Regeneration , Proliferation and Trans-differentiation of Adult Hepatic Oval Stem Cells into Functioning Beta-Cells and Exocrine Acinar Cells of the Pancreas in Diabetic Adult Rats


Back ground: Although adult stem cells possess plasticity that permit differentiation along newlineages, production of exocrine and endocrine pancreatic cells and insulin-secreting beta-cells fromadult non pancreatic stem cells has been considered controversial. We present that highly purifiedadult rat hepatic oval stem cells, which are capable of differentiation to hepatocytes and bile ductsepithelium, can also trans-differentiate into pancreatic exocrine-endocrine tissue, when homogenizedhepatic tissue is implanted into subcutaneous tissue .Methods and Materials: A total of 60 adult Swiss albino rats were divided into two groups . Group I, control group (30 animals) was injected with normal saline into the subcutaneous and pancreatictissue, group II (30 animals) has been exposed to 90% subtotal pancreatectomy with implantation ofhepatic tissue homogenate into marked areas of subcutaneous tissue .Results: During the first three weeks the animals of group II showed both high blood glucose andserum AFP levels, then gradually started to decline and became normal around the period of sixweeks and continued being normal till the end of experiment. The histological study showedregeneration and proliferation of small hepatic oval stem cells in the subcutaneous tissue around thesecond week and trans-differentiation of these cells into islet like cells and acinar like cells around thesixth week.Conclusions: Hepatic oval stem cell has multipotent character and can differentiate into new-lineagesand formation of different clonal cells, such as islet-like cells and acinar cells of the pancreas.