Overexpression of GFAT activates PAI-1 promoter in mesangial cells

James, Leighton R.; Fantus, I. George; Goldberg, Harry; Ly, Hao; Scholey, James W.

doi:10.1152/ajprenal.2000.279.4.f718

Cited by 45 publications

(56 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Techniques such as over expression of OGT (Zachara et al 2004b), OGlcNAcase (Slawson et al 2005), and GFAT (Chen et al 1997;Marshall et al 2004;James et al 2000) by both transient transfection and viral transduction have been successful, as has reducing the expression of these enzymes using RNA interference (Zachara et al 2004b;Ngoh et al 2009a;Hsieh et al 2012). OGT has also been overexpressed using a tetracycline-inducible OGT stably expressed in HeLa cells, although for effective overexpression a histone deacetylase inhibitor was included with the tetracycline for appropriate regulation of OGT (Marshall et al 2003).…”

Section: In Vitro and In Vivo Modulation Of O-glcnac Levelsmentioning

confidence: 99%

Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis

Groves

Lee

Yildirir

et al. 2013

Cell Stress and Chaperones

114

107

View full text Add to dashboard Cite

O-linked N-acetyl-β-D-glucosamine (O-GlcNAc) is a ubiquitous and dynamic post-translational modification known to modify over 3,000 nuclear, cytoplasmic, and mitochondrial eukaryotic proteins. Addition of O-GlcNAc to proteins is catalyzed by the O-GlcNAc transferase and is removed by a neutral-N-acetyl-β-glucosaminidase (OGlcNAcase). O-GlcNAc is thought to regulate proteins in a manner analogous to protein phosphorylation, and the cycling of this carbohydrate modification regulates many cellular functions such as the cellular stress response. Diverse forms of cellular stress and tissue injury result in enhanced O-GlcNAc modification, or O-GlcNAcylation, of numerous intracellular proteins. Stress-induced OGlcNAcylation appears to promote cell/tissue survival by regulating a multitude of biological processes including: the phosphoinositide 3-kinase/Akt pathway, heat shock protein expression, calcium homeostasis, levels of reactive oxygen species, ER stress, protein stability, mitochondrial dynamics, and inflammation. Here, we will discuss the regulation of these processes by O-GlcNAc and the impact of such regulation on survival in models of ischemia reperfusion injury and trauma hemorrhage. We will also discuss the misregulation of O-GlcNAc in diseases commonly associated with the stress response, namely Alzheimer's and Parkinson's diseases. Finally, we will highlight recent advancements in the tools and technologies used to study the O-GlcNAc modification.

show abstract

Section: In Vitro and In Vivo Modulation Of O-glcnac Levelsmentioning

confidence: 99%

Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis

Groves

Lee

Yildirir

et al. 2013

Cell Stress and Chaperones

114

107

View full text Add to dashboard Cite

show abstract

“…lux through the hexosamine pathway has been implicated in some of the adverse consequences of high glucose and may also play a role in the development of diabetic kidney disease (1)(2)(3). Under physiologic conditions, a small percentage (1-3%) of glucose that enters cells is shunted through the hexosamine pathway (4).…”

mentioning

confidence: 99%

“…The end product of the hexosamine pathway, UDP N-acetylglucosamine is the substrate for O-and N-glycosylation of protein (5). In mesangial cells (MCs), flux through the hexosamine pathway has been implicated in glucose-induced increases in transforming growth factor ␤1 (TGF-␤1) and plasminogen activator inhibitor type 1 (PAI-1) expression (1,2,6), cytokines that are important in tissue injury and sclerosis (7)(8)(9). O-glycosylation of protein may mediate hexosamine pathway effects (10).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Flux Through the Hexosamine Pathway Is a Determinant of Nuclear Factor κB– Dependent Promoter Activation

