4-hydroxy-2-nonenal (4-HNE) induced transcriptional changes in Listeria monocytogenes

Pathogens must counteract a wide array of antimicrobial responses, including the reactive oxygen species (ROS) burst. ROS mediated oxidation of host membrane poly-unsaturated fatty acids (PUFAs) leads to the production of the toxic alpha-beta carbonyl 4-hydroxy-2-nonenal (4-HNE). 4-HNE has been studied extensively in the context of sterile inflammation but understanding of its role during bacterial infection remains limited. In this work we found that 4-HNE is generated during bacterial infection and that the intracellular pathogen Listeria monocytogenes induces a specific set of genes in response to 4-HNE exposure. L. monocytogenes grown to mid-log (0.4-0.8 OD) in tryptic soy broth at 37C, then a bolus of 640 micromolar 4-HNE or vehicle (ethanol) was added. Bacteria were exposed to 4-HNE for 20 minutes at 37C after which they were quenched with methanol and RNA was extracted for transcriptional analysis.