Limits...
Mechanisms of life span extension by rapamycin in the fruit fly Drosophila melanogaster.

Bjedov I, Toivonen JM, Kerr F, Slack C, Jacobson J, Foley A, Partridge L - Cell Metab. (2010)

Bottom Line: We show here that feeding rapamycin to adult Drosophila produces the life span extension seen in some TOR mutants.Analysis of the underlying mechanisms revealed that rapamycin increased longevity specifically through the TORC1 branch of the TOR pathway, through alterations to both autophagy and translation.Rapamycin could increase life span of weak insulin/Igf signaling (IIS) pathway mutants and of flies with life span maximized by dietary restriction, indicating additional mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, UK.

Show MeSH

Related in: MedlinePlus

Rapamycin Treatment of Adult Drosophila Downregulates TOR Activity(A) Western blot analysis of phospho-S6K on whole-fly protein extracts. Flies were sampled after 1, 3, 5, or 12 days of rapamycin treatment at concentrations of 200 or 400 μM. A dose-dependent reduction in phospho-T398-S6K levels was observed and the degree of inhibition increased with longer treatment time. For all western blots, relative band intensity was estimated using Image J.(B) Western blot analysis of phospho-S6K in different body parts of wDah flies. Flies were maintained with or without 200 μM rapamycin for 2 weeks prior to preparation of protein extracts from heads, thoraces, and abdominal segments. Rapamycin was found to efficiently reduce levels of phospho-T398-S6K in all fly body parts.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2824086&req=5

fig1: Rapamycin Treatment of Adult Drosophila Downregulates TOR Activity(A) Western blot analysis of phospho-S6K on whole-fly protein extracts. Flies were sampled after 1, 3, 5, or 12 days of rapamycin treatment at concentrations of 200 or 400 μM. A dose-dependent reduction in phospho-T398-S6K levels was observed and the degree of inhibition increased with longer treatment time. For all western blots, relative band intensity was estimated using Image J.(B) Western blot analysis of phospho-S6K in different body parts of wDah flies. Flies were maintained with or without 200 μM rapamycin for 2 weeks prior to preparation of protein extracts from heads, thoraces, and abdominal segments. Rapamycin was found to efficiently reduce levels of phospho-T398-S6K in all fly body parts.

Mentions: We measured phosphorylation of S6K, a well-described downstream target of TORC1, as an indicator of rapamycin efficacy, by western blot analysis using a phospho-Thr398-dependent S6K antibody. We observed a significant dose-dependent reduction in phospho-T398-S6K levels after rapamycin treatment for 1–3 days, confirming that rapamycin reduced TOR signaling in vivo (Figure 1A). To determine bioavailability of rapamycin throughout the fly, we measured S6K phosphorylation in different regions of the fly body. Phospho-T398-S6K levels were decreased to similar levels in heads, thoraces, and abdomens (Figure 1B), suggesting that TOR signaling is ubiquitously downregulated in adult flies upon rapamycin treatment.


Mechanisms of life span extension by rapamycin in the fruit fly Drosophila melanogaster.

Bjedov I, Toivonen JM, Kerr F, Slack C, Jacobson J, Foley A, Partridge L - Cell Metab. (2010)

Rapamycin Treatment of Adult Drosophila Downregulates TOR Activity(A) Western blot analysis of phospho-S6K on whole-fly protein extracts. Flies were sampled after 1, 3, 5, or 12 days of rapamycin treatment at concentrations of 200 or 400 μM. A dose-dependent reduction in phospho-T398-S6K levels was observed and the degree of inhibition increased with longer treatment time. For all western blots, relative band intensity was estimated using Image J.(B) Western blot analysis of phospho-S6K in different body parts of wDah flies. Flies were maintained with or without 200 μM rapamycin for 2 weeks prior to preparation of protein extracts from heads, thoraces, and abdominal segments. Rapamycin was found to efficiently reduce levels of phospho-T398-S6K in all fly body parts.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2824086&req=5

fig1: Rapamycin Treatment of Adult Drosophila Downregulates TOR Activity(A) Western blot analysis of phospho-S6K on whole-fly protein extracts. Flies were sampled after 1, 3, 5, or 12 days of rapamycin treatment at concentrations of 200 or 400 μM. A dose-dependent reduction in phospho-T398-S6K levels was observed and the degree of inhibition increased with longer treatment time. For all western blots, relative band intensity was estimated using Image J.(B) Western blot analysis of phospho-S6K in different body parts of wDah flies. Flies were maintained with or without 200 μM rapamycin for 2 weeks prior to preparation of protein extracts from heads, thoraces, and abdominal segments. Rapamycin was found to efficiently reduce levels of phospho-T398-S6K in all fly body parts.
Mentions: We measured phosphorylation of S6K, a well-described downstream target of TORC1, as an indicator of rapamycin efficacy, by western blot analysis using a phospho-Thr398-dependent S6K antibody. We observed a significant dose-dependent reduction in phospho-T398-S6K levels after rapamycin treatment for 1–3 days, confirming that rapamycin reduced TOR signaling in vivo (Figure 1A). To determine bioavailability of rapamycin throughout the fly, we measured S6K phosphorylation in different regions of the fly body. Phospho-T398-S6K levels were decreased to similar levels in heads, thoraces, and abdomens (Figure 1B), suggesting that TOR signaling is ubiquitously downregulated in adult flies upon rapamycin treatment.

Bottom Line: We show here that feeding rapamycin to adult Drosophila produces the life span extension seen in some TOR mutants.Analysis of the underlying mechanisms revealed that rapamycin increased longevity specifically through the TORC1 branch of the TOR pathway, through alterations to both autophagy and translation.Rapamycin could increase life span of weak insulin/Igf signaling (IIS) pathway mutants and of flies with life span maximized by dietary restriction, indicating additional mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, UK.

Show MeSH
Related in: MedlinePlus