Identification of protein profile in metacyclic and amastigote-like stages of Leishmania tropica: a proteomic approach

Abstract

Leishmaniasis is a tropical disease that leads to various clinical phenotypes. This study aimed to investigate protein expression changes in metacyclic and amastigote-like stages of L. tropica isolated from Iranian cutaneous leishmaniasis patients. Isolated samples were cultured and species type identified using PCR–RFLP technique. The promastigotes were grown in RPMI1640 media and differentiated to metacyclic and amastigote-like forms, followed by the extracted proteins of both successive stages carried out for proteomics and bioinformatics analysis. Using SWATH-MS quantitative proteomics technique, a total 176 and 155 distinct proteins were identified in metacyclic and axenic amastigote stages, respectively. Of these, 65 proteins were altered significantly (p-value < 0.05 and fold change ≥ 2) between studied stages. Several gene ontology (GO) categories were enriched for biological process during conversion of metacyclic promastigotes into amastigote-like, which “metabolic process” (GO: 0044281, P-Value: 6.52e-5), and “translation” (GO: 0006412, p-value: 5.01e–14) were disclosed as the top category in up and down-regulated proteins, respectively. Also, the KEGG pathway analysis indicated “metabolic pathways” and “ribosome” term as the most important pathways in up and down-regulated proteins, respectively. According to protein interaction network analysis, enolase (ENOL) has been detected as main hub proteins during differentiation, followed by Putative NADH-dependent fumarate reductase (LmjF.35.1180) and 40S ribosomal protein S2 (LmjF.32.0450). Overall, protein changes possibly play important roles in L. tropica biology. Anabolic pathways were down-regulated, whereas catabolic pathways were up-regulated during L. tropica differentiation. These protein expression changes could provide parasite survival in host macrophages, and could use as novel potential drug and vaccine targets for leishmaniasis. Graphical Abstract

Ribosome Specialization in Protozoa Parasites

“…The authors, through genomic, transcriptomic, and proteomic analyses, demonstrated that some biological processes such as “ribosome biogenesis”, “ribosome assembly” and “rRNA processing” have an important role in fitness gain by forming “fitness-adapted ribosomes”, which can change the translation specificity or efficiency and allows the environment adaptation of Leishmania to changing conditions [ 111 ]. Likewise, a quantitative proteomic analysis also revealed that some ribosomal proteins are differentially expressed in the life cycle of L. tropica , L. major , and L. donovani, being up or down-regulated in different stages of the differentiation process in all species, indicating that ribosomal proteins are involved in the most important pathways of the metacyclogenesis mechanisms [ 112 , 113 , 114 ] ( Figure 5 and Figure 6 A–F).…”

“…Several proteomic analyses have shown that ribosomal proteins as well as proteins related to ribosome biogenesis are some of the most up or downregulated proteins in the transition stage [ 108 , 112 , 113 , 141 ]. However, it is necessary to highlight that some ribosomal proteins exhibit extraribosomal functions in other organisms, such as acting as DNA endonucleases (RPS3/uS3) [ 142 , 143 ], helping in antiviral responses (RPL10/uL16, RPL13A/uL13) [ 144 , 145 ], and even being part of the small nucleolar ribonucleoproteins (snoRNP) (RPL7/uL30) [ 146 ]; some act in autoregulation of RP synthesis and as sentinels in ribosome biosynthesis, among other functions [ 147 , 148 , 149 , 150 ].…”

“…The blue Table illustrates RPs regulated in the differentiation of L. major from procyclic to metacyclic promastigotes [ 112 ]. The light red Table includes RPs regulated in the differentiation of L. tropica from metacyclic promastigotes to amastigotes-like [ 113 ]. The purple table shows RPs differentially expressed in amastigotes compared to promastigotes of L. donovani [ 114 ].…”