4 to regulating downstream signals. Combined all of the evidence, we conclude that GLUT4 has shown valuable unknown functions and is of clinical significance in cancers, which deserves our in-depth discussion and design compounds by structure basis to achieve therapeutic effects. Thus, we intend to write up a most updated review manuscript to include the most recent and critical research findings elucidating how and why GLUT4 plays an essential role in carcinogenesis, which may have broad interests and impacts on this field.
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Affiliation(s)
- Yu-Chan Chang
- Department of Biomedical Imaging and Radiological Science, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ming-Hsien Chan
- Department of Biomedical Imaging and Radiological Science, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Fang Yang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Chien-Hsiu Li
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Michael Hsiao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan; Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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3
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Saxton MW, Perry BW, Evans Hutzenbiler BD, Trojahn S, Gee A, Brown AP, Merrihew GE, Park J, Cornejo OE, MacCoss MJ, Robbins CT, Jansen HT, Kelley JL. Serum plays an important role in reprogramming the seasonal transcriptional profile of brown bear adipocytes. iScience 2022; 25:105084. [PMID: 36317158 PMCID: PMC9617460 DOI: 10.1016/j.isci.2022.105084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/30/2022] [Accepted: 09/01/2022] [Indexed: 11/19/2022] Open
Abstract
Understanding how metabolic reprogramming happens in cells will aid the progress in the treatment of a variety of metabolic disorders. Brown bears undergo seasonal shifts in insulin sensitivity, including reversible insulin resistance in hibernation. We performed RNA-sequencing on brown bear adipocytes and proteomics on serum to identify changes possibly responsible for reversible insulin resistance. We observed dramatic transcriptional changes, which depended on both the cell and serum season of origin. Despite large changes in adipocyte gene expression, only changes in eight circulating proteins were identified as related to the seasonal shifts in insulin sensitivity, including some that have not previously been associated with glucose homeostasis. The identified serum proteins may be sufficient for shifting hibernation adipocytes to an active-like state. Hibernation in grizzly bears is marked by insulin resistance Bear adipocytes were stimulated with active and hibernating bear blood serum Serum elicited dramatic gene expression responses related to insulin signaling Eight serum proteins were implicated in driving this transcriptional response
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Affiliation(s)
- Michael W. Saxton
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | - Blair W. Perry
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | | | - Shawn Trojahn
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | - Alexia Gee
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | - Anthony P. Brown
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | | | - Jea Park
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Omar E. Cornejo
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Charles T. Robbins
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
- School of the Environment, Washington State University, Pullman, WA 99163, USA
| | - Heiko T. Jansen
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99163, USA
| | - Joanna L. Kelley
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
- Corresponding author
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Liu B, Ou WC, Fang L, Tian CW, Xiong Y. Myocyte Enhancer Factor 2A Plays a Central Role in the Regulatory Networks of Cellular Physiopathology. Aging Dis 2022; 14:331-349. [PMID: 37008050 PMCID: PMC10017154 DOI: 10.14336/ad.2022.0825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/25/2022] [Indexed: 11/18/2022] Open
Abstract
Cell regulatory networks are the determinants of cellular homeostasis. Any alteration to these networks results in the disturbance of cellular homeostasis and induces cells towards different fates. Myocyte enhancer factor 2A (MEF2A) is one of four members of the MEF2 family of transcription factors (MEF2A-D). MEF2A is highly expressed in all tissues and is involved in many cell regulatory networks including growth, differentiation, survival and death. It is also necessary for heart development, myogenesis, neuronal development and differentiation. In addition, many other important functions of MEF2A have been reported. Recent studies have shown that MEF2A can regulate different, and sometimes even mutually exclusive cellular events. How MEF2A regulates opposing cellular life processes is an interesting topic and worthy of further exploration. Here, we reviewed almost all MEF2A research papers published in English and summarized them into three main sections: 1) the association of genetic variants in MEF2A with cardiovascular disease, 2) the physiopathological functions of MEF2A, and 3) the regulation of MEF2A activity and its regulatory targets. In summary, multiple regulatory patterns for MEF2A activity and a variety of co-factors cause its transcriptional activity to switch to different target genes, thereby regulating opposing cell life processes. The association of MEF2A with numerous signaling molecules establishes a central role for MEF2A in the regulatory network of cellular physiopathology.
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Affiliation(s)
- Benrong Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
- Correspondence should be addressed to: Dr. Benrong Liu, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong, China. E-mail: ; or Yujuan Xiong, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangdong, China. .
| | - Wen-Chao Ou
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Lei Fang
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Chao-Wei Tian
- General Practice, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Yujuan Xiong
- Department of Laboratory Medicine, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.
- Correspondence should be addressed to: Dr. Benrong Liu, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong, China. E-mail: ; or Yujuan Xiong, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangdong, China. .
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5
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AKT2 regulates development and metabolic homeostasis via AMPK-depedent pathway in skeletal muscle. Clin Sci (Lond) 2021; 134:2381-2398. [PMID: 32880392 DOI: 10.1042/cs20191320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Skeletal muscle is responsible for the majority of glucose disposal in the body. Insulin resistance in the skeletal muscle accounts for 85-90% of the impairment of total glucose disposal in patients with type 2 diabetes (T2D). However, the mechanism remains controversial. The present study aims to investigate whether AKT2 deficiency causes deficits in skeletal muscle development and metabolism, we analyzed the expression of molecules related to skeletal muscle development, glucose uptake and metabolism in mice of 3- and 8-months old. We found that AMP-activated protein kinase (AMPK) phosphorylation and myocyte enhancer factor 2 (MEF2) A (MEF2A) expression were down-regulated in AKT2 knockout (KO) mice, which can be inverted by AMPK activation. We also observed reduced mitochondrial DNA (mtDNA) abundance and reduced expression of genes involved in mitochondrial biogenesis in the skeletal muscle of AKT2 KO mice, which was prevented by AMPK activation. Moreover, AKT2 KO mice exhibited impaired AMPK signaling in response to insulin stimulation compared with WT mice. Our study establishes a new and important function of AKT2 in regulating skeletal muscle development and glucose metabolism via AMPK-dependent signaling.
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Programming Skeletal Muscle Metabolic Flexibility in Offspring of Male Rats in Response to Maternal Consumption of Slow Digesting Carbohydrates during Pregnancy. Nutrients 2020; 12:nu12020528. [PMID: 32092940 PMCID: PMC7071425 DOI: 10.3390/nu12020528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/14/2020] [Accepted: 02/15/2020] [Indexed: 01/20/2023] Open
Abstract
Skeletal muscle plays a relevant role in metabolic flexibility and fuel usage and the associated muscle metabolic inflexibility due to high-fat diets contributing to obesity and type 2 diabetes. Previous research from our group indicates that a high-fat and rapid-digesting carbohydrate diet during pregnancy promotes an excessive adipogenesis and also increases the risk of non-alcoholic fatty liver disease in the offspring. This effect can be counteracted by diets containing carbohydrates with similar glycemic load but lower digestion rates. To address the role of the skeletal muscle in these experimental settings, pregnant rats were fed high-fat diets containing carbohydrates with similar glycemic load but different digestion rates, a high fat containing rapid-digesting carbohydrates diet (HF/RD diet) or a high fat containing slow-digesting carbohydrates diet (HF/SD diet). After weaning, male offspring were fed a standard diet for 3 weeks (weaning) or 10 weeks (adolescence) and the impact of the maternal HF/RD and HF/SD diets on the metabolism, signaling pathways and muscle transcriptome was analyzed. The HF/SD offspring displayed better muscle features compared with the HF/RD group, showing a higher muscle mass, myosin content and differentiation markers that translated into a greater grip strength. In the HF/SD group, metabolic changes such as a higher expression of fatty acids (FAT/CD36) and glucose (GLUT4) transporters, an enhanced glycogen content, as well as changes in regulatory enzymes such as muscle pyruvate kinase and pyruvate dehydrogenase kinase 4 were found, supporting an increased muscle metabolic flexibility and improved muscle performance. The analysis of signaling pathways was consistent with a better insulin sensitivity in the muscle of the HF/SD group. Furthermore, increased expression of genes involved in pathways leading to muscle differentiation, muscle mass regulation, extracellular matrix content and insulin sensitivity were detected in the HF/SD group when compared with HF/RD animals. In the HF/SD group, the upregulation of the ElaV1/HuR gene could be one of the main regulators in the positive effects of the diet in early programming on the offspring. The long-lasting programming effects of the HF/SD diet during pregnancy may depend on a coordinated gene regulation, modulation of signaling pathways and metabolic flexibility that lead to an improved muscle functionality. The dietary early programming associated to HF/SD diet has synergic and positive crosstalk effects in several tissues, mainly muscle, liver and adipose tissue, contributing to maintain the whole body homeostasis in the offspring.
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7
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Hevener AL, Ribas V, Moore TM, Zhou Z. The Impact of Skeletal Muscle ERα on Mitochondrial Function and Metabolic Health. Endocrinology 2020; 161:5735479. [PMID: 32053721 PMCID: PMC7017798 DOI: 10.1210/endocr/bqz017] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 02/11/2020] [Indexed: 12/16/2022]
Abstract
The incidence of chronic disease is elevated in women after menopause. Increased expression of ESR1 (the gene that encodes the estrogen receptor alpha, ERα) in muscle is highly associated with metabolic health and insulin sensitivity. Moreover, reduced muscle expression levels of ESR1 are observed in women, men, and animals presenting clinical features of the metabolic syndrome (MetSyn). Considering that metabolic dysfunction elevates chronic disease risk, including type 2 diabetes, heart disease, and certain cancers, treatment strategies to combat metabolic dysfunction and associated pathologies are desperately needed. This review will provide published work supporting a critical and protective role for skeletal muscle ERα in the regulation of mitochondrial function, metabolic homeostasis, and insulin action. We will provide evidence that muscle-selective targeting of ERα may be effective for the preservation of mitochondrial and metabolic health. Collectively published findings support a compelling role for ERα in the control of muscle metabolism via its regulation of mitochondrial function and quality control. Studies identifying ERα-regulated pathways essential for disease prevention will lay the important foundation for the design of novel therapeutics to improve metabolic health of women while limiting secondary complications that have historically plagued traditional hormone replacement interventions.
