Concurrent regulation of AMP-activated protein kinase and SIRT1 in mammalian cells - PubMed (original) (raw)

Concurrent regulation of AMP-activated protein kinase and SIRT1 in mammalian cells

Gabriela Suchankova et al. Biochem Biophys Res Commun. 2009.

Abstract

We examined in HepG2 cells whether glucose-induced changes in AMP-activated protein kinase (AMPK) activity could be mediated by SIRT1, an NAD(+)-dependent histone/protein deacetylase that has been linked to the increase in longevity caused by caloric restriction. Incubation with 25 vs. 5mM glucose for 6h concurrently diminished the phosphorylation of AMPK (Thr 172) and ACC (Ser 79), increased lactate release, and decreased the abundance and activity of SIRT1. In contrast, incubation with pyruvate (0.1 and 1mM) for 2h increased AMPK phosphorylation and SIRT1 abundance and activity. The putative SIRT1 activators resveratrol and quercetin also increased AMPK phosphorylation. None of the tested compounds (low or high glucose, pyruvate, and resveratrol) significantly altered the AMP/ATP ratio. Collectively, these findings raise the possibility that glucose-induced changes in AMPK are linked to alterations in SIRT1 abundance and activity and possibly cellular redox state.

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Figures

Figure 1

Figure 1. Increasing the ambient glucose concentration decreases the phosphorylation of AMPK and ACC, and the abundance and activity of SIRT1 in HepG2 cells

HepG2 cells incubated in 5 or 25 mM glucose for 6 h. (A) Western blot analysis for p-AMPK (Thr 172), p-ACC (Ser 79), and SIRT1. (B) Quantification of representative blot shown in A, results are means ± SE (n=5); *,p<0.05. (C) PGC-1α acetylation after 6 h incubation in 5 or 25 mM glucose. (D) Quantification of Acetyl-Lys/HA-PGC-1α. Results are means ± SE, (n = 4); *, p<0.05.

Figure 2

Figure 2. Increasing pyruvate concentration increases p-AMPK, p-ACC, and SIRT1 abundance and activity

(A) Western blot analysis of HepG2 cells following 2 h incubation with the indicated concentrations of pyruvate. (B) Quantification of p-AMPK, p-ACC, and SIRT1 relative to β-actin. Results are means ± SE (n = 6); *, p<0.05 vs. 0 mM. (C) PGC-1α acetylation after 2 h incubation ± 1 mM pyruvate. (D) Quantification of Acetyl-Lys/HA-PGC-1α. Results are means ± SE, (n = 4); *, p<0.05.

Figure 3

Figure 3. Nicotinamide increases PGC-1α acetylation and decreases the phosphorylation of AMPK and ACC

(A) PGC-1α acetylation in HepG2 cells incubated ± 10 mM nicotinamide (NAM) for 6 h. (B) Quantification of Acetyl-Lys/HA-PGC-1α. Results are means ± SE, (n = 4); *, p<0.05. (C) Western blot analysis of p-AMPK and p-ACC. (D) Quantification of representative blot shown in C. Results are means ± SE, (n = 4); *, p<0.05.

Figure 4

Figure 4. Resveratrol and quercetin increase the phosphorylation of AMPK and ACC in HepG2 cells

(A, B) Dose response of p-AMPK and p-ACC to 1 h resveratrol incubation. Results are means ± SE (n = 2); *,p<0.05 vs. 0 µM resveratrol. (C) Time course of changes in p-AMPK and p-ACC caused by 100 µM resveratrol. (D) Western blot analysis showing enhanced p-AMPK and p-ACC following 1 h incubation with increasing concentrations of quercetin.

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References

    1. Hardie DG, Scott JW, Pan DA, Hudson ER. Management of cellular energy by the AMP-activated protein kinase system. FEBS Lett. 2003;546:113–120. - PubMed
    1. Kahn B, Alquier T, Carling D, Hardie G. AMP-activated protein kinase: Ancient energy gauge provides clues to modern understanding of metabolism. Cell Metabolism. 2005;1:15–25. - PubMed
    1. Zang M, Zuccollo A, Hou X, Nagata D, Walsh K, Herscovitz H, Brecher P, Ruderman NB, Cohen RA. AMP-activated protein kinase is required for the lipid-lowering effect of metformin in insulin-resistant human HepG2 cells. J Biol Chem. 2004;279:47898–47905. - PubMed
    1. Kemp BE, Stapleton D, Campbell DJ, Chen ZP, Murthy S, Walter M, Gupta A, Adams JJ, Katsis F, van Denderen B, Jennings IG, Iseli T, Michell BJ, Witters LA. AMP-activated protein kinase, super metabolic regulator. Biochem Soc Trans. 2003;31:162–168. - PubMed
    1. Beauloye C, Marsin AS, Bertrand L, Krause U, Hardie DG, Vanoverschelde JL, Hue L. Insulin antagonizes AMP-activated protein kinase activation by ischemia or anoxia in rat hearts, without affecting total adenine nucleotides. FEBS Lett. 2001;505:348–352. - PubMed

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