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High throughput screening for anti-Trypanosoma cruzi drug discovery.

Alonso-Padilla J, Rodríguez A - PLoS Negl Trop Dis (2014)

Bottom Line: Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable.Thus, there is an urgent need for new, improved anti-T. cruzi drugs.These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

View Article: PubMed Central - PubMed

Affiliation: New York University School of Medicine, Department of Microbiology, Division of Parasitology, New York, New York, United States of America.

ABSTRACT
The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti-T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS) as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

No MeSH data available.


Related in: MedlinePlus

Anti–Trypanosoma cruzi compounds.Chemical structures of anti–T. cruzi compounds currently in clinical use (*) and currently or recently in clinical trials (•), and of the most promising compounds retrieved out of the Broad Institute HTS campaign [44] and the screening of a smaller, diversity-oriented chemical library [39], [43] (#).
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pntd-0003259-g001: Anti–Trypanosoma cruzi compounds.Chemical structures of anti–T. cruzi compounds currently in clinical use (*) and currently or recently in clinical trials (•), and of the most promising compounds retrieved out of the Broad Institute HTS campaign [44] and the screening of a smaller, diversity-oriented chemical library [39], [43] (#).

Mentions: The most important impact of the developed in vitro assays based on transgenic parasites has been their amenability to HTS [39], [40]. In terms of impact, the adaptation of the T. cruzi β-galactosidase–based assay [26] to HTS standards established a milestone in the anti-Chagas early drug discovery process. After a protocol improvement to reduce the assay time, but still at its original 96-well plate format, the assay showed its reliability in the screening of a 2,000 compounds chemical library [27]. The β-galactosidase reporter assay was developed into a 384-well format with a luminescent readout allowing higher throughput for the HTS campaign at the Broad Institute, where screening of 303,224 compounds (the NIH library) yielded 4,394 hits. After the confirmation of activity and determination of efficacy and cytotoxicity of the hits, 3,005 compounds with an IC50 <10 µM and>10-fold selectivity against the parasite versus the host cells were selected [39]. All information, including the chemical structures of the hits, is publicly available at Pubchem (AID 1885). Further analysis of the hits selected by this HTS revealed that a high percentage of them were not reproducible in a similar assay. It is likely that the reason for such discrepancies resided in the quality of the chemical compounds used for the original HTS [41]. Another HTS of a diversity-oriented synthesis chemical library of 77,312 compounds has been performed [42]. The most attractive confirmed hits in terms of potency, selectivity, and predicted drug-like physicochemical properties between these two HTSs were picked up for further development and the data obtained from them have served as the basis for different initiatives (Figure 1) [43]–[46]. The access to high-quality large chemical libraries will be of fundamental importance for the advance of drug discovery against neglected diseases, as it will be to get the resources and know-how to mine and test them. In this perspective, collaboration between pharmaceutical companies and academic laboratories becomes a key aspect for the successful development of future drugs.


High throughput screening for anti-Trypanosoma cruzi drug discovery.

Alonso-Padilla J, Rodríguez A - PLoS Negl Trop Dis (2014)

Anti–Trypanosoma cruzi compounds.Chemical structures of anti–T. cruzi compounds currently in clinical use (*) and currently or recently in clinical trials (•), and of the most promising compounds retrieved out of the Broad Institute HTS campaign [44] and the screening of a smaller, diversity-oriented chemical library [39], [43] (#).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256210&req=5

pntd-0003259-g001: Anti–Trypanosoma cruzi compounds.Chemical structures of anti–T. cruzi compounds currently in clinical use (*) and currently or recently in clinical trials (•), and of the most promising compounds retrieved out of the Broad Institute HTS campaign [44] and the screening of a smaller, diversity-oriented chemical library [39], [43] (#).
Mentions: The most important impact of the developed in vitro assays based on transgenic parasites has been their amenability to HTS [39], [40]. In terms of impact, the adaptation of the T. cruzi β-galactosidase–based assay [26] to HTS standards established a milestone in the anti-Chagas early drug discovery process. After a protocol improvement to reduce the assay time, but still at its original 96-well plate format, the assay showed its reliability in the screening of a 2,000 compounds chemical library [27]. The β-galactosidase reporter assay was developed into a 384-well format with a luminescent readout allowing higher throughput for the HTS campaign at the Broad Institute, where screening of 303,224 compounds (the NIH library) yielded 4,394 hits. After the confirmation of activity and determination of efficacy and cytotoxicity of the hits, 3,005 compounds with an IC50 <10 µM and>10-fold selectivity against the parasite versus the host cells were selected [39]. All information, including the chemical structures of the hits, is publicly available at Pubchem (AID 1885). Further analysis of the hits selected by this HTS revealed that a high percentage of them were not reproducible in a similar assay. It is likely that the reason for such discrepancies resided in the quality of the chemical compounds used for the original HTS [41]. Another HTS of a diversity-oriented synthesis chemical library of 77,312 compounds has been performed [42]. The most attractive confirmed hits in terms of potency, selectivity, and predicted drug-like physicochemical properties between these two HTSs were picked up for further development and the data obtained from them have served as the basis for different initiatives (Figure 1) [43]–[46]. The access to high-quality large chemical libraries will be of fundamental importance for the advance of drug discovery against neglected diseases, as it will be to get the resources and know-how to mine and test them. In this perspective, collaboration between pharmaceutical companies and academic laboratories becomes a key aspect for the successful development of future drugs.

Bottom Line: Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable.Thus, there is an urgent need for new, improved anti-T. cruzi drugs.These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

View Article: PubMed Central - PubMed

Affiliation: New York University School of Medicine, Department of Microbiology, Division of Parasitology, New York, New York, United States of America.

ABSTRACT
The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti-T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS) as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

No MeSH data available.


Related in: MedlinePlus