Oliveira Graciele A, Tahara Erich B, Gombert Andreas K, Barros Mario H, Kowaltowski Alicia J
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
J Bioenerg Biomembr. 2008 Aug;40(4):381-8. doi: 10.1007/s10863-008-9159-5. Epub 2008 Aug 15.
Calorie restriction is a dietary regimen capable of extending life span in a variety of multicellular organisms. A yeast model of calorie restriction has been developed in which limiting the concentration of glucose in the growth media of Saccharomyces cerevisiae leads to enhanced replicative and chronological longevity. Since S. cerevisiae are Crabtree-positive cells that present repression of aerobic catabolism when grown in high glucose concentrations, we investigated if this phenomenon participates in life span regulation in yeast. S. cerevisiae only exhibited an increase in chronological life span when incubated in limited concentrations of glucose. Limitation of galactose, raffinose or glycerol plus ethanol as substrates did not enhance life span. Furthermore, in Kluyveromyces lactis, a Crabtree-negative yeast, glucose limitation did not promote an enhancement of respiratory capacity nor a decrease in reactive oxygen species formation, as is characteristic of conditions of caloric restriction in S. cerevisiae. In addition, K. lactis did not present an increase in longevity when incubated in lower glucose concentrations. Altogether, our results indicate that release from repression of aerobic catabolism is essential for the beneficial effects of glucose limitation in the yeast calorie restriction model. Potential parallels between these changes in yeast and hormonal regulation of respiratory rates in animals are discussed.
热量限制是一种能够延长多种多细胞生物寿命的饮食方案。已经建立了一种热量限制的酵母模型，其中限制酿酒酵母生长培养基中葡萄糖的浓度会导致复制寿命和时序寿命延长。由于酿酒酵母是Crabtree阳性细胞，在高葡萄糖浓度下生长时会出现有氧分解代谢的抑制，我们研究了这种现象是否参与酵母的寿命调节。酿酒酵母仅在有限浓度的葡萄糖中孵育时才表现出时序寿命的增加。限制半乳糖、棉子糖或甘油加乙醇作为底物并不会延长寿命。此外，在克勒克酵母（一种Crabtree阴性酵母）中，葡萄糖限制并没有像酿酒酵母热量限制条件下那样促进呼吸能力的增强或活性氧形成的减少。另外，克勒克酵母在较低葡萄糖浓度下孵育时寿命也没有增加。总之，我们的结果表明，有氧分解代谢抑制的解除对于酵母热量限制模型中葡萄糖限制的有益作用至关重要。讨论了酵母中的这些变化与动物呼吸速率的激素调节之间的潜在相似之处。
