Javamide-I-O-methyl ester increases p53 acetylation and induces cell death via activating caspase 3/7 in monocytic THP-1 cells

Abstract

BackgroundJavamide-I and-II are phenolic amide compounds found in Coffea sp. Previous study suggested that javamide-II may be a potent compound with Sirt1/2 inhibition activity. PurposeHowever, the effects of javamide-I and the its O-methyl ester on Sirt inhibition, p53 acetylation and cell death have not been investigated. MethodsThe isolation and synthesis of javamide-I and its O-methyl ester analogue were confirmed by NMR. Their potential effects on Sirt1/2/3, p53 acetylation and cell death were examined using sirt assay, silico analysis, Western blot, caspase 3/7 and apoptotic assay methods. ResultsJavamide-I and its O-methyl ester demonstrated a similar inhibition pattern; Sirt1 (IC50 of 19µM) better than Sirt2 (IC50 of 104µM) and Sirt3 (IC50 of 160µM). However, javamide-I and its O-methyl ester were found to inhibit Sirt1 better than Sirt2, which is different from javamide-II able to inhibit Sirt2 stronger than Sirt1. In silico analysis, javamide-I and its O-methyl ester showed a competitive binding pattern against NAD+, which was also supported by the kinetic analysis with Ki=20.1µM for javamide-I and 19.5µM for the O-methyl ester. However, the O-methyl ester increased p53 acetylation better than javamide-I in monocytic THP-1 cells. Since caspase 3/7 activation is often followed by the p53 activation, we investigated their effects on caspase 3/7, and found that O-methyl ester again activated caspase 3/7 greater than javamide-I in the cells, eventually leading to apoptotic cell death. ConclusionThese data suggest that the O-methyl modification in javamide-I may play a critical role in increasing p53 acetylation, activating caspase, and eventually inducing the THP-1 cell death.