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Affiliation(s)
- Andrea L Hevener
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension, University of California, Los Angeles, California
- Iris Cantor-UCLA Women’s Health Research Center, University of California, Los Angeles, California
- Correspondence: Andrea L. Hevener, PhD, University of California, Los Angeles, David Geffen School of Medicine, Division of Endocrinology, Diabetes, and Hypertension, 650 Charles E. Young Drive, CHS Suite 34-115B, Los Angeles, California 90095–7073. E-mail:
| | - Vicent Ribas
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension, University of California, Los Angeles, California
- Current Affiliation: Vicent Ribas, Department of cell death and proliferation Instituto de Investigaciones Biomédicas de Barcelona, (IIBB-CSIC) Spanish National Research Council C/Rosselló 179, 6th floor 08036, Barcelona Spain
| | - Timothy M Moore
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension, University of California, Los Angeles, California
| | - Zhenqi Zhou
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension, University of California, Los Angeles, California
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Cytotoxicity and in vitro evaluation of whey protein-based hydrogels for diabetes mellitus treatment. INTERNATIONAL JOURNAL OF INDUSTRIAL CHEMISTRY 2019. [DOI: 10.1007/s40090-019-0185-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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NURR1 activation in skeletal muscle controls systemic energy homeostasis. Proc Natl Acad Sci U S A 2019; 116:11299-11308. [PMID: 31110021 DOI: 10.1073/pnas.1902490116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Skeletal muscle plays a central role in the control of metabolism and exercise tolerance. Analysis of muscle enhancers activated after exercise in mice revealed the orphan nuclear receptor NURR1/NR4A2 as a prominent component of exercise-responsive enhancers. We show that exercise enhances the expression of NURR1, and transgenic overexpression of NURR1 in skeletal muscle enhances physical performance in mice. NURR1 expression in skeletal muscle is also sufficient to prevent hyperglycemia and hepatic steatosis, by enhancing muscle glucose uptake and storage as glycogen. Furthermore, treatment of obese mice with putative NURR1 agonists increases energy expenditure, improves glucose tolerance, and confers a lean phenotype, mimicking the effects of exercise. These findings identify a key role for NURR1 in governance of skeletal muscle glucose metabolism, and reveal a transcriptional link between exercise and metabolism. Our findings also identify NURR1 agonists as possible exercise mimetics with the potential to ameliorate obesity and other metabolic abnormalities.
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10
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Koh JH, Hancock CR, Han DH, Holloszy JO, Nair KS, Dasari S. AMPK and PPARβ positive feedback loop regulates endurance exercise training-mediated GLUT4 expression in skeletal muscle. Am J Physiol Endocrinol Metab 2019; 316:E931-E939. [PMID: 30888859 PMCID: PMC6580175 DOI: 10.1152/ajpendo.00460.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The objective of this study is to determine whether AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α), or peroxisome proliferator-activated receptor β (PPARβ) can independently mediate the increase of glucose transporter type 4 (GLUT4) expression that occurs in response to exercise training. We found that PPARβ can regulate GLUT4 expression without PGC-1α. We also found AMPK and PPARβ are important for maintaining normal physiological levels of GLUT4 protein in the sedentary condition as well following exercise training. However, AMPK and PPARβ are not essential for the increase in GLUT4 protein expression that occurs in response to exercise training. We discovered that AMPK activation increases PPARβ via myocyte enhancer factor 2A (MEF2A), which acted as a transcription factor for PPARβ. Furthermore, exercise training increases the cooperation of AMPK and PPARβ to regulate glucose uptake. In conclusion, cooperation between AMPK and PPARβ via NRF-1/MEF2A pathway enhances the exercise training mediated adaptive increase in GLUT4 expression and subsequent glucose uptake in skeletal muscle.
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Affiliation(s)
- Jin-Ho Koh
- Department of Internal Medicine, Mayo Clinic , Rochester, Minnesota
- Department of Physiology, College of Medicine, Yeungnam University , Daegu , Korea
| | - Chad R Hancock
- Department of Nutrition, Dietetics and Food Science, Brigham Young University , Provo, Utah
| | - Dong-Ho Han
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine , St. Louis, Missouri
| | - John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine , St. Louis, Missouri
| | | | - Surendra Dasari
- Department of Health Sciences Research, Mayo Clinic , Rochester, Minnesota
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11
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Hevener AL, Zhou Z, Moore TM, Drew BG, Ribas V. The impact of ERα action on muscle metabolism and insulin sensitivity - Strong enough for a man, made for a woman. Mol Metab 2018; 15:20-34. [PMID: 30005878 PMCID: PMC6066787 DOI: 10.1016/j.molmet.2018.06.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/16/2018] [Accepted: 06/18/2018] [Indexed: 12/25/2022] Open
Abstract
Background The incidence of chronic disease is elevated in women after menopause. Natural variation in muscle expression of the estrogen receptor (ER)α is inversely associated with plasma insulin and adiposity. Moreover, reduced muscle ERα expression levels are observed in women and animals presenting clinical features of the metabolic syndrome (MetSyn). Considering that metabolic dysfunction impacts nearly a quarter of the U.S. adult population and elevates chronic disease risk including type 2 diabetes, heart disease, and certain cancers, treatment strategies to combat metabolic dysfunction and associated pathologies are desperately needed. Scope of the review This review will provide evidence supporting a critical and protective role for skeletal muscle ERα in the regulation of metabolic homeostasis and insulin sensitivity, and propose novel ERα targets involved in the maintenance of metabolic health. Major conclusions Studies identifying ERα-regulated pathways essential for disease prevention will lay the important foundation for the rational design of novel therapeutics to improve the metabolic health of women while limiting secondary complications that have plagued traditional hormone replacement interventions.
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Affiliation(s)
- Andrea L Hevener
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
| | - Zhenqi Zhou
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Timothy M Moore
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Brian G Drew
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Vicent Ribas
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
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12
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Amoasii L, Olson EN, Bassel-Duby R. Control of Muscle Metabolism by the Mediator Complex. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029843. [PMID: 28432117 DOI: 10.1101/cshperspect.a029843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Exercise represents an energetic challenge to whole-body homeostasis. In skeletal muscle, exercise activates a variety of signaling pathways that culminate in the nucleus to regulate genes involved in metabolism and contractility; however, much remains to be learned about the transcriptional effectors of exercise. Mediator is a multiprotein complex that links signal-dependent transcription factors and other transcriptional regulators with the basal transcriptional machinery, thereby serving as a transcriptional "hub." In this article, we discuss recent studies highlighting the role of Mediator subunits in metabolic regulation and glucose metabolism, as well as exercise responsiveness. Elucidation of the roles of Mediator subunits in metabolic control has revealed new mechanisms and molecular targets for the modulation of metabolism and metabolic disorders.
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Affiliation(s)
- Leonela Amoasii
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
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13
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Kjøbsted R, Hingst JR, Fentz J, Foretz M, Sanz MN, Pehmøller C, Shum M, Marette A, Mounier R, Treebak JT, Wojtaszewski JFP, Viollet B, Lantier L. AMPK in skeletal muscle function and metabolism. FASEB J 2018; 32:1741-1777. [PMID: 29242278 PMCID: PMC5945561 DOI: 10.1096/fj.201700442r] [Citation(s) in RCA: 249] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Skeletal muscle possesses a remarkable ability to adapt to various physiologic conditions. AMPK is a sensor of intracellular energy status that maintains energy stores by fine-tuning anabolic and catabolic pathways. AMPK’s role as an energy sensor is particularly critical in tissues displaying highly changeable energy turnover. Due to the drastic changes in energy demand that occur between the resting and exercising state, skeletal muscle is one such tissue. Here, we review the complex regulation of AMPK in skeletal muscle and its consequences on metabolism (e.g., substrate uptake, oxidation, and storage as well as mitochondrial function of skeletal muscle fibers). We focus on the role of AMPK in skeletal muscle during exercise and in exercise recovery. We also address adaptations to exercise training, including skeletal muscle plasticity, highlighting novel concepts and future perspectives that need to be investigated. Furthermore, we discuss the possible role of AMPK as a therapeutic target as well as different AMPK activators and their potential for future drug development.—Kjøbsted, R., Hingst, J. R., Fentz, J., Foretz, M., Sanz, M.-N., Pehmøller, C., Shum, M., Marette, A., Mounier, R., Treebak, J. T., Wojtaszewski, J. F. P., Viollet, B., Lantier, L. AMPK in skeletal muscle function and metabolism.
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Affiliation(s)
- Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Janne R Hingst
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Joachim Fentz
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Marc Foretz
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Maria-Nieves Sanz
- Department of Cardiovascular Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, and.,Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Christian Pehmøller
- Internal Medicine Research Unit, Pfizer Global Research and Development, Cambridge, Massachusetts, USA
| | - Michael Shum
- Axe Cardiologie, Quebec Heart and Lung Research Institute, Laval University, Québec, Canada.,Institute for Nutrition and Functional Foods, Laval University, Québec, Canada
| | - André Marette
- Axe Cardiologie, Quebec Heart and Lung Research Institute, Laval University, Québec, Canada.,Institute for Nutrition and Functional Foods, Laval University, Québec, Canada
| | - Remi Mounier
- Institute NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM Unité 1217, CNRS UMR, Villeurbanne, France
| | - Jonas T Treebak
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Benoit Viollet
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA.,Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee, USA
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14
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Hevener AL, Zhou Z, Drew BG, Ribas V. The Role of Skeletal Muscle Estrogen Receptors in Metabolic Homeostasis and Insulin Sensitivity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1043:257-284. [PMID: 29224099 DOI: 10.1007/978-3-319-70178-3_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Women in the modern era are challenged with facing menopausal symptoms as well as heightened disease risk associated with increasing adiposity and metabolic dysfunction for up to three decades of life. Treatment strategies to combat metabolic dysfunction and associated pathologies have been hampered by our lack of understanding regarding the biological causes of these clinical conditions and our incomplete understanding regarding the effects of estrogens and the tissue-specific functions and molecular actions of its receptors. In this chapter we provide evidence supporting a critical and protective role for skeletal muscle estrogen receptor α in the maintenance of metabolic homeostasis and insulin sensitivity. Studies identifying the critical ER-regulated pathways essential for disease prevention will lay the important foundation for the rational design of novel therapeutic strategies to improve the health of women while limiting secondary complications that have plagued traditional hormone replacement interventions.
