Characterization of D-glucose transport in Trypanosoma rangeli

Abstract

Like in other trypanosomatids D-glucose is a crucial source of energy to Trypanosoma rangeli, a non-pathogenic parasite that in Central and South America infects triatomine vectors and different mammalian species, including humans. In several trypanosome species, D-glucose transporters were already described and cloned. In this study, we characterized the D-glucose transport activity present in 2 life-stage forms of T. rangeli (epimastigotes and trypomastigotes) using D-[U-14C]glucose as substrate. Our results indicate that T. rangeli transports D-glucose with high affinity in both epimastigote (Km 30 microM) and trypomastigotes (Km 80 microM) life-forms. Both transport activities were inhibited by Cytochalasin B and Phloretin, indicating that probably D-glucose uptake in T. rangeli is mediated by facilitated diffusion of the sugar. Significant differences were observed between epimastigotes and trypomastigotes in relation to their affinity for D-glucose analogues, and the predicted amino acid sequence of a putative D-glucose transporter from T. rangeli (TrHT1) showed a larger identity with the T. cruzi D-glucose transporter encoded by the TcrHT1 gene than with other transporters already characterized in trypanosomatids.

Oleanonic acid from Lippia lupulina (Verbenaceae) shows strong in vitro antileishmanial and antitrypanosomal activity

“…Similar results were observed for sakuranetin (5) in our experiments against epimastigote forms of T. cruzi Y strain (IC 50 47.5 µg mL -1 , Table 2). Although the dihydrochalcone phloretin (4) did not show detectable trypanocidal activity in our work (IC 50 higher than 365 µM, Table 2), it has been described to influence the glucose metabolism of T. cruzi, T. brucei, and T. rangeli (Bakker et al 1999;Einicker-Lamas et al 2000;Miletti et al 2006). …”

High Affinity Nanobodies against the Trypanosome brucei VSG Are Potent Trypanolytic Agents that Block Endocytosis

“…Clearly, both transporter-mediated and fluid-phase uptake were reduced rapidly following the addition of lytic Nbs and this suggests that the presence of these Nbs in some manner obstructs endocytosis. Furthermore, Nb_An05 or Nb_An46 greatly reduced 2-deoxy-D-[ 3 H]glucose uptake, which relies primarily on facilitated diffusion through glucose transporters, rather than endocytic activity [35], [36] (Fig. 4G).…”

Intraspecies Variation in Trypanosoma cruzi GPI-Mucins: Biological Activities and Differential Expression of α-Galactosyl Residues

“…They are synthesized in the lumen of the Golgi and endoplasmic reticulum because of the action of membrane transporters and glycosyltransferases. 40 In trypanosomatids, some of those components have been reported for Leishmania, 41,42 T. rangeli, 43 and T. cruzi. 44,45 The intra-and interspecies variations in glycoconjugate assembly may originate from innumerous combinatory sequences dependent on the action and specificity of glycosidases and glycosyltransferases.…”