GSE126008
Isolating the Escherichia coli transcriptomic responses to superoxide generation and stress from cadmium chalcogenide quantum dots
In this study we investigate the transcriptomic response of Escherichia coli to CdTe-2.4 and benign CdSe-2.4 quantum dots, each with and without illumination to elucidate the phototherapeutic effect of CdTe-2.4. Our analysis sought to separate the transcriptomic responses of E. coli to the presence of superoxide and the presence of cadmium chalcogenide nanoparticles. We found eight genes to be consistently differentially expressed as a response to superoxide generation, and these genes demonstrate a consistent association with the DNA damage response and deactivation of iron-sulfur clusters, characteristic of a superoxide response. We found eighteen genes associated the presence of cadmium-based quantum dots, in isolation from the superoxide effect. In further analysis of these genes, we performed both amino acid supplementation and gene knockout experiments, identifying the importance of leucyl-tRNA downregulation as a cadmium-based QD response, as well as reinforcing the relationship between CdTe-2.4 stress and iron-sulfur clusters through the gene tusA. This study demonstrates the transcriptomic response of E. coli to CdTe-2.4 and CdSe-2.4 quantum dots and parses the different effects of superoxide versus material effects on the bacteria. Our findings may provide useful information towards the development of quantum dot-based antibacterial therapy in the future. Overall design: Examination of differential expression of genes between CdTe and CdSe conditions both with and without illumination, as compared to a no treatment control.