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Affiliation(s)
- Andrea L Hevener
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
| | - Zhenqi Zhou
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Brian G Drew
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Vicent Ribas
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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15
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Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells. PLoS One 2016; 11:e0158055. [PMID: 27348124 PMCID: PMC4922563 DOI: 10.1371/journal.pone.0158055] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/09/2016] [Indexed: 11/19/2022] Open
Abstract
Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin.
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16
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Wu H, Deng X, Shi Y, Su Y, Wei J, Duan H. PGC-1α, glucose metabolism and type 2 diabetes mellitus. J Endocrinol 2016; 229:R99-R115. [PMID: 27094040 DOI: 10.1530/joe-16-0021] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 04/11/2016] [Indexed: 12/24/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by glucose metabolic disturbance. A number of transcription factors and coactivators are involved in this process. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is an important transcription coactivator regulating cellular energy metabolism. Accumulating evidence has indicated that PGC-1α is involved in the regulation of T2DM. Therefore, a better understanding of the roles of PGC-1α may shed light on more efficient therapeutic strategies. Here, we review the most recent progress on PGC-1α and discuss its regulatory network in major glucose metabolic tissues such as the liver, skeletal muscle, pancreas and kidney. The significant associations between PGC-1α polymorphisms and T2DM are also discussed in this review.
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Affiliation(s)
- Haijiang Wu
- Department of PathologyHebei Medical University, Shijiazhuang, China Key Laboratory of Kidney Diseases of Hebei ProvinceShijiazhuang, China
| | - Xinna Deng
- Departments of Oncology & ImmunotherapyHebei General Hospital, Shijiazhuang, China
| | - Yonghong Shi
- Department of PathologyHebei Medical University, Shijiazhuang, China Key Laboratory of Kidney Diseases of Hebei ProvinceShijiazhuang, China
| | - Ye Su
- Mathew Mailing Centre for Translational Transplantation StudiesLawson Health Research Institute, London Health Sciences Centre, London, Ontario, Canada Departments of Medicine and PathologyUniversity of Western Ontario, London, Ontario, Canada
| | - Jinying Wei
- Department of PathologyHebei Medical University, Shijiazhuang, China Key Laboratory of Kidney Diseases of Hebei ProvinceShijiazhuang, China
| | - Huijun Duan
- Department of PathologyHebei Medical University, Shijiazhuang, China Key Laboratory of Kidney Diseases of Hebei ProvinceShijiazhuang, China
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17
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Nutter CA, Jaworski EA, Verma SK, Deshmukh V, Wang Q, Botvinnik OB, Lozano MJ, Abass IJ, Ijaz T, Brasier AR, Garg NJ, Wehrens XHT, Yeo GW, Kuyumcu-Martinez MN. Dysregulation of RBFOX2 Is an Early Event in Cardiac Pathogenesis of Diabetes. Cell Rep 2016; 15:2200-2213. [PMID: 27239029 DOI: 10.1016/j.celrep.2016.05.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 01/25/2016] [Accepted: 04/27/2016] [Indexed: 12/27/2022] Open
Abstract
Alternative splicing (AS) defects that adversely affect gene expression and function have been identified in diabetic hearts; however, the mechanisms responsible are largely unknown. Here, we show that the RNA-binding protein RBFOX2 contributes to transcriptome changes under diabetic conditions. RBFOX2 controls AS of genes with important roles in heart function relevant to diabetic cardiomyopathy. RBFOX2 protein levels are elevated in diabetic hearts despite low RBFOX2 AS activity. A dominant-negative (DN) isoform of RBFOX2 that blocks RBFOX2-mediated AS is generated in diabetic hearts. DN RBFOX2 interacts with wild-type (WT) RBFOX2, and ectopic expression of DN RBFOX2 inhibits AS of RBFOX2 targets. Notably, DN RBFOX2 expression is specific to diabetes and occurs at early stages before cardiomyopathy symptoms appear. Importantly, DN RBFOX2 expression impairs intracellular calcium release in cardiomyocytes. Our results demonstrate that RBFOX2 dysregulation by DN RBFOX2 is an early pathogenic event in diabetic hearts.
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Affiliation(s)
- Curtis A Nutter
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Elizabeth A Jaworski
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Sunil K Verma
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Vaibhav Deshmukh
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qiongling Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Olga B Botvinnik
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Mario J Lozano
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Ismail J Abass
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Talha Ijaz
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Allan R Brasier
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Nisha J Garg
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Medicine/Cardiology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92037, USA; Institute for Genomic Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Muge N Kuyumcu-Martinez
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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18
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Hevener AL, Clegg DJ, Mauvais-Jarvis F. Impaired estrogen receptor action in the pathogenesis of the metabolic syndrome. Mol Cell Endocrinol 2015; 418 Pt 3:306-21. [PMID: 26033249 PMCID: PMC5965692 DOI: 10.1016/j.mce.2015.05.020] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/13/2022]
Abstract
Considering the current trends in life expectancy, women in the modern era are challenged with facing menopausal symptoms as well as heightened disease risk associated with increasing adiposity and metabolic dysfunction for up to three decades of life. Treatment strategies to combat metabolic dysfunction and associated pathologies have been hampered by our lack of understanding regarding the biological underpinnings of these clinical conditions and our incomplete understanding of the effects of estrogens and the tissue-specific functions and molecular actions of its receptors. In this review we provide evidence supporting a critical and protective role for the estrogen receptor α specific form in the maintenance of metabolic homeostasis and insulin sensitivity. Studies identifying the ER-regulated pathways required for disease prevention will lay the important foundation for the rational design of targeted therapeutics to improve women's health while limiting complications that have plagued traditional hormone replacement interventions.
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Affiliation(s)
- Andrea L Hevener
- Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension, David Geffen School of Medicine, Iris Cantor-UCLA Women's Health Center, University of California, Los Angeles, CA 90095, USA.
| | - Deborah J Clegg
- Department of Biomedical Sciences, Diabetes and Obesity Research Institute Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Franck Mauvais-Jarvis
- Section of Endocrinology, Department of Medicine Tulane University, Health Science Center New Orleans, New Orleans, LA 70112, USA
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19
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Alves-Wagner AB, Mori RC, Sabino-Silva R, Fatima LA, da Silva Alves A, Britto LR, D'Agord Schaan B, Machado UF. Beta-adrenergic blockade increases GLUT4 and improves glycemic control in insulin-treated diabetic Wistar rats. Auton Neurosci 2015; 193:108-16. [DOI: 10.1016/j.autneu.2015.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/25/2015] [Accepted: 10/27/2015] [Indexed: 12/20/2022]
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20
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Inhibition of MEF2A prevents hyperglycemia-induced extracellular matrix accumulation by blocking Akt and TGF-β1/Smad activation in cardiac fibroblasts. Int J Biochem Cell Biol 2015; 69:52-61. [DOI: 10.1016/j.biocel.2015.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/19/2015] [Accepted: 10/13/2015] [Indexed: 02/07/2023]
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21
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trans-Cinnamaldehyde stimulates mitochondrial biogenesis through PGC-1α and PPARβ/δ leading to enhanced GLUT4 expression. Biochimie 2015; 119:45-51. [DOI: 10.1016/j.biochi.2015.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/01/2015] [Indexed: 11/22/2022]
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22
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Liang Y, Yuan W, Zhu W, Zhu J, Lin Q, Zou X, Deng C, Fu Y, Zheng X, Yang M, Wu S, Yu X, Shan Z. Macrophage migration inhibitory factor promotes expression of GLUT4 glucose transporter through MEF2 and Zac1 in cardiomyocytes. Metabolism 2015; 64:1682-93. [PMID: 26455966 DOI: 10.1016/j.metabol.2015.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 08/20/2015] [Accepted: 09/08/2015] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Evidence shows that both macrophage migration inhibitory factor (MIF) and GLUT4 glucose transporter are involved in diabetic cardiomyopathy (DCM), but it remains largely unknown whether and how MIF regulates GLUT4 expression in cardiomyocytes. The present study aims to investigate the mechanism underlying the modulation of GLUT4 by MIF in cardiomyocytes. MATERIAL AND METHODS Activations of AKT and AMPK signaling, and expressions of MIF, GLUT4 and the candidate GLUT4 regulation associated transcription factors in the diabetic mouse myocardium were determined. The screened transcription factors mediating MIF-promoted GLUT4 expression were verified by RNA interference (RNAi) and electrophoretic mobility shift assay (EMSA), respectively. RESULTS MIF was increased, but GLUT4 was decreased in the diabetic mouse myocardium. MIF could enhance glucose uptake and up-regulate GLUT4 expression in NMVCs. Expressions of transcription factor MEF2A, -2C, -2D and Zac1 were significantly up-regulated in MIF-treated neonatal mouse ventricular cardiomyocytes (NMVCs), and markedly reduced in the diabetic myocardium. Knockdown of MEF2A, -2C, -2D and Zac1 could significantly inhibit glucose uptake and GLUT4 expression in cardiomyocytes. Moreover, EMSA results revealed that transcriptional activities of MEF2 and Zac1 were significantly increased in MIF-treated NMVCs. AMPK signaling was activated in MIF-stimulated NMVCs, and AMPK activator AICAR could enhance MEF2A, -2C, -2D, Zac1 and GLUT4 expression. Additionally, MIF effects were inhibited by an AMPK inhibitor compound C and siRNA targeting MIF receptor CD74, suggesting the involvement of CD74-dependent AMPK activation. CONCLUSIONS Transcription factor MEF2 and Zac1 mediate MIF-induced GLUT4 expression through CD74-dependent AMPK activation in cardiomyocytes.
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Affiliation(s)
- Yeyou Liang
- Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, China.
| | - Weiwei Yuan
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Wensi Zhu
- Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, China.
| | - Jiening Zhu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Qiuxiong Lin
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xiao Zou
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Chunyu Deng
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Yongheng Fu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xilong Zheng
- The Libin Cardiovascular Institute of AB, Department of Biochemistry & Molecular Biology, Cumming School of Medicine, The University of Calgary, Calgary, Canada.
| | - Min Yang
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Shulin Wu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xiyong Yu
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Zhixin Shan
- Medical Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China.
