7A). On the contrary, we found that SVIGF-I-treated rats exhibited significant up-regulation of HNF4α, a hepatocyte nuclear factor that stimulates the expression of genes characterizing the mature hepatocyte phenotype (Fig. 7B).20 It seems possible that this effect

might contribute to the improvement of liver function observed in IGF-I-treated cirrhotic rats. We also assessed the safety of SVIGF-I in normal rats. To this aim, control healthy rats, rats Roxadustat concentration injected with SVIGF-I or with SVLuc were sacrificed 8 weeks after vector administration. IGF-I, IGFBP3, and HGF were up-regulated in the liver of rats given SVIGF-I but histopathological analysis of several organs and evaluation of different serum biochemical parameters showed no significant differences between the groups (Supporting Fig. 4 and data not shown). To evaluate the robustness of IGF-I therapy we tested SVIGF-I in a different model of liver cirrhosis more difficult to revert. To this aim, Palbociclib we administered saline or recombinant SV40 vectors encoding SVLuc or IGF-I (SVIGF-I) to rats in which cirrhosis had been previously induced by TAA administration for 7 weeks. All animals and healthy controls were evaluated 8 weeks after vector administration. Similar to what was observed in the

CCl4 model, SVIGF-I vector was able to express functional IGF-I protein in the TAA cirrhotic liver. Thus, both IGF-I and IGF-IBP3 mRNAs were increased in IGF-I-treated animals compared to controls (Fig. 8A). This was accompanied by improved liver biochemistry, being the levels Bcl-w of serum ALP and serum bilirubin significantly lower than in cirrhotic controls and similar to values found in healthy animals (Fig. 8B). Also, the liver of IGF-I-treated animals exhibited less nodularity macroscopically (data not shown) and on histological

examination showed a marked decrease of liver fibrosis and less ductular proliferation in portal tracts compared to cirrhotic controls (Fig. 8C,D). Reduced fibrosis correlated with a strong decrease of activated HSCs as detected by immunohistochemistry and quantification of αSMA mRNA (Fig. 8C,E). In parallel to findings in the CCl4 model, rats with TAA-induced cirrhosis treated with SVIGF-I showed in liver tissue up-regulation of HGF accompanied by increased expression of MMPs and decreased levels of TIMP-1 (Fig. 8A, Supporting Fig. 5). Because liver transplantation can be offered to only a limited number of cirrhotic patients, alternative therapies for advanced liver cirrhosis are urgently needed. In keeping with the fact that IGF-I deficiency is a key feature of liver cirrhosis, a previous work by our group showed that daily administration of recombinant IGF-I to cirrhotic patients induces a significant amelioration of liver function.4 However, the amount of recombinant protein needed to accomplish hormone replacement therapy is high and a prolonged treatment would be exceedingly costly.