Environmental carcinogen benzo[a]pyrene alters neutral lipid storage via a cyp-35A2 mediated pathway in Caenorhabditis elegans

Polycyclic aromatic hydrocarbons (PAHs), in particular benzo [a]pyrene (BaP), have been identified as carcinogenic components of tobacco smoke. In mammals, the toxicological response to BaP-diol-epoxide is driven by cytochrome P450 (CYP1A1), a pathway which is absent in Caenorhabditis elegans. In contrast, in worms prominently the CYP-35 enzyme family seems to be induced after BaP exposure. In C. elegans, BaP exposure reduces the accumulation of lysosomal neutral lipids in a dose dependent manner and the deletion of cyp-35A2 results in a significant elevation of neutral lipid metabolism. A cyp-35A2:mCherry;unc-47:GFP dual-labelled reporter strain facilitated the identification of three potential upstream regulators that drive BaP metabolism in worms, namely elt-2, nhr-49 and fos-1. This newly described reporter line is a powerful resource for future large-scale RNAi regarding toxicology and lipid metabolism screens.

Automated summary

Polycyclic aromatic hydrocarbons (PAHs), including benzo [a]pyrene (BaP), are carcinogenic components of tobacco smoke. The toxicological response to BaP-diol-epoxide is driven by cytochrome P450 (CYP1A1) in mammals, but absent in Caenorhabditis elegans. In worms, the CYP-35 enzyme family is induced after BaP exposure. BaP exposure reduces the accumulation of lysosomal neutral lipids in a dose dependent manner in C. elegans, while deletion of the cyp-35A2 gene increases neutral lipid metabolism. A dual-labelled reporter strain, cyp-35A2:mCherry;unc-47:GFP, helps identify upstream regulators elt-2, nhr-49, and fos-1 driving BaP metabolism in worms, making it a valuable resource for toxicology and lipid metabolism research.