Proceedings of The Physiological Society
University of Oxford (2011) Proc Physiol Soc 23, PC107
Sulforaphane modulates redox signalling in human aortic adventitial fibroblasts
T. Mughal1, J. Wong1, G. E. Mann1, M. Parsons2, R. C. Siow1
1. Cardiovascular Division, King''s College London, London, United Kingdom. 2. Randall Division of Cell & Molecular Biophysics, King's College London, London, United Kingdom.
Migration and proliferation of adventitial fibroblasts (AF) contributes to vascular remodelling  which may be mediated by enhanced generation of reactive oxygen species (ROS) . Sulforaphane (SFN), an isothiocyanate present in cruciferous vegetables such as broccoli, protects cells against oxidative stress and inflammation through activation of the transcription factor Nrf2  which mediates induction of antioxidant defence pathways such as glutathione (GSH) and heme oxygenase-1 (HO-1) via activation of antioxidant response elements . GSH is the predominant intracellular antioxidant and HO-1 catabolises the pro-oxidant heme to generate the vasodilator carbon monoxide and antioxidant biliverdin. To address whether SFN can elicit changes in redox signalling in primary cultured human AF, cells were treated (0-24 h) in medium containing SFN (0-10 μM). Cellular HO-1 and nuclear Nrf2 protein expression were determined by western blot analyses using specific antibodies with α-tubulin used as a reference protein while total GSH levels were measured using a fluorometric assay. Treatment of AF with SFN (2 h) elicited a marked 2 fold increase in nuclear Nrf2 levels with a concomitant significant decrease (50%, 2-8 h) in GSH levels which returned to baseline by 24 h, while HO-1 expression was significantly increased by 2-4 fold in AF treated with 5-10 μM SFN for 8-24h (n=3, p<0.05, Student's paired t-test). These findings demonstrate for the first time that SFN can elicit changes in redox signalling in human aortic AF involving Nrf2 activation. Dietary SFN may therefore contribute to protection against vascular remodelling in atherosclerosis and restenosis through attenuating AF phenotypic modulation to myofibroblasts.
Where applicable, experiments conform with Society ethical requirements