Role of redox-sensitive transcription factor in the progression of atherosclerosis Possible application to gene therapy.

本研究的目的是鉴定氧化还原敏感转录因子，并分析其在血管中的作用。血管紧张素II在血管平滑肌细胞中诱导活性氧的产生，激活cAMP反应元件结合蛋白（CREB），一种43KDa的核转录因子。过氧化氢（1-1202）也能激活CREB （VSMC）。刺激15分钟后，H_2O_2以erk和p38mapk依赖的方式瞬时激活CREB。一种表皮生长因子受体（EGF-R）抑制剂也能抑制h_2o_2诱导的CREB激活，提示EGF-R的反激活在CREB激活中起重要作用。事实上，H_2O_2诱导酪氨酸磷酸化EGF-R。有效的抗氧化剂n -乙酰半胱氨酸可抑制All对CREB的激活，提示活性氧在All信号传导中起关键作用。这些数据表明CREB是一种氧化还原敏感的转录因子。腺病毒载体过表达显性阴性CREB可降低VSMC中Bcl-2的表达，诱导细胞凋亡。表达显性阴性CREB的腺病毒感染抑制大鼠颈动脉球囊损伤后新内膜的形成，TUNEL阳性细胞增加。这些数据表明CREB是一个重要的氧化还原敏感转录因子，介导VSMC的存活和增殖。提示CREB可能是治疗血管疾病的新靶点。

The aim of the present study is to identify redox-sensitive transcription factors and to analyze their role in the blood vessel. Angiotensin II that induces production of reactive oxygen species activated cAMP response element binding protein (CREB), a 43KDa nuclear transcription factor, in vascular smooth muscle cells. Hydrogen peroxide (1-1202) also activated CREB, (VSMC). H_2O_2 transiently activated CREB after 15 minutes of stimulation in ERK-and p38MAPK-dependent manner. An inhibitor for epidermal growth factor receptor (EGF-R) also suppressed H_2O_2-induced activation of CREB, suggesting that transactivation of EGF-R plays an important role in the activation of CREB. Indeed, H_2O_2 induced tyrosine phosphorylation of EGF-R. Activation of CREB by All was inhibited by N-acetylcysteine, a potent antioxidant, suggesting a critical role of reactive oxygen species in All signaling. These data suggest that CREB is a redox-sensitive transcription factor. Overexpression of dominant negative CREB by an adenovirus vector decreased Bcl-2 expression in VSMC and resulted in the induction of apoptosis. Infection of adenovirus expressing dominant negative CREB suppressed neointimal formation after balloon injury of rat carotid artery with an increase in TUNEL positive cells. These data suggest that CREB is an important redox-sensitive transcription factor that mediates survival and proliferation of VSMC. And it was suggested that CREB may be a novel therapeutic target to treat vascular diseases.