Reversal of Hepatic Fibrosis by Human CD34+ Stem/Progenitor Cell Transplantation in Rats

Human umbilical cord blood (UCB) cells have many advantages as grafts for cell transplantation. Here, we transplant UCB cells into injured liver fibrosis, investigated the hepatic potential of UCB cells both in vitro and in vivo. a CCl4 rat model with liver fibrosis was prepared. Human (UCB) CD34(+) stem cell was separated with MACS (magnetic cell sorting). Cells were cultured with and without hepatic differentiation medium. Rats were divided into 3 groups; group (1): control healthy, group (2): CCl4 injected rats and group 3: CCl4/CD34(+)injected rats with human differentiated and undifferentiated cells through intrahepatic (IH) and intravenous (IV) routes. A significant elevation was detected in serum albumin in CCl4/CD34(+) compared to the CCl4 group (p<0.001). Serum ALT, had a significant decrease of its level after administration of stem cells compared to the CCl4 group (p<0.001). However, it was still significantly higher than control (p<0.001) with no significant difference between the groups that received stem cells. Histopathological examination of liver tissue showed that stem cells have a significant antifibrotic effect. Concerning gene expression, the collagen gene (rat) was highly expressed in the CCl4 group whereas its expression was significantly decreased after administration of stem cells. Human albumin and matrix metalloproteinase (MMP2) genes were expressed in liver tissues in the groups that received stem cells. Highest expression was in the group that received un-differentiated cells I.V. human UCB CD34(+) stem cells can ameliorate liver fibrosis in rats.