title: Negative regulation of hepatocyte growth factor gene expression in human lung fibroblasts and leukemic cells by transforming growth factor-beta 1 and glucocorticoids.
abstract: Hepatocyte growth factor (HGF), a mesenchymal-derived factor which regulates growth, motility, and morphogenesis of epithelial and endothelial cells, functions as a hepatotrophic and renotrophic factor for regeneration of the liver and kidney. We have now obtained evidence that transforming growth factor-beta 1 (TGF-beta 1) and glucocorticoids are negative regulators for HGF gene expression. When TGF-beta 1 or dexamethasone was added to cultures of MRC-5 human embryonic lung fibroblasts and HL-60 human promyelocytic leukemic cells, the amount of HGF secreted into the culture medium was inhibited to 30-40% of that of control cultures by 10 ng/ml TGF-beta 1 and to 40-50% by 10(-6) M dexamethasone. The inhibitory effect of TGF-beta 1 and dexamethasone on HGF synthesis in MRC-5 cells was additive, thereby suggesting that TGF-beta 1 and dexamethasone exert effects through distinct mechanisms. Hydrocortisone also inhibited HGF synthesis with the same potency as dexamethasone; however, testosterone, estriol, and beta-estradiol had no effect. The rate of HGF synthesis in MRC-5 cells, as measured by pulse labeling with [35S]methionine and subsequent immunoprecipitation, was suppressed to 30-40% of the control with 10 ng/ml TGF-beta 1, and to 30-45% by 10(-6) M dexamethasone. HGF mRNA levels in MRC-5 cells and HL-60 cells were dose-dependently suppressed by TGF-beta 1 and dexamethasone; 10 ng/ml TGF-beta 1 suppressed HGF mRNA levels to 32% and 35% of control culture, respectively, in MRC-5 cells and HL-60 cells, and 10(-6) M dexamethasone suppressed to 43% and 38%, respectively. Thus, TGF-beta 1 and glucocorticoids seem to inhibit HGF synthesis by suppressing the expression of the HGF gene. We propose that a negative regulation of HGF gene expression by TGF-beta 1 or glucocorticoids may be involved in physiological or pathological processes during tissue regeneration.
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: H
authors.initials: H
authors.lastname: Tajima
authors.forename: H
authors.initials: H
authors.lastname: Okazaki
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D016466:CHO Cells; D002117:Calcitriol / Q000494:pharmacology; D002460:Cell Line; D006224:Cricetinae; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology; D004964:Estriol / Q000494:pharmacology; D005347:Fibroblasts; D005786:Gene Expression Regulation / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005938:Glucocorticoids / Q000494:pharmacology*; D017228:Hepatocyte Growth Factor / Q000235:genetics*; D006854:Hydrocortisone / Q000494:pharmacology; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D008168:Lung; D011239:Prednisolone / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000494:pharmacology; D013739:Testosterone / Q000494:pharmacology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D005938:Glucocorticoids; D012333:RNA, Messenger; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D013739:Testosterone; D004958:Estradiol; D017228:Hepatocyte Growth Factor; D003907:Dexamethasone; D011239:Prednisolone; D004964:Estriol; D002117:Calcitriol; D006854:Hydrocortisone