Benzene Exposure and Heart Failure

项目摘要 长期接触空气污染物被认为是心血管疾病的危险因素，包括 心肌缺血和心力衰竭。最近的流行病学和实验数据表明，许多不稳定的 苯等有机化合物导致进展性心脏病患者预后恶化 疾病苯是最丰富的空气污染物，主要来自汽车尾气和烟草 抽烟尽管空气污染物中苯的含量很高，但人们对吸入苯的直接影响知之甚少。 苯对心力衰竭发病率和死亡率的良好对照动物研究。我们最近的研究表明， 苯暴露类似于中度到高度的人类暴露， 超负荷诱导小鼠。苯引起的心功能恶化伴随着内皮细胞 心脏中粒细胞的活化和浸润以及CXCL 1趋化因子基因表达的上调 和alarmin S100 A8/A9复合物，其通过以下途径促进中性粒细胞和单核细胞的趋化性和粘附： TLR 4和信号转导。我们新的初步数据表明，环境苯暴露导致内皮细胞 在人类中，慢性低剂量暴露刺激内皮活化/损伤，在小鼠中，慢性低剂量暴露刺激内皮活化/损伤。使用 压力超负荷引起的心功能不全的动物模型，我们将检查环境的影响， 苯暴露对心功能不全的影响（超声心动图、心脏肥大、成分分析和 浸润免疫细胞的激活状态）在心脏重塑（目的1），并检查分子 苯加剧心功能障碍的机制（目的2）。成功完成这些研究 将首次展示苯如何影响进展性心力衰竭患者的心脏功能， 为这个过程提供了一个机械的视角。

Project Summary Long-term exposure air pollutant exposure is recognized as a risk factor for cardiovascular diseases including myocardial ischemia and heart failure. Recent epidemiological and experimental data indicate that many volatile organic compounds including benzene contribute to worsening outcomes in patients with progressive heart disease. Benzene is the most abundant air pollutant mostly generated from automobile exhaust and tobacco smoke. Despite high prevalence of benzene in air-pollutants, little is known about the direct effects of inhaled benzene on heart failure morbidity and mortality in well-controlled animal studies. Our recent studies show that benzene exposure resembling moderate to high levels of human exposure worsens cardiac function in pressure overload-induced mice. The benzene-induced worsening of cardiac functions was accompanied by endothelial activation and infiltration of granulocytes in the heart and upregulation of gene expression for CXCL1 chemokine and alarmin S100A8/A9 complex which promotes neutrophil and monocyte chemotaxis and adhesion through TLR4 and RAGE signaling. Our new preliminary data show that ambient benzene exposure causes endothelial activation/injury in humans and chronic low dose exposure stimulates endothelial activation/injury in mice. Using animal model of pressure overload-induced cardiac dysfunction, we will examine the effects of environmental benzene exposure on cardiac dysfunction (echocardiography, cardiac hypertrophy, analysis of composition and activation status of infiltrating immune cells) during heart remodeling (Aim 1), and examine the molecular mechanisms by which benzene exacerbate cardiac dysfunction (Aim 2). Successful completion of these studies will, for the first time, show how benzene affect cardiac function in patients with progressing heart failure and provide mechanistic insight into this process.