Effects of Angiotensin II and Shear Stress Interaction on Vascular Inflammation

ABSTRACT

BACKGROUND: Angiotensin II (AngII) and abnormal oscillatory shear stress are highly associated with vascular inflammation including atherosclerosis. However, it is poorly understood how interactions between AngII and shear stress in human aortic endothelial cells (HAEC) are involved in mechanisms by which cellular adhesion molecules are expressed. The purpose of this study was to improve that understanding. METHODS: AngII (10(-7)M for 6 hr) and two-types of shear stress treatments were used: laminar shear stress (LS: unidirectional, 12 dynes/cm2) and oscillatory shear stress (OS: bi-directional, 5 dynes/cm2, 1 Hz) in HAEC. Immunoblotting was used to detect expression of cellular adhesion molecules markers such as vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecule 1 (ICAM1). RESULTS: AngII significantly increased VCAM1 and ICAM1 expression in HAEC that had been reduced due to pretreatment with telmisartan. AngII-LS co-stimulation and AngII-OS co-stimulation significantly increased VCAM1 and ICAM1 expression in HAEC. The expression levels of VCAM1 and ICAM1 were also, significantly reduced when pretreated with telmisartan. However, VCAM1 and ICAM1 expression were significantly reduced under LS and OS stimulation. CONCLUSIONS: Telmisartan may modulate the expressions of VCAM1 and ICAM1 via different types of shear stress in HAEC that are activated by AngII.