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Didier Garnham, M.

Publications and source records attributed to Didier Garnham, M..

2 recordsLinked to original sources

Prioritization of chemical scaffolds using the TDR Targets database: an integrative workflow for Trypanosoma cruzi drug discovery

Chagas disease, caused by the parasite Trypanosoma cruzi, faces a critical innovation gap in drug development, with current treatments hindered by toxicity and limited efficacy. To address this, we implemented an integrative chemogenomic workflow using the TDR Targets database to prioritize drug candidates. To prioritize repurposing candidates for T. cruzi, we designed a query to retrieve compounds active against validated targets in other organisms, provided an orthologous gene exists in T. cruzi and the compound has no recorded activity against trypanosomatids and their associations predicted by the TDR Targets multilayer network. On those associations we applied sequential filters based on metabolic relevance, and commercial availability via the MolPort API obtaining a focused set of 378 high-priority compounds. A central feature of this workflow was the partitioning of these compounds into 16 distinct chemical libraries, each defined by unique scaffolds such as benzamidines, sulfonamides, and azoles. For experimental validation, we manually curated two of these libraries, containing piperazine and nitro derivatives. From the 21 compounds acquired for in vitro testing against T. cruzi in intracellular models of infection, 7 demonstrated selective trypanocidal activity, with two lead hits achieving submicromolar EC50 values. Crucially, while our experimental focus was on these two series, the remaining 14 curated libraries, representing a broad range of chemical space and putative target associations, which are fully available for public exploration and further biological assaying. These results demonstrate the efficiency of our prioritization pipeline and provide the scientific community with a pre-filtered, commercially accessible resource to accelerate the discovery of new leads for Chagas disease. Author summaryChagas disease, caused by the parasite Trypanosoma cruzi, is a neglected tropical disease with limited treatment options. To accelerate drug discovery, we developed an integrative computational workflow using the TDR Targets database as a starting point to prioritize compounds for repurposing. We retrieved compounds active against validated targets in other organisms, ensuring they had no recorded activity against trypanosomatids and that their associations were predicted by the TDR Targets multilayer network. Based on this work we provide a 12 chemical libraries with 378 prioritized chemical scaffolds for furhter experimental validation. In this work we focused on two of these sublibraries for experimental validation, and from 21 compounds tested, 7 showed selective activity against the parasite. The remaining curated chemical libraries, represent a broad range of chemical space and putative target associations, and are fully available for exploration and further biological assaying. This study demonstrates the efficiency of our prioritization pipeline and provides a valuable resource to accelerate the discovery of new leads for Chagas disease.

microbiology↗

Identification of antifungal agents AR-12 and Fosmanogepix as anti-Trypanosoma cruzi drugs through an enhanced fluorogenic β-galactosidase phenotypic screening assay

Phenotypic screening remains essential for identifying and characterizing bioactive compounds or their combinations against human parasitic pathogens. In the case of Trypanosoma cruzi, the etiological agent of Chagas disease, transgenic parasites expressing the reporter enzyme {beta}-galactosidase have been extensively used to this end. Here, we replaced the traditional chromogenic substrate chlorophenol red-{beta}-D-galactopyranoside (CPRG) with the fluorogenic 4-methylumbelliferyl-{beta}-D-glucopyranoside (MUG) to derive a highly sensitive, continuous enzymatic assay to obtain a quantitative surrogate of parasite growth in T. cruzi cultures. The assay detects as few as 3x103 trypomastigotes/well, tracks linearly with the parasite load in a two-order range (3x103-2x105 trypomastigotes/well), takes 1 hour, and has a similar cost per assay as its colorimetric counterpart. To demonstrate its convenience and versatility, we used this assay to estimate the half-maximal inhibitory concentration (IC50) of six emerging antifungal compounds, not targeting CYP-51 and novel for T. cruzi. Finally, the assay was adapted to a semi-automatic methodology and used to explore dual combinations of the active antifungals in the primary screening and with benznidazole. The multitarget compound AR-12 (IC50 = 1.9 M) and the Gwt1 inhibitor Fosmanogepix (IC50 = 7.2 M) resulted in bona fide hits, inhibiting parasite replication with only low-to-moderate toxicity on Vero host cells, thus suggesting potential for repurposing to Chagas disease.

microbiology↗