Long-term culture of cholangiocytes from liver fibro-granulomatous lesions

BACKGROUND: Extensive bile duct proliferation is a key feature of the tissue reaction to clinical and experimental forms of liver injury. Experimental infection of mice by Schistosoma mansoni is a well-studied model of liver fibrosis with bile duct hyperplasia. However, the regulatory mechanisms of bile duct changes are not well understood. In this study we report the reproducible isolation of long-term cultures of cholangiocytes from mice livers with schistosomal fibrosis. METHODS: We have isolated a cholangiocyte cell line from Schistosoma-induced liver granulomas using a combination of methods including selective adhesion and isopyknic centrifugation in Percoll. RESULTS: The cell line was characterized by morphological criteria in optical and transmission electron microscopy, ability to form well differentiated ductular structures in collagen gels and by a positive staining for cytokeratin 18 and cytokeratin 19. To our knowledge, this is the first murine cholangiocyte cell line isolated from schistosomal fibrosis reported in the literature. CONCLUSION: After 9 months and 16 passages this diploid cell line maintained differentiated characteristics and a high proliferative capacity. We believe the method described here may be a valuable tool to study bile duct changes during hepatic injury

Ultrastructural distribution of DNA within the nucleolus of various animal cell lines or tissues revealed by terminal deoxynucleotidyl transferase.

We have used the highly sensitive in situ terminal deoxynucleotidyl transferase method, applied to ultrathin sections, to investigate the location of DNA within nucleoli of various animal cells. In all the nucleoli studied, intense labelling is revealed over the peri- and intranucleolar condensed chromatin. Gold particles are also consistently found over the fibrillar centres, especially at their periphery, namely in the border area between the fibrillar centres and the dense fibrillar component, whereas the dense fibrillar component itself seems to be free of label in nucleoli in which these two compartments can be distinguished. We conclude that, in transcriptionally active nucleoli of this type, DNA is a characteristic constituent of the fibrillar centres, distinguishing them functionally from the dense fibrillar component. Some nucleoli exhibit neither fibrillar centres nor a dense fibrillar component, but have a single, albeit heterogeneous accumulation of fibrillar material; gold particles are consistently seen over some parts of this fibrillar compartment. This suggests that certain parts of the fibrillar material are functionally similar to the fibrillar centres of those nucleoli that possess them