Project description:This SuperSeries is composed of the following subset Series: GSE21008: Linking toxicant physiological mode of action with induced gene expression changes in Caenorhabditis elegans: atrazine GSE21010: Linking toxicant physiological mode of action with induced gene expression changes in Caenorhabditis elegans: cadmium GSE21011: Linking toxicant physiological mode of action with induced gene expression changes in Caenorhabditis elegans: fluoranthene Refer to individual Series
Project description:We describe the development of a novel anti-leishmanial drug-like chemical series based on a pyrazolopyrimidine scaffold. The leading compound is efficacious in a mouse model of visceral leishmaniasis, and has suitable physicochemical, pharmacokinetic and toxicological properties for further development and has been declared a preclinical candidate. Detailed mode of action studies indicate that compounds from this series act principally by inhibiting the parasite protein kinases.
Project description:Naphthalene and its alkyl-substituted derivatives are among the most abundant polycyclic aromatic hydrocarbons (PAHs) in environmental and human exposure studies, yet their developmental toxicity and mode of action remain poorly understood due to challenges in testing of semi-volatile compounds. This study developed a vial based high through-put method to effectively assess the activity of naphthalenes and a set of 24 alkyl-substituted naphthalenes. Early life stage zebrafish were exposed to a concentration series of each chemical (0-50 µM) in rotating sealed glass vials to minimize volatilization. Benchmark concentration (BMC50) values were calculated for morphological endpoints and lowest effect levels were determined for behavioral effects. The data were assessed for evidence of a narcotic mode of action using body burden measurements for select chemicals and logKow modeling. Targeted transcriptomics at a single concentration and timepoint as well as in silico molecular docking were conducted to generate mode of action hypothesis. The vial method enabled detection of highly variable developmental toxicity not previously observed using standard 96-well plate exposures. LogKow and body burden were poor predictors of toxicity, suggesting a non-narcotic mode of action. Transcriptomic analysis revealed a limited but notable set of differentially expressed genes, with evidence for the disruption of glucocorticoid signaling pathways. Molecular docking identified potential protein targets (e.g., CYP1A2, NT5E, FOLR1) that may mediate observed effects. This study demonstrates the importance of appropriate exposure methods for semi-volatile compounds, reveals structure-dependent toxicity among alkyl-substituted naphthalenes, and provides a foundation for further mechanistic studies and improved risk assessment of alkyl-substituted PAHs.
Project description:The global prevalence of antibacterial resistance requires new antibacterial drugs with novel chemical scaffolds and modes of action. It is also vital to design compounds with optimal physicochemical properties to permeate the bacterial cell envelope. We described an approach of combining and integrating whole cell screening and metabolomics into early antibacterial drug discovery using a library of small polar compounds. Whole cell screening of a diverse library of small polar compounds against <i>Staphylococcus aureus</i> gave compound <b>2</b>. Hit expansion was carried out to determine structure-activity relationships. A selection of compounds from this series, together with other screened active compounds, was subjected to an initial metabolomics study to provide a metabolic fingerprint of the mode of action. It was found that compound <b>2</b> and its analogues have a different mode of action from some of the known antibacterial compounds tested. This early study highlighted the potential of whole cell screening and metabolomics in early antibacterial drug discovery. Future works will require improving potency and performing orthogonal studies to confirm the modes of action.