Dexamethasone-induced changes in morphology and keratin organization of rat thymic epithelial cells in primary culture.
Dexamethasone (DM)-induced changes in morphology and keratin organization of rat thymic epithelial cells (TECs) in primary culture were studied. The morphology and keratin organization of TECs were greatly altered by the addition of more than 10 nM DM. In control cultures, small slender cells were predominant and grew faster than cells of other types. Most of them had keratin bundles on day 3, but lost the bundles on day 7. In experimental cultures containing more than 10 nM DM, the morphology of TECs altered to a polygonal form and the TECs formed colonies. They had fine interlacing bundles of keratin filaments all over the cytoplasm, and the bundles were maintained or increased in number with the day of culture. Keratin proteins in TECs treated with 100 nM DM for 7 days were 2-fold for 46 500 D, 4-fold for 49 000 D, 1.7-fold for 52 000 D and 3.5-fold for 55 500 D keratins to those in control TECs, respectively. Growth of TECs was inhibited by the addition of more than 10 nM DM. The effects of DM were reversible to some extent, for the morphology and keratin organization of TECs gradually changed into the control type by the removal of DM. These results suggested that DM greatly involved the growth and differentiation of rat TECs.
A
A
Masuda
Y
Y
Nishimoto
T
T
Morita
M
M
Matsuyama
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D003593:Cytoplasm / Q000032:analysis; D003907:Dexamethasone / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D007633:Keratins / Q000032:analysis*; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects; D014746:Vimentin / Q000032:analysis
D014746:Vimentin; D007633:Keratins; D003907:Dexamethasone