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23
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Co-activator binding protein PIMT mediates TNF-α induced insulin resistance in skeletal muscle via the transcriptional down-regulation of MEF2A and GLUT4. Sci Rep 2015; 5:15197. [PMID: 26468734 PMCID: PMC4606566 DOI: 10.1038/srep15197] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/21/2015] [Indexed: 12/18/2022] Open
Abstract
The mechanisms underlying inflammation induced insulin resistance are poorly understood. Here, we report that the expression of PIMT, a transcriptional co-activator binding protein, was up-regulated in the soleus muscle of high sucrose diet (HSD) induced insulin resistant rats and TNF-α exposed cultured myoblasts. Moreover, TNF-α induced phosphorylation of PIMT at the ERK1/2 target site Ser298. Wild type (WT) PIMT or phospho-mimic Ser298Asp mutant but not phospho-deficient Ser298Ala PIMT mutant abrogated insulin stimulated glucose uptake by L6 myotubes and neonatal rat skeletal myoblasts. Whereas, PIMT knock down relieved TNF-α inhibited insulin signaling. Mechanistic analysis revealed that PIMT differentially regulated the expression of GLUT4, MEF2A, PGC-1α and HDAC5 in cultured cells and skeletal muscle of Wistar rats. Further characterization showed that PIMT was recruited to GLUT4, MEF2A and HDAC5 promoters and overexpression of PIMT abolished the activity of WT but not MEF2A binding defective mutant GLUT4 promoter. Collectively, we conclude that PIMT mediates TNF-α induced insulin resistance at the skeletal muscle via the transcriptional modulation of GLUT4, MEF2A, PGC-1α and HDAC5 genes.
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24
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Talari M, Kapadia B, Kain V, Seshadri S, Prajapati B, Rajput P, Misra P, Parsa KVL. MicroRNA-16 modulates macrophage polarization leading to improved insulin sensitivity in myoblasts. Biochimie 2015; 119:16-26. [PMID: 26453808 DOI: 10.1016/j.biochi.2015.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/05/2015] [Indexed: 12/11/2022]
Abstract
Uncontrolled inflammation leads to several diseases such as insulin resistance, T2D and several types of cancers. The functional role of microRNAs in inflammation induced insulin resistance is poorly studied. MicroRNAs are post-transcriptional regulatory molecules which mediate diverse biological processes. We here show that miR-16 expression levels are down-regulated in different inflammatory conditions such as LPS/IFNγ or palmitate treated macrophages, palmitate exposed myoblasts and insulin responsive tissues of high sucrose diet induced insulin resistant rats. Importantly, forced expression of miR-16 in macrophages impaired the production of TNF-α, IL-6 and IFN-β leading to enhanced insulin stimulated glucose uptake in co-cultured skeletal myoblasts. Further, ectopic expression of miR-16 enhanced insulin stimulated glucose uptake in skeletal myoblasts via the up-regulation of GLUT4 and MEF2A, two key players involved in insulin stimulated glucose uptake. Collectively, our data highlight the important role of miR-16 in ameliorating inflammation induced insulin resistance.
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Affiliation(s)
- Malathi Talari
- Department of Biology, Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, Telangana, India
| | - Bandish Kapadia
- Department of Biology, Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, Telangana, India
| | - Vasundhara Kain
- Department of Biology, Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, Telangana, India
| | - Sriram Seshadri
- Institute of Science, Nirma University, Sarkhej Gandhinagar Highway, Ahmedabad, Gujarat, India
| | - Bhumika Prajapati
- Institute of Science, Nirma University, Sarkhej Gandhinagar Highway, Ahmedabad, Gujarat, India
| | - Parth Rajput
- Institute of Science, Nirma University, Sarkhej Gandhinagar Highway, Ahmedabad, Gujarat, India
| | - Parimal Misra
- Department of Biology, Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, Telangana, India
| | - Kishore V L Parsa
- Department of Biology, Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, Telangana, India.
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25
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Jung H, Han S, Kim S. The Construction of Regulatory Network for Insulin-Mediated Genes by Integrating Methods Based on Transcription Factor Binding Motifs and Gene Expression Variations. Genomics Inform 2015; 13:76-80. [PMID: 26523131 PMCID: PMC4623444 DOI: 10.5808/gi.2015.13.3.76] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/15/2015] [Accepted: 09/21/2015] [Indexed: 01/22/2023] Open
Abstract
Type 2 diabetes mellitus is a complex metabolic disorder associated with multiple genetic, developmental and environmental factors. The recent advances in gene expression microarray technologies as well as network-based analysis methodologies provide groundbreaking opportunities to study type 2 diabetes mellitus. In the present study, we used previously published gene expression microarray datasets of human skeletal muscle samples collected from 20 insulin sensitive individuals before and after insulin treatment in order to construct insulin-mediated regulatory network. Based on a motif discovery method implemented by iRegulon, a Cytoscape app, we identified 25 candidate regulons, motifs of which were enriched among the promoters of 478 up-regulated genes and 82 down-regulated genes. We then looked for a hierarchical network of the candidate regulators, in such a way that the conditional combination of their expression changes may explain those of their target genes. Using Genomica, a software tool for regulatory network construction, we obtained a hierarchical network of eight regulons that were used to map insulin downstream signaling network. Taken together, the results illustrate the benefits of combining completely different methods such as motif-based regulatory factor discovery and expression level-based construction of regulatory network of their target genes in understanding insulin induced biological processes and signaling pathways.
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Affiliation(s)
- Hyeim Jung
- Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Korea
| | - Seonggyun Han
- Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Korea
| | - Sangsoo Kim
- Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Korea
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26
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Pecorella SRH, Potter JVF, Cherry AD, Peacher DF, Welty-Wolf KE, Moon RE, Piantadosi CA, Suliman HB. The HO-1/CO system regulates mitochondrial-capillary density relationships in human skeletal muscle. Am J Physiol Lung Cell Mol Physiol 2015; 309:L857-71. [PMID: 26186946 DOI: 10.1152/ajplung.00104.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/14/2015] [Indexed: 12/14/2022] Open
Abstract
The heme oxygenase-1 (HO-1)/carbon monoxide (CO) system induces mitochondrial biogenesis, but its biological impact in human skeletal muscle is uncertain. The enzyme system generates CO, which stimulates mitochondrial proliferation in normal muscle. Here we examined whether CO breathing can be used to produce a coordinated metabolic and vascular response in human skeletal muscle. In 19 healthy subjects, we performed vastus lateralis muscle biopsies and tested one-legged maximal O2 uptake (V̇o2max) before and after breathing air or CO (200 ppm) for 1 h daily for 5 days. In response to CO, there was robust HO-1 induction along with increased mRNA levels for nuclear-encoded mitochondrial transcription factor A (Tfam), cytochrome c, cytochrome oxidase subunit IV (COX IV), and mitochondrial-encoded COX I and NADH dehydrogenase subunit 1 (NDI). CO breathing did not increase V̇o2max (1.96 ± 0.51 pre-CO, 1.87 ± 0.50 post-CO l/min; P = not significant) but did increase muscle citrate synthase, mitochondrial density (139.0 ± 34.9 pre-CO, 219.0 ± 36.2 post-CO; no. of mitochondrial profiles/field), myoglobin content and glucose transporter (GLUT4) protein level and led to GLUT4 localization to the myocyte membrane, all consistent with expansion of the tissue O2 transport system. These responses were attended by increased cluster of differentiation 31 (CD31)-positive muscle capillaries (1.78 ± 0.16 pre-CO, 2.37 ± 0.59 post-CO; capillaries/muscle fiber), implying the enrichment of microvascular O2 reserve. The findings support that induction of the HO-1/CO system by CO not only improves muscle mitochondrial density, but regulates myoglobin content, GLUT4 localization, and capillarity in accordance with current concepts of skeletal muscle plasticity.
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Affiliation(s)
- Shelly R H Pecorella
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
| | - Jennifer V F Potter
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
| | - Anne D Cherry
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
| | - Dionne F Peacher
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
| | - Karen E Welty-Wolf
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Richard E Moon
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Department of Medicine, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
| | - Claude A Piantadosi
- Department of Medicine, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Hagir B Suliman
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina; and
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Yuasa K, Aoki N, Hijikata T. JAZF1 promotes proliferation of C2C12 cells, but retards their myogenic differentiation through transcriptional repression of MEF2C and MRF4-Implications for the role of Jazf1 variants in oncogenesis and type 2 diabetes. Exp Cell Res 2015; 336:287-97. [PMID: 26101156 DOI: 10.1016/j.yexcr.2015.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/09/2015] [Accepted: 06/15/2015] [Indexed: 11/16/2022]
Abstract
Single-nucleotide polymorphisms associated with type 2 diabetes (T2D) have been identified in Jazf1, which is also involved in the oncogenesis of endometrial stromal tumors. To understand how Jazf1 variants confer a risk of tumorigenesis and T2D, we explored the functional roles of JAZF1 and searched for JAZF1 target genes in myogenic C2C12 cells. Consistent with an increase of Jazf1 transcripts during myoblast proliferation and their decrease during myogenic differentiation in regenerating skeletal muscle, JAZF1 overexpression promoted cell proliferation, whereas it retarded myogenic differentiation. Examination of myogenic genes revealed that JAZF1 overexpression transcriptionally repressed MEF2C and MRF4 and their downstream genes. AMP deaminase1 (AMPD1) was identified as a candidate for JAZF1 target by gene array analysis. However, promoter assays of Ampd1 demonstrated that mutation of the putative binding site for the TR4/JAZF1 complex did not alleviate the repressive effects of JAZF1 on promoter activity. Instead, JAZF1-mediated repression of Ampd1 occurred through the MEF2-binding site and E-box within the Ampd1 proximal regulatory elements. Consistently, MEF2C and MRF4 expression enhanced Ampd1 promoter activity. AMPD1 overexpression and JAZF1 downregulation impaired AMPK phosphorylation, while JAZF1 overexpression also reduced it. Collectively, these results suggest that aberrant JAZF1 expression contributes to the oncogenesis and T2D pathogenesis.
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Affiliation(s)
- Katsutoshi Yuasa
- Department of Anatomy and Cell Biology, Research Institute of Pharmaceutical Science, Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Natsumi Aoki
- Department of Anatomy and Cell Biology, Research Institute of Pharmaceutical Science, Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Takao Hijikata
- Department of Anatomy and Cell Biology, Research Institute of Pharmaceutical Science, Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan.
