Increased oxidative stress in atherosclerosis-predisposed regions of the mouse aorta.
OBJECTIVE
The localization of atherosclerotic lesions to predictable regions in mammalian arteries has been recognized for over a century. We sought to investigate the association between oxidative stress and regional susceptibility of the mouse aorta to atherosclerosis.


METHODS
En face confocal microscopy was employed to assess oxidative stress in the aortic intima of atherosclerosis-susceptible and protected regions of wild-type C57BL/6 mouse. Expression of reactive oxygen species and antioxidant producing genes were compared in endothelial cells from the susceptible and protected regions.


RESULTS
In vivo administration of redox-sensitive fluorescent dyes revealed an increase in the production of reactive oxygen species (ROS) in the atherosclerosis-susceptible regions relative to the protected regions. In contrast, Hoechst a redox-insensitive dye distributed evenly in the susceptible and protected regions. Accumulation of superoxide in the susceptible regions of the aorta was significantly blocked by the administration of Diphenyleneiodonium, a flavoprotein inhibitor. mRNA levels of superoxide-producing and scavenging enzymes were significantly increased in the regions predisposed to atherosclerosis. The regional difference in oxidative stress was at a lesser magnitude in BALB/c than the atherosclerosis-susceptible mouse (C57BL/6).


CONCLUSIONS
Our study for the first time demonstrated an augmented oxidative stress in atherosclerosis-susceptible regions of the normal mouse aorta.
Haidari
Mehran
M
University of Texas Health Science Center at Houston and Texas Heart Institute, Houston, TX, USA. mehran.haidari@uth.tmc.edu
Ali
Muzammil
M
Gangehei
Leila
L
Chen
Mian
M
Zhang
Wei
W
Cybulsky
Myron I
MI
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001011:Aorta / Q000503:physiopathology*; D050197:Atherosclerosis / Q000503:physiopathology*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011973:Receptors, LDL / Q000235:genetics; D013481:Superoxides / Q000378:metabolism; D017539:Tunica Intima / Q000473:pathology
D000975:Antioxidants; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D011973:Receptors, LDL; D013481:Superoxides