Effect of nicotine on postischemic brain inflammation.

描述（由申请方提供）：大量证据表明，尼古丁通过诱导血脑屏障破坏和脑血管内皮改变，对脑血流和外周血栓形成产生不良影响。脑内皮细胞表型和功能的一些改变被表示为促炎性，表明尼古丁可能调节一些促炎介质如细胞因子和粘附分子的表达。我们的初步数据支持这一观察结果，并表明长期暴露于尼古丁（14天）对缺血后损伤（梗死面积增加2倍）和炎症反应的进展有深远的影响。特别是，尼古丁的管理显着增加白细胞迁移到postischemic小鼠脑，也诱导趋化因子CCL 2的高表达。该趋化因子是协调免疫应答的主要因素，并且在化学后炎症期间在白细胞募集中起关键作用。为了进一步探讨这个问题，我们提出了一个研究计划，旨在验证这一假设：“尼古丁通过诱导趋化因子表达的长期增加来增强脑缺血后的炎症反应。“具体地说，我们将确定尼古丁和/或科托努暴露是否可以通过刺激这些细胞中的CCL 2表达来诱导或维持脑内皮细胞的炎症反应，在体外和体内基础（即，正常的氧和葡萄糖供应）和缺血/再灌注（I/R）条件（具体目标1），并建立信号传导途径的组分（转录因子NF：B和Rho/Rho激酶途径），其是在缺血后损伤期间尼古丁上调小鼠脑内皮细胞中CCL 2表达的基础（具体目标2）。为了实现我们的目标，我们将进行体外和体内实验。对于体外实验，脑微血管内皮细胞培养物将经受组合的氧葡萄糖剥夺，然后恢复（I/R的体外模型）。将在脑I/R损伤（短暂性大脑中动脉闭塞）的小鼠模型上进行体内实验。总的来说，这些实验将首次阐明尼古丁如何调节缺血后炎症反应。公共卫生相关性：吸烟被广泛认为是中风的主要可改变的危险因素，并且与更差的中风结局有因果关系。本研究的目的是提供一个更好的了解吸烟和中风之间的关系，这可能会导致设计一个合理的治疗方法，吸烟者中风。

DESCRIPTION (provided by applicant): A substantial body of evidence suggests that nicotine adversely affects cerebral blood flow and peripheral thrombus formation by inducing breakdown of the blood-brain barrier and alterations in the cerebrovascular endothelium. Some of the alterations in brain endothelial phenotype and function are denoted as proinflammatory, indicating that nicotine may regulate expression of some proinflammatory mediators such as cytokines and adhesion molecules. Our preliminary data support this observation and indicate that chronic exposure to nicotine (14 days) has a profound effect on postischemic injury (2-fold increase in infarct size) and on the progression of the inflammatory response. Particularly, administration of nicotine markedly increased leukocyte migration into postischemic mouse brain and also induced high expression of chemokine CCL2. That chemokine is a major factor orchestrating the immune response and it plays a pivotal role in leukocyte recruitment during postichemic inflammation. To further explore this issue, we propose a research plan directed to test the hypothesis: "Nicotine augments postischemic inflammatory response in the brain by inducing a prolonged increase in expression of chemokines." Specifically, we will determine whether nicotine and/or cotonine exposure can induce or maintain the inflammatory response of brain endothelial cells through the stimulation of CCL2 expression in these cells under in vitro and in vivo basal (i.e., normal oxygen and glucose supply) and ischemia/reperfusion (I/R) conditions (specific aim 1) and to establish the components of the signaling pathway (transcription factor NF:B and Rho/Rho kinase pathway) that underlie the upregulation of CCL2 expression in mouse brain endothelial cells by nicotine during postischemic injury (specific aim 2). To accomplish our goal, we will conduct both in vitro and in vivo experiments. For in vitro experiments, brain microvessel endothelial cell cultures will be subjected to combined oxygen glucose deprivation followed by recovery (in vitro model of I/R). In vivo experiments will be performed on a mouse model of brain I/R injury (transient middle cerebral artery occlusion). Collectively, these experiments will serve to illuminate, for the first time, how nicotine can regulate postischemic inflammatory response. PUBLIC HEALTH RELEVANCE: Cigarette smoking is widely recognized as a major modifiable risk factor for stroke and it is causally associated with a worse stroke outcome. The purpose of this study is to provide a better understanding of the relationship between cigarette smoking and stroke and this may lead to the design of a rational therapeutic approach to stroke in smokers.