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Steinbacher P, Feichtinger RG, Kedenko L, Kedenko I, Reinhardt S, Schönauer AL, Leitner I, Sänger AM, Stoiber W, Kofler B, Förster H, Paulweber B, Ring-Dimitriou S. The single nucleotide polymorphism Gly482Ser in the PGC-1α gene impairs exercise-induced slow-twitch muscle fibre transformation in humans. PLoS One 2015; 10:e0123881. [PMID: 25886402 PMCID: PMC4401702 DOI: 10.1371/journal.pone.0123881] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/23/2015] [Indexed: 12/13/2022] Open
Abstract
PGC-1α (peroxisome proliferator-activated receptor γ co-activator 1α) is an important regulator of mitochondrial biogenesis and a master regulator of enzymes involved in oxidative phosphorylation. Recent evidence demonstrated that the Gly482Ser single nucleotide polymorphism (SNP) in the PGC-1α gene affects insulin sensitivity, blood lipid metabolism and binding to myocyte enhancer factor 2 (MEF2). Individuals carrying this SNP were shown to have a reduced cardiorespiratory fitness and a higher risk to develop type 2 diabetes. Here, we investigated the responses of untrained men with the Gly482Ser SNP to a 10 week programme of endurance training (cycling, 3 x 60 min/week, heart rate at 70-90% VO2peak). Quantitative data from analysis of biopsies from vastus lateralis muscle revealed that the SNP group, in contrast to the control group, lacked a training-induced increase in content of slow contracting oxidative fibres. Capillary supply, mitochondrial density, mitochondrial enzyme activities and intramyocellular lipid content increased similarly in both groups. These results indicate that the impaired binding of MEF2 to PGC-1α in humans with this SNP impedes exercise-induced fast-to-slow muscle fibre transformation.
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Affiliation(s)
- Peter Steinbacher
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
- * E-mail:
| | - René G. Feichtinger
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pedicatrics, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Lyudmyla Kedenko
- First Department of Internal Medicine, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Igor Kedenko
- First Department of Internal Medicine, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Sandra Reinhardt
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
| | - Anna-Lena Schönauer
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
| | - Isabella Leitner
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
| | - Alexandra M. Sänger
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
| | - Walter Stoiber
- Department of Cell Biology, Paris Lodron-University of Salzburg, Salzburg, Austria
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pedicatrics, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Holger Förster
- Medical Office in Pediatrics and Sports Medicine, Salzburg, Austria
| | - Bernhard Paulweber
- First Department of Internal Medicine, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Susanne Ring-Dimitriou
- Department of Sport Science and Kinesiology, Paris Lodron-University of Salzburg, Hallein, Austria
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29
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Anderson CM, Hu J, Barnes RM, Heidt AB, Cornelissen I, Black BL. Myocyte enhancer factor 2C function in skeletal muscle is required for normal growth and glucose metabolism in mice. Skelet Muscle 2015; 5:7. [PMID: 25789156 PMCID: PMC4364460 DOI: 10.1186/s13395-015-0031-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/28/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Skeletal muscle is the most abundant tissue in the body and is a major source of total energy expenditure in mammals. Skeletal muscle consists of fast and slow fiber types, which differ in their energy usage, contractile speed, and force generation. Although skeletal muscle plays a major role in whole body metabolism, the transcription factors controlling metabolic function in muscle remain incompletely understood. Members of the myocyte enhancer factor 2 (MEF2) family of transcription factors play crucial roles in skeletal muscle development and function. MEF2C is expressed in skeletal muscle during development and postnatally and is known to play roles in sarcomeric gene expression, fiber type control, and regulation of metabolic genes. METHODS We generated mice lacking Mef2c exclusively in skeletal muscle using a conditional knockout approach and conducted a detailed phenotypic analysis. RESULTS Mice lacking Mef2c in skeletal muscle on an outbred background are viable and grow to adulthood, but they are significantly smaller in overall body size compared to control mice and have significantly fewer slow fibers. When exercised in a voluntary wheel running assay, Mef2c skeletal muscle knockout mice aberrantly accumulate glycogen in their muscle, suggesting an impairment in normal glucose homeostasis. Consistent with this notion, Mef2c skeletal muscle knockout mice exhibit accelerated blood glucose clearance compared to control mice. CONCLUSIONS These findings demonstrate that MEF2C function in skeletal muscle is important for metabolic homeostasis and control of overall body size.
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Affiliation(s)
- Courtney M Anderson
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Jianxin Hu
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Ralston M Barnes
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Analeah B Heidt
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Ivo Cornelissen
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Brian L Black
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA ; Department of Biochemistry and Biophysics, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
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30
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Chen L, Cheng B, Li L, Zhan S, Wang L, Zhong T, Chen Y, Zhang H. The molecular characterization and temporal-spatial expression of myocyte enhancer factor 2 genes in the goat and their association with myofiber traits. Gene 2014; 555:223-30. [PMID: 25447896 DOI: 10.1016/j.gene.2014.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/16/2014] [Accepted: 11/05/2014] [Indexed: 12/18/2022]
Abstract
The myocyte enhancer factor-2 (MEF2) gene family in vertebrates includes MEF2A, MEF2B, MEF2C, and MEF2D, which have important functions in the regulation of muscular growth and development. To investigate their temporal-spatial expression and functions in the goat, these genes were cloned (accession nos. JN967621-24) and their expression patterns characterized at five postnatal stages (3, 30, 60, 90, and 120days). Association analysis was then applied regarding MEF2 expression levels and myofiber diameter and density. MEF2B was shown to be weakly homologous with other species, the distant branches with other members and the lowest expression levels, suggesting that it is distinct from other family members. Expression of the other three MEF2 genes was widely distributed, but this was largely accumulated in the skeletal muscle and myocardium compared with the viscera at all developmental stages. MEF2A and MEF2D expression levels were higher overall than MEF2B and MEF2C in six tissues, and were significantly positively correlated with the myofiber diameter of the longissimus dorsi. These findings suggest that goat MEF2 genes mainly function in the skeletal muscle and myocardium, and that MEF2A and MEF2D are likely to effectively promote muscular growth and development during postnatal stages. MEF2A expression was highest in the myocardium, where MEF2C expression increased with age, implying that both gene products are related to the growth and development of postnatal myocardium.
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Affiliation(s)
- Li Chen
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Bo Cheng
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Li Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Siyuan Zhan
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Linjie Wang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Tao Zhong
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China
| | - Yu Chen
- Institute of Nanjiang Yellow Goat Breeding Science, Nanjiang 635600, China
| | - Hongping Zhang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 610000, China.
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31
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Gannon NP, Conn CA, Vaughan RA. Dietary stimulators of GLUT4 expression and translocation in skeletal muscle: a mini-review. Mol Nutr Food Res 2014; 59:48-64. [PMID: 25215442 DOI: 10.1002/mnfr.201400414] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/07/2014] [Accepted: 09/08/2014] [Indexed: 12/23/2022]
Abstract
Chronic insulin resistance can lead to type II diabetes mellitus, which is also directly influenced by an individual's genetics as well as their lifestyle. Under normal circumstances, insulin facilitates glucose uptake in skeletal muscle and adipose tissue by stimulating glucose transporter 4 (GLUT4) translocation and activity. GLUT4 activity is directly correlated with the ability to clear elevated blood glucose and insulin sensitivity. In diabetes, energy excess and prolonged hyperinsulinemia suppress muscle and adipose response to insulin, in part through reduced GLUT4 membrane levels. This work uniquely describes much of the experimental data demonstrating the effects of various dietary components on GLUT4 expression and translocation in skeletal muscle. These observations implicate several individual dietary chemicals as potential adjuvant therapies in the maintenance of diabetes and insulin resistance.
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Affiliation(s)
- Nicholas P Gannon
- Department of Biochemistry and Molecular Biology, University of New Mexico, Health Sciences Center, School of Medicine, Albuquerque, NM, USA
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32
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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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Korenčič A, Košir R, Bordyugov G, Lehmann R, Rozman D, Herzel H. Timing of circadian genes in mammalian tissues. Sci Rep 2014; 4:5782. [PMID: 25048020 PMCID: PMC5376044 DOI: 10.1038/srep05782] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 07/03/2014] [Indexed: 11/17/2022] Open
Abstract
Circadian clocks are endogenous oscillators driving daily rhythms in physiology. The cell-autonomous clock is governed by an interlocked network of transcriptional feedback loops. Hundreds of clock-controlled genes (CCGs) regulate tissue specific functions. Transcriptome studies reveal that different organs (e.g. liver, heart, adrenal gland) feature substantially varying sets of CCGs with different peak phase distributions. To study the phase variability of CCGs in mammalian peripheral tissues, we develop a core clock model for mouse liver and adrenal gland based on expression profiles and known cis-regulatory sites. ‘Modulation factors’ associated with E-boxes, ROR-elements, and D-boxes can explain variable rhythms of CCGs, which is demonstrated for differential regulation of cytochromes P450 and 12 h harmonics. By varying model parameters we explore how tissue-specific peak phase distributions can be generated. The central role of E-boxes and ROR-elements is confirmed by analysing ChIP-seq data of BMAL1 and REV-ERB transcription factors.
