Transcriptional remodeling during metacyclogenesis in Trypanosoma cruzi I

Abstract

Metacyclogenesis is one of the most important processes in the life cycle of Trypanosoma cruzi. In this stage, noninfective epimastigotes become infective metacyclic trypomastigotes. However, the transcriptomic changes that occur during this transformation remain uncertain. Illumina RNA-sequencing of epimastigotes and metacyclic trypomastigotes belonging to T. cruzi DTU I was undertaken. Sequencing reads were aligned and mapped against the reference genome, differentially expressed genes between the two life cycle stages were identified, and metabolic pathways were reconstructed. Gene expression differed significantly between epimastigotes and metacyclic trypomastigotes. The cellular pathways that were mostly downregulated during metacyclogenesis involved glucose energy metabolism (glycolysis, pyruvate metabolism, the Krebs cycle, and oxidative phosphorylation), amino acid metabolism, and DNA replication. By contrast, the processes where an increase in gene expression was observed included those related to autophagy (particularly Atg7 and Atg8 transcripts), corroborating its importance during metacyclogenesis, endocytosis, by an increase in the expression of the AP-2 complex subunit alpha, protein processing in the endoplasmic reticulum and meiosis. Study findings indicate that in T. cruzi metacyclic trypomastigotes, metabolic processes are decreased, and expression of genes involved in specific cell cycle processes is increased to facilitate transformation to this infective stage.

A Trypanosoma cruzi zinc finger protein that is implicated in the control of epimastigote-specific gene expression and metacyclogenesis

“…Among a total of 3780 transcripts that showed increased levels in epimastigotes compared to the other two forms (log 2 fold change >1 and P adj value < 0.05), GO analyses revealed groups of genes encoding proteins involved with oxidation-reduction process (GO:0055114), ion transport (GO:0006811), amino acid metabolism (GO:0006520), translation (GO:0006520) and ATP metabolic process (GO:0046034). These results are in accordance with previously published epimastigote transcriptomes from other T. cruzi strains, namely Dm28c, Y and Sylvio (Smircich et al ., 2015; Li et al ., 2016; Cruz-Saavedra et al ., 2020 b ). Also, members of the beta amastin sub-family, whose epimastigote-specific expressions have been previously described by our group (Kangussu-Marcolino et al ., 2013), as well as members of the family of PADs, which have been characterized in T. brucei (Dean et al ., 2009) but not in T. cruzi , were also found among the genes that are up-regulated in CL Brener epimastigotes (Table S5).…”

“…TcZC3H31 gene knockout (KO) resulted in inhibited metacyclogenesis and an arrest of epimastigotes into an intermediate state (Alcantara et al ., 2018). It has been shown that differentiation between life cycle stages that occurs into the insect and mammalian hosts is accompanied by changes in the expression of a large number of T. cruzi genes (Smircich et al ., 2015; Li et al ., 2016; Cruz-Saavedra et al ., 2020 a , 2020 b ). By performing global gene expression analysis, we have identified all RBPs with differential expression (DE) between epimastigotes, trypomastigotes and amastigotes.…”

Metabolic Alteration of Trypanosoma cruzi during Differentiation of Epimastigote to Trypomastigote Forms

“…Here, an HPLC analysis of short-chain carboxylic acid from glycolytic and Krebs cycle of T. cruzi showed differences in the concentration of various compounds during its growth in BHI medium (Figure 1) and its differentiation in TAU3AAG medium (Figure 2). These differences indicate that both energetic pathways are modulated and most likely reflect the dramatic changes in the physiological state of the parasite [26,39,40]. In the total extract from epimastigotes cultured in BHI media (Figure 4), the aldolase activity remained constant and appeared enhanced in the lag and log phases (24-72 h) as well as at the beginning of the stationary phase (120 h).…”

“…Although the basic knowledge about trypanosomatid carbohydrate metabolism and its particularities has been unraveled in the previous decades [24,25], new information has become available in recent years, showing that the process is more elaborate and has additional information on peculiar features [13,[26][27][28]. These features have been evaluated through enzymatic measurements [16,29,30], enzyme expression studies [16,[28][29][30], predictions through computational approaches [31], gene expression/genomic analyses [32][33][34], and metabolomics [26,35].…”

Higher expression of proline dehydrogenase altered mitochondrial function and increased Trypanosoma cruzi differentiation in vitro and in the insect vector

“…In T. brucei, for example, the intracellular accumulation of P5C/γGS has a detrimental effect on procyclic form viability [49]. The physiological role of increased H 2 O 2 via P5CDH remains elusive and warrants further investigation, as this protein has been shown to be upregulated in MT and bloodstream trypomastigotes [23,50]. In addition, previous work using T. cruzi-infected triatomine insects has shown that extracellular addition of antioxidants enhances metacyclogenesis when assessed in the vector midgut [51].…”