Limits...
Calorie restriction hysteretically primes aging Saccharomyces cerevisiae toward more effective oxidative metabolism.

Tahara EB, Cunha FM, Basso TO, Della Bianca BE, Gombert AK, Kowaltowski AJ - PLoS ONE (2013)

Bottom Line: Here, we measured wild-type and respiratory incompetent (ρ(0)) S. cerevisiae biomass formation, pH, oxygen and glucose consumption, and the evolution of ethanol, glycerol, acetate, pyruvate and succinate levels during the course of 28 days of chronological aging, aiming to identify metabolic changes responsible for the effects of CR.Instead, we found that CR primed the cells for earlier, faster and more efficient metabolism of respiratory substrates, especially ethanol.Since lifespan-enhancing effects of CR are absent in respiratory incompetent ρ(0) cells, we propose that the hysteretic effect of glucose limitation on oxidative metabolism is central toward chronological lifespan extension by CR in this yeast.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil.

ABSTRACT
Calorie restriction (CR) is an intervention known to extend the lifespan of a wide variety of organisms. In S. cerevisiae, chronological lifespan is prolonged by decreasing glucose availability in the culture media, a model for CR. The mechanism has been proposed to involve an increase in the oxidative (versus fermentative) metabolism of glucose. Here, we measured wild-type and respiratory incompetent (ρ(0)) S. cerevisiae biomass formation, pH, oxygen and glucose consumption, and the evolution of ethanol, glycerol, acetate, pyruvate and succinate levels during the course of 28 days of chronological aging, aiming to identify metabolic changes responsible for the effects of CR. The concomitant and quantitative measurements allowed for calculations of conversion factors between different pairs of substrates and products, maximum specific substrate consumption and product formation rates and maximum specific growth rates. Interestingly, we found that the limitation of glucose availability in CR S. cerevisiae cultures hysteretically increases oxygen consumption rates many hours after the complete exhaustion of glucose from the media. Surprisingly, glucose-to-ethanol conversion and cellular growth supported by glucose were not quantitatively altered by CR. Instead, we found that CR primed the cells for earlier, faster and more efficient metabolism of respiratory substrates, especially ethanol. Since lifespan-enhancing effects of CR are absent in respiratory incompetent ρ(0) cells, we propose that the hysteretic effect of glucose limitation on oxidative metabolism is central toward chronological lifespan extension by CR in this yeast.

Show MeSH

Related in: MedlinePlus

Acetate, pyruvate and succinate levels during chronological aging.Acetate (Panels A and D), pyruvate (Panels B and E) and succinate (Panel C and F) concentrations in the culture media during WT (Panels A-C) and ρ0 (Panels D-F) S. cerevisiae chronological lifespan were measured as described in Materials and Methods.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3569431&req=5

pone-0056388-g004: Acetate, pyruvate and succinate levels during chronological aging.Acetate (Panels A and D), pyruvate (Panels B and E) and succinate (Panel C and F) concentrations in the culture media during WT (Panels A-C) and ρ0 (Panels D-F) S. cerevisiae chronological lifespan were measured as described in Materials and Methods.

Mentions: The avoidance of acetate formation and resulting acidification and toxicity has also been previously related to the increase of longevity associated with CR cultures ([39], but see ref. [9]). Accordingly, we measured acetate levels during chronological aging (Fig. 4A). We found evidence that acetate toxicity itself cannot directly account for the differences in pH between CR and control cultures, since it is only detectable in respiratory-competent WT cells before the 72nd h (day 3) in culture, while pH differences persist throughout the 28 days. Indeed, large differences in the levels of other organic acids (pyruvate, Fig. 4B and succinate, Fig. 4C) could be observed between control and CR cells as they aged in culture, and differences in pH certainly reflect the added effect of many different metabolites. Furthermore, even when acetate consumption was absent in respiratory-incompetent ρ0 cells (Fig. 4D), the levels of this acid in the culture media did not surpass ∼0.6 g/L (10 mM), at least 10 times less than those found to affect cell survival [39].


