title: Cell position-dependent reciprocal feedback regulation of type I collagen gene expression in cultured human skin fibroblasts.
abstract: In order to investigate possible cell positional effects on the gene expression of human dermal fibroblasts, the authors cultured the cells on non-coated polystyrene culture dishes, type I collagen-coated dishes, or collagen gels formed by type I collagen, or suspended them in type I collagen gels and measured collagen synthesis by the cells. The production rate of type I collagen was similar whether cells were cultured on non-coated polystyrene or on type I collagen-coated dishes, but it was suppressed significantly when the cells were placed within the collagen gel matrix. Time-dependent expression of genes for alpha 1 (I) and alpha 2 (I) collagen chains was measured by Northern blot analysis. A significant increase in mRNA levels for these chains was observed when the cells were cultured for three days on type I collagen-coated dishes or on collagen gels. On the other hand, a significant decrease in the mRNA levels was observed after 2 days and later, when the cells were cultured within type I collagen gel matrix. These results indicate that human dermal fibroblasts recognize their position on or in type I collagen (extracellular matrix) and respond by changing their expression patterns of type I collagen chain genes. The results of the kinetics of gene expression also suggest that upregulation and downregulation of type I collagen genes are controlled by different mechanisms.
authors.affiliation: Department of Molecular Pathogenesis, Tokyo Medical and Dental University, Japan. r.hata.tis@mri1.mri.tmd.ac.jp
authors.forename: R
authors.initials: R
authors.lastname: Hata
authors.forename: J
authors.initials: J
authors.lastname: Akai
authors.forename: A
authors.initials: A
authors.lastname: Kimura
mesh_terms: D015152:Blotting, Northern; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D005246:Feedback; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D011137:Polystyrenes; D011392:Proline / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000378:metabolism*