Could telomeres and inositol pyrophosphates play important roles in the metacyclogenesis and virulence of Leishmania?

• Grant number: 22/00923-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): February 01, 2023
• Effective date (End): January 31, 2026
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Marcelo Santos da Silva
• Grantee: Vitor Luiz da Silva
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/10753-2 - Investigation on the role of inositol pyrophosphates (PP-IPs) in DNA repair pathways and telomere dynamics using trypanosomatids as a model, AP.JP

Abstract

Leishmaniases refer to a group of diseases caused by parasites of the Leishmania genus, which mainly affect people in a social vulnerability state. Currently, the drugs available for the treatment of leishmaniasis contribute to the appearance of other clinical comorbidities due to their side effects, which does the search for new therapeutic targets fundamental. In model eukaryotes, inositol pyrophosphates (PP-IPs), mainly IP7 and IP8, are involved in a wide range of cellular processes, such as regulation of telomere length and homologous recombination (HR). However, the target proteins of PP-IPs, as well as their mechanism of action, are still open questions. IP7 and IP8 are synthesized by pathways involving the participation of kinases IP6K and PP-IP5K, respectively. Trypanosomatids do not have orthologous genes for PP-IP5K, which makes them excellent models for the study of IP7. Thus, our hypothesis is that PP-IPs (mainly IP7) play an important role in telomeric dynamics in Leishmania, organisms that have a high proliferative capacity. We also hypothesize that PP-IPs may participate in other metabolic pathways in this microbe. Thus, we intend to apply approaches involving loss of function of the IP6K gene (responsible for the IP7 synthesis) and telomerase (responsible for telomeres elongation) using the CRISPR/Cas9 system and later carry out assays that allow evaluating the possible correlation of PP-IPs with telomeres. We will also evaluate the bulk and single-cell expression profile during metacyclogenesis through transcriptomic assays to track possible pathways that may be altered due to the lack of IP7 and/or telomerase. Metabolomics assays will also be performed for this purpose. Finally, assuming that there is a differential phenotype and that IP6K can be a possible target for drug development, we will perform virulence analyzes to evaluate the infective capacity in the generated Leishmania lineages. The data obtained from this project will allow us to better understand the function of PP-IPs, as well as the telomeric dynamics of this parasite. Moreover, our results may pave the way for the development of specific therapies against leishmaniasis since kinases are excellent targets for drug development and telomeres are considered the molecular clock of eukaryotic cells. (AU)