ROS production and the NADPH oxidase expression in human abdominal aortic aneurysm-derived smooth muscle cells

• Main Authors: Ying-Hui Chen, 陳應輝
• Other Authors: Meei-Jyh Jiang
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/50897172642248514288

碩士 === 國立成功大學 === 細胞生物及解剖學研究所 === 93 === 　Abdominal aortic aneurysms (AAAs) are present in 3-8% of people over 60 years of age in America. It usually occurs below the renal arteries and may extend into the iliac arteries. Progression of AAA involves dilation, stretching, or ballooning of the aorta. The causes of AAA may include infection, congenital weakening of the connective tissue component of the artery wall, or trauma. This is often a silent disorder until the catastrophic event of aneurysm rupture occurs. Most AAAs occurs in association with advanced atherosclerosis and hypertension. In the past decade, reactive oxygen species (ROS) have been proposed to contribute to the pathogenesis of aneurysm though the exact cause is still unknown. ROS is often considered cytotoxic metabolites during oxidative process from oxygen to water. NAD(P)H oxidase has been reported as a major enzyme for producing ROS in most of the vascular inflammatory diseases. Miller et al showed that tissue of aneurysm produced more ROS then adjacent area. In this study, we hypothesized that AAA-derived human aortic smooth muscle cells (HASMCs) are capable of more ROS production accompanied by higher NAD(P)H oxidase activity. Six AAA specimens were collected from surgery under normal surgical procedure. Specimens from the punctured hole of ascending aorta in patients with coronary artery bypass graft surgery were collected as the controls. HASMCs were cultured from medial layer of the specimens by explant method and the identity of HASMCs was verified by immunostaining with specific markers. AAA-derived and control HASMCs exhibited similar morphological and immunostaining features in culture. The proliferation rate determined by MTT assay showed no difference between the two groups. Angiotensin II-stimulated superoxide anion production as detected by dihydroethidium-derived fluorescence was markedly greater in AAA-derived HASMCs compared to the control HASMCs while no difference was detected in the absence of stimulation. Similarly, angiotensin II stimulation resulted in 2-fold in NAD(P)H oxidase activity assay in AAA-derived HASMCs compared to control HASMCs with similar basal activity in both groups. The above experiments may characterize the important roles of ROS and NAD(P)H oxidase in mediating the disease of AAA.