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Affiliation(s)
- Anja Korenčič
- 1] Institute for Theoretical Biology, 10115 Berlin, Germany [2] Centre for Functional Genomics and Biochips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Rok Košir
- 1] Centre for Functional Genomics and Biochips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia [2] Diagenomi Ltd, 1000 Ljubljana, Slovenia
| | | | - Robert Lehmann
- Institute for Theoretical Biology, 10115 Berlin, Germany
| | - Damjana Rozman
- Centre for Functional Genomics and Biochips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
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Alves-Wagner AB, Sabino-Silva R, Campello RS, Mori RC, Machado UF. Decreased diabetes-induced glycemic impairment in WKY and SHR involves enhanced skeletal muscle Slc2a4/GLUT4 expression. Diabetol Metab Syndr 2014; 6:97. [PMID: 25228927 PMCID: PMC4164711 DOI: 10.1186/1758-5996-6-97] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/04/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Hypertension has been associated to diabetes, and participates in the development of diabetic complications. The spontaneously hypertensive rat (SHR) is the gold standard model for the study of hypertension, and experimental diabetes has been currently investigated in SHR. Wistar-Kyoto rat is usually taken as control for SHR, however, regarding the glycemic homeostasis, WKY may be similar to SHR, when compared to the standard Wistar rat, importantly affecting the interpretation of data. Slc2a4 gene, which encodes the GLUT4 protein, is expressed in insulin-sensitive tissues, such as muscle cells and adipocytes, and alteration in Slc2a4/GLUT4 expression is inversely related to glycemic levels. We investigated the effect of diabetes on the expression of Slc2a4/GLUT4 and glycemic control in Wistar-Kyoto and SHR. FINDINGS Slc2a4 mRNA (Northern-blotting) and GLUT4 protein (Western-blotting) were investigated in skeletal muscles (soleus and extensor digitorum longus) of Wistar, Wistar-Kyoto and SHR, rendered or not diabetic for 1 month. Non-diabetic SHR shows hyperinsulinemia, and unaltered GLUT4 expression. The hyperglycemia was significantly attenuated in diabetic Wistar-Kyoto and SHR, compared to that observed in diabetic Wistar, although all of them presented the same hypoinsulinemic levels. Besides, diabetes significantly reduced Slc2a4/GLUT4 in Wistar, as expected; however, that was not observed in diabetic Wistar-Kyoto and SHR. CONCLUSIONS Non-diabetic SHR is insulin resistant, despite unaltered GLUT4 expression. Diabetic Wistar-Kyoto and diabetic SHR presented high Slc2a4/GLUT4 expression in skeletal muscle, as compared to diabetic Wistar. This Slc2a4/GLUT4 regulation does not depend on insulin level and possibly protects the WKY and SHR from severe glycemic impairment.
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Affiliation(s)
- Ana Barbara Alves-Wagner
- />Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP Brazil
| | - Robinson Sabino-Silva
- />Institute of Biomedical Sciences (ICBIM), Federal University of Uberlandia (UFU), Uberlandia, MG Brazil
| | - Raquel S Campello
- />Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP Brazil
| | - Rosana C Mori
- />Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP Brazil
| | - Ubiratan F Machado
- />Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP Brazil
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Manczinger M, Kemény L. Novel factors in the pathogenesis of psoriasis and potential drug candidates are found with systems biology approach. PLoS One 2013; 8:e80751. [PMID: 24303025 PMCID: PMC3841158 DOI: 10.1371/journal.pone.0080751] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/15/2013] [Indexed: 01/12/2023] Open
Abstract
Psoriasis is a multifactorial inflammatory skin disease characterized by increased proliferation of keratinocytes, activation of immune cells and susceptibility to metabolic syndrome. Systems biology approach makes it possible to reveal novel important factors in the pathogenesis of the disease. Protein-protein, protein-DNA, merged (containing both protein-protein and protein-DNA interactions) and chemical-protein interaction networks were constructed consisting of differentially expressed genes (DEG) between lesional and non-lesional skin samples of psoriatic patients and/or the encoded proteins. DEGs were determined by microarray meta-analysis using MetaOMICS package. We used STRING for protein-protein, CisRED for protein-DNA and STITCH for chemical-protein interaction network construction. General network-, cluster- and motif-analysis were carried out in each network. Many DEG-coded proteins (CCNA2, FYN, PIK3R1, CTGF, F3) and transcription factors (AR, TFDP1, MEF2A, MECOM) were identified as central nodes, suggesting their potential role in psoriasis pathogenesis. CCNA2, TFDP1 and MECOM might play role in the hyperproliferation of keratinocytes, whereas FYN may be involved in the disturbed immunity in psoriasis. AR can be an important link between inflammation and insulin resistance, while MEF2A has role in insulin signaling. A controller sub-network was constructed from interlinked positive feedback loops that with the capability to maintain psoriatic lesional phenotype. Analysis of chemical-protein interaction networks detected 34 drugs with previously confirmed disease-modifying effects, 23 drugs with some experimental evidences, and 21 drugs with case reports suggesting their positive or negative effects. In addition, 99 unpublished drug candidates were also found, that might serve future treatments for psoriasis.
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Affiliation(s)
- Máté Manczinger
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
- * E-mail:
| | - Lajos Kemény
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
- Dermatological Research Group of the Hungarian Academy of Sciences, Szeged, Hungary
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36
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Holloszy JO. Regulation of mitochondrial biogenesis and GLUT4 expression by exercise. Compr Physiol 2013; 1:921-40. [PMID: 23737207 DOI: 10.1002/cphy.c100052] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Endurance exercise training can induce large increases mitochondria and the GLUT4 isoform of the glucose transporter in skeletal muscle. For a long time after the discovery in the 1960s that exercise results in an increase in muscle mitochondria, there was no progress in elucidation of the mechanisms involved. The reason for this lack of progress was that nothing was known regarding how expression of the genes-encoding mitochondrial proteins is coordinately regulated. This situation changed rapidly after discovery of transcription factors that control transcription of genes-encoding mitochondrial proteins and, most importantly, the discovery of peroxisome proliferator-gamma coactivator-1α (PGC-1α). This transcription coactivator binds to and activates transcription factors that regulate transcription of genes-encoding mitochondrial proteins. Thus, PGC-1α activates and coordinates mitochondrial biogenesis. It is now known that exercise rapidly activates and induces increased expression of PGC-1α. The exercise-generated signals that lead to PGC-1α activation and increased expression are the increases in cytosolic Ca(2+) and decreases in ATP and creatine phosphate (∼P). Ca(2+) mediates its effect by activating CAMKII, while the decrease in ∼P mediates its effect via activation of AMPK. Expression of the GLUT4 isoform of the glucose transporter is regulated in parallel with mitochondrial biogenesis via the same signaling pathways. This review describes what is known regarding the regulation of mitochondrial biogenesis and GLUT4 expression by exercise. A major component of this review deals with the physiological and metabolic consequences of the exercise-induced increase in mitochondria and GLUT4.
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Affiliation(s)
- John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri, USA.
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37
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Verma SK, Deshmukh V, Liu P, Nutter CA, Espejo R, Hung ML, Wang GS, Yeo GW, Kuyumcu-Martinez MN. Reactivation of fetal splicing programs in diabetic hearts is mediated by protein kinase C signaling. J Biol Chem 2013; 288:35372-86. [PMID: 24151077 DOI: 10.1074/jbc.m113.507426] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Diabetic cardiomyopathy is one of the complications of diabetes that eventually leads to heart failure and death. Aberrant activation of PKC signaling contributes to diabetic cardiomyopathy by mechanisms that are poorly understood. Previous reports indicate that PKC is implicated in alternative splicing regulation. Therefore, we wanted to test whether PKC activation in diabetic hearts induces alternative splicing abnormalities. Here, using RNA sequencing we identified a set of 22 alternative splicing events that undergo a developmental switch in splicing, and we confirmed that splicing reverts to an embryonic pattern in adult diabetic hearts. This network of genes has important functions in RNA metabolism and in developmental processes such as differentiation. Importantly, PKC isozymes α/β control alternative splicing of these genes via phosphorylation and up-regulation of the RNA-binding proteins CELF1 and Rbfox2. Using a mutant of CELF1, we show that phosphorylation of CELF1 by PKC is necessary for regulation of splicing events altered in diabetes. In summary, our studies indicate that activation of PKCα/β in diabetic hearts contributes to the genome-wide splicing changes through phosphorylation and up-regulation of CELF1/Rbfox2 proteins. These findings provide a basis for PKC-mediated cardiac pathogenesis under diabetic conditions.
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Affiliation(s)
- Sunil K Verma
- From the Departments of Biochemistry and Molecular Biology and
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Abstract
Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions. Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose uptake relies on GLUT4 translocation, glucose uptake also depends on muscle GLUT4 expression which is increased following exercise. AMPK and CaMKII are key signaling kinases that appear to regulate GLUT4 expression via the HDAC4/5-MEF2 axis and MEF2-GEF interactions resulting in nuclear export of HDAC4/5 in turn leading to histone hyperacetylation on the GLUT4 promoter and increased GLUT4 transcription. Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.
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Affiliation(s)
- Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
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Mauvais-Jarvis F, Clegg DJ, Hevener AL. The role of estrogens in control of energy balance and glucose homeostasis. Endocr Rev 2013; 34:309-38. [PMID: 23460719 PMCID: PMC3660717 DOI: 10.1210/er.2012-1055] [Citation(s) in RCA: 772] [Impact Index Per Article: 70.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Estrogens play a fundamental role in the physiology of the reproductive, cardiovascular, skeletal, and central nervous systems. In this report, we review the literature in both rodents and humans on the role of estrogens and their receptors in the control of energy homeostasis and glucose metabolism in health and metabolic diseases. Estrogen actions in hypothalamic nuclei differentially control food intake, energy expenditure, and white adipose tissue distribution. Estrogen actions in skeletal muscle, liver, adipose tissue, and immune cells are involved in insulin sensitivity as well as prevention of lipid accumulation and inflammation. Estrogen actions in pancreatic islet β-cells also regulate insulin secretion, nutrient homeostasis, and survival. Estrogen deficiency promotes metabolic dysfunction predisposing to obesity, the metabolic syndrome, and type 2 diabetes. We also discuss the effect of selective estrogen receptor modulators on metabolic disorders.
