Isolation of fetal liver oval cells in physiologic conditions form their natural niche

The liver is characterized by a remarkable ability to proliferate and self-renew. In the situation of mild or moderate liver damage, hepatocytes carry out regeneration. Nevertheless, when liver damage is far too much extensive and the number of residual mature hepatocytes is not enough to accomplish regeneration, or likewise when mature hepatocyte proliferation is inhibited, hepatic regeneration depends on the activation of liver stem cells that give rise to oval cells. The population of liver stem cells is scant in normal liver. It is considered that in fetal liver this population is just over 1% of the cells. For this reason, it is necessary to isolate and enrich them for their study. With this goal several models of hepatic damage that permit the isolation of oval cells af ter the induction of massive hepatic injure have been developed. Here we present a simple methodology that allows the isolation of oval cells from rat fetal liver without prior induction of liver damage. The use of oval cell 2 (OC2) and oval cell 3 (OC3) antigens as molecular markers allowed the highly precise characterization of this cell population. Furthermore, the in vitro culture in presence of HGF yielded a substantial enrichment of the oval cell population.