Exploring Iron Metabolism and Antimonial Resistance in Leishmania amazonensis: A Metabolomic and Genetic Analysis of AQP1 and LIRG1

• Grant number: 24/21947-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: May 30, 2025
• End date: February 27, 2026
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Maria Fernanda Laranjeira da Silva
• Grantee: Romário Lopes Boy
• Supervisor: Coral Barbas
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Universidad Ceu San Pablo, Spain
• Associated to the scholarship: 22/04551-0 - Characterization of genes potentially involved in the metabolism and transport of iron to the Leishmania glycosome, BP.DR

Abstract

Protozoan parasites of the genus Leishmania are the causative agents of leishmaniases, impacting millions globally. These parasites cycle between invertebrate and vertebrate hosts, where they thrive within macrophages despite nutrient limitations, particularly iron scarcity. Previous studies have shown that iron deprivation in Leishmania triggers the expression of several putative genes, some encoding proteins with glycosomal targeting signals. Glycosomes are unique organelles in trypanosomatids that compartmentalize essential proteins, including iron-dependent enzymes; however, iron trafficking within these organelles remains largely uncharacterized. In prior research, we conducted an in-silico analysis of transcripts modulated by iron deprivation in L. amazonensis, identifying 11 genes with predicted glycosomal targeting signals. Immunofluorescence analysis of promastigotes overexpressing these genes confirmed the glycosomal localization of proteins encoded by LmxM.24.1090 (lirg1) and LmxM.30.0020 (aqp1). Using CRISPR/Cas9, we generated knockout and genetically complemented lines of aqp1 and partial knockouts of lirg1. Our findings indicate that lirg1 is essential for parasite viability, as full deletion was achieved only in the presence of extrachromosomal copies of lirg1. Deficiencies in both genes led to increased superoxide dismutase activity, impaired replication in promastigote and intracellular amastigote stages, and reduced virulence. Additionally, the aqp1 knockout strain exhibited increased resistance to trivalent antimony (SbIII) and elevated intracellular levels of iron and manganese. In this BEPE proposal, our main objective is to investigate the metabolomic profile of aqp1 and lirg1 mutant strains of L. amazonensis compared to wild-type, with a focus on transition metal metabolism and antimonial resistance.