Calorie restriction hysteretically primes aging Saccharomyces cerevisiae toward more effective oxidative metabolism.

Tahara EB, Cunha FM, Basso TO, Della Bianca BE, Gombert AK, Kowaltowski AJ - PLoS ONE (2013)

Acetate, pyruvate and succinate levels during chronological aging.Acetate (Panels A and D), pyruvate (Panels B and E) and succinate (Panel C and F) concentrations in the culture media during WT (Panels A-C) and ρ0 (Panels D-F) S. cerevisiae chronological lifespan were measured as described in Materials and Methods.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569431&req=5

pone-0056388-g004: Acetate, pyruvate and succinate levels during chronological aging.Acetate (Panels A and D), pyruvate (Panels B and E) and succinate (Panel C and F) concentrations in the culture media during WT (Panels A-C) and ρ0 (Panels D-F) S. cerevisiae chronological lifespan were measured as described in Materials and Methods.
Mentions: The avoidance of acetate formation and resulting acidification and toxicity has also been previously related to the increase of longevity associated with CR cultures ([39], but see ref. [9]). Accordingly, we measured acetate levels during chronological aging (Fig. 4A). We found evidence that acetate toxicity itself cannot directly account for the differences in pH between CR and control cultures, since it is only detectable in respiratory-competent WT cells before the 72nd h (day 3) in culture, while pH differences persist throughout the 28 days. Indeed, large differences in the levels of other organic acids (pyruvate, Fig. 4B and succinate, Fig. 4C) could be observed between control and CR cells as they aged in culture, and differences in pH certainly reflect the added effect of many different metabolites. Furthermore, even when acetate consumption was absent in respiratory-incompetent ρ0 cells (Fig. 4D), the levels of this acid in the culture media did not surpass ∼0.6 g/L (10 mM), at least 10 times less than those found to affect cell survival [39].

Bottom Line: Here, we measured wild-type and respiratory incompetent (ρ(0)) S. cerevisiae biomass formation, pH, oxygen and glucose consumption, and the evolution of ethanol, glycerol, acetate, pyruvate and succinate levels during the course of 28 days of chronological aging, aiming to identify metabolic changes responsible for the effects of CR.Instead, we found that CR primed the cells for earlier, faster and more efficient metabolism of respiratory substrates, especially ethanol.Since lifespan-enhancing effects of CR are absent in respiratory incompetent ρ(0) cells, we propose that the hysteretic effect of glucose limitation on oxidative metabolism is central toward chronological lifespan extension by CR in this yeast.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil.

ABSTRACT
Calorie restriction (CR) is an intervention known to extend the lifespan of a wide variety of organisms. In S. cerevisiae, chronological lifespan is prolonged by decreasing glucose availability in the culture media, a model for CR. The mechanism has been proposed to involve an increase in the oxidative (versus fermentative) metabolism of glucose. Here, we measured wild-type and respiratory incompetent (ρ(0)) S. cerevisiae biomass formation, pH, oxygen and glucose consumption, and the evolution of ethanol, glycerol, acetate, pyruvate and succinate levels during the course of 28 days of chronological aging, aiming to identify metabolic changes responsible for the effects of CR. The concomitant and quantitative measurements allowed for calculations of conversion factors between different pairs of substrates and products, maximum specific substrate consumption and product formation rates and maximum specific growth rates. Interestingly, we found that the limitation of glucose availability in CR S. cerevisiae cultures hysteretically increases oxygen consumption rates many hours after the complete exhaustion of glucose from the media. Surprisingly, glucose-to-ethanol conversion and cellular growth supported by glucose were not quantitatively altered by CR. Instead, we found that CR primed the cells for earlier, faster and more efficient metabolism of respiratory substrates, especially ethanol. Since lifespan-enhancing effects of CR are absent in respiratory incompetent ρ(0) cells, we propose that the hysteretic effect of glucose limitation on oxidative metabolism is central toward chronological lifespan extension by CR in this yeast.

Show MeSH
Related in: MedlinePlus