Design, Synthesis, and Biological Evaluation of Sirtinol Analogues as Class III Histone/Protein Deacetylase (Sirtuin) Inhibitors

Mai, Antonello; Massa, S.; Lavu, Siva; Pezzi, R; Simeoni, Silvia; Ragno, Rino; Mariotti, Francesca Romana; Chiani, Francesco; Camilloni, Giorgio; Sinclair, David A.

doi:10.1021/jm050100l

Cited by 160 publications

(123 citation statements)

References 62 publications

(107 reference statements)

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“…The IC 50 of sirtinol to SIRT1 in the assay using the p53 peptide was 120.2 μM (Table 2). This result is consistent with the previous data (131 μM) from a different fluorimetric assay (26). On the other hand, the IC 50 of compound 17 against SIRT1 was 40.3 μM and lower than that of sirtinol.…”

Section: Discussionsupporting

confidence: 93%

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

et al. 2008

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Abstract. SIRT1 is one of seven mammalian orthologs of yeast silent information regulator 2 (Sir2), and it functions as a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase. Recently, resveratrol and its analogues, which are polyphenols, have been reported to activate the deacetylase activity of SIRT1 in an in vitro assay and to expand the life-span of several species through Sir2 and the orthologs. To find activators or inhibitors to SIRT1, we examined thirty-six polyphenols, including stilbenes, chalcones, flavanones, and flavonols, with the SIRT1 deacetylase activity assay using the acetylated peptide of p53 as a substrate. The results showed that 3,2',3',4'-tetrahydroxychalcone, a newly synthesized compound, inhibited the SIRT1-mediated deacetylation of a p53 acetylated peptide and recombinant protein in vitro. In addition, this agent induced the hyperacetylation of endogenous p53, increased the endogenous p21 CIP1/ WAF1 in intact cells, and suppressed the cell growth. These results indicated that 3,2',3',4'-tetrahydroxychalcone had a stronger inhibitory effect on the SIRT1-pathway than sirtinol, a known SIRT1-inhibitor. Our results mean that 3,2',3',4'-tetrahydroxychalcone is a novel inhibitor of SIRT1 and produces physiological effects on organisms probably through inhibiting the deacetylation by SIRT1.

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Section: Discussionsupporting

confidence: 93%

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

et al. 2008

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“…Small molecule inhibitors of the SIRT1 deacetylase have been proposed as novel anticancer agents [22][23][24] , presumably through activating the apoptotic response in cancer cells. On the other hand, activation of SIRT1 in mice also protects them against dietinduced obesity and insulin resistance, mainly through regulating metabolic pathways 25,26 .…”

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confidence: 99%

Negative regulation of the deacetylase SIRT1 by DBC1

Zhao

Kruse

Tang

et al. 2008

Nature

424

487

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SIRT1 is an NAD-dependent deacetylase critically involved in stress responses, cellular metabolism and, possibly, ageing [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] . The tumour suppressor p53 represents the first non-histone substrate functionally regulated by acetylation and deacetylation 16,17 ; we and others previously found that SIRT1 promotes cell survival by deacetylating p53 (refs 4-6 ). These results were further supported by the fact that p53 hyperacetylation and increased radiation-induced apoptosis were observed in Sirt1-deficient mice 10 . Nevertheless, SIRT1-mediated deacetylase function is also implicated in p53-independent pathways under different cellular contexts, and its effects on transcriptional factors such as members of the FOXO family and PGC-1α directly modulate metabolic responses [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] . These studies validate the importance of the deacetylase activity of SIRT1, but how SIRT1 activity is regulated in vivo is not well understood. Here we show that DBC1 (deleted in breast cancer 1) acts as a native inhibitor of SIRT1 in human cells. DBC1-mediated repression of SIRT1 leads to increasing levels of p53 acetylation and upregulation of p53-mediated function. In contrast, depletion of endogenous DBC1 by RNA interference (RNAi) stimulates SIRT1-mediated deacetylation of p53 and inhibits p53-dependent apoptosis. Notably, these effects can be reversed in cells by concomitant knockdown of endogenous SIRT1. Our study demonstrates that DBC1 promotes p53-mediated apoptosis through specific inhibition of SIRT1.To understand the regulation of SIRT1-mediated deacetylation in vivo, biochemical purification was used to identify cellular factors that stably interact with SIRT1. We isolated physiologically formed protein complexes containing SIRT1 from cell extracts of native HeLa cells by conducting affinity chromatography with affinity-purified antisera raised against the carboxy (C) terminus (amino acids 480-737) of SIRT1 ( Supplementary Fig. 1a). As expected, we identified SIRT1 as the major component of the complexes, but several protein bands were also co-purified with SIRT1. Mass spectrometry of a prominent protein band of approximately 130 kilodaltons (kDa) from the SIRT1 complexes revealed peptide sequences corresponding to the DBC1 protein ( Supplementary Fig. 1b, Gi: 24432106). The DBC1 gene was initially identified as it is localized to a region of chromosome 8p21 that was homozygously deleted in human breast cancer; however, the molecular function of DBC1 is poorly understood 18,19 .To examine the interaction between endogenous DBC1 and SIRT1, cell extracts from human osteosarcoma U2OS cells were immunoprecipitated with the anti-SIRT1 antibody or with the

