Fig. 1.

Identification of liver progenitor/stem cells in posttransplant human liver tissues. Immunohistochemical labeling of posttransplant human liver tissue taken from living donor liver transplant 4 weeks after transplantation. The tissue is labeled for the presence of ELF (A, arrows) and Oct4 (B, arrows). Sections are taken consecutively to enable identical localization. (C–N) Confocal images of human liver at 3 months after living-related liver transplantation. (C–E) The tissue is labeled with stem cell proteins Stat3 and Oct4 and prodifferentiation TGF-β signaling component ELF. (F) These proteins coexpress in a small cluster of two to four cells. (G) DAPI represents nuclear labeling. (H) Differential interference chromatography (DIC) represents a transmission image of this cluster of cells. (I–K) Regenerative liver tissue from another liver transplant is labeled with p-histone H3 (Ser¹⁰), Oct4, and ELF. (L) These proteins coexpress in this cluster of progenitor-like cells. (M and N) DAPI represents nuclear labeling (M), and DIC represents transmission images (N). Arrows point to the nuclei of the progenitor-like cells. (Scale bars for all figures are in micrometers.)