Advanced glycation end products upregulate lysyl oxidase and endothelin-1 in human aortic endothelial cells via parallel activation of ERK1/2-NF-[kappa]B and JNK-AP-1 signaling pathways

• Published in: Cellular and molecular life sciences : CMLS 2016-04, Vol.73 (8), p.1685
• Main Authors: Adamopoulos, Christos, Piperi, Christina, Gargalionis, Antonios N, Dalagiorgou, Georgia, Spilioti, Eliana, Korkolopoulou, Penelope, Diamanti-kandarakis, Evanthia, Papavassiliou, Athanasios G
• Format: Article
• Language: English
• Subjects: Cellular biology; Deregulation; Enzymes; Gene expression; Signal transduction
• ISSN: 1420-682X; 1420-9071
• DOI: 10.1007/s00018-015-2091-z

Endothelial dysfunction involves deregulation of the key extracellular matrix (ECM) enzyme lysyl oxidase (LOX) and the vasoconstrictor protein, endothelin-1 (ET-1), whose gene expression can be modulated by the transcriptional activators nuclear factor kappa B (NF-[kappa]B) and activator protein-1 (AP-1). Advanced glycation end products (AGEs) present an aggravating factor of endothelial dysfunction which upon engagement to their receptor RAGE induce upregulation of mitogen-activated protein kinases (MAPKs), leading to NF-[kappa]B and AP-1 potentiation. We hypothesized that AGEs could induce NF-[kappa][Beta]- and AP-1-dependent regulation of LOX and ET-1 expression via the AGE/RAGE/MAPK signaling axis. Western blot, real-time qRT-PCR, FACS analysis and electrophoretic mobility-shift assays were employed in human aortic endothelial cells (HAECs) following treatment with AGE-bovine serum albumin (AGE-BSA) to investigate the signaling pathway towards this hypothesis. Furthermore, immunohistochemical analysis of AGEs, RAGE, LOX and ET-1 expression was conducted in aortic endothelium of a rat experimental model exposed to high- or low-AGE content diet. HAECs exposed to AGE-BSA for various time points exhibited upregulation of LOX and ET-1 mRNA levels in a dose- and time-dependent manner. Exposure of HAECs to AGE-BSA also showed specific elevation of phospho(p)-ERK1/2 and p-JNK levels in a dose- and time-dependent fashion. AGE administration significantly increased NF-[kappa][Beta]- and AP-1-binding activity to both LOX and ET-1 cognate promoter regions. Moreover, LOX and ET-1 overexpression in rat aortic endothelium upon high-AGE content diet confirmed the functional interrelation of these molecules. Our findings demonstrate that AGEs trigger NF-[kappa][Beta]- and AP-1-mediated upregulation of LOX and ET-1 via the AGE/RAGE/MAPK signaling cascade in human endothelial cells, thus contributing to distorted endothelial homeostasis by impairing endothelial barrier function, altering ECM biomechanical properties and cell proliferation.