SOLVING THE PUZZLE OF COPPER METABOLISM IN Trypanosoma cruzi

MERLI ML; MEDIAVILLA MG; ACOSTA OVIEDO H; CRICCO JA

Rosario

Congreso; LIX Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2023

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB)

Trypanosoma cruzi is the Chagas disease agent, the most prevalent parasitic disease in manycountries of America. This parasite has a complex life cycle, which involves a mammalian host and atriatomine insect vector. Along its life cycle, it acquires copper from the different hosts it encountersthrough the action of many importers and chaperons, first at the plasma membrane, then within thecytosol and finally inside the organelles, especially in the mitochondria. Copper is an essential ion fororganisms of all kingdoms, especially for aerobic organisms, but it is also a toxic ion. Free Cu ion cancause oxidative damage via the Fenton-like reaction, so its metabolism must be regulated. Despite itsimportance, Cu metabolism has not been studied in T. cruzi. In this work, we characterized the effect ofchanges in Cu ion availability along the life cycle of T. cruzi: at epimastigote, trypomastigote andintracellular amastigote stages. Stress conditions were obtained by the addition of copper sulfate orcopper chelators, and intracellular copper content was verified by ICP-OES. Our results show that Cu isan essential ion for epimastigotes proliferation and metacyclogenesis process. In contrast, Cu caused anegative effect on intracellular amastigote replication. In this sense, Cu ions are part of defensemechanisms against intracellular pathogens used by mammalian cells. By bioinformatic methods, weidentified several proteins that could be involved in Cu reduction, importation, and distribution acrossthe organelles. Even so, we did not identify cytosolic chaperones for intracellular distribution. Theexpression of these genes was studied across the life cycle stages as well as their response to Cuconcentration. We determined that these genes are overexpressed in the infective stages of theparasites and that some of them respond to copper availability. In conclusion, T. cruzi needs copper asa cofactor along its life cycle and at the same time needs to tolerate copper stress. With the dataobtained, for these functions we propose that the transmembrane importer TcIT at the plasmaticmembrane and the transmembrane transporter TcCuATPAse at Golgi complex are involved in copperuptake and distribution, and we present a model for Cu transportation and intracellular regulation.