High-glucose-altered endothelial cell function involves both disruption of cell-to-cell connection and enhancement of force development.
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-11 alpha,9 alpha-epoxymethano prostaglandin F(2 alpha); 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.
Nobe
Koji
K
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-0555, Japan. kojinobe@pharm.showa-u.ac.jp
Miyatake
Mari
M
Sone
Tomoko
T
Honda
Kazuo
K
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D016227:Benzoquinones / Q000494:pharmacology; D015820:Cadherins / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002199:Capillary Permeability / Q000187:drug effects; D002417:Cattle; D002450:Cell Communication / Q000187:drug effects*; D002478:Cells, Cultured; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007537:Isometric Contraction / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D000098:Acetophenones; D001578:Benzopyrans; D016227:Benzoquinones; D015820:Cadherins; D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D004533:Egtazic Acid; C087469:stemphone; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C085746:rottlerin; D005947:Glucose; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium