Inhibition of Polyamine Synthesis Arrests Trichomonad Growth and Induces Destruction of Hydrogenosomes

Abstract

Trichomonad parasites such as Tritrichomonas foetusproduce large amounts of putrescine (1,4-diaminobutane), which is transported out of the cell via an antiport mechanism which results in the uptake of a molecule of spermine. The importance of putrescine to the survival of the parasite and its role in the biology of T. foetus was investigated by use of the putrescine analogue 1,4-diamino-2-butanone (DAB). Growth of T. foetus in vitro was significantly inhibited by 20 mM DAB, which was reversed by the addition of exogenous 40 mM putrescine. High-performance liquid chromatography analysis of 20 mM DAB-treated T. foetusrevealed that putrescine, spermidine, and spermine levels were reduced by 89, 52, and 43%, respectively, compared to those in control cells. The DAB treatment induced several ultrastructural alterations, which were primarily observed in the redox organelles termed hydrogenosomes. These organelles were progressively degraded, giving rise to large vesicles that displayed material immunoreactive with an antibody to β-succinyl-coenzyme A synthetase, a hydrogenosomal enzyme. A protective role for polyamines as stabilizing agents in the trichomonad hydrogenosomal membrane is proposed.

Putrescine analogue cytotoxicity against Trypanosoma cruzi

“…Formazan precipitation was determined spectrophometrically at 570 nm. Both concentrations significantly (P<0.05) diminished mitochondrial activity (Valentim et al, unpublished) and redox ATP-producing trichomonad hydrogenosomes (Reis et al 1999).…”

“…The putrescine analogue 1,4-diamino-2-butanone (DAB) inhibits the in vitro proliferation of the trichomonad Tritrichomonas foetus (Reis et al 1999), Entamoeba invadens (Calvo-Méndez et al 1993), and Entamoeba histolytica (Arteaga-Nieto et al 1996), as well as of Leishmania amazonensis (Valentim et al, unpublished) and fungi (Martinez-Pacheco et al 1989;Ueno et al 2004), comprising a tool to approach putrescine's role in pathogens. Here we report the effects of this compound on the putrescine auxotroph T. cruzi.…”

Effects of a putrescine analog on Giardia lamblia

“…We have previously noticed that DAB leads to the destruction of redox organelles such as the trichomonad hydrogenosomes (Reis et al 1999) and trypanosomatid mitochondria (Menezes et al 2006). Because polyamines (Tabor and Tabor 1984) and putrescine (Tkachenko and Nesterova 2003) display antioxidant activity, we decided to assess the oxidative stress using TBARS detection.…”

“…The putrescine analog, 1,4-diamino-2-butanone (DAB), was reported to be effective against DFMO-resistant parasites even in complex media (Calvo-Mendez et al 1993;Reis et al 1999).…”

“…We have previously noticed that DAB inhibits the growth of anaerobic trichomonad parasite Tritrichomonas foetus (Reis et al 1999) and T. cruzi (Menezes et al 2006), but little is known about the role of putrescine in Giardia cell biology. Here, we examined the effects of DAB in G. lamblia trophozoite proliferation, differentiation, ultrastructure, and oxidative stress.…”