Redox experimental medicine and liver regeneration

Abstract

The liver is characterized by unique regenerative properties to restore its mass and function after a partial loss. Hepatic regeneration arises after resection or following acute and chronic injuries. Resection and acute liver damage normally induce a regenerative process characterized by phenotypic fidelity, in which each cell type promotes its own replication and replacement. This process fails in chronic liver damage, where trans-differentiation of parenchymal cells or activation of facultative progenitors occurs. Both liver resection and acute/chronic damages alter redox homeostasis, as a consequence of blood flow changes, hypoxia, metabolism modification, and activation of inflammatory response. Even though formerly described as ‘oxidative stress’, altered redox homeostasis leads to the fine regulation of several pathways involved in liver regeneration, including the proliferation of parenchymal cells, trans-differentiation, and activation of facultative progenitors. Several redox-dependent transcription factors and pathways implicated in the regenerative process of the liver were described, but pre-clinical experiments using different antioxidants were not fully conclusive. Even though accurate study designs to define appropriate dosages, treatment duration, and routes of administration are required, modulation of redox-dependent molecular pathways to enhance liver regeneration is even more intriguing. Preliminary studies focused on the identification of these targets will pave the way for viable therapies to be tested in clinical trials.