Prestes Elisa Beatriz, Stoco Patrícia Hermes, de Moraes Milene Höehr, Moura Hércules, Grisard Edmundo Carlos
Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Laboratório de Inflamação e Imunidade, IMPG/CCS, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
Exp Parasitol. 2019 Sep;204:107727. doi: 10.1016/j.exppara.2019.107727. Epub 2019 Jul 22.
Trypanosoma rangeli is a protozoan parasite that is non-virulent to the mammalian host and is morphologically and genomically related to Trypanosoma cruzi, whose proliferation within the mammalian host is controversially discussed.
We aimed to investigate the T. rangeli cell cycle in vitro and in vivo by characterizing the timespan of the parasite life cycle and by proposing a molecular marker to assess cytokinesis.
The morphological events and their timing during the cell cycle of T. rangeli epimastigotes were assessed using DNA staining, flagellum labelling and bromodeoxyuridine incorporation. Messenger RNA levels of four genes previously associated with the cell cycle of trypanosomatids (AUK1, PLK, MOB1 and TRACK) were evaluated in the different T. rangeli forms.
T. rangeli epimastigotes completed the cell cycle in vitro in 20.8 h. PLK emerged as a potential molecular marker for cell division, as its mRNA levels were significantly increased in exponentially growing epimastigotes compared with growth-arrested parasites or in vitro-differentiated trypomastigotes. PLK expression in T. rangeli can be detected near the flagellum protrusion site, reinforcing its role in the cell cycle. Interestingly, T. rangeli bloodstream trypomastigotes exhibited very low mRNA levels of PLK and were almost entirely composed of parasites in G1 phase.
Our work is the first to describe the T. rangeli cell cycle in vitro and proposes that PLK mRNA levels could be a useful tool to investigate the T. rangeli ability to proliferate within the mammalian host bloodstream.
兰氏锥虫是一种对哺乳动物宿主无致病性的原生动物寄生虫，在形态和基因组上与克氏锥虫相关，而克氏锥虫在哺乳动物宿主体内的增殖存在争议。
我们旨在通过描述寄生虫生命周期的时长并提出一种评估胞质分裂的分子标志物，来研究兰氏锥虫在体外和体内的细胞周期。
使用DNA染色、鞭毛标记和溴脱氧尿苷掺入法评估兰氏锥虫前鞭毛体细胞周期中的形态学事件及其发生时间。在兰氏锥虫的不同形态中评估了先前与锥虫细胞周期相关的四个基因（AUK1、PLK、MOB1和TRACK）的信使RNA水平。
兰氏锥虫前鞭毛体在体外20.8小时内完成细胞周期。PLK成为细胞分裂的潜在分子标志物，因为与生长停滞的寄生虫或体外分化的锥鞭毛体相比，其信使RNA水平在指数生长的前鞭毛体中显著增加。兰氏锥虫中PLK的表达可在鞭毛突出部位附近检测到，这加强了其在细胞周期中的作用。有趣的是，兰氏锥虫血液中的锥鞭毛体PLK信使RNA水平非常低，几乎完全由处于G1期的寄生虫组成。
我们的工作首次描述了兰氏锥虫在体外的细胞周期，并提出PLK信使RNA水平可能是研究兰氏锥虫在哺乳动物宿主血液中增殖能力的有用工具。
