A study shows that human hepatocytes and cholangiocytes can originate from bone marrow-derived stem cells. Researchers analyzed liver tissues from patients who received bone marrow or liver transplants, with gender mismatch between donor and recipient. Using immunohistochemistry and fluorescence in situ hybridization (FISH), they identified Y-chromosome-positive cells in liver tissues, indicating bone marrow-derived cells. The study found that Y-positive hepatocytes and cholangiocytes ranged from 4% to 43% and 4% to 38%, respectively, in study specimens. The highest engraftment was observed in a patient with fibrosing cholestatic hepatitis C. The findings suggest that bone marrow-derived stem cells can differentiate into mature hepatocytes and cholangiocytes, contributing to liver regeneration. This process may occur through two pathways: direct engraftment of stem cells into liver cords or via oval-like cell intermediates through the canals of Hering. The study supports the existence of bipotent hepatic stem cells in humans, likely of bone marrow origin. These cells may play a role in liver regeneration and could have therapeutic implications for liver diseases. The study also highlights the potential for bone marrow transplantation to correct defects in hepatocyte function.A study shows that human hepatocytes and cholangiocytes can originate from bone marrow-derived stem cells. Researchers analyzed liver tissues from patients who received bone marrow or liver transplants, with gender mismatch between donor and recipient. Using immunohistochemistry and fluorescence in situ hybridization (FISH), they identified Y-chromosome-positive cells in liver tissues, indicating bone marrow-derived cells. The study found that Y-positive hepatocytes and cholangiocytes ranged from 4% to 43% and 4% to 38%, respectively, in study specimens. The highest engraftment was observed in a patient with fibrosing cholestatic hepatitis C. The findings suggest that bone marrow-derived stem cells can differentiate into mature hepatocytes and cholangiocytes, contributing to liver regeneration. This process may occur through two pathways: direct engraftment of stem cells into liver cords or via oval-like cell intermediates through the canals of Hering. The study supports the existence of bipotent hepatic stem cells in humans, likely of bone marrow origin. These cells may play a role in liver regeneration and could have therapeutic implications for liver diseases. The study also highlights the potential for bone marrow transplantation to correct defects in hepatocyte function.