Prevalidation of liver slices as a model for the early onset of liver fibrosis to test anti-fibrotic drugs

Liver fibrosis is the progressive accumulation of connective tissue that affects the normal function of the liver and will eventually lead to liver cirrhosis. The aim of this study is to prevalidate precision-cut liver slices (PCLS) as an in vitro model to investigate the early onset of liver fibrosis and as a test system for anti-fibrotic drugs. Rat PCLS were incubated up to 48 hours, viability was assessed by ATP content and the gene expression of the fibrotic markers Heat Shock Protein 47 (HSP47), α-Smooth Muscle Actin (αSMA) and Pro-collagen1A1 (PCOL1A1) was determined. Furthermore, during 48 hours the effects of anti-fibrotic drugs inhibiting the PDGF signaling pathway (Gleevec (G), Sorafenib (So) and Sunitinib (Su)) and drugs inhibiting the TGFβ signaling pathway (Valproic acid (Va), Perindopril (Pe)) and drugs that directly affect the collagen expression (Colchicine (Co), Pirfenidone (Pi) and Tetrandrine (Te)), all used at a non-toxic concentration, were determined. In PCLS incubated up to 48 hours an increased gene expression of HSP47, αSMA and PCOL1A1 was found. Addition of G, So or Su resulted in an inhibition of the gene expression of 60, 75 and 80% (G), 35, 60 and 70% (So) and 60, 80 and 90% (Su) of HSP47, αSMA and PCOL1A1 respectively. However, only the highest concentration of Va inhibited the gene expression of the fibrotic markers by 60%. Pe inhibited the gene expression of PCOL1A1 only at the highest concentration by 20%. Co inhibited gene expression of αSMA and PCOL1A1 by 50%, while Pi caused an inhibition of the gene expression of HSP47 (30%), αSMA (60%) and PCOL1A1 (70%) and Te caused only an inhibition of the gene expression of PCOL1A1 by 25%. Rat PCLS incubated for 48 hours show characteristics of early onset of liver fibrosis. This effect is inhibited by anti-fibrotic drugs acting directly on collagen and on the PDGF-pathway, but not on the TGFβ pathway, indicating that PCLS are a model for testing such anti-fibrotic compounds in vitro.