Sepsis upregulates the DNA binding activity of the inflammatory transcription factors NF-κB, C/EBP and AP-1 in rat skeletal muscle

The purpose of this study was to investigate the potential role of creatine in GLUT4 gene expression in rat skeletal muscle. Female Wistar rats were fed normal rat chow (controls) or chow containing 2% creatine monohydrate ad libitum for 3 wk. GLUT4 protein levels of creatine-fed rats were significantly increased in extensor digitorum longus (EDL), triceps, and epitrochlearis muscles compared with muscles from controls ( P < 0.05), and triceps GLUT4 mRNA levels were ∼100% greater in triceps muscles from creatine-fed rats than in muscles from controls ( P < 0.05). In epitrochlearis muscles from creatine-fed animals, glycogen content was ∼40% greater ( P < 0.05), and insulin-stimulated glucose transport rates were higher ( P < 0.05) than in epitrochlearis muscles from controls. Despite no changes in [ATP], [creatine], [phosphocreatine], or [AMP], creatine feeding increased AMP-activated protein kinase (AMPK) phosphorylation by 50% in rat EDL muscle ( P < 0.05). Creatinine content of EDL muscle was almost twofold higher for creatine-fed animals than for controls ( P < 0.05). Creatine feeding increased protein levels of myocyte enhancer factor 2 (MEF2) isoforms MEF2A (∼70%, P < 0.05), MEF2C (∼60%, P < 0.05), and MEF2D (∼90%, P < 0.05), which are transcription factors that regulate GLUT4 expression, in creatine-fed rat EDL muscle nuclear extracts. Electrophoretic mobility shift assay showed that DNA binding activity of MEF2 was increased by ∼40% ( P < 0.05) in creatine-fed rat EDL compared with controls. Our data suggest that creatine feeding enhances the nuclear content and DNA binding activity of MEF2 isoforms, which is concomitant with an increase in GLUT4 gene expression.

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C/EBP DNA-binding activity is upregulated by a glucocorticoid-dependent mechanism in septic muscle

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00512.2001 ◽

2002 ◽

Vol 282 (2) ◽

pp. R439-R444 ◽

Cited By ~ 46

Author(s):

Gail Penner ◽

Gyu Gang ◽

Xiaoyan Sun ◽

Curtis Wray ◽

Per-Olof Hasselgren

Keyword(s):

Skeletal Muscle ◽

Transcription Factors ◽

Dna Binding ◽

Cecal Ligation ◽

Binding Activity ◽

Nuclear Fraction ◽

Mobility Shift ◽

Protein Levels ◽

Dna Binding Activity ◽

Mobility Shift Assay

Sepsis-induced muscle cachexia is associated with increased expression of several genes in the ubiquitin-proteasome proteolytic pathway, but little is known about the activation of transcription factors in skeletal muscle during sepsis. We tested the hypothesis that sepsis upregulates the expression and activity of the transcription factors CCAAT/enhancer binding protein (C/EBP)-β and -δ in skeletal muscle. Sepsis was induced in rats by cecal ligation and puncture, and control rats were sham operated. C/EBP-β and -δ DNA-binding activity was determined by electrophoretic mobility shift assay and supershift analysis. In addition, C/EBP-β and -δ nuclear protein levels were determined by Western blot analysis. Sepsis resulted in increased DNA-binding activity of C/EBP, and supershift analysis suggested that this reflected activation of the β- and δ-isoforms of C/EBP. Concomitantly, C/EBP-β and -δ protein levels were increased in the nuclear fraction of skeletal muscle. In additional experiments, we tested the role of glucocorticoids in sepsis-induced activation of C/EBP-β and -δ by treating rats with the glucocorticoid receptor antagonist RU-38486. This treatment inhibited the sepsis-induced activation of C/EBP-β and -δ, suggesting that glucocorticoids participate in the upregulation of C/EBP in skeletal muscle during sepsis. The present results suggest that C/EBP-β and -δ are activated in skeletal muscle during sepsis and that this response is, at least in part, regulated by glucocorticoids.

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Direct inhibition of the DNA-binding activity of POU transcription factors Pit-1 and Brn-3 by selective binding of a phenyl-furan-benzimidazole dication

Nucleic Acids Research ◽

10.1093/nar/gkn208 ◽

2008 ◽

Vol 36 (10) ◽

pp. 3341-3353 ◽

Cited By ~ 41

Author(s):

Paul Peixoto ◽

Yang Liu ◽

Sabine Depauw ◽

Marie-Paule Hildebrand ◽

David W. Boykin ◽

...

Keyword(s):

Transcription Factors ◽

Dna Binding ◽

Binding Activity ◽

Direct Inhibition ◽

Selective Binding ◽

Dna Binding Activity

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Treatment of cultured myotubes with the proteasome inhibitor β-lactone increases the expression of the transcription factor C/EBPβ

AJP Cell Physiology ◽

10.1152/ajpcell.00282.2006 ◽

2007 ◽

Vol 292 (1) ◽

pp. C216-C226 ◽

Cited By ~ 6

Author(s):

Wei Wei ◽

Hongmei Yang ◽

Michael Menconi ◽

Peirang Cao ◽

Chester E. Chamberlain ◽

...

