Glucose metabolism in Trypanosoma cruzi

Abstract

The causative agent of Chagas disease, Trypanosoma cruzi, metabolizes glucose through two major pathways: glycolysis and the pentose phosphate pathway. Glucose is taken up via one facilitated transporter and its catabolism by the glycolytic pathway leads to the excretion of reduced products, succinate and l-alanine, even in the presence of oxygen; the first six enzymes are located in a peroxisome-like organelle, the glycosome, and the lack of regulatory controls in hexokinase and phosphofructokinase results in the lack of the Pasteur effect. All of the enzymes of the pentose phosphate pathway are present in the four major stages of the parasite's life cycle, and some of them are possible targets for chemotherapy. The gluconeogenic enzymes phosphoenolpyruvate carboxykinase and fructose-1,6-bisphosphatase are present, but there is no reserve polysaccharide.

Benznidazole induces in vitro anaerobic metabolism in Trypanosoma cruzi epimastigotes

“…It is interesting to highlight that all the descriptions of the metabolic pathways of T. cruzi are in accordance to the organic acids detected in the 3rd day of culture [7]. However, the metabolic differences were not found in the literature when the parasite undergoes culture growth, and how different concentrations of benznidazole affect their metabolism is not found as well.…”

“…The detection of citrate indicates the presence of the mitochondrial metabolic pathway of energy production [7]. However, the decrease in the citrate, succinate and fumarate concentrations throughout the experimental days indicates that these pathways are being suppressed while the epimastigotes tend to undergo metacyclogenesis in the culture medium [22].…”

“…alpha-ketoglutarate indicates the preferential use of the glycosomal metabolic pathways for energy production due to the consumption of succinate to produce pyruvate in the epimastigotes of T. cruzi [7,21].…”

“…cruzi has been described in its different evolutive forms such as trypomastigote, epimastigote and amastigote [7]. There are glucose transporters expressed in all its evolutive stages and the parasite may use both glucose and amino-acids such as L-proline as energy sources.…”

“…There are glucose transporters expressed in all its evolutive stages and the parasite may use both glucose and amino-acids such as L-proline as energy sources. After the glucose incorporation an aerobic fermentation is undertaken within the parasite and the main products of these metabolic pathways in epimastigotes are succinate and alanine [7,8].…”