Evidence for the Rapid Onset of Apoptosis in Medial Smooth Muscle Cells After Balloon Injury

作者：Harris Perlman, Luc Maillard, Kevin L. Krasinski, Kenneth Walsh · 发表于：Circulation · 年份：1997 · DOI：10.1161/01.cir.95.4.981 · 被引用次数：283 · 研究领域：Cell death mechanisms and regulation、Atherosclerosis and Cardiovascular Diseases、Angiogenesis and VEGF in Cancer

BACKGROUND: Vascular myocyte apoptotic cell death has been reported in human atherectomy and endarterectomy specimens and for neointimal smooth muscle cells (SMCs) in balloon-injured rat carotid arteries between 7 and 30 days after injury. However, the immediate effect of balloon injury on medial SMC viability has not been examined. METHODS AND RESULTS: Rat carotid arteries were harvested at the time of balloon injury (T = 0) and at 0.5, 1, 2, and 4 hours after injury. Uninjured vessels or vessels harvested at the time of injury (T = 0) did not display evidence of apoptosis. However, as early as 30 minutes after injury, 70% of medial SMCs appeared apoptotic by TdT-mediated dUTP nick end labeling (TUNEL) analysis and by the appearance of condensed chromatin. High frequencies of TUNEL-positive cells were also observed at 1 and 2 hours after injury but not at 4 hours. Transmission electron microscopy revealed many cells with morphological characteristics of apoptosis in the injured sections. A marked decrease in bcl-X expression was detected in the most luminal layers of the media. To corroborate these findings in a second animal model, rabbit external iliac arteries were analyzed after balloon angioplasty. Apoptotic cell death was evident in rabbit arteries at 30 minutes and at 4 hours after injury. CONCLUSIONS: As early as 30 minutes after balloon injury, myocytes appear to undergo apoptotic cell death at a high frequency as shown by TUNEL staining, chromatin condensation, and...