Son Y.-O.,University of Kentucky |
Heo J.-S.,Institute of Oral Biosciences and BK 21 Program |
Kim T.-G.,Chonbuk National University |
Jeon Y.-M.,Institute of Oral Biosciences and BK 21 Program |
And 3 more authors.
BMB Reports | Year: 2010
Activator protein-1 can induce either cell survival or death, which is controlled by opposing effects of different Jun members. It is generally accepted that c-Jun is pro-apoptotic, but that JunD is anti-apoptotic in stress-exposed cells. Additionally, although there are reports suggesting that JunB plays a protective role, its role in stress-induced apoptosis remains unclear. Here, we investigated the role of JunB in H2O2-induced cell death using cells that over-expressed the protein or were transfected with si-JunB. Inhibition of JunB expression accelerated H2O2-mediated loss of mitochondrial membrane potential (MMP) and cytotoxicity. Conversely, over-expression of JunB protein led to significant inhibition of the MMP loss and cell death. The increase in JunB expression also attenuated nuclear relocation of apoptosis-inducing factor and mitochondrial Bcl-2 reduction that occurred following H2O2 exposure. These results suggest that JunB can signal survival against oxidant-mediated cell death by suppressing mitochondrial stress.