title: Epithelial vs myofibroblast differentiation in immortal rat lung cell lines--modulating effects of bleomycin.
abstract: Two alveolar epithelial cell lines R3/1 and L2 were screened by immunocytochemical and RT-PCR analysis of epithelial and mesenchymal/contractile marker proteins. R3/1 and L2 cells were tested for their sensitivity to bleomycin (BLM), an anticancer drug, which is proposed to induce changes in lung cell differentiation. Both epithelial cell lines exhibited a mixed phenotype consisting of epithelial (E-cadherin, aquaporin-5 and cytokeratin 8) and myofibroblast-like (vimentin, alpha-SMA and caveolin-3) properties suggesting that the cell lines are arrested in vitro at a certain developmental stage during epithelial-mesenchymal transition (EMT). BLM treatment of R3/1 cells resulted in a partial reversal of this process modifying the cells in an epithelial direction, e.g., upregulation of E-cadherin, aquaporin-5 and other lung epithelial antigens at the mRNA and protein level. L2 cells showed similar alterations following BLM exposure.Immunohistochemical investigation of lung tissue from two different animal models of BLM-induced fibrosis (mouse and rat), revealed no signs of EMT, e.g., myofibroblastic differentiation of alveolar epithelial cells in situ. Immunohistological analysis of tissue samples of the rat model showed a heterogeneous population of myofibroblasts (alpha-SMA+/caveolin-3+, alpha-SMA-/caveolin-3+, and alpha-SMA+/caveolin-3-). These results suggest that BLM, on one hand, induces fibrosis and on the other hand possibly suppresses EMT during fibrogenesis.
authors.affiliation: Institute of Anatomy, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Fiedlerstr. 42, 01307, Dresden, Germany. Kathrin.Barth@mailbox.tu-dresden.de
authors.forename: K
authors.initials: K
authors.lastname: Barth
authors.forename: J
authors.initials: J
authors.lastname: Reh
authors.forename: A
authors.initials: A
authors.lastname: Sturrock
authors.forename: M
authors.initials: M
authors.lastname: Kasper
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D023421:Models, Animal; D010641:Phenotype; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000473:pathology; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship
chemical_list: D001761:Bleomycin