背景:查加斯病可导致危及生命的心脏表现。区域因素,包括循环锥虫的遗传特征(T.克鲁兹),作为恰加斯病表型表达和恰加斯心肌病(CCM)进展的可能决定因素引起了关注。我们的目的是阐明由遗传离散T.cruzi菌株感染引起的心肌细胞的差异转录组特征,并探讨它们与CCM发病机理和进展的关系。
方法:HL-1啮齿动物心肌细胞被哥伦比亚的克氏锥虫感染,Y,或Tulahuen菌株。感染后连续分离RNA用于微阵列分析。差异表达基因(倍数变化≥2或≤0.5)的富集分析强调了过度表达的生物学途径。比较了T.cruzi感染和未感染的HL-1心肌细胞的细胞内活性氧(ROS)水平。
结果:我们发现氧化应激相关基因本体论术语(GO术语),\'肥大模型\',\'细胞凋亡\',和“MAPK信号通路”(均为P<0.01)上调。谷胱甘肽和一碳代谢途径,和“细胞氮化合物代谢过程”GO术语(均为P<0.001)仅在感染哥伦比亚/Y菌株的心肌细胞中上调。与未感染的心肌细胞相比,克氏锥虫感染的心肌细胞中ROS的平均胞内水平显著更高(P<0.0001)。
结论:氧化应激相关和肥大途径的上调构成了克氏锥虫感染引起的心肌细胞反应的普遍标志。氮代谢上调和谷胱甘肽代谢失衡可能暗示亚硝化应激与氧自由基清除不良之间的关系是恰加斯心肌病独特的病理生理学。
BACKGROUND: Chagas disease can lead to life-threatening cardiac manifestations. Regional factors, including genetic characteristics of circulating Trypanosoma cruzi (T. cruzi), have attracted attention as likely determinants of Chagas disease phenotypic expression and Chagas cardiomyopathy (CCM) progression. Our objective was to elucidate the differential transcriptomic signatures of cardiomyocytes resulting from infection with genetically discrete T. cruzi strains and explore their relationships with CCM pathogenesis and progression.
METHODS: HL-1 rodent cardiomyocytes were infected with T. cruzi trypomastigotes of the Colombian, Y, or Tulahuen strain. RNA was serially isolated post-infection for microarray analysis. Enrichment analyses of differentially expressed genes (fold-change ≥ 2 or ≤ 0.5) highlighted over-represented biological pathways. Intracellular levels of reactive oxygen species (ROS) were compared between T. cruzi-infected and non-infected HL-1 cardiomyocytes.
RESULTS: We found that oxidative stress-related gene ontology terms (GO terms), \'Hypertrophy model\', \'Apoptosis\', and \'MAPK signaling\' pathways (all with P < 0.01) were upregulated. \'Glutathione and one-carbon metabolism\' pathway, and \'Cellular nitrogen compound metabolic process\' GO term (all with P < 0.001) were upregulated exclusively in the cardiomyocytes infected with the Colombian/Y strains. Mean intracellular levels of ROS were significantly higher in the T. cruzi-infected cardiomyocytes compared to the non-infected (P < 0.0001).
CONCLUSIONS: The upregulation of oxidative stress-related and hypertrophic pathways constitutes the universal hallmarks of the cardiomyocyte response elicited by T. cruzi infection. Nitrogen metabolism upregulation and glutathione metabolism imbalance may implicate a relationship between nitrosative stress and poor oxygen radicals scavenging in the unique pathophysiology of Chagas cardiomyopathy.