title: Regulation of collagen VI expression in fibroblasts. Effects of cell density, cell-matrix interactions, and chemical transformation.
abstract: Collagen VI expression was studied in cultured human skin fibroblasts and mouse 3T3 cells using cDNA probes specific for alpha 1(VI), alpha 2(VI), and alpha 3(VI) chains. A 2-3-fold increase of these mRNAs was observed when fibroblasts were grown at increasing densities while only minimal changes occurred for the mRNA levels of collagens I and III, fibronectin, and beta-actin. Changes in mRNA correlated well with an increased production of corresponding proteins as determined by immunological assays. A comparable increase of alpha 1(VI) and alpha 2(VI) but not of alpha 3(VI) chain mRNAs was found for fibroblasts grown in a three-dimensional collagen gel after gel contraction. These conditions resulted, however, in a decrease of steady-state levels of collagens I and III and actin mRNAs. Transformation of 3T3 cells by phorbol ester did not change collagen VI mRNAs but caused a 3-5-fold reduction in mRNA levels for the other extracellular matrix proteins. These data strongly imply different regulatory mechanisms for the expression of collagen VI compared with collagens I and III and fibronectin. The differences may be correlated to changes in cell shape and reflect the requirement for collagen VI as a cell-binding protein.
authors.affiliation: Dermatologische Klinik der Universität München, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hatamochi
authors.forename: M
authors.initials: M
authors.lastname: Aumailley
authors.forename: C
authors.initials: C
authors.lastname: Mauch
authors.forename: M L
authors.initials: ML
authors.lastname: Chu
authors.forename: R
authors.initials: R
authors.lastname: Timpl
authors.forename: T
authors.initials: T
authors.lastname: Krieg
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D015152:Blotting, Northern; D002452:Cell Count; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D003094:Collagen / Q000235:genetics*; D015342:DNA Probes; D004220:Disulfides; D005353:Fibronectins / Q000235:genetics; D005786:Gene Expression Regulation; D019791:Guanidine; D006146:Guanidines / Q000494:pharmacology; D006801:Humans; D051379:Mice; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000096:biosynthesis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000199:Actins; D015342:DNA Probes; D004220:Disulfides; D005353:Fibronectins; D006146:Guanidines; D012333:RNA, Messenger; D003094:Collagen; D019791:Guanidine; D013755:Tetradecanoylphorbol Acetate