Immunohistochemical analyses of cell cycle progression and gene expression of biliary epithelial cells during liver regeneration after partial hepatectomy of the XXXX .

@entity16525 @entity67743 @entity14160 @entity19 @entity25036 @entity22437 @entity4698 @entity27947 @entity1189
UNASSIGNED: The liver has a remarkable regeneration capacity, and, after surgical removal of its mass, the remaining tissue undergoes rapid regeneration through compensatory growth of its constituent cells. Although hepatocytes synchronously proliferate under the control of various signaling molecules from neighboring cells, there have been few detailed analyses on how biliary cells regenerate for their cell population after liver resection. The present study was undertaken to clarify how biliary cells regenerate after partial hepatectomy of @entity19 through extensive analyses of their cell cycle progression and gene expression using immunohistochemical and RT-PCR techniques. When expression of @entity4698 , @entity14160 antigen, topoisomerase @entity25036 and phosphorylated histone H3, which are cell cycle markers, was immunohistochemically examined during liver regeneration, hepatocytes had a peak of the S phase and M phase at 48-72 h after resection. By contrast, biliary epithelial cells had much lower proliferative activity than that of hepatocytes, and their peak of the S phase was delayed. Mitotic figures were rarely detectable in biliary cells. RT-PCR analyses of gene expression of biliary markers such as @entity1189 (osteopontin), @entity27947 and @entity67743 demonstrated that they were upregulated during liver regeneration. Periportal hepatocytes expressed some of biliary markers, including @entity1189 mRNA and protein. Some periportal hepatocytes had downregulated expression of @entity16525 and @entity22437 . Gene expression of Notch signaling molecules responsible for cell fate decision of hepatoblasts to biliary cells during development was upregulated during liver regeneration. Notch signaling may be involved in biliary regeneration.
