title: Modulation of collagen gene expression by cytokines: stimulatory effect of transforming growth factor-beta1, with divergent effects of epidermal growth factor and tumor necrosis factor-alpha on collagen type I and collagