scienze della vita roma, 22-23 ottobre 2012 - SIF

NRF2 TRANSCRIPTION FACTOR ACTIVATION MODULATES
ENDOTHELIAL INFLAMMATORY RESPONSE TRIGGERED
BY TNF-ALPHA
Antonio Speciale*, Sirajudheen Anwar*, Deborah Fratantonio*, Andrea Azzerboni***, Antonella
Saija*, Fabio Virgili**, Francesco Cimino*
*Dep. Farmaco-Biologico, School of Pharmacy, University of Messina, Viale Annunziata, 98168,
Messina, Italy
**National Research Institute on Food and Nutrition (INRAN), Rome, Italy
***OU of Obstetrics & Gynecology, Policlinico Universitario “G. Martino”, Messina, Italy
Oxidants are one of the etiologies of multiple diseases and disorders. Cells are continously exposed
to the deleterious consequences of reactive oxigen species generated endogenously and
exogenously. However, cells have developed multiple stress adaptive responses, including the
system regulated by the transcription factor Nrf2 that modulates a set of cytoprotective genes (such
as HO-1, NQO1, -GCS). Up today there are few data supporting the atheroprotective and antiinflammatory
activity of the Nrf2 pathway in endothelial cells. Since activation of endogenous
cellular defense mechanisms can represent an innovative approach to therapeutic intervention in
pathological conditions characterized by chronic tissue damage, a better understanding of adaptive
response mechanisms at the cellular and molecular levels can lead to novel strategies for the
prevention and treatment of many different diseases. Thus, to test the potential atheroprotective and
anti-inflammatory role of the Nrf2 pathway we have investigated if some changes in the
intracellular redox status, such as those related to endogenous antioxidants depletion, might be able
to alter the response to the inflammatory cytokine TNF-α in cultured human endothelial cells
through the activation of this pathway.
In this study, we revealed that an oxidative intracellular status consequent to an intracellular
glutathione depletion induced by HUVECs exposure to buthionine sulfoximine (BSO), an inhibitor
of -glutamylcysteine synthetase ( -GCS), a rate-limiting enzyme in glutathione biosynthesis, is
able to induce a cellular adaptive response. Interestingly we demonstrated that, in our experimental
conditions, activation of Nrf2 pathway is able to reduce endothelial dysfunction by decreasing NFkB
nuclear translocation and adhesion molecules gene expression in HUVECs. Furthermore, we
confirmed that Nrf2 nuclear translocation activated by GSH depletion is dependent on extracellular
signal-regulated kinases 1/2 phosphorylation. In conclusion, we showed that the coordinate
induction of endogenous cytoprotective proteins through activation of the Nrf2 pathway might serve
as a new therapeutic approach for prevention or treatment of endothelial dysfunction.
Corresponding author: Antonio Speciale (specialea@gmail.com)
67