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Affiliation(s)
- Franck Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
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Carvajal R, Rosas C, Kohan K, Gabler F, Vantman D, Romero C, Vega M. Metformin augments the levels of molecules that regulate the expression of the insulin-dependent glucose transporter GLUT4 in the endometria of hyperinsulinemic PCOS patients. Hum Reprod 2013; 28:2235-44. [PMID: 23595973 DOI: 10.1093/humrep/det116] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY QUESTION Does treatment with the insulin sensitizer metformin modify the levels and activation of proteins related to the expression of the insulin-dependent glucose transporter (GLUT4), such as adenosine monophosphate-activated protein kinase (AMPK) and myocyte enhancer factor 2A (MEF2A), in endometria from hyperinsulinemic hyperandrogenemic polycystic ovary syndrome (PCOS h-Ins) patients? SUMMARY ANSWER In PCOS h-Ins patients, metformin increases endometrial levels of GLUT4 mRNA and protein levels by normalizing the quantity and activation of molecules that regulate GLUT4 expression to healthy values. These changes could improve endometrial metabolic function. WHAT IS ALREADY KNOWN PCOS is an endocrine-metabolic disorders closely associated with insulin resistance. In particular, the insulin signaling pathway is impaired in endometria from these patients and the concentration of GLUT4, as well as the molecules involved in its translocation to the cell surface, is decreased. However, there are limited data about the mechanisms that regulate the GLUT4 expression in the endometria and the effect of metformin on them. STUDY DESIGN, SIZE AND DURATION This is a case-control study in the setting of a research unit, approved by the Ethical Committees of our institution. The groups whose endometria were studied were PCOS h-Ins (n = 8); PCOS patients with hyperandrogenemia hyperinsulinemia taking only metformin for at least 3 months (PCOS-MTF, n = 8) and healthy fertile women at the time of hysterectomy because of benign pathology as controls (CE, n = 8). PARTICIPANTS/MATERIALS, SETTING, METHODS Steroids and sex hormone-binding globulin were measured and glucose and insulin levels were evaluated during an oral glucose tolerance test. Protein levels for αAMPK (catalytic subunit of AMPK), phosphorylated (p)-AMPKαThr(172) (activating phosphorylation site), MEF2A, p-MEF2AThr312 (activating phosphorylation site) and GLUT4 were assessed by western blot and immunohistochemistry. In addition, GLUT4 gene expression was evaluated by RT-PCR. MAIN RESULTS AND THE ROLE OF CHANCE We found significantly lower levels of MEF2A and p-MEF2AThr312 in PCOS h-Ins compared with CE endometria (P < 0.05). Also, we detected lower levels of p-AMPKαThr(172) in PCOS h-Ins endometria compared with the PCOS-MTF group (P < 0.05). The ratios of phospho-AMPK/total AMPK and phospho-MEF2A/total MEF2A were significantly increased in the PCOS-MTF compared with the PCOS h-Ins group (P < 0.05). The RT-PCR experiments showed lower levels of GLUT4 mRNA transcripts in PCOS h-Ins compared with PCOS-MTF-treated group (P < 0.05), the protein levels of GLUT4 were decreased in a similar way. LIMITATIONS, REASONS FOR CAUTION The limited number of patients included in this study who presented large clinical variability. Therefore, it would be necessary to recruit a greater number of patients to minimize our data dispersion in order to prove the clinical benefits of metformin described by others. WIDER IMPLICATIONS OF THE FINDINGS Since the insulin sensitizer metformin increases the expression of the GLUT4, it may improve endometrial physiology in PCOS patients and, therefore, promote better reproductive outcomes. These results suggest that in PCOS patients, metformin may act directly at the endometrial level and decrease insulin resistance condition by increasing the expression of GLUT4 and, in this way, indirectly restore endometrial function. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by Fondo Nacional de Desarrollo Científico y Tecnológico (grant number 1095127 to M.V.). None of the authors has any conflict of interest to declare.
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Affiliation(s)
- Rodrigo Carvajal
- Laboratory of Endocrinology and Reproductive Biology, University of Chile Clinical Hospital, Santos Dumont # 999, Independencia, Santiago, Chile
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Gong H, Xie J, Zhang N, Yao L, Zhang Y. MEF2A binding to the Glut4 promoter occurs via an AMPKα2-dependent mechanism. Med Sci Sports Exerc 2011; 43:1441-50. [PMID: 21233771 DOI: 10.1249/mss.0b013e31820f6093] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The role of AMP-activated protein kinase α2 (AMPKα2) in regulating MEF2A nucleus translocation, nuclear histone deacetylase 5 (HDAC5) association with MEF2, HDAC5 nuclear export, MEF2A binding to the Glut4 promoter, and GLUT4 expression was investigated. METHODS This was investigated in muscles from AMPKα2 overexpression (OE) mice, AMPKα2 knockout (KO) mice, and corresponding wild-type (WT) mice that had undertaken a 28-d program of treadmill training by: 1) AMPKα-Thr172 phosphorylation by Western blot, 2) total and nuclear MEF2A by Western blot, 3) nuclear HDAC5 association with MEF2 by coimmunoprecipitation, 4) total and nuclear HDAC5 by Western blot, 5) bound MEF2A at the Glut4 MEF2 cis-element by chromatin immunoprecipitation, and 6) GLUT4 expression by real-time polymerase chain reaction and Western blot. RESULTS OE or KO of AMPKα2 isoform heightened or attenuated the training-induced increase in nuclear MEF2A content, Glut4 promoter-bound MEF2A. However, OE or KO of the AMPKα2 isoform did not have any effect on the content of nuclear HDAC5 association with MEF2 after 28 d of exercise training, although 35% lower nuclear HDAC5 protein content was found in α2-OE training muscles. Lastly, OE of the α2-isoform was associated with 120% and 155% higher GLUT4 protein and mRNA in training muscles. However, the training-induced increases of GLUT4 protein and mRNA contents were normal in α2-KO muscles despite the reduced AMPK signaling. CONCLUSIONS Exercise training increases the nuclear MEF2A content and binding of MEF2A to their binding sites on the Glut4 gene by an AMPKα2-dependent mechanism, but intracellular signaling molecules other than AMPKα2 are important in regulating training-induced HDAC5 nuclear export. Furthermore, although AMPKα2 mediates the training-induced increase in Glut4 promoter-bound MEF2A, the present data do not support an essential role of AMPKα2 in regulating training-induced GLUT4 expression in skeletal muscle.
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Eivers SS, McGivney BA, Gu J, MacHugh DE, Katz LM, Hill EW. PGC-1α encoded by the PPARGC1A gene regulates oxidative energy metabolism in equine skeletal muscle during exercise. Anim Genet 2011; 43:153-62. [DOI: 10.1111/j.1365-2052.2011.02238.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Calalb MB, McKinsey TA, Newkirk S, Huynh K, Sucharov CC, Bristow MR. Increased phosphorylation-dependent nuclear export of class II histone deacetylases in failing human heart. Clin Transl Sci 2010; 2:325-32. [PMID: 20443916 DOI: 10.1111/j.1752-8062.2009.00141.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In the failing human heart (FHH) the induction of a fetal contractile protein gene program is directly and selectively associated with the dilated cardiomyopathy (DCM) phenotype and involves multiple signaling pathways. In response to cardiac stress signals, class II HDACs are subject to phosphorylation dependent nuclear export, which allows for activation of fetal cardiac genes via the transcription factor MEF2. The current study tests the hypothesis that MEF2 activation produced by class II HDAC de-repression is present in the FHH. In this study, human left ventricular tissue from nonfailing and failing adult hearts was analyzed for the presence of MEF2, HDACs 4 and 5. CaMK and HDAC kinase activities were measured in tissue homogenates. In nuclear fractions from failing ventricles, HDAC4 and HDAC5 protein was decreased versus nonfailing controls. MEF2 was not reduced in failing nuclear fractions. CaMK and HDAC kinase activities were increased in failing versus nonfailing hearts. PKCmu (PKD1) activity was increased in nuclear fractions from failing human LVs. These data provide support for decreased nuclear compartment class II HDACs in the FHH, associated with increased activities of kinases known to phosphorylate class II HDACs.
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Affiliation(s)
- Mihail B Calalb
- University of Colorado Cardiovascular Institute, Denver, USA
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Czubryt MP, Lamoureux L, Ramjiawan A, Abrenica B, Jangamreddy J, Swan K. Regulation of cardiomyocyte Glut4 expression by ZAC1. J Biol Chem 2010; 285:16942-50. [PMID: 20363751 DOI: 10.1074/jbc.m109.097246] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The transcription factor ZAC1 is expressed in a variety of tissues including the developing heart, but its physiological role is unclear. We examined the role of ZAC1 in regulating expression of the insulin-responsive glucose transporter GLUT4 and whether ZAC1 expression is altered in cardiomyocyte hypertrophy. We demonstrated expression of Zac1 mRNA and protein in rat cardiomyocytes by PCR and Western blotting, respectively. Using a combination of chromatin immunoprecipitation and luciferase assays, we showed that ZAC1 regulates Glut4 expression via a specific binding site in the Glut4 promoter. Overexpression of ZAC1 increased Glut4 mRNA and protein expression and resulted in increased glucose uptake in cardiomyocytes as determined by a fluorescent analog uptake assay. Induction of hypertrophy by phenylephrine or isoproterenol resulted in increased Zac1 expression. We identified a novel putative promoter in the Zac1 gene and demonstrated increased binding of MEF2 to this promoter in response to hypertrophic stimulation. MEF2 regulated transactivation of the Zac1 promoter and ZAC1 protein expression. This work identifies ZAC1 as a novel and previously unknown regulator of cardiomyocyte Glut4 expression and glucose uptake. Our results also implicate MEF2 as a regulator of ZAC1 expression in response to induction of hypertrophy.
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Affiliation(s)
- Michael P Czubryt
- Department of Physiology, University of Manitoba, Institute of Cardiovascular Sciences, St Boniface General Hospital Research Centre, Winnipeg, Manitoba R2H 2A6, Canada
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Feng L, Song YF, Guan QB, Liu HJ, Ban B, Dong HX, Hou XL, Lee KO, Gao L, Zhao JJ. Long-term ethanol exposure inhibits glucose transporter 4 expression via an AMPK-dependent pathway in adipocytes. Acta Pharmacol Sin 2010; 31:329-40. [PMID: 20173759 DOI: 10.1038/aps.2010.11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
AIM The roles of AMP-activated protein kinase (AMPK) and myocyte enhancer factor 2 isoforms (MEF2A, D) as mediators of the effects of ethanol on glucose transporter 4 (GLUT4) expression are unclear. We studied the effects of ethanol in adipocytes in vivo and in vitro. METHODS Thirty-six male Wistar rats were divided into three groups and given ethanol in a single daily dose of 0, 0.5, or 5 g/kg for 22 weeks. The expression of AMPK, MEF2 isoforms A and D, and GLUT4 was measured and compared in the three groups. The existence of the AMPK/MEF2/GLUT4 pathway in adipocytes and the effects of ethanol on this pathway were studied in (a) epididymal adipose tissue from six male Wistar rats subcutaneously injected with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR, an AMPK activator) or with 0.9% NaCl (control); and (b) isolated rat and human adipocytes treated with or without ethanol, AICAR, and compound C (a selective AMPK inhibitor). Expression of AMPK, MEF2, and GLUT4 was measured by RT-PCR and Western blotting. RESULTS (1) Long-term ethanol exposure decreased activated AMPK, MEF2A, MEF2D, and GLUT4 expression in rat adipose tissue. (2) In rat and human adipocytes, AICAR-induced AMPK activation, with subsequent elevation of MEF2 and GLUT4 expression, was inhibited by compound C. (3) In vitro ethanol-treatment suppressed the AMPK/MEF2/GLUT4 pathway. CONCLUSION The AMPK/MEF2/GLUT4 pathway exists in both rat and human adipocytes, and activated AMPK may positively regulate MEF2 and GLUT4 expression. Ethanol inhibition of this pathway leads to decreased GLUT4 expression, thus reducing insulin sensitivity and glucose tolerance.
