Identification and Inhibition of GLUT like proteins in Trichuris spp as a druggable target

Abstract

Over a quarter of the worlds population is at risk of infection by soil transmitted helminths (STH). Among the STHs Trichuris trichiura infects approximately 7% of people globally, causing a loss of 232,000 DALYS. The main strategy to combat T. trichiura infection focusses on mass drug administration with the benzimidazoles. Whilst albendazole and mebendazole have been effective at reducing the burden of other STHs, the cure rate for whipworm is less than 50% with resistance alleles rising. Glucose is the most studied nutrient in Trichuris spp, however we have no understanding, at the molecular level of the mechanism of uptake in Trichuris spp. We sought to identify putative glucose transporters in Trichuris and investigate how these can be inhibited with phloretin. Using the C. elegans Facilitated Glucose Transporter 1 (FGT) sequence we identified two potential homologs in T. muris (TmGLT) and T. trichiura (TtGLT). We should both proteins contained sequence similarity to FGT1 and contained multiple sequence domains associated with glucose and sugar transport. Further, using Alphafold and molecular docking we show glucose docking sites consistent with transport. To asses the ability of phloretin to inhibit glucose transport, we also performed molecular docking with phloretin, showing possible inhibition. To validate the potential inhibition in vitro we measured the 48h LC50 of phloretin which we showed to be 111 ug/ml against adult T. muris worms, around half that of mebendazole in the same conditions. In contrast phloretin exhibited no effect on worm burden or fecundity in vivo. Together these findings provide the first in silico characterisation of putative glucose transporters in Trichuris spp and have identified glucose transport inhibition as a promising avenue for anthelminthic drug discovery. Whilst further work is required to optimise in vivo efficacy, our results highlight parasite glucose acquisition pathways as potential druggable targets in whipworm. Author SummaryOver a quarter of the worlds population is at risk of infection with soil-transmitted parasitic worms. One of these parasites, Trichuris trichiura (whipworm), infects millions of people worldwide. Current treatments rely on two drugs, albendazole and mebendazole, but these are much less effective against whipworm than other parasites, and there is growing concern about resistance. This highlights the need for new treatment strategies. In this study, we investigated how whipworms take up glucose, an essential energy source required for survival. Using computational approaches, we identified candidate glucose transporter proteins in both the human parasite (T. trichiura) and a laboratory model species (T. muris). We then tested whether these proteins could be targeted using the compound phloretin. Our results suggest that phloretin may block glucose uptake at the molecular level, and we show that it reduces worm survival in laboratory experiments. However, it did not have the same effect in animal infections. Together, our findings identify glucose uptake as a potential weakness in whipworms and provide a starting point for developing new treatments.