Investigating cell proliferation control mechanisms in Trypanosoma cruzi and their impact on resistance to Benznidazole

• Grant number: 24/20554-5
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2025
• End date: May 31, 2028
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Simone Guedes Calderano
• Grantee: Simone Guedes Calderano
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: André Gustavo Tempone Cardoso ; Carlos Renato Machado ; John Morrison Kelly ; Julia Pinheiro Chagas da Cunha ; Marcelo Santos da Silva ; Maria Carolina Quartim Barbosa Elias Sabbaga ; Rosangela Aparecida Wailemann Mansano

Abstract

Trypanosoma cruzi is the causative agent of Chagas disease, identified in 1909 by Carlos Ribeiro Justiniano das Chagas, and remains a public health concern in Brazil to this day. Classified as a neglected disease by the World Health Organization, its treatment is limited to two drugs, benznidazole and nifurtimox, which were introduced in the 1960s. These drugs, however, cause severe side effects, often leading patients to discontinue treatment. The genetic diversity among T. cruzi strains (DTUs) and the differing levels of drug sensitivity between strains are factors that complicate the development of new treatments. Additionally, a critical factor in the persistence of T. cruzi infection is its replicative capacity: amastigote forms can spontaneously enter quiescence, resisting treatment and retaining infectivity after treatment completion. Treatment with benznidazole itself may also induce resistance, impacting the replication rate of amastigote forms.In this context, it is essential to understand the mechanisms regulating cell proliferation in T. cruzi. While cell cycle events are well-established in mammals and yeast through the action of cyclins and CDKs (cyclin-dependent kinases), little is known in trypanosomatids. CRKs (Cdc2-related kinases) are the homologous genes of CDKs, and trypanosomatids also possess cyclins that activate these CRKs. Our group has focused on studying cell cycle control in T. cruzi, with an emphasis on the kinases CRK1 and CRK3, cyclin 5, and the CRK-inhibiting kinase, Wee1. Our data indicate that during the transition from replicative forms, epimastigotes, to non-replicative metacyclic trypomastigotes, the expression of CRK3, cyclin 5, and Wee1 significantly decreases, while CRK1 remains expressed in non-replicative trypomastigote forms (metacyclic and bloodstream forms). However, we do not yet know whether CRK1 retains kinase activity in these forms and plays any role, or if its expression is necessary to ensure proliferation resumes after differentiation into amastigotes.This project thus proposes to further explore the cell cycle proteins CRK1, CRK3, and Wee1, aiming to establish how modulating their expression impacts the cell cycle and benznidazole resistance in T. cruzi. The data generated will contribute to understanding the regulation of cell proliferation and pave the way for new drug development strategies, as dormancy induction can be explored to identify drugs capable of overcoming this cellular resistance mechanism. (AU)