A pilot study of the modulation of sirtuins on arylamine N-acetyltransferase 1 and 2 enzymatic activity

• Published in: Acta pharmaceutica Sinica. B Vol. 8; no. 2; pp. 188 - 199
• Main Authors: Turiján-Espinoza, Eneida, Salazar-González, Rául Alejandro, Uresti-Rivera, Edith Elena, Hernández-Hernández, Gloria Estela, Ortega-Juárez, Montserrat, Milán, Rosa, Portales-Pérez, Diana
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-03-2018; Elsevier
• Subjects: Arylamine N-acetyltransferase; NAT; Nicotinamide; Original; Peripheral blood mononuclear cells; Resveratrol; Sirtuins; NAT; Sirtuins; SMZ; INH; PAS; ER81; Arylamine N-acetyltransferase; Ac-INH; CHO; FOXO1; HeLa; DMEM; FITC; PABA; Resveratrol; E2F1; SREBP2; Peripheral blood mononuclear cells; SREBP1a; HPLC; Ac-PABA; PBS; PGAM1; PGC-1α; PBMC; RUNX3; NAD; APC; RSV; Nicotinamide; NAM; SIRT; APC, allophycocyanin; NAD, nicotinamide adenine dinucleotide; PBMC, peripheral blood mononuclear cells; PGAM1, phosphoglycerate mutase 1; SIRT, sirtuin; HeLa, adenocarcinoma epithelial cells; PAS, p-aminosalicilic acid; RSV, resveratrol; HPLC, high performance liquid chromatography; CHO, Chinese hamster ovary cells; RUNX3, runt-related transcription factor 3; PBS, phosphate-buffered saline; DMEM, Dulbecco's modified Eagle's medium; SMZ, sulfamethazine; E2F1, E2F transctriptios factor 1; PABA, p-aminobenzoic acid; SREBP1a, sterol regulatory element-binding protein 1a; ER81, ETS-related protein 81; INH, isoniazid; PGC-1α, peroxisome proliferator-activated receptor-gamma coactivator 1α; SREBP2, sterol regulatory element-binding protein 2; NAM, nicotinamide; Ac-INH, acetyl-Isoniazid; FITC, fluorescein IsoTioCyanate; FOXO1, forkhead box protein O1; Ac-PABA, acetyl-p-aminobenzoic acid; NAT, arylamine N-acetyltranferase
• ISSN: 2211-3835; 2211-3843
• DOI: 10.1016/j.apsb.2017.11.008

Arylamine N-acetyltransferase (NAT; E.C. 2.3.1.5) enzymes are responsible for the biotransformation of several arylamine and hydrazine drugs by acetylation. In this process, the acetyl group transferred to the acceptor substrate produces NAT deacetylation and, in consequence, it is susceptible of degradation. Sirtuins are protein deacetylases, dependent on nicotine adenine dinucleotide, which perform post-translational modifications on cytosolic proteins. To explore possible sirtuin participation in the enzymatic activity of arylamine NATs, the expression levels of NAT1, NAT2, SIRT1 and SIRT6 in peripheral blood mononuclear cells (PBMC) from healthy subjects were examined by flow cytometry and Western blot. The in situ activity of the sirtuins on NAT enzymatic activity was analyzed by HPLC, in the presence or absence of an agonist (resveratrol) and inhibitor (nicotinamide) of sirtuins. We detected a higher percentage of positive cells for NAT2 in comparison with NAT1, and higher numbers of SIRT1+ cells compared to SIRT6 in lymphocytes. In situ NAT2 activity in the presence of NAM inhibitors was higher than in the presence of its substrate, but not in the presence of resveratrol. In contrast, the activity of NAT1 was not affected by sirtuins. These results showed that NAT2 activity might be modified by sirtuins.
The present study exhibited a highly significant effect (P<0.005) on NAT2 activity in peripheral blood mononuclear cells once deacetylation function of sirtuins is inhibited by nicotinamide (NAM) generating high levels of Ac-INH which suggests a post-translational regulatory mechanism. [Display omitted]