Bucillamine induces glutathione biosynthesis via activation of the transcription factor Nrf2

Wielandt, AM; Vollrath, V; Farias M.; Chianale, J

Abstract

The properties of bucillamine, a synthetic antioxidant, have been attributed mainly to the donation of thiol groups to glutathione (GSH). We recently demonstrated that glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme of GSH biosynthesis, and the multidrug-resistance-associated protein 2 (Mrp2/MRP2) are coordinately induced in response to xenobiotic through the activation of the antioxidant-response element (ARE) by nuclear factor-erythroid 2 p45-related factor (Nrf2). We tested the hypothesis that bucillamine and its oxidized metabolite SA 981 also activate the Nrf2 pathway, thereby increasing glutathione biosynthesis in human HepG2 and murine Hepa 1-6 hepatoma cell lines, through the induction of the GCLC enzyme as well as the Mrp2/MRP2 transporter, which mediates the excretion of glutathione and its conjugates from hepatocytes. Both bucillamine and SA 981 produced a significant dose-dependent increase in the mRNA levels of Mrp2/MRP2 and GCLC after 24 h. The levels of the transcription factor Nrf2 in the nuclei were maximal at 3 h, remained elevated at 6 h, and decreased to control values at 24 h in both cell lines. Moreover, both bucillamine and SA 981 significantly increased the expressions of Mrp2/MRP2 and GCLC proteins in both cell lines. Finally, in both cell lines, bucillamine and SA 981 increased the GSH content two- to three-fold. These results demonstrate that bucillamine and SA 981 activate the ARE-ARE pathway increasing the expression of ARE-driven genes such as those of GCLC and Mrp2/MRP2. The role of bucillamine as a chemopreventive agent against cancer remains to be elucidated. © 2006 Elsevier Inc. All rights reserved.

Más información

Título según WOS: Bucillamine induces glutathione biosynthesis via activation of the transcription factor Nrf2
Título según SCOPUS: Bucillamine induces glutathione biosynthesis via activation of the transcription factor Nrf2
Título de la Revista: BIOCHEMICAL PHARMACOLOGY
Volumen: 72
Número: 4
Editorial: PERGAMON-ELSEVIER SCIENCE LTD
Fecha de publicación: 2006
Página de inicio: 455
Página final: 462
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S0006295206003121
DOI:

10.1016/j.bcp.2006.05.011

Notas: ISI, SCOPUS