Cellular susceptibility and oxidative stress response to menadione of logarithmic, quiescent, and nonquiescent Saccharomyces cerevisiae cell populations

Abstract

The aim of the present study was to compare cellular susceptibility and oxidative stress response of S. cerevisiae logarithmic (log), quiescent (Q), and non-quiescent (NQ) cell populations to menadione – a well-known inducer of oxidative stress. Three main approaches were used: microbiological – cell survival, molecular – constant field gel electrophoresis for detection of DNA double-strand breaks (DSB), and biochemical – measurement of reactive oxygen species (ROS) levels, oxidized proteins, lipid peroxidation, glutathione, superoxide dismutase (SOD) and catalase on S. cerevisiae haploid strain BY4741. The doses causing 20% (LD20) and 50% (LD50) lethality were calculated. The effect of menadione as a well-known oxidative stress inducer is compared in the log, Q, and NQ cells. Survival data reveal that Q cells are the most susceptible to menadione with LD50 corresponding to 9 µM menadione. On the other hand, dose-dependent DSB induction is found only in Q cells confirming the results shown above. No effect on DSBs levels is observed in log and NQ cells. Further, the oxidative stress response of the cell populations is clarified. Results show significantly higher levels of SOD and ROS in Q cells than in log cells after the treatment with 100 µM menadione. On the other side, higher induction of oxidized proteins, malondialdehyde, and glutathione is observed after menadione treatment of log cells. Our study provides evidence that Saccharomyces cerevisiae quiescent cells are the most susceptible to the menadione action. It might be suggested that the DNA damaging and genotoxic action of menadione in Saccharomyces cerevisiae quiescent cells could be related to ROS production.