RNA-seq transcriptional profiling of Leishmania amazonensis reveals an arginasedependent gene expression regulation
RNA-seq transcriptional profiling of Leishmania amazonensis reveals an arginasedependent gene expression regulation
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DOI：
10.1371/journal.pntd.0006026
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发表时间：
2017-10-01
影响因子：
3.8
通讯作者：
Floeter-Winter, Lucile Maria
中科院分区：
文献类型：
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作者：
Aoki, Juliana Ide;Muxel, Sandra Marcia;Floeter-Winter, Lucile Maria
背景利什曼原虫是一种原生动物寄生虫，其生活周期在白蛉媒介和哺乳动物宿主之间交替。这种变化涉及环境变化，并导致寄生虫在形态、代谢、细胞信号传导和基因表达调控方面发生动态变化，以快速适应新的条件。L-精氨酸途径在L.亚马逊原虫在寄生虫生命周期中是重要的，并且干扰哺乳动物巨噬细胞中感染的建立和维持。宿主精氨酸酶是一种免疫调节酶，可以减少活化的巨噬细胞产生的一氧化氮，将L-精氨酸的可用性引导到多胺途径，导致寄生虫复制。在这项工作中，我们进行了转录谱，以确定差异表达的基因在L。亚马逊野生型（La-WT）与L.方法/主要发现在La-WT和La-arg -前鞭毛体和无鞭毛体中总共鉴定了8253个转录物，其中约60%编码假设的蛋白质和443个新的转录物，其不匹配任何先前注释的基因。我们的RNA-seq数据显示，85%的基因是组成型表达的。转录组和代谢组数据的比较显示，与前鞭毛体相比，La-WT无菌无鞭毛体中的谷氨酸-5-激酶水平较低，谷氨酸-5-激酶水平较高。在前鞭毛体中没有乙酰化酶活性增加了吡咯啉5-羧酸还原酶的水平，但降低了乙酰琥珀酸合成酶、吡咯啉5-羧酸脱氢酶、乙酰鸟氨酸脱乙酰酶和亚精胺合成酶转录物的水平。这些观察结果可以解释先前的代谢组学数据，这些数据表明L-精氨酸、瓜氨酸和L-谷氨酸增加，天冬氨酸、脯氨酸、鸟氨酸和腐胺减少。总之，这些结果表明，在利什曼原虫的分化和适应环境变化的过程中，酶活性是重要的基因表达调节。在这里，我们证实了这一假设的差异基因表达的酶参与生物合成的氨基酸，精氨酸和脯氨酸代谢和精氨酸biosynthesis.Conclusions/ Significance所有的数据提供了有关的转录组分析和表达水平的La-WT和La-精氨酸（-）promastigotes和纯无鞭毛体的信息。这些研究结果揭示了在寄生虫的生存和分化的重要性，并表明存在一个协调的反应，在没有精氨酸和多胺途径相关的酶活性。
Background Leishmania is a protozoan parasite that alternates its life cycle between the sand-fly vector and the mammalian host. This alternation involves environmental changes and leads the parasite to dynamic modifications in morphology, metabolism, cellular signaling and regulation of gene expression to allow for a rapid adaptation to new conditions. The L-arginine pathway in L. amazonensis is important during the parasite life cycle and interferes in the establishment and maintenance of the infection in mammalian macrophages. Host arginase is an immune-regulatory enzyme that can reduce the production of nitric oxide by activated macrophages, directing the availability of L-arginine to the polyamine pathway, resulting in parasite replication. In this work, we performed transcriptional profiling to identify differentially expressed genes in L. amazonensis wild-type (La-WT) versus L. amazonensis arginase knockout (La-arg(-)) promastigotes and axenic amastigotes.Methodology/ Principal findings A total of 8253 transcripts were identified in La-WT and La-arg -promastigotes and axenic amastigotes, about 60% of them codifying hypothetical proteins and 443 novel transcripts, which did not match any previously annotated genes. Our RNA-seq data revealed that 85% of genes were constitutively expressed. The comparison of transcriptome and metabolome data showed lower levels of arginase and higher levels of glutamate-5-kinase in La-WT axenic amastigotes compared to promastigotes. The absence of arginase activity in promastigotes increased the levels of pyrroline 5-carboxylate reductase, but decreased the levels of arginosuccinate synthase, pyrroline 5-carboxylate dehydrogenase, acetylornithine deacetylase and spermidine synthase transcripts levels. These observations can explain previous metabolomic data pointing to the increase of L-arginine, citrulline and L-glutamate and reduction of aspartate, proline, ornithine and putrescine. Altogether, these results indicate that arginase activity is important in Leishmania gene expression modulation during differentiation and adaptation to environmental changes. Here, we confirmed this hypothesis with the identification of differential gene expression of the enzymes involved in biosynthesis of amino acids, arginine and proline metabolism and arginine biosynthesis.Conclusions/ Significance All data provided information about the transcriptomic profiling and the expression levels of La-WT and La-arg(-) promastigotes and axenic amastigotes. These findings revealed the importance of arginase in parasite survival and differentiation, and indicated the existence of a coordinated response in the absence of arginase activity related to arginine and polyamine pathways.