Editorial: Chagas disease novel drug targets and treatments

Cystatin from Austrelaps superbus snake venom as a model for identifying potential inhibitors of Trypanosoma cruzi cruzain

Background

Chagas disease (CD), caused by Trypanosoma cruzi, affects approximately seven million individuals worldwide, with the highest number of cases in Latin America. CD has two phases, of which the chronic phase is characterized by reduced efficacy in drug therapies. This and other factors make developing new strategies that aim to identify molecules capable of becoming alternatives to or complement current chemotherapy vitally important.

Methods

Cruzain and AsCystatin were obtained recombinantly through expression in E. coli. Bioinformatic assays were conducted with both molecules, followed by in vitro enzyme inhibition assays. Subsequently, in silico studies allowed for the design of peptides, which were then assessed for molecular interactions with cruzain. The designed peptides were synthesized, and their inhibitory potential on cruzain and their trypanocidal and cytotoxic effects in vitro were finally assessed.

Results

AsCystatin, a potential inhibitor of cysteine proteases, was identified from previously published scientific literature. In silico assays suggested that AsCystatin interacts with key regions of cruzain, and was subsequently produced through heterologous expression, obtaining a protein with a high degree of purity. Next, the inhibition of AsCystatin on the activity of cruzain was assessed, observing that approximately 20 µM of cystatin could inhibit 50% of the catalytic activity of the recombinant enzyme. Based on the in-silico analysis performed previously, original, and modified peptides were designed and tested, which allowed for identifying four peptides with inhibitory capacity on the enzymatic activity of cruzain. Finally, three of these peptides showed trypanocidal activity on epimastigote forms of T. cruzi in in vitro models.

Conclusion

It was possible to identify AsCystatin and four peptides derived from this protein with inhibitory activity on cruzain, highlighting the trypanocidal effect of these peptides observed in in vitro assays.

AI-powered drug discovery for neglected diseases: accelerating public health solutions in the developing world

The emergence of artificial intelligence (AI) in drug discovery represents a transformative development in addressing neglected diseases, particularly in the context of the developing world. Neglected diseases, often overlooked by traditional pharmaceutical research due to limited commercial profitability, pose significant public health challenges in low- and middle-income countries. AI-powered drug discovery offers a promising solution by accelerating the identification of potential drug candidates, optimising the drug development process, and reducing the time and cost associated with bringing new treatments to market. However, while AI shows promise, many of its applications are still in their early stages and require human validation to ensure the accuracy and reliability of predictions. Additionally, AI models are limited by the availability of high-quality data, which is often sparse in regions where neglected diseases are most prevalent. This viewpoint explores the application of AI in drug discovery for neglected diseases, examining its current impact, related ethical considerations, and the broader implications for public health in the developing world. It also highlights the challenges and opportunities presented by AI in this context, emphasising the need for ongoing research, ethical oversight, and collaboration between public health stakeholders to fully realise its potential in transforming global health outcomes.

Fifteen Years after the Definition of Trypanosoma cruzi DTUs: What Have We Learned?

Trypanosoma cruzi, the protozoan causative of Chagas disease (ChD), exhibits striking genetic and phenotypic intraspecific diversity, along with ecoepidemiological complexity. Human-pathogen interactions lead to distinct clinical presentations of ChD. In 2009, an international consensus classified T. cruzi strains into six discrete typing units (DTUs), TcI to TcVI, later including TcBat, and proposed reproducible genotyping schemes for DTU identification. This article aims to review the impact of classifying T. cruzi strains into DTUs on our understanding of biological, ecoepidemiological, and pathogenic aspects of T. cruzi. We will explore the likely origin of DTUs and the intrinsic characteristics of each group of strains concerning genome organization, genomics, and susceptibility to drugs used in ChD treatment. We will also provide an overview of the association of DTUs with mammalian reservoirs, and summarize the geographic distribution, and the clinical implications, of prevalent specific DTUs in ChD patients. Throughout this review, we will emphasize the crucial roles of both parasite and human genetics in defining ChD pathogenesis and chemotherapy outcome.