Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Hospital São Paulo, Brazil.
Mol Microbiol. 2024 Nov;122(5):704-719. doi: 10.1111/mmi.15279. Epub 2024 May 30.
Trypanosoma cruzi, a flagellated protozoan, is the causative agent of Chagas disease. The parasite has developed various mechanisms to get through its intricate life cycle and adapt to different evolutionary phases. T. cruzi proliferates in the insect vector's digestive tract as an epimastigote form, encountering fluctuating nutrient availability and oxidative stress caused by the digestion of red blood cells from the mammalian host blood meal. To unravel how the parasite's metabolism adapts to these changing conditions, we conducted an analysis of the chemical species present in epimastigote forms. This involved comparing cultured parasites with those subjected to nutritional deficiency or oxidative stress using untargeted metabolomics. We looked at 21 samples: seven biological copies of parasites that were actively growing, seven samples that were put in a medium without nutrients for 3 h, and seven samples that were treated with glucose oxidase for 30 min to make HO continuously. Importantly, in all conditions, parasite viability was maintained when the samples were collected. Upon nutrient removal, we observed a substantial decrease in amino acids and carbohydrate metabolites, accompanied by the accumulation of fatty acids and steroids, with the predominance of inositol and sphingolipid metabolism, along with a simultaneous decrease in the levels of HO. In the presence of HO, a significant rise in components of the pentose pathway and specific amino acids such as methionine and serine occurred, along with pathways related to an increase in antioxidant species metabolism such as ribulose 5-phosphate and glyceric acid. Conversely, fatty acid and steroid levels decrease. We found no common increase in metabolites or lipids. In contrast, eight species (succinic acid, glutamic acid, valine, 2-hydroxyisocaproic acid, alanine, indolelactic acid, proline, and lanosterol) were consumed under both stresses. These findings underscore the rapid and distinct enrichment responses in amino acids, lipids, and carbohydrates required to cope with each different environmental condition. We concluded that T. cruzi presents a flexible metabolism that rapidly adapts to variable changes in the environment.
克氏锥虫是一种鞭毛原生动物,是恰加斯病的病原体。该寄生虫已经发展出各种机制来完成其复杂的生命周期,并适应不同的进化阶段。克氏锥虫在昆虫载体的消化道中以滋养体形式增殖,遇到来自哺乳动物宿主血液餐的红细胞消化引起的波动的营养可用性和氧化应激。为了揭示寄生虫的代谢如何适应这些变化的条件,我们对滋养体形式中存在的化学物质进行了分析。这涉及使用无靶向代谢组学比较培养的寄生虫与经历营养缺乏或氧化应激的寄生虫。我们研究了 21 个样本:七个活跃生长的寄生虫生物学副本,七个在没有营养的培养基中放置 3 小时的样本,和七个用葡萄糖氧化酶处理 30 分钟以连续产生 HO 的样本。重要的是,在收集样本时,所有条件下寄生虫的活力都得到维持。在去除营养物质后,我们观察到氨基酸和碳水化合物代谢物大量减少,同时脂肪酸和类固醇积累,伴随着肌醇和鞘脂代谢的优势,以及 HO 水平的同时下降。在 HO 的存在下,戊糖途径的成分和特定氨基酸(如蛋氨酸和丝氨酸)显著增加,同时与抗氧化物质代谢相关的途径(如核酮糖 5-磷酸和甘油酸)增加。相反,脂肪酸和类固醇水平下降。我们没有发现代谢物或脂质的共同增加。相比之下,在两种应激下,有八种物质(琥珀酸、谷氨酸、缬氨酸、2-羟基异己酸、丙氨酸、吲哚乳酸、脯氨酸和羊毛甾醇)被消耗。这些发现强调了快速而明显的氨基酸、脂质和碳水化合物富集反应,以应对每种不同的环境条件。我们得出结论,克氏锥虫具有灵活的新陈代谢,可以快速适应环境的变化。