ISSN:
1573-0778
Keywords:
α-smooth-muscle actin
;
β-actin
;
fibrosis myofibroblast
;
ionizing radiation
;
skin
;
three dimensional culture model
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract To characterize the differences between fibrotic myofibroblasts and normal fibroblasts, we studied two differentiation markers: α-smooth muscle (SM) actin, a specific marker of myofibroblast differentiation, and β-actin, which is overexpressed in the fibrotic tissue. Experiments were performed on fibroblasts isolated from normal pig skin and on subcutaneous myofibroblasts isolated from pig radiation-induced fibrosis. Three culture models were used: cells in monolayers, equivalent dermis, consisting of fibroblasts embedded into a matrix composed of type I collagen, and in vitro reconstituted skin, in which the matrix and containing life fibroblasts were overlaid with keratinocytes. Samples were studied using immunofluorescence and western-blotting. In monolayers cultures, both fibrosis and normal cells expressed α-SM actin. Furthermore, similar amounts of β-actin protein were found. In these conditions, the resulting alterations in the phenotypes of cells made comparison of cultured fibrotic and normal cells irrelevant. Under the two 3-D culture models, normal fibroblasts no longer expressed α-SM actin. They expressed β-actin at the basal level. Moreover, the fibrotic myofibroblasts in both 3-D models retained their differentiation features, expressing α-SM actin and overexpressing β-actin. We found that this normalization was mainly related to the genomic programmation acquired by the cells in the tissue. Cellular motility and microenvironment were also involved, whereas cellular proliferation was not a major factor. Consequently, both three-dimensional models allowed the study of radiation-induced fibrosis in vitro, provided good extrapolations to in vivo conditions and avoided certain of culture artefacts.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007992824966
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