A role for Nrf2 in UVA-mediated heme oxygenase induction and protection from membrane damage in human skin fibroblasts

Our previous study has shown that Ultraviolet-A (UVA) irradiation induces heme oxygenase 1 (HO-1) expression in cultured human primary skin fibroblasts FEK4. In the present study, we demonstrate a coordinated induction of HO-1 and NF-E2-related factor 2 (Nrf2) following UVA irradiation or hemin treatment. The induction of HO-1 by either UVA irradiation or hemin treatment was largely abolished by down-regulation of Nrf2 with its targeted short interfering RNA (siNrf2). The study further reveals that knockdown of Nrf2 protein increased UVA-induced cell death measured by MTS assay. These findings together indicate that Nrf2-mediated induction of HO-1 expression may provide a cytoprotection for human skin cells from oxidative damage.