Mechanisms of Responses to Diesel Exhaust and Stress

描述(由申请人提供) 拟议的职业发展和研究计划将使候选人做好准备，利用动物模型进行独立研究，重点是如何在易感人群中修改空气污染物的毒性影响。流行病学研究的证据表明，既往患有心血管(CV)疾病的人因颗粒物空气污染(PM)而发生心血管效应的风险增加。该研究计划将检验这样一种假设，即PM的CV效应是通过对肺部局部损伤和炎症的全身炎症反应来介导的，并且肺和肝脏中巨噬细胞数量和活性的改变有助于提高载脂蛋白E缺陷(ApoE-/-)小鼠对这些影响的敏感性。此外，共同暴露在压力之下，毒性效应将会增强。为了验证这一假设，候选人将使用新生成的柴油尾气(DE)作为PM暴露的模型。第一个目标是确定ApoE-/-小鼠是否表现出对DE诱导的肺部和全身炎症以及血栓前活动的易感性增加。APOE-/-和对照组小鼠将暴露于DE(30-1000 mU/g/m~3 PM)或对照组3-6小时，结果在暴露后0-72小时测量。将评估肺、肝、血液和血管中的炎症标志物，包括细胞计数、细胞因子表达、循环急性时相蛋白和细胞黏附分子。第二个目的是确定ApoE-/-小鼠对DE敏感性的增加是否是由于肺和肝脏中巨噬细胞数量和活性的增加。DE诱导的巨噬细胞效应的依赖性将通过使用脂质体选择性地耗尽这些细胞来测试。第三个目的是确定应激是否改变DE诱导的炎症反应和血栓前活性。在有和没有急性应激源的DE暴露后，将分析ApoE-/-和对照组小鼠的炎症和血栓前活性。职业发展计划包括通过有监督的研究和有组织的教育活动进行吸入毒理学和心理神经免疫学方面的指导和培训。需要学习的实验室技术包括动物暴露、手术、细胞培养、免疫印迹、酶联免疫吸附试验、原位杂交、RT-PCR和组织化学程序。职业发展计划将使候选人能够实现他的总体目标，即进行将动物研究与人类暴露研究相结合的研究。这些实验研究将有助于阐明PM心血管效应的潜在机制

DESCRIPTION (provided by applicant) The proposed career development and research plans will prepare the candidate to conduct independent research focusing on how the toxic effects of air pollutants may be modified in susceptible individuals, using animal models. Evidence from epidemiological studies indicates that individuals with pre-existing cardiovascular (CV) disease are at increased risk of CV effects from particulate matter air pollution (PM). The research plan will test the hypothesis that the CV effects of PM are mediated by systemic inflammatory responses to local injury and inflammation in the lungs, and that altered macrophage numbers and activity in lung and liver contribute to increased sensitivity of apolipoprotein E-deficient (ApoE-/-) mice to these effects. Moreover, toxic effects will be enhanced by co-exposure to stress. To test this hypothesis, the candidate will use freshly generated diesel exhaust (DE) as a model PM exposure. The first aim is to determine if ApoE-/- mice exhibit increased susceptibility to DE-induced pulmonary and systemic inflammation and prothrombotic activity. ApoE-/- and control mice will be exposed to DE (30-1000 mu/g/m3 PM) or control for 3-6 hours, with outcomes measured at 0-72 hours post-exposure. Markers of inflammation will be assessed in the lung, liver, blood, and blood vessels, including cell counts, cytokine expression, circulating acute phase proteins, and cell adhesion molecules. The second aim is to determine if increases in the sensitivity of ApoE-/- mice to DE are due to increased macrophage numbers and activity in the lung and liver. Dependence of DE-induced effects on macrophages will be tested by selectively depleting these cells using liposomes. The third aim is to determine if stress alters DE-induced inflammatory responses and prothrombotic activity. Inflammation and prothrombotic activity will be analyzed in ApoE-/- and control mice after exposure to DE with and without an acute stressor. Career development plans include mentorship and training in inhalation toxicology and psychoneuroimmunology through supervised research and structured educational activities. Laboratory techniques to be learned include animal exposures, surgery, cell culture, western blotting, ELISA, in situ hybridization, RT-PCR and histochemical procedures. The career development plan will enable the candidate to achieve his overall goal of conducting research that integrates animal studies with human exposure studies. The experimental studies will contribute to elucidating mechanisms underlying CV effects of PM.