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Identification of a bipotential precursor cell in hepatic cell lines derived from transgenic mice expressing cyto-Met in the liver.

Spagnoli FM, Amicone L, Tripodi M, Weiss MC - J. Cell Biol. (1998)

Bottom Line: Palmate cells show none of these properties.Derivation of epithelial from palmate cells is confirmed by characterization of the progeny of individually fished cells.The clonal isolation of the palmate cell, an immortalized nontransformed bipotential cell that does not yet express the liver-enriched transcription factors and is a precursor of the epithelial-hepatocyte in MMH lines, provides a new tool for the study of mechanisms controlling liver development.

View Article: PubMed Central - PubMed

Affiliation: Unité de Génétique de la Différenciation, URA 1773 du Centre National de la Recherche Scientifique, Institut Pasteur, 75724 Paris Cedex 15, France.

ABSTRACT
Met murine hepatocyte (MMH) lines were established from livers of transgenic mice expressing constitutively active human Met. These lines harbor two cell types: epithelial cells resembling the parental populations and flattened cells with multiple projections and a dispersed growth habit that are designated palmate. Epithelial cells express the liver-enriched transcription factors HNF4 and HNF1alpha, and proteins associated with epithelial cell differentiation. Treatments that modulate their differentiation state, including acidic FGF, induce hepatic functions. Palmate cells show none of these properties. However, they can differentiate along the hepatic cell lineage, giving rise to: (a) epithelial cells that express hepatic transcription factors and are competent to express hepatic functions; (b) bile duct-like structures in three-dimensional Matrigel cultures. Derivation of epithelial from palmate cells is confirmed by characterization of the progeny of individually fished cells. Furthermore, karyotype analysis confirms the direction of the phenotypic transition: palmate cells are diploid and the epithelial cells are hypotetraploid. The clonal isolation of the palmate cell, an immortalized nontransformed bipotential cell that does not yet express the liver-enriched transcription factors and is a precursor of the epithelial-hepatocyte in MMH lines, provides a new tool for the study of mechanisms controlling liver development.

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Immunofluores- cence analysis of expression  of epithelial and stage-specific markers of the hepatic  cell lineage (CKs 8, 18, and  19). Phase-contrast micrographs and immunofluorescence staining of the E14 epithelial and palmate clones  for the expression and localization of E-cadherin (E-cad.)  and ZO-1, and of the three  CKs 8, 18, and 19. (The cytokeratin antibodies were  used on liver sections as a  control where they showed  the expected staining patterns: CK 8 and 18 on hepatocytes, and CK 19 primarily  on bile ducts). For the epithelial clone the E-cad. staining and the phase-contrast  image are of the same field;  for the palmate clone the  CK 8 field corresponds to the  phase-contrast image. Bar,  20 μm.
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Figure 2: Immunofluores- cence analysis of expression of epithelial and stage-specific markers of the hepatic cell lineage (CKs 8, 18, and 19). Phase-contrast micrographs and immunofluorescence staining of the E14 epithelial and palmate clones for the expression and localization of E-cadherin (E-cad.) and ZO-1, and of the three CKs 8, 18, and 19. (The cytokeratin antibodies were used on liver sections as a control where they showed the expected staining patterns: CK 8 and 18 on hepatocytes, and CK 19 primarily on bile ducts). For the epithelial clone the E-cad. staining and the phase-contrast image are of the same field; for the palmate clone the CK 8 field corresponds to the phase-contrast image. Bar, 20 μm.

Mentions: To explore possible differences in proteins that are implicated in defining cell morphology, immunofluorescence analysis was carried out to explore the localization and expression of several markers of differentiated epithelial cells in both epithelial and palmate clones. As shown in Fig. 2, in the epithelial cells there is strong expression of membrane-bound E-cadherin, an epithelium-specific adhesion molecule. ZO-1 is clearly visible as a fine network on the membrane areas of cell–cell contact. The palmate cells, as expected from their dispersed growth habit, show only weak and diffuse staining for E-cadherin and for the epithelial-polarity marker ZO-1. Interestingly, monoclonal antibodies directed against CK 8, CK 18, and CK 19, stage-specific markers of the hepatic cell lineage, reveal a difference in organization of the filaments in the two classes of clones, the epithelial cells showing weak staining of a dense network of filaments surrounding the nucleus, and the palmate cells' intense staining of a loosely organized network (Fig. 2).