et al. 2002

Self Cite

View full text Add to dashboard Cite

The hexosamine pathway may mediate some of the toxic effects of glucose. We hypothesized that flux through this pathway might regulate the activity of nuclear factor B (NF-B)-dependent genes in mesangial cells (MCs). In MCs, RT-PCR revealed that high glucose (30 mmol/l) and glucosamine (1 mmol/l) increased mRNA levels for vascular cell adhesion molecule 1 (VCAM-1) and increased the activity of an NF-B enhancer by 1.5-and 2-fold, respectively. Overexpression of glutamine: fructose-6-phosphate amidotransferase (GFAT), the rate-limiting enzyme for flux through the hexosamine pathway, led to a 2.2-fold increase in NF-B enhancer activity; the combination of GFAT overexpression and high glucose increased activity 2.8-fold, and these increases were prevented by 40 mol/l O-diazoacetyl-Lserine (azaserine) or 6-diazo-5-oxonorleucine. High glucose, glucosamine, and GFAT overexpression increased binding of MC nuclear proteins to NF-B consensus sequences. Immunoblotting revealed that the p65 subunit of NF-B was O-glycosylated in MC cultured in physiologic glucose and that significant enhancement occurred with high glucose and glucosamine. Both glucose and glucosamine dose-dependently increased human VCAM-1 promoter activity. In addition, GFAT overexpression activated the VCAM-1 promoter (2.25-fold), with further augmentation by high glucose and abrogation by inhibitors of GFAT, NF-B, and O-glycosylation. Inactivation of the two NF-B sites in the VCAM-1 promoter abolished its response to high glucose, glucosamine, and GFAT overexpression. These results suggest that increased flux through the hexosamine pathway leads to NF-B-dependent promoter activation in MCs.

show abstract

“…Furthermore, in porcine and rat mesangial cells the addition of glucosamine [6,7], a precursor of the HBP, or over-expression of GFAT [8] increases TGFβ1 expression, a key factor in the pathogenesis of diabetic glomerulosclerosis [9,10,11,12,13]. However, there is currently no information on the role of the HBP in the induction of TGFβ1 expression in human renal cells or on the intracellular signalling pathways involved.…”

mentioning

confidence: 99%

P38 mitogen-activated protein kinase mediates hexosamine-induced TGFβ1 mRNA expression in human mesangial cells

et al. 2003

View full text Add to dashboard Cite

Aims/hypothesis. The hexosamine pathway has been implicated in the induction of TGFβ1 expression and in the pathophysiology of diabetic glomerulopathy. Glucose-induced TGFβ1 expression is mediated by p38 mitogen-activated-protein-kinase (p38-MAPK) and this kinase is activated in the diabetic glomeruli. We examined whether the p38-MAPK is implicated in hexosamine-induced TGFβ1 mRNA expression in human mesangial cells. Methods. The products of the hexosamine biosynthetic pathway were increased by the addition of glucosamine or by the overexpression of the rate-limiting enzyme of the hexosamine pathway, glutamine: fructose-6-phosphate amidotransferase (GFAT).Results. Glucosamine addition resulted in cell death. UDP-N-Acetylglucosamine, one of the major hexosamine end-products, was increased in normal (7 mmol/l) and high (25 mmol/l) glucose conditions in GFAT-transfected cells compared to control transfected cells by twofold and 1.7-fold respectively (p≤0.04) and this was accompanied by a 1.6-and 2.3-fold increase (p≤0.02) in TGFβ1 mRNA expression. Addition of the GFAT inhibitor azaserine (10 µmol/l) prevented the induction of TGFβ1 in GFAT transfected cells. GFAT overexpression induced an increase in p38-MAPK activation after 6 and 12 h incubation in normal glucose, and this was prevented by the GFAT inhibitor azaserine. Furthermore, high glucose enhanced p38-MAPK activation in GFAT tranfected cells (p≤0.04). P38-MAPK inhibition using SB202190 (1 µmol/l) reduced hexosamine-induced TGFβ1 expression in normal and high glucose. The activation of the p38-MAPK was dependent on protein kinase-C. Conclusion/interpretation. Overexpression of GFAT increases hexosamine accumulation which mediates TGFβ1 expression via a protein kinase-C and p38-MAPK dependent mechanism. Increased glucose concentrations magnify these effects. [Diabetologia (2003) 46:531-537]

show abstract

Overexpression of GFAT activates PAI-1 promoter in mesangial cells

Cited by 45 publications

References 54 publications

Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis

Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis

Flux Through the Hexosamine Pathway Is a Determinant of Nuclear Factor κB– Dependent Promoter Activation

P38 mitogen-activated protein kinase mediates hexosamine-induced TGFβ1 mRNA expression in human mesangial cells

Contact Info

Product

Resources

About