Search bioRxiv⌕ Search

Biology subjects

Santarossa, B. A.

Publications and source records attributed to Santarossa, B. A..

2 recordsLinked to original sources

Reduced levels of inositol hexakisphosphate kinase (IP6K) impair life-cycle transitions and the intracellular development of Trypanosoma cruzi within human cardiomyocytes

Trypanosoma cruzi is the etiological agent of Chagas disease. During its life cycle, T. cruzi undergoes several key differentiation processes that are essential for its survival. The precise mechanisms that regulate these processes remain elusive, and any interference in this cycle would represent a breakthrough in the development of effective therapy against Chagas disease. Here, after depleting a single IP6K allele of T. cruzi, we observed that key differentiation processes (metacyclogenesis, amastigogenesis and trypomastigogenesis) were profoundly impaired. Epimastigote forms of IP6K-deficient T. cruzi exhibited morphological alterations and reduced metacyclogenesis. IP6K-deficient metacyclic forms had reduced infective potential in human cardiomyocytes. IP6K-deficient amastigote forms showed impaired ability to transform into trypomastigotes, with most of the population egressing from human cardiomyocytes without completing trypomastigogenesis. Together, our results suggest that IP6K is critical to sustain the T. cruzi life cycle. Since disruption of both IP6K alleles was lethal and the primary structure of IP6K shares only [~]25% similarity with its human homolog, this kinase emerges as a promising target for drug development against Chagas disease. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=153 HEIGHT=200 SRC="FIGDIR/small/700787v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1cb37f0org.highwire.dtl.DTLVardef@c59fb8org.highwire.dtl.DTLVardef@791cb7org.highwire.dtl.DTLVardef@14c68fd_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Stage-Specific MCM Protein Expression in Trypanosoma cruzi: Insights Into Metacyclogenesis and G1 Arrested epimastigotes.

Trypanosoma cruzi is a protozoan parasite that is the etiological agent of Chagas disease, which is endemic to Latin America with reported cases in non-endemic regions such as Europe, Asia, and Oceania due to migration. During its lifecycle, T. cruzi alternates between replicative and non-replicative infective lifeforms. Metacyclogenesis is the most studied transition in which replicative epimastigotes differentiate into infective metacyclic trypomastigotes inside the gut of the triatomine vector. This early-branching organism presents a divergent pre-replication complex (pre-RC) where the only conserved component is the MCM2-7 protein family. Given the role of pre-RC components in cell cycle regulation, we investigated whether MCM expression and location could be involved in proliferation control in epimastigotes and during metacyclogenesis. Our findings reveal that MCMs are consistently expressed and localized to the nucleus throughout the epimastigote cell cycle, including in G1/G0-arrested cells. However, MCM proteins are degraded during metacyclogenesis as cells enter the G0 state, marking the transition to replication arrest. Therefore, epimastigotes arrested in G1/G0 can either maintain MCM expression and resume the cell cycle when conditions become favorable, or they can undergo metacyclogenesis, exiting the cell cycle and entering a G0 state, where MCMs are degraded as part of the replication repression mechanism.

cell biology↗