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Feng B, Chen S, George B, Feng Q, Chakrabarti S. miR133a regulates cardiomyocyte hypertrophy in diabetes. Diabetes Metab Res Rev 2010; 26:40-9. [PMID: 20013939 DOI: 10.1002/dmrr.1054] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Diabetic cardiomyopathy, characterized by cardiac hypertrophy and contractile dysfunction, eventually leads to heart failure. We have previously shown that alterations of a number of key molecules are involved in producing cardiomyocyte hypertrophy in diabetes. The aim of the present study was to determine whether microRNAs (miRNA) play a role in mediating altered gene expression and structural/functional deficits in the heart in diabetes. METHODS STZ-induced diabetic mice were haemodynamically investigated after 2 months of diabetes to establish the development of cardiomyopathy. The tissues were then examined for gene expression and microRNA analysis. We further investigated neonatal rat cardiomyocytes to identify the mechanisms of glucose-induced hypertrophy and the potential role of miR133a. RESULTS Diabetic mice showed myocardial contractile dysfunction and augmented mRNA expression of atrial and brain natriuretic peptides (ANP, BNP), MEF2A and MEF2C, SGK1 and IGF1R compared to age- and sex-matched controls. Cardiac tissues from these mice showed alteration of multiple miRNAs by array analysis including miR133a, which was confirmed by RT-PCR. In vitro exposure of cardiomyocytes to high levels of glucose produced hypertrophic changes and reduced expression of miRNA133a. Finally, transfection of miR133a mimics prevented altered gene expression and hypertrophic changes. CONCLUSION Data from these studies demonstrate a novel glucose-induced mechanism regulating gene expression and cardiomyocyte hypertrophy in diabetes which is mediated through miR133a.
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Affiliation(s)
- Biao Feng
- Department of Pathology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
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Lima GA, Anhê GF, Giannocco G, Nunes MT, Correa-Giannella ML, Machado UF. Contractile activity per se induces transcriptional activation of SLC2A4 gene in soleus muscle: involvement of MEF2D, HIF-1a, and TRalpha transcriptional factors. Am J Physiol Endocrinol Metab 2009; 296:E132-8. [PMID: 18957617 DOI: 10.1152/ajpendo.90548.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Skeletal muscle is a target tissue for approaches that can improve insulin sensitivity in insulin-resistant states. In muscles, glucose uptake is performed by the GLUT-4 protein, which is encoded by the SLC2A4 gene. SLC2A4 gene expression increases in response to conditions that improve insulin sensitivity, including chronic exercise. However, since chronic exercise improves insulin sensitivity, the increased SLC2A4 gene expression could not be clearly attributed to the muscle contractile activity per se and/or to the improved insulin sensitivity. The present study was designed to investigate the role of contractile activity per se in the regulation of SLC2A4 gene expression as well as in the participation of the transcriptional factors myocyte enhancer factor 2D (MEF2D), hypoxia inducible factor 1a (HIF-1a), and thyroid hormone receptor-alpha (TRalpha). The performed in vitro protocol excluded the interference of metabolic, hormonal, and neural effects. The results showed that, in response to 10 min of electrically induced contraction of soleus muscle, an early 40% increase in GLUT-4 mRNA (30 min) occurred, with a subsequent 65% increase (120 min) in GLUT-4 protein content. EMSA and supershift assays revealed that the stimulus rapidly increased the binding activity of MEF2D, HIF-1a, and TRalpha into the SLC2A4 gene promoter. Furthermore, chromatin immunoprecipitation assay confirmed, in native nucleosome, that contraction induced an approximate fourfold (P < 0.01) increase in MEF2D and HIF-1a-binding activity. In conclusion, muscle contraction per se enhances SLC2A4 gene expression and that involves MEF2D, HIF-1a, and TRalpha transcription factor activation. This finding reinforces the importance of physical activity to improve glycemic homeostasis independently of other additional insulin sensitizer approaches.
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Affiliation(s)
- Guilherme Alves Lima
- Dept. of Physiology and Biophysics, Institute of Biomedical Sciences, Univ. of Sao Paulo, Av. Prof. Lineu Prestes, 1524, 05508-900 Sao Paulo, Brazil
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Karnieli E, Armoni M. Transcriptional regulation of the insulin-responsive glucose transporter GLUT4 gene: from physiology to pathology. Am J Physiol Endocrinol Metab 2008; 295:E38-45. [PMID: 18492767 DOI: 10.1152/ajpendo.90306.2008] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The insulin-responsive glucose transporter 4 (GLUT4) plays a key role in glucose uptake and metabolism in insulin target tissues. Being a rate-limiting step in glucose metabolism, the expression and function of the GLUT4 isoform has been extensively studied and found to be tightly regulated at both mRNA and protein levels. Adaptation to states of enhanced metabolic demand is associated with increased glucose metabolism and GLUT4 gene expression, whereas states of insulin resistance such as type 2 diabetes mellitus (DM2), obesity, and aging are associated with impaired regulation of GLUT4 gene expression and function. The present review focuses on the interplay among hormonal, nutritional, and transcription factors in the regulation of GLUT4 transcription in health and sickness.
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Affiliation(s)
- Eddy Karnieli
- Institute of Endocrinology, Diabetes and Metabolism, 12 Haliah St., PO Box 9602, Rambam Medical Center, Haifa 31096, Israel.
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Girón MD, Sevillano N, Vargas AM, Domínguez J, Guinovart JJ, Salto R. The glucose-lowering agent sodium tungstate increases the levels and translocation of GLUT4 in L6 myotubes through a mechanism associated with ERK1/2 and MEF2D. Diabetologia 2008; 51:1285-95. [PMID: 18483800 DOI: 10.1007/s00125-008-1003-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 03/16/2008] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS The aim of this study was to investigate the action of the glucose-lowering compound sodium tungstate on glucose transport in muscle myotubes and to unravel the molecular events underlying the effects observed. METHODS We studied the effects of tungstate on 2-deoxy-D: -glucose uptake, levels and translocation of the glucose transporters GLUT4 and GLUT1, and Glut4 (also known as Slc2a4) promoter activity. We also measured the modifications of individual components of the signalling pathways involved in the effects observed. RESULTS Tungstate increased 2-deoxy-D: -glucose uptake in differentiated L6 myotubes through an increase in the total amount and translocation of GLUT4 transporter. The effects on glucose uptake were additive to those of insulin. Tungstate activated transcription of the Glut4 promoter, as shown by an increase in Glut4 mRNA, and by a promoter reporter assay. The assay of deletions of the Glut4 promoter indicated that the effect of tungstate is mediated by the myocyte enhancer factor 2 (MEF2)-binding domain. Accordingly, MEF2 levels and DNA binding activities were increased in response to the treatment. Tungstate-induced glucose uptake and GLUT4 transcriptional activation were dependent on the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), while no changes were observed in the phosphorylation state of the beta subunit of the insulin receptor, in the phosphatidylinositol 3-kinase pathway or in the activation of 5'AMP-activated protein kinase. CONCLUSIONS/INTERPRETATION Tungstate activates glucose uptake in myotubes through a novel ERK1/2-dependent mechanism. This effect is exerted by an increase in the content and translocation of the GLUT4 transporter. This is the first report of a glucose-lowering compound activating Glut4 transcription through an ERK1/2-dependent increase in MEF2 levels.
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Affiliation(s)
- M D Girón
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, Campus de Cartuja sn, 18071, Granada, Spain
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Sakuma K, Akiho M, Nakashima H, Nakao R, Hirata M, Inashima S, Yamaguchi A, Yasuhara M. Cyclosporin A modulates cellular localization of MEF2C protein and blocks fiber hypertrophy in the overloaded soleus muscle of mice. Acta Neuropathol 2008; 115:663-74. [PMID: 18369646 DOI: 10.1007/s00401-008-0371-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 03/13/2008] [Accepted: 03/14/2008] [Indexed: 12/26/2022]
Abstract
The molecular signaling pathway linked to hypertrophy of the anti-gravity/postural soleus muscle after mechanical overloading has not been identified. Using reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemical analyses, we investigated whether the amounts of myocyte enhancer factor (MEF)2C, MEF2D, and myogenin change in the mechanically overloaded soleus muscle after treatment with the calcineurin inhibitor cyclosporine A (CsA). Adult male ICR mice were subjected to a surgical ablation of the gastrocnemius muscle and treated with either CsA (25 mg/kg) or vehicle, once daily. They were killed at 2, 4, 7, 10, and 14 days post-injury. Mechanical overloading resulted in a significant increase in the wet weight and the cross-sectional area of slow and fast fibers of the soleus muscle in placebo-treated mice but not CsA-treated mice. RT-PCR analysis did not show a marked difference in MEF2C and MEF2D mRNA levels in the overloaded soleus muscle in placebo- or CsA-administered mice. After 2 days of mechanical overloading, we observed co-localization of MEF2C and myogenin in several mononuclear cells under both conditions. These MEF2C-positive mononuclear cells also possessed immunoreactivity for c-Met, a satellite cell marker. At 4 days, mechanical overloading induced marked expression of MEF2C but not MEF2D in the subsarcolemmal region in a group of myotubes and/or myofibers. Such a MEF2C-positive region emerged less often in the hypertrophied soleus muscle subjected to the treatment with CsA. At 7 days, we observed many mononuclear cells possessing both MEF2C and myogenin protein in mice treated with CsA, but not the placebo. Our results demonstrated that CsA treatment modulates the amount and cellular localization of MEF2C protein. The modulation of MEF2C by CsA treatment may inhibit the hypertrophic process in the soleus muscle after mechanical overloading.
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Affiliation(s)
- Kunihiro Sakuma
- Health Science Center, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi 441-8580, Japan.
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