41 Med J Malaysia Vol 65 October 2010 Isolation of a Clonal Mesenchymal Stem Cell Line from Rat Bone Marrow and Its Application for Preventing Acute Fatal and Chronic Liver Failure Marhaen Hardjo* , **, S Fadilah Abdul Wahid* *Cell Therapy Centre, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), **Medical Faculty of Hasanuddin University, Makassar Indonesia SUMMARY The use of a clonal mesenchymal stem cell as a source of hepatocytes has not been extensively studied. Here we report the isolation and establishment of several clonal mesenchymal stem cell lines from rat bone marrow. One of these cell lines, rBM25/S3 cells, small and asteroid in shape, were maintained in the presence of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)-BB on a fibronectin substratum. The cells expressed CD29, CD44, CD49b, CD90, vimentin and fibronectin but not CD45, indicating that they are of mesenchymal cell origin. When cultured in the presence of HGF and FGF-4 on Matrigel, the cells efficiently (~100%) differentiated within 7 days into hepatocyte-like cells (HLC) that expressed albumin. Intrasplenic transplantation of these differentiated cells prevented fatal liver failure in 90%- hepatectomized rats, while the undifferentiated cells most effectively suppressed liver fibrosis. In conclusion, a clonal MSC line derived from adult rat bone marrow could differentiated into HLC, and transplantation of the cells could prevented fatal liver failure in 90%-hepatectomized rats and suppressed carbon tetrachloride-induced liver fibrosis. The present results indicate a promising strategy for treating human fatal liver disease.