ROS homeostasis, a key determinant in liver ischemic-preconditioning.

ABSTRACT

Reactive Oxygen Species (ROS) are key mediators of ischemia-reperfusion injury but also required for the induction of the stress response that limits tissue injury and underlies the protection provided by ischemic-preconditioning protocols. Liver steatosis is an important risk factor for liver transplant failure. Liver steatosis is associated with mitochondrial dysfunction and excessive mitochondrial ROS production. Studies aiming at decreasing the sensibility of the steatotic liver to ischemia-reperfusion injury using pre-conditioning protocols, have shown that the steatotic liver has a reduced capacity to respond to these protocols. Recent studies indicate that these effects are related to a reduced capacity of the steatotic liver to respond to elevated ROS levels following reperfusion by inducing a compensatory response. This failure to respond to ROS is associated with reduced levels of antioxidants, mitochondrial damage, hepatocyte cell death, activation of the immune system and induction of pro-fibrotic mediators.