Involvement of RAGE, NADPH Oxidase, and Ras/Raf-1 Pathway in Glycated LDL-Induced Expression of Heat Shock Factor-1 and Plasminogen Activator Inhibitor-1 in Vascular Endothelial Cells

Endocrinology ◽  
2010 ◽  
Vol 151 (9) ◽  
pp. 4455-4466 ◽  
Author(s):  
Ganesh V. Sangle ◽  
Ruozhi Zhao ◽  
Tooru M. Mizuno ◽  
Garry X. Shen
Keyword(s):  
Vascular Endothelial Cells ◽  
Plasminogen Activator Inhibitor ◽  
Heat Shock Factor 1 ◽  
Vascular Endothelial ◽  
Diabetic Mice ◽  
Plasminogen Activator Inhibitor 1 ◽  
Small Interference Rna ◽  
Activator Inhibitor ◽  
Pai 1 ◽  
Interference Rna

Atherothrombotic cardiovascular diseases are the predominant causes of mortality of diabetic patients. Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor for fibrinolysis, and it is also implicated in inflammation and tissue remodeling. Increased levels of PAI-1 and glycated low-density lipoprotein (glyLDL) were detected in patients with diabetes. Previous studies in our laboratory demonstrated that heat shock factor-1 (HSF1) is involved in glyLDL-induced PAI-1 overproduction in vascular endothelial cells (EC). The present study investigated transmembrane signaling mechanisms involved in glyLDL-induced HSF1 and PAI-1 up-regulation in cultured human vascular EC and streptozotocin-induced diabetic mice. Receptor for advanced glycation end products (RAGE) antibody prevented glyLDL-induced increase in the abundance of PAI-1 in EC. GlyLDL significantly increased the translocation of V-Ha-Ras Harvey rat sarcoma viral oncogene homologue (H-Ras) from cytoplasm to membrane compared with LDL. Farnesyltransferase inhibitor-277 or small interference RNA against H-Ras inhibited glyLDL-induced increases in HSF1 and PAI-1 in EC. Treatment with diphenyleneiodonium, a nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitor, blocked glyLDL-induced translocation of H-Ras, elevated abundances of HSF1 and PAI-1 in EC, and increased release of hydrogen peroxide from EC. Small interference RNA for p22phox prevented glyLDL-induced expression of NOX2, HSF1, and PAI-1 in EC. GlyLDL significantly increased V-raf-1 murine leukemia viral oncogene homolog 1 (Raf-1) phosphorylation. Treatment with Raf-1 inhibitor blocked glyLDL-induced increase of PAI-1 mRNA in EC. The levels of RAGE, H-Ras, NOX4, HSF1, and PAI-1 were increased in hearts of streptozotocin-diabetic mice and positively correlated with plasma glucose. The results suggest that RAGE, NOX, and H-Ras/Raf-1 are implicated in the up-regulation of HSF1 or PAI-1 in vascular EC under diabetes-associated metabolic stress.

Involvement of NADPH oxidase in oxidized LDL-induced upregulation of heat shock factor-1 and plasminogen activator inhibitor-1 in vascular endothelial cells

2009 ◽  
Vol 297 (1) ◽  
pp. E104-E111 ◽  
Author(s):  
Ruozhi Zhao ◽  
Xiuli Ma ◽  
Xueping Xie ◽  
Garry X. Shen
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Oxidized Ldl ◽  
Plasminogen Activator Inhibitor ◽  
Heat Shock Factor 1 ◽  
Vascular Endothelial ◽  
Plasminogen Activator Inhibitor 1 ◽  
Induced Expression ◽  
Activator Inhibitor ◽  
Pai 1

Plasminogen activator inhibitor-1 (PAI-1) is implicated in thrombogenesis, inflammation, and extracellular matrix remodeling. Previous studies indicated that oxidized low-density lipoprotein (LDL) stimulated the generation of PAI-1 in vascular endothelial cells (EC). The present study demonstrated that LDL oxidized by copper, iron, or 3-morpholinosydnonimine increased the expression of NADPH oxidase (NOX) 2, PAI-1, and heat shock factor-1 (HSF1) in human umbilical vein EC or coronary artery EC compared with LDL or vehicle. Diphenyleneiodonium, a NOX inhibitor, prevented the increases of the expression of HSF1 and PAI-1 in EC induced by oxidized LDLs. Small-interference RNA (siRNA) for p22phox, an essential subunit of NOX, prevented oxidized LDL-induced expression of NOX2, HSF1, and PAI-1 in EC. HSF1 siRNA inhibited oxidized LDL-induced expression of PAI-1 and HSF1, but not NOX2, in EC. The binding of HSF1 to PAI-1 promoter and the activity of PAI-1 promoter in EC were enhanced by oxidized LDL. Butylated hydroxytulene, a potent antioxidant, inhibited oxidized LDL-induced release of hydrogen peroxide (H2O2) and the expression of NOX2, HSF1, and PAI-1 in EC. Treatment with H2O2 increased the abundance of NOX2, HSF1, and PAI-1 in EC. The results of the present study indicate that oxidized LDL-induced expression of NOX may lead to the elevated release of reactive oxygen species, the activation of HSF1, and the enhancement of the transcription of PAI-1 gene in cultured vascular EC.

Transmembrane signaling pathway mediates oxidized low-density lipoprotein-induced expression of plasminogen activator inhibitor-1 in vascular endothelial cells

2008 ◽  
Vol 295 (5) ◽  
pp. E1243-E1254 ◽  
Author(s):  
Ganesh V. Sangle ◽  
Ruozhi Zhao ◽  
Garry X. Shen
Keyword(s):  
Vascular Endothelial Cells ◽  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Plasminogen Activator Inhibitor ◽  
Vascular Endothelial ◽  
Oxidized Low Density Lipoprotein ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Atherosclerotic cardiovascular disease is the number one cause of death for adults in Western society. Plasminogen activator inhibitor-1 (PAI-1), the major physiological inhibitor of plasminogen activators, has been implicated in both thrombogenesis and atherogenesis. Previous studies demonstrated that copper-oxidized low-density lipoprotein (C-oLDL) stimulated production of PAI-1 in vascular endothelial cells (EC). The present study examined the involvement of lectin-like oxidized LDL receptor-1 (LOX-1) and Ras/Raf-1/ERK1/2 pathway in the upregulation of PAI-1 in cultured EC induced by oxidized LDLs. The results demonstrated that C-oLDL or FeSO4-oxidized LDL (F-oLDL) increased the expression of PAI-1 or LOX-1 in human umbilical vein EC (HUVEC) or coronary artery EC (HCAEC). Treatment with C-oLDL significantly increased the levels of H-Ras mRNA, protein, and the translocation of H-Ras to membrane fraction in EC. LOX-1 blocking antibody, Ras farnesylation inhibitor (FTI-277), or small interference RNA against H-Ras significantly reduced C-oLDL or LDL-induced expression of H-Ras and PAI-1 in EC. Incubation with C-oLDL or F-oLDL increased the phosphorylation of Raf-1 and ERK1/2 in EC compared with LDL or vehicle. Treatment with Raf-1 inhibitor blocked Raf-1 phosphorylation and the elevation of PAI-1 mRNA level in EC induced by C-oLDL or LDL. Treatment with PD-98059, an ERK1/2 inhibitor, blocked C-oLDL or LDL-induced ERK1/2 phosphorylation or PAI-1 expression in EC. The results suggest that LOX-1, H-Ras, and Raf-1/ERK1/2 are implicated in PAI-1 expression induced by oxidized LDLs or LDL in cultured EC.

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