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Epithelial Lineage (epithelial + lineage)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Timing and sequence of differentiation of embryonic rat hepatocytes along the biliary epithelial lineage

HEPATOLOGY, Issue 3 2003
Robbert G. E. Notenboom
To study the differentiation of hepatocytes along the biliary epithelial lineage in vivo, embryonic day 14 (E14) rat hepatocytes were isolated by differential centrifugation and transplanted as single-cell suspensions into the spleen of adult syngeneic rats. Hepatocytes and cholangiocytes were identified and their maturation characterized by the level of expression of ,-fetoprotein (AFP), glutamate dehydrogenase (GDH), and carbamoyl phosphate synthetase I (CPS); annexin IV, annexin V, cytokeratin 19 (CK-19), and cystic fibrosis transmembrane conductance regulator (CFTR); and electron microscopy. By correlating morphologic changes with the timing in the expression of these markers, we show that the organization of the transplanted E14 hepatocytes into lobular structures is accompanied by the formation and maturation of bile ducts around these developing lobules. Morphologic differentiation of the emerging bile ducts was accompanied by a gradual loss of hepatocyte markers and a gradual acquisition of cholangiocyte markers, with markers identifying a large-cholangiocyte phenotype appearing latest. Once fully differentiated, the intrasplenic liver lobules developed cholestatic features. The accompanying proliferation of bile ducts was due to cholangiocyte proliferation, but ductular transformation of hepatocytes was also observed. In conclusion, (1) bile duct formation at the interface between hepatocytes and connective tissue is an inherent component of liver development and (2) the susceptibility of developing hepatocytes to bile duct-inducing signals is highest in the fetal liver but that (3) this capacity is not irreversibly lost in otherwise mature hepatocytes. [source]

In vitro differentiation of human mesenchymal stem cells to epithelial lineage

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2007
Virgil P, unescu
Abstract Our study examined whether human bone marrow-derived MSCs are able to differentiate, in vitro, into functional epithelial-like cells. MSCs were isolated from the sternum of 8 patients with different hematological disorders. The surface phenotype of these cells was characterized. To induce epithelial differentiation, MSCs were cultured using Epidermal Growth Factor, Keratinocyte Growth Factor, Hepatocyte Growth Factor and Insulin-like growth Factor-II. Differentiated cells were further characterized both morphologically and functionally by their capacity to express markers with specificity for epithelial lineage. The expression of cytokeratin 19 was assessed by immunocytochemistry, and cytokeratin 18 was evaluated by quantitative RT-PCR (Taq-man). The data demonstrate that human MSCs isolated from human bone marrow can differentiate into epithelial-like cells and may thus serve as a cell source for tissue engineering and cell therapy of epithelial tissue. [source]

Transforming Growth Factor-, Induces the Differentiation of Sarcomatoid Cholangiocarcinoma Cells

CANCER SCIENCE, Issue 2 2000
Munechika Enjoji
A sarcomatoid cholangiocarcinoma cell line, ETK-1, was established from a patient. Phenotypically, the cells corresponded to immature biliary epithelial cells. Because a small number of ETK-1 cells appeared to differentiate spontaneously along a biliary epithelial lineage in continuous culture, we examined the factors that initiate and/or promote the differentiation of the cells. Transforming growth factor-, (TGF,) induced significant changes in ETK-1 cells. After stimulation with the factor, ETK-1 cells displayed morphologic transformation at a much higher frequency, with the appearance of many large cells with intracytoplasmic vacuoles, and the production of mucinous substances. These morphologically transformed cells were phenotypically similar to welldifferentiated adenocarcinoma cells. The expression pattern of integrins after TGF, treatment also supported the maturation of the ETK-1 cells. The antibody against the receptor of TGF, inhibited these changes by TGF,. Moreover, the proliferation rate of ETK-1 cells was suppressed by TGF,. Our data suggest that TGF, can act as a differentiation factor along a biliary epithelial lineage. [source]

Redefining epithelial progenitor potential in the developing thymus

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2007
Simona
Abstract Cortical and medullary epithelium represent specialised cell types that play key roles in thymocyte development, including positive and negative selection of the T cell repertoire. While recent evidence shows that these epithelial lineages share a common embryonic origin, the phenotype and possible persistence of such progenitor cells in the thymus at later stages of development remain controversial. Through use of a panel of reagents including the putative progenitor marker Mts24, we set out to redefine the stages in the development of thymic epithelium. In the early embryonic day (E)12 thymus anlagen we find that almost all epithelial cells are uniformly positive for Mts24 expression. In addition, while the thymus at later stages of development was found to contain distinct Mts24+ and Mts24, epithelial subsets, thymus grafting experiments show that both Mts24+ and Mts24, epithelial subsets share the ability to form organised cortical and medullary thymic microenvironments that support T cell development, a function shown previously to be lost in the Mts24, cells by E15 when lower cell doses were used. Our data help to clarify stages in thymic epithelial development and provide important information in relation to currently used markers of epithelial progenitors. See accompanying commentary: http://dx.doi.org/10.1002/eji.200737709 [source]