Identification of a bipotential precursor cell in hepatic cell lines derived from transgenic mice expressing cyto-Met in the liver.

Spagnoli FM, Amicone L, Tripodi M, Weiss MC - J. Cell Biol. (1998)

Immunofluores- cence analysis of expression  of epithelial and stage-specific markers of the hepatic  cell lineage (CKs 8, 18, and  19). Phase-contrast micrographs and immunofluorescence staining of the E14 epithelial and palmate clones  for the expression and localization of E-cadherin (E-cad.)  and ZO-1, and of the three  CKs 8, 18, and 19. (The cytokeratin antibodies were  used on liver sections as a  control where they showed  the expected staining patterns: CK 8 and 18 on hepatocytes, and CK 19 primarily  on bile ducts). For the epithelial clone the E-cad. staining and the phase-contrast  image are of the same field;  for the palmate clone the  CK 8 field corresponds to the  phase-contrast image. Bar,  20 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2132947&req=5

Figure 2: Immunofluores- cence analysis of expression of epithelial and stage-specific markers of the hepatic cell lineage (CKs 8, 18, and 19). Phase-contrast micrographs and immunofluorescence staining of the E14 epithelial and palmate clones for the expression and localization of E-cadherin (E-cad.) and ZO-1, and of the three CKs 8, 18, and 19. (The cytokeratin antibodies were used on liver sections as a control where they showed the expected staining patterns: CK 8 and 18 on hepatocytes, and CK 19 primarily on bile ducts). For the epithelial clone the E-cad. staining and the phase-contrast image are of the same field; for the palmate clone the CK 8 field corresponds to the phase-contrast image. Bar, 20 μm.
Mentions: To explore possible differences in proteins that are implicated in defining cell morphology, immunofluorescence analysis was carried out to explore the localization and expression of several markers of differentiated epithelial cells in both epithelial and palmate clones. As shown in Fig. 2, in the epithelial cells there is strong expression of membrane-bound E-cadherin, an epithelium-specific adhesion molecule. ZO-1 is clearly visible as a fine network on the membrane areas of cell–cell contact. The palmate cells, as expected from their dispersed growth habit, show only weak and diffuse staining for E-cadherin and for the epithelial-polarity marker ZO-1. Interestingly, monoclonal antibodies directed against CK 8, CK 18, and CK 19, stage-specific markers of the hepatic cell lineage, reveal a difference in organization of the filaments in the two classes of clones, the epithelial cells showing weak staining of a dense network of filaments surrounding the nucleus, and the palmate cells' intense staining of a loosely organized network (Fig. 2).

Bottom Line: Palmate cells show none of these properties.Derivation of epithelial from palmate cells is confirmed by characterization of the progeny of individually fished cells.The clonal isolation of the palmate cell, an immortalized nontransformed bipotential cell that does not yet express the liver-enriched transcription factors and is a precursor of the epithelial-hepatocyte in MMH lines, provides a new tool for the study of mechanisms controlling liver development.

View Article: PubMed Central - PubMed

Affiliation: Unité de Génétique de la Différenciation, URA 1773 du Centre National de la Recherche Scientifique, Institut Pasteur, 75724 Paris Cedex 15, France.

ABSTRACT
Met murine hepatocyte (MMH) lines were established from livers of transgenic mice expressing constitutively active human Met. These lines harbor two cell types: epithelial cells resembling the parental populations and flattened cells with multiple projections and a dispersed growth habit that are designated palmate. Epithelial cells express the liver-enriched transcription factors HNF4 and HNF1alpha, and proteins associated with epithelial cell differentiation. Treatments that modulate their differentiation state, including acidic FGF, induce hepatic functions. Palmate cells show none of these properties. However, they can differentiate along the hepatic cell lineage, giving rise to: (a) epithelial cells that express hepatic transcription factors and are competent to express hepatic functions; (b) bile duct-like structures in three-dimensional Matrigel cultures. Derivation of epithelial from palmate cells is confirmed by characterization of the progeny of individually fished cells. Furthermore, karyotype analysis confirms the direction of the phenotypic transition: palmate cells are diploid and the epithelial cells are hypotetraploid. The clonal isolation of the palmate cell, an immortalized nontransformed bipotential cell that does not yet express the liver-enriched transcription factors and is a precursor of the epithelial-hepatocyte in MMH lines, provides a new tool for the study of mechanisms controlling liver development.

Show MeSH