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“…Physiological studies, target confirmation, and drug development have been hampered, however, by shortcomings of available Sirtuin inhibitors, which mostly show limited potency and/or isoform specificity and exploit unknown binding sites and mechanisms (21,22). The widely used inhibitor sirtinol, for example, has an IC 50 of 38 μM against Sirt2 and no effect on Sirt5, inhibits Sirt1 only approximately threefold weaker, and its effect on other isoforms and its mechanism are unknown (23)(24)(25). Ex-527 (6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide; Fig.…”

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confidence: 99%

Ex-527 inhibits Sirtuins by exploiting their unique NAD ⁺ -dependent deacetylation mechanism

Gertz

Fischer

Nguyen

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

269

228

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Sirtuins are protein deacetylases regulating metabolism and stress responses. The seven human Sirtuins (Sirt1-7) are attractive drug targets, but Sirtuin inhibition mechanisms are mostly unidentified. We report the molecular mechanism of Sirtuin inhibition by 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide (Ex-527). Inhibitor binding to potently inhibited Sirt1 and Thermotoga maritima Sir2 and to moderately inhibited Sirt3 requires NAD + , alone or together with acetylpeptide. Crystal structures of several Sirtuin inhibitor complexes show that Ex-527 occupies the nicotinamide site and a neighboring pocket and contacts the ribose of NAD + or of the coproduct 2'-O-acetyl-ADP ribose. Complex structures with native alkylimidate and thio-analog support its catalytic relevance and show, together with biochemical assays, that only the coproduct complex is relevant for inhibition by Ex-527, which stabilizes the closed enzyme conformation preventing product release. Ex-527 inhibition thus exploits Sirtuin catalysis, and kinetic isoform differences explain its selectivity. Our results provide insights in Sirtuin catalysis and inhibition with important implications for drug development.

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Design, Synthesis, and Biological Evaluation of Sirtinol Analogues as Class III Histone/Protein Deacetylase (Sirtuin) Inhibitors

Cited by 160 publications

References 62 publications

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

Negative regulation of the deacetylase SIRT1 by DBC1

Ex-527 inhibits Sirtuins by exploiting their unique NAD ⁺ -dependent deacetylation mechanism

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Design, Synthesis, and Biological Evaluation of Sirtinol Analogues as Class III Histone/Protein Deacetylase (Sirtuin) Inhibitors

Cited by 160 publications

References 62 publications

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

A Novel Chalcone Polyphenol Inhibits the Deacetylase Activity of SIRT1 and Cell Growth in HEK293T Cells

Negative regulation of the deacetylase SIRT1 by DBC1

Ex-527 inhibits Sirtuins by exploiting their unique NAD + -dependent deacetylation mechanism

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Ex-527 inhibits Sirtuins by exploiting their unique NAD ⁺ -dependent deacetylation mechanism