TY - JOUR T1 - High-Glucose-Altered Endothelial Cell Function Involves Both Disruption of Cell-to-Cell Connection and Enhancement of Force Development JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 530 LP - 539 DO - 10.1124/jpet.106.105015 VL - 318 IS - 2 AU - Koji Nobe AU - Mari Miyatake AU - Tomoko Sone AU - Kazuo Honda Y1 - 2006/08/01 UR - http://jpet.aspetjournals.org/content/318/2/530.abstract N2 - Vascular endothelial cells (ECs), which regulate vascular tonus, serve as a barrier at the interface of vascular tissue. It is generally believed that alteration of this barrier is correlated with diabetic complications; however, a detailed mechanism has not been elucidated. This study examined alteration of bovine arterial EC functions stimulated by a thromboxane A2 analog (9,11-dideoxy-11α,9α-epoxymethano prostaglandin F2α; U46619) under normal and high-glucose (HG) conditions. U46619 treatment increased EC layer permeability in a time- and dose-dependent fashion. This response initially disrupted calcium-dependent EC-to-EC connections, namely, vascular endothelial cadherin (VE-CaD). Thereafter, EC force development in association with morphological changes was detected employing a reconstituted EC fiber technique, resulting in paracellular hole formation in the EC layer. Thus, we confirmed that U46619-induced enhancement of EC layer permeability involves these sequential steps. Similar trials were performed using a concentration twice that of normal glucose (22.2 mM glucose for 48 h). This treatment significantly enhanced U46619-induced EC layer permeability; furthermore, increases in both rate of VE-CaD disruption and EC fiber contraction were evident. Inhibition of calcium-independent protein kinase C and diacylglycerol kinase indicated that the glucose-dependent increase in VE-CaD disruption was mediated by a calcium-independent mechanism. Moreover, EC contraction was regulated by a typical calcium-independent pathway associated with rho kinase and actin stress fiber. Contraction was also enhanced under HG conditions. This investigation revealed that glucose-dependent enhancement of EC layer permeability is related to increases in VE-CaD disruption and EC contraction. Increases in both parameters were mediated by alteration of a calcium-independent pathway. The American Society for Pharmacology and Experimental Therapeutics ER -