Molecular mechanisms of Trypanosoma cruzi induced colon pathogenesis

项目摘要 原生动物寄生虫克氏锥虫是一种被忽视的热带疾病恰加斯病的病原体。 一种疾病，给患者造成严重的发病率、死亡率和经济负担。这种疾病， 最初流行于拉丁美洲国家，现在已成为所有重大的新的全球卫生问题 经济发达的国家由于现代全球化。约30%的克氏毛滴虫感染者 最终出现心脏、胃肠道和/或神经疾病或其组合。 巨结肠是恰加斯病的主要病理之一，伴有胃肠道肥大、纤维化。 肠道和胃肠动力障碍。克鲁兹毛滴虫感染引起心脏、胃肠道疾病的机制 而患病个体的神经障碍仍在调查中。这项提议的目的是 破译早期感染过程中克氏毛滴虫失调的分子机制 到巨结肠病理学。河马信号通路已被认为是导致纤维化疾病的因素之一。 不同类型的组织。河马下游效应分子YAP的激活启动纤维化的转录 基因。我们最近发现，在猪传染性支原体感染的早期阶段，克氏锥虫可以激活YAP核翻译。 心脏内皮细胞。Thombospondin-1(TSP-1)先前被证明是被寄生虫上调的 以便于感染。心脏内皮细胞TSP-1基因敲除降低YAP平均荧光 TSP-1与河马信号通路的相互作用十分活跃。 克鲁兹病毒感染。Piwi相互作用RNA(PiRNAs)是一类与胃肠道有关的小分子非编码RNA 胃癌、结肠癌和结直肠癌等疾病。我们最近证明了piRNAs可以 靶向和调节与克氏锥虫致病相关的基因，如TGFB1、FOS和NFATC2。然而， 在克氏毛滴虫感染过程中，piRNAs在结肠细胞中的作用尚未被研究。基于这些观察， 我们推测这种寄生虫在早期阶段失调了河马信号通路和piRNAs。 感染的可能性。该假说将以以下具体目标进行评估：(1)评估 河马感染弓形虫早期的信号通路及(2)piRNAs和PIWIL的作用 在感染早期调节下游促纤维化基因的蛋白质。这个项目是 意义重大，因为它将：识别河马信号在克氏锥虫感染结肠细胞过程中的作用；描绘 TSP-1和河马信号在寄生虫感染过程中的相互作用；研究PIWIL蛋白的功能作用 而在感染过程中，使用原代人类结肠上皮和平滑肌的piRNAs显示增加 细胞。在团契培训期间，我将能够巩固和获得新的技术技能，为 手稿，并参与职业发展活动，如科学交流，科学写作， 和教书。Meharry医学院和Meharry-Vanderbilt联盟为此提供了设备 项目。

Project Summary The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, a neglected tropical disease which causes severe morbidity, mortality, and economic burden in afflicted individuals. The disease, originally endemic in Latin American countries, has now become a new global health problem in all major economically advanced countries due to modern globalization. About 30% of T. cruzi infected individuals eventually present with cardiac, gastrointestinal tract and/or neurological disorders or a combination thereof. Megacolon, one of Chagas disease major pathologies, is accompanied by an enlarged, fibrotic gastrointestinal tract and GI motility disorders. The mechanisms through which T. cruzi infection causes cardiac, gastrointestinal and neurological disorders in afflicted individuals remains under investigation. The objective of this proposal is to decipher the molecular mechanisms dysregulated by T. cruzi during early infection that contribute to megacolon pathology. The hippo signaling pathway has been identified as a contributor to fibrotic disease across tissue types. Activation of downstream hippo effector molecule YAP initiates transcription of fibrotic genes. We recently showed that T. cruzi activates YAP nuclear translation during the early phase of infection of heart endothelial cells. Thombospondin-1 (TSP-1) was previously shown to be upregulated by the parasite in order to facilitate infection. Knockout of TSP-1 in heart endothelial cells decreased YAP mean fluorescence intensity within the nucleus, indicating that TSP-1 actively interacts with the hippo signaling pathway during T. cruzi infection. PIWI-interacting RNAs (piRNAs), a class of small noncoding RNAs, contribute to gastrointestinal diseases such as gastric cancer, colon cancer, and colorectal cancer. We recently showed that piRNAs can target and regulate genes involved in T. cruzi pathogenesis, such as TGFB1, FOS, and NFATC2. However, the role of piRNAs have not been investigated in colon cells during T. cruzi infection. Based on these observations, we hypothesize that the parasite dysregulates the hippo signaling pathway and piRNAs during the early phase of infection. The hypothesis will be evaluated with the following specific aims: (1) Evaluate the dysregulation of hippo signaling pathway during early phase of T. cruzi infection and (2) Asses the role of piRNAs and PIWIL proteins in the regulation of downstream profibrotic genes during the early phase of infection. This project is significant because it will: identify the role of hippo signaling during T. cruzi infection of colon cells; delineate TSP-1 and hippo signaling interplay during parasite infection; characterize the functional roles of PIWIL proteins and piRNAs shown to be increased during infection using primary human colon epithelial and smooth muscle cells. During the fellowship training period, I will be able to solidify and gain new technical skills, prepare manuscripts, and participate in career developing activities such as scientific communication, scientific writing, and teaching. Meharry Medical College and Meharry-Vanderbilt alliance provide access to equipment for this project.