During the past years, a number of studies have demonstrated the positive effect of apple on ageing and different diseases such as cancer, degenerative and cardiovascular diseases. The unicellular yeast Saccharomyces cerevisiae represents a simple eukaryotic model to study the effects of different compounds on lifespan. We previously demonstrated that apple extracts have anti-ageing effects in this organism because of their antioxidant properties. In particular, the effect is related to the presence in this fruit of polyphenols, which give a large contribution to the antioxidant activity of apples. We we used a clonogenic assay to assess the viability and the resistance to oxidative stress of S. cerevisiae cells in the presence of Annurca apple extracts. The production of ROS and the aberrant morphology of nuclei were detected by cell staining with the fluorescent dies Dihydrorhodamine 123 and DAPI, respectively. Mitochondrial morphology was analyzed by following the localization of the mito-GFP protein into the mitochondrial matrix. In this study, we show that apple extracts can increase yeast lifespan, reduce the levels of reactive oxygen species and cell sensitivity to oxidative stress, and prevent nuclei and mitochondria fragmentation protecting cells from regulated cell death. In this paper, by using the yeast S. cerevisiae as a model, we have demonstrated that Annurca extracts possess antioxidant properties thanks to which the extracts can reduce the intracellular ROS levels and have anti-apoptotic functions thus prolonging cell lifespan. These results contribute to knowledge on the effects of natural compounds on ageing and support the use of yeast as a model organism for the development of simple tests to assess the effectiveness of bioactive substances from natural sources.
LSM4 is an essential yeast gene encoding a component of different LSM complexes involved in the regulation of mRNA splicing, stability, and translation. In previous papers, we reported that the expression in S. cerevisiae of the K. lactis LSM4 gene lacking the C-terminal Q/N-rich domain in an Lsm4 null strain S. cerevisiae (Sclsm4Δ1) restored cell viability. Nevertheless, in this transformed strain, we observed some phenotypes that are typical markers of regulated cell death, reactive oxygen species (ROS), and oxidated RNA accumulation. In this paper, we report that a similar truncation operated in the S. cerevisiae LSM4 gene confers on cells the same phenotypes observed with the K. lactis lsm4Δ1 gene. Up until now, there was no evidence of the direct involvement of LSM4 in autophagy. Here we found that the Sclsm4Δ1 mutant showed a block in the autophagic process and was very sensitive to nitrogen starvation or treatment with low doses of rapamycin, an inducer of autophagy. Moreover, both during nitrogen starvation and aging, the Sclsm4Δ1 mutant accumulated cytoplasmic autophagy-related structures, suggesting a role of Lsm4 in a later step of the autophagy process.
LSM4 is an essential yeast gene encoding a component of different LSM complexes involved in the regulation of mRNA splicing, stability and translation. In previous papers we reported that the expression in S. cerevisiae of the K. lactis Lsm4 gene lacking the C-terminal Q/N-rich domain in a Lsm4 null strain S. cerevisiae (Sclsm4D1) restored cell viability. Nevertheless, in this transformed strain we observed some phenotypes which are typical markers of regulated cell death, Reactive Oxygen Species and oxidated RNA accumulation. In this paper we report that a similar truncation operated in the S. cerevisiae LSM4 gene confers to cells the same phenotypes observed with the K.lactis LSM4D1 gene. Up to now there was no evidence on the direct involvement of LSM4 in autophagy. Here we found that the Sclsm4D1 mutant showed defects in the induction of autophagy and it was very sensitive to nitrogen starvation or treatment with low doses of rapamycin, an inducer of autophagy. Moreover, both during nitrogen starvation and ageing, the Sclsm4D1 mutant accumulated cytoplasmic autophagy-related structures, suggesting a role of Lsm4 in Phagophore Assembly Site (PAS) processing and/or vacuolar autophagosome internalization
The budding yeast Saccharomyces cerevisiae has long served as a valuable model for investigating the molecular mechanisms underlying aging. Calorie restriction (CR) is a well-established intervention that extends lifespan across species, yet the underlying molecular mechanisms remain incompletely understood. In this study, we examined the effects of CR on the chronological lifespan, oxidative stress response, and autophagic activity of the Saccharomyces cerevisiae mutant Sclsm4Δ1, which exhibits premature aging and elevated reactive oxygen species (ROS) levels due to defects in mRNA decapping and processing-bodies (PB) dynamics. We found that both moderate (0.1% glucose) and extreme (water incubation) CR significantly extended the lifespan of Sclsm4Δ1 mutants and markedly reduced intracellular ROS accumulation without activating autophagy. These findings indicate that the beneficial effects of CR stem from improved redox homeostasis and metabolic adaptation, rather than from canonical autophagic pathways. Similar protective effects were observed in a chromosomal lsm4Δ1 mutant generated via CRISPR–Cas9, confirming that CR rescues aging-related phenotypes in different genetic backgrounds. These insights reinforce the roles of nutrient signaling, RNA metabolism, and redox balance in lifespan regulation, offering new perspectives on the conserved anti-aging effects of calorie restriction.