Ludovico Paula, Sousa Maria João, Silva Manuel T, Leão Cecı Lia, Côrte-Real Manuela
Imunologia Comparada, Instituto de Biologia Molecular e Celular (IBMC), 4150-171 Porto, Portugal2.
Centro de Ciências do Ambiente-Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4719-057 Braga, Portugal1.
Microbiology (Reading). 2001 Sep;147(Pt 9):2409-2415. doi: 10.1099/00221287-147-9-2409.
Recent evidence has revealed the occurrence of an apoptotic phenotype in Saccharomyces cerevisiae that is inducible with oxidative stress. Here, exposure of S. cerevisiae to 20-200 mM acetic acid for 200 min at pH 3.0 resulted in cell death. Yeast mortality induced by 120-200 mM acid was not inhibited by cycloheximide and was accompanied by ultrastructural alterations typical of necrosis. In contrast, alterations associated with cell death induced by 20-80 mM acetic acid included: (i) cycloheximide-inhibitable chromatin condensation along the nuclear envelope; (ii) exposure of phosphatidylserine on the surface of the cytoplasmic membrane, revealed by the FITC-annexin V reaction; and (iii) the occurrence of DNA strand breaks, demonstrated by the TUNEL assay. These results show that a programmed cell death process sharing common features with an apoptotic phenotype can be induced by acetic acid in S. cerevisiae. This observation raises the possibility of this mode of cell death being more generalized in yeasts than previously considered and extended to cell death induced by other stress agents.
最近的证据表明，酿酒酵母中存在一种可被氧化应激诱导的凋亡表型。在此，将酿酒酵母在pH 3.0条件下暴露于20 - 200 mM乙酸中200分钟会导致细胞死亡。120 - 200 mM乙酸诱导的酵母死亡率不受环己酰亚胺抑制，并伴有典型坏死的超微结构改变。相比之下，20 - 80 mM乙酸诱导的细胞死亡相关改变包括：(i) 沿核膜的环己酰亚胺可抑制的染色质凝聚；(ii) 通过FITC - 膜联蛋白V反应显示，细胞质膜表面磷脂酰丝氨酸的暴露；以及(iii) 通过TUNEL检测证明的DNA链断裂。这些结果表明，乙酸可在酿酒酵母中诱导一种与凋亡表型具有共同特征的程序性细胞死亡过程。这一观察结果增加了这种细胞死亡模式在酵母中比以前认为的更普遍，并扩展到由其他应激因素诱导的细胞死亡的可能性。
