POLLUTION EXPOSURE INDUCED p53-MEDIATED OXIDATIVE STRESS AND DNA DAMAGE IN BLOOD CELLS OF TILAPIA SP

ABSTRACT The acute effects of pollution environment on fish have been widely studied. However, the molecular mechanism of toxic injury remains largely unknown. In the present study, we examined the cellular responses of Tilapia to pollution exposure-induced oxidative stress. Furthermore, we determined how acute toxic stress activates the p53 signal pathway. We measured the up regulation of reactive oxygen species (ROS) production, the tail DNA values and the malondialdehyde (MDA) level in the blood cells. The results suggest that oxidative stress and DNA damage occurred in tilapia in conditions where the pollution occurs. The parameters measured were related to pollution induced DNA damage, and all parameters changed in the blood cells through time. The effects of heavy metal exposure on the expression of p53 and p21 were investigated in tilapia blood cells. The results showed that toxic stress induced upregulation of p53 and p21 are associated with increasing of DNA damage in blood cells. Therefore, it suggests that pollution exposure-induced oxidative stress may cause DNA damage or apoptosis, and cooperatively activate p53 pathway, which may leads to the activation of p21