Keyword(s):

Skeletal Muscle ◽

Transcription Factor ◽

Dna Binding ◽

Proteasome Inhibitor ◽

Binding Activity ◽

Dominant Negative ◽

Dna Binding Activity ◽

Cultured Myotubes ◽

Nuclear Levels ◽

Factor C

The role of the proteasome in the regulation of cellular levels of the transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) is poorly understood. We tested the hypothesis that C/EBPβ levels in cultured myotubes are regulated, at least in part, by proteasome activity. Treatment of cultured L6 myotubes, a rat skeletal muscle cell line, with the specific proteasome inhibitor β-lactone resulted in increased nuclear levels of C/EBPβ as determined by Western blotting and immunofluorescent detection. This effect of β-lactone reflected inhibited degradation of C/EBPβ. Surprisingly, the increased C/EBPβ levels in β-lactone-treated myotubes did not result in increased DNA-binding activity. In additional experiments, treatment of the myotubes with β-lactone resulted in increased nuclear levels of growth arrest DNA damage/C/EBP homologous protein (Gadd153/CHOP), a dominant-negative member of the C/EBP family that can form heterodimers with other members of the C/EBP family and block DNA binding. Coimmunoprecipitation and immunofluorescent detection provided evidence that C/EBPβ and Gadd153/CHOP interacted and colocalized in the nuclei of the β-lactone-treated myotubes. When Gadd153/CHOP expression was downregulated by transfection of myotubes with siRNA targeting Gadd153/CHOP, C/EBPβ DNA-binding activity was restored in β-lactone-treated myotubes. The results suggest that C/EBPβ is degraded by a proteasome-dependent mechanism in skeletal muscle cells and that Gadd153/CHOP can interact with C/EBPβ and block its DNA-binding activity. The observations are important because they increase the understanding of the complex regulation of the expression and activity of C/EBPβ in skeletal muscle.

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Ozone-induced IL-8 expression and transcription factor binding in respiratory epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1997.272.3.l504 ◽

1997 ◽

Vol 272 (3) ◽

pp. L504-L511 ◽

Cited By ~ 33

Author(s):

I. Jaspers ◽

E. Flescher ◽

L. C. Chen

Keyword(s):

Transcription Factors ◽

Dna Binding ◽

Epithelial Cells ◽

Inflammatory Cells ◽

Binding Activity ◽

Ozone Exposure ◽

Air Exposure ◽

Dna Binding Activity ◽

Nf Kappab

Ozone, one of the most reactive oxidant gases to which humans are routinely exposed, induces inflammation in the lower airways. The airway epithelium is one of the first targets that inhaled ozone will encounter, but its role in airway inflammation is not well understood. Expression of inducible genes involved in the inflammatory response, such as interleukin (IL)-8, is controlled by transcription factors. Expression of the IL-8 gene is regulated by the transcription factors nuclear factor (NF)-kappaB, NF-IL-6, and possibly activator protein-1 (AP-1). Type II-like epithelial cells (A549) were grown on a collagen-coated membrane and exposed in vitro to 0.1 ppm ozone or air. Exposure to ozone induced DNA-binding activity of NF-kappaB, NF-IL-6, and AP-1. IL-8 mRNA and IL-8 protein levels were also increased after ozone exposure. These results link ozone-induced DNA-binding activity of transcription factors and the production of IL-8 by epithelial cells thus demonstrating a potential cellular cascade resulting in the recruitment of inflammatory cells into the airway lumen.

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CD43-mediated Signals Induce DNA Binding Activity of AP-1, NF-AT, and NFκB Transcription Factors in Human T Lymphocytes

Journal of Biological Chemistry ◽

10.1074/jbc.m005231200 ◽

2000 ◽

Vol 275 (40) ◽

pp. 31460-31468 ◽

Cited By ~ 37

Author(s):

M. Angélica Santana ◽

Gustavo Pedraza-Alva ◽

Norma Olivares-Zavaleta ◽

Vicente Madrid-Marina ◽

Vaclav Horejsi ◽

...

Keyword(s):

Transcription Factors ◽

T Lymphocytes ◽

Dna Binding ◽

Binding Activity ◽

Human T Lymphocytes ◽

Dna Binding Activity

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Expression of the genes encoding CCAAT-enhancer binding protein isoforms in the mouse mammary gland during lactation and involution

Biochemical Journal ◽

10.1042/bj3340205 ◽

1998 ◽

Vol 334 (1) ◽

pp. 205-210 ◽

Cited By ~ 28

Author(s):

Georgios SABATAKOS ◽

Gareth E. DAVIES ◽

Maria GROSSE ◽

Anthony CRYER ◽

Dipak P. RAMJI

Keyword(s):

Transcription Factors ◽

Mammary Gland ◽

Dna Binding ◽

Binding Protein ◽

Mouse Mammary Gland ◽

Binding Activity ◽

Protein Isoforms ◽

Dna Binding Activity ◽

Enhancer Binding Protein ◽

Ccaat Enhancer Binding Protein

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the activation of gene expression in the mammary gland during lactation. We have therefore investigated the detailed expression profile of the C/EBP family during lactation and involution of the mouse mammary gland. The expression of C/EBPβ and C/EBPδ mRNA was low during lactation, increased dramatically at the beginning of involution and remained constant thereafter. In contrast, C/EBPα mRNA expression was relatively high during the early stages of lactation, declined to low levels during the late stages of lactation and at the start of involution, and increased again during involution. Electrophoretic mobility-shift assays showed a close correlation between the expression of the C/EBP genes and the functional C/EBP DNA-binding activity and, additionally, demonstrated the participation of heterodimers, formed from among the three proteins, in DNA–protein interactions. The DNA-binding activity of the activator protein 1 (AP1) family of transcription factors was also induced during involution. These results therefore point to potentially important regulatory roles for both the C/EBP and the AP1 family during lactation and involution of the mammary gland.

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