Unveiling the Molecular Networks Underlying Cellular Impairment in Saccharomyces cerevisiae: Investigating the Effects of Magnesium oxide Nanoparticles on Cell Wall Integrity and Endoplasmic Reticulum Stress Response

Magnesium oxide nanoparticles (MgO-NPs) are highly versatile and have been extensively utilized in diverse industrial and biomedical applications due to their exceptional physical and chemical properties. However, the potential harms to human health and the environment from their use continue to be of great trepidation. In this study, we delved deep into the intricate molecular mechanisms underlying the detrimental effects of MgO-NPs on the growth and viability of the model yeast Saccharomyces cerevisiae. Our findings demonstrate that as the concentration of MgO-NPs increases, it leads to a dose-dependent reduction in the growth and viability of the yeast cells. We further investigated the underlying mechanisms of MgO-NP toxicity and found that it causes damage to the cell membrane, which in turn triggers an endoplasmic reticulum (ER) stress response. The response to ER stress involves an increase in the expression of genes that play a role in protein folding, maintaining protein quality, and removing misfolded proteins via ER-associated degradation (ERAD). In response to treatment with MgO-NPs, we observed the activation of the cell wall integrity (CWI) pathway, it caused the activation of chitin production genes and an increase in the amount of chitin in the cells. These findings highlight the multifaceted detrimental nature of MgO-NPs, which involve the interplay of various molecular networks and signaling pathways.