T. cruzi: pathogenesis modulation by eicosanoids

描述(由申请人提供)：二十烷类化合物是心血管系统在健康和疾病中的重要介体。查加西克心肌病是世界上许多流行地区心血管疾病的最重要原因之一。感染克氏毛滴虫会导致这种疾病，这种疾病具有许多类似于某些二十烷类药物(如血栓素)的影响的特征。这种感染会导致炎症级联反应的激活。它还会引起血管收缩、血小板聚集和平滑肌细胞增殖。我们的初步数据表明，宿主血栓素类前列腺素受体(TP)的离散信号通路调节宿主-寄生虫的关系。在TP基因敲除(KO)和WT小鼠分离的内皮细胞中，我们发现突变的TP在TP-KO内皮细胞中的表达可以作为一种分析细胞内寄生虫生长的分子调控的方法。我们证明G-AlphaQ或G-Alpha11在一定程度上负责控制细胞内寄生虫的生长。我们将进行更多的实验，以确认这些途径直接与宿主TP抑制寄生虫生长有关，从而确定第二信使影响寄生虫生长的机制(S)。要检测的终点包括这些细胞对这种寄生虫的易感性、黏附和穿透、寄生虫的生长以及Gα-Q的下游信号通路。从各种常规小鼠和KO小鼠中获得的ECS将用于确定这种感染的发病机制中的重要途径。除内皮细胞外，其他细胞都有TP，但在我们的研究中，我们使用小鼠心脏内皮细胞，因为它们很容易获得，很容易转化，并保持其表型。其他类型的细胞，如小鼠心肌细胞，很难在纯形态下获得，并且在培养中不能保持其表型。因此，内皮细胞可作为所有TP细胞的替代物，是表征TP信号作用的模型。二十烷类途径不同部分被删除的小鼠将被用来评估在先天性心脏病发病机制中重要的信号途径。在从这种寄生虫中鉴定并克隆了一个可能的血栓素合酶基因后，我们还计划检测二十烷类KO，并表征这些KO的表型。二十烷醇途径已经为心血管疾病的治疗提供了靶点，我们目前的研究很可能为这种重要的人类寄生虫病的治疗提供更多的靶点。花生四烯酸合成的二十烷酸类化合物是心血管系统的重要介体。我们的研究表明，二十烷基类化合物是由寄生虫克氏锥虫合成的，克氏锥虫是查加斯病的病原体，与心血管异常有关。我们计划研究二十烷类化合物及其受体在心脏病这一重要原因中的作用。

DESCRIPTION (provided by applicant): Eicosanoids are important mediators of the cardiovascular system in health and disease. Chagasic cardiomyopathy is one of the most important causes of cardiovascular diseases in many endemic areas of the world. Infection with the parasite T. cruzi causes this disease which has many characteristics similar to the effects of certain eicosanoids such as thromboxane. This infection leads to activation of the inflammatory cascade. It also causes vasoconstriction, platelet aggregation and smooth muscle cell proliferation. Our preliminary data indicate that discrete signaling pathways from host thromboxane prostanoid recptor (TP) regulate the host- parasite relationship. In endothelial cells (ECs) isolated from TP knockout (KO) and WT mice we found that expression of mutated TP in TP-KO ECs can be used as an approach to dissect the molecular regulation of intracellular parasite growth. We demonstrated that G-alpha q or G- alpha11 are responsible, in part, for the control of intracellular parasite growth. We will perform additional experiments to confirm that those pathways are directly responsible for the suppression of parasite growth by host TP and thus define the mechanism(s) through which second messenger's affects parasite growth. The endpoints to be examined include susceptibility of these cells to this parasite, adhesion and penetration, parasite growth and down-stream signaling pathways of G alpha -q. ECs obtained from various conventional and KO mice will be used to determine important pathways in the pathogenesis of this infection. Cells other than ECs have TP but in our studies we use murine cardiac ECs because they are readily obtained, easily transfectable and maintain their phenotype. Other cell types, such as murine cardiac myocytes, are difficult to obtain in pure form and do not maintain their phenotype in culture. Therefore, ECs act as a surrogate for all cells with TP and are a model for the characterization of the effects of TP signaling. Mice in which various parts of the eicosanoid pathway have been deleted will be used to evaluate signaling pathways important in the pathogenesis of chagasic heart disease. Having identified and cloned a putative thromboxane synthase gene from this parasite we also plan to examine eicosanoid KOs and characterize the phenotype of these KOs. The eicosanoid pathway has already provided targets for the treatment of cardiovascular disease and our current studies are likely to provide additional targets for the treatment of this important human parasitic disease. Eicosanoids which are synthesized from arachidonic acid are important mediators in the cardiovascular system. Our studies indicate that eicosanoids are synthesized by the parasite Trypanosoma cruzi, the causative agent of Chagas' disease which is associated with cardiovascular abnormalities. We plan to investigate the role of eicosanoids and their receptors in this important cause of heart disease.