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

• Published in: Endocrinology (Philadelphia) Vol. 151; no. 9; pp. 4455 - 4466
• Main Authors: Sangle, Ganesh V, Zhao, Ruozhi, Mizuno, Tooru M, Shen, Garry X
• Format: Journal Article
• Language: English
• Published: Chevy Chase, MD Endocrine Society 01.09.2010
• Subjects: Advanced glycosylation end products; Animals; Antibodies; Antibodies - pharmacology; Biological and medical sciences; Blood Glucose - metabolism; Blotting, Western; Cell Line; CYBB protein; Cytoplasm; Diabetes mellitus; Diabetes Mellitus, Experimental - blood; Diabetes Mellitus, Experimental - chemically induced; Diabetes Mellitus, Experimental - metabolism; DNA-Binding Proteins - metabolism; Endothelial cells; Endothelial Cells - cytology; Endothelial Cells - drug effects; Endothelial Cells - metabolism; Farnesyl-diphosphate farnesyltransferase; Fibrinolysis; Fundamental and applied biological sciences. Psychology; Glucose; H-Ras protein; Heart; Heat shock; Heat Shock Transcription Factors; HSF1 protein; Humans; Lipoproteins; Lipoproteins (low density); Lipoproteins, LDL - pharmacology; Male; Mice; Mice, Inbred C57BL; Mortality; NAD(P)H oxidase; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; NOX4 protein; Oncogenes; Onium Compounds - pharmacology; Phosphorylation; plasminogen; Plasminogen Activator Inhibitor 1 - genetics; Plasminogen Activator Inhibitor 1 - metabolism; Plasminogen activator inhibitors; Proto-Oncogene Proteins c-raf - metabolism; Ras protein; ras Proteins - metabolism; Receptor for Advanced Glycation End Products; Receptors, Immunologic - immunology; Receptors, Immunologic - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA-mediated interference; Sarcoma; Signal transduction; Signal Transduction - drug effects; siRNA; Streptozocin; Stress; Transcription Factors - metabolism; Translocation; Vertebrates: endocrinology; Shock; Plasminogen activator inhibitor 1; Temperature; Endothelial cell; Heat; NADPH oxidase; Environmental factor; Protein kinase Raf-1
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2010-0323

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. Glycated LDL stimulates the expression of plasminogen activator inhibitor-1 in vascular endothelial cells through the activation of receptor of AGEs, H-Ras, Raf1, and NADPH oxidase.