Transcriptional and antioxidative responses to endogenous polyunsaturated fatty acid accumulation in yeast

Abstract

Pathophysiology of polyunsaturated fatty acids (PUFAs) is associated with aberrant lipid and oxygen metabolism. In particular, under oxidative stress, PUFAs are prone to autocatalytic degradation via peroxidation, leading to formation of reactive aldehydes with numerous potentially harmful effects. However, the pathological and compensatory mechanisms induced by lipid peroxidation are very complex and not sufficiently understood. In our study, we have used yeast capable of endogenous PUFA synthesis in order to understand the effects triggered by PUFA accumulation on cellular physiology of a eukaryotic organism. The mechanisms induced by PUFA accumulation in S. cerevisiae expressing Hevea brasiliensis Δ12-fatty acid desaturase include down-regulation of components of electron transport chain in mitochondria as well as up-regulation of pentose-phosphate pathway and fatty acid β-oxidation at the transcriptional level. Interestingly, while no changes were observed at the transcriptional level, activities of two important enzymatic antioxidants, catalase and glutathione-S-transferase, were altered in response to PUFA accumulation. Increased intracellular glutathione levels further suggest an endogenous oxidative stress and activation of antioxidative defense mechanisms under conditions of PUFA accumulation. Finally, our data suggest that PUFA in cell membrane causes metabolic changes which in turn lead to adaptation to endogenous oxidative stress.

Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry yeast production

“…This effect would enhance biomass yield, but not fermentative capacity, which agrees with our results. Moreover, it has been found that accumulation of fatty acids allows an adaptation to the endogenous oxidative stress associated with higher levels of reduced glutathione 38 , which is also consistent with our results. Finally, caffeic acid has been linked with apoptosis and anticancer and antifungal activities 16 and, at low doses, diminishes lipid peroxidation and blocks ROS due to activation of the cell wall integrity (CWI) pathway 39 40 and GSH homeostasis regulation 41 .…”

Physiological and Transcriptional Responses of Candida parapsilosis to Exogenous Tyrosol

“…PUFAs (stearidonic acid, eicosapentaenoic acid, and docosapentaenoic acid) are major components of the cell membrane of C. parapsilosis, accounting for approximately 30% of the fatty acid content, and have a remarkable antioxidant effect (17). Tyrosol-induced inhibition of the expression of FAD2 and FAD3 found in this study therefore decreases the antioxidant level in cell membranes, which may contribute to the antifungal effect of tyrosol against C. albicans or C. parapsilosis (16)(17)(18). Although tyrosol was reported to exert an antioxidant effect, this was measured only at micromolar concentrations (19), while the concentration used in this study was 15 mM.…”

Traumatic Acid Reduces Oxidative Stress and Enhances Collagen Biosynthesis in Cultured Human Skin Fibroblasts

“…As effects of this process, a diversity of reactive aldehydes arises and these aldehydes play an important role in human metabolism. 4-HNE, as one of the reactive aldehydes, influences cellular response to stress, causing an increase in antioxidant enzyme activity, such as catalase [52, 53]. Regarding the data obtained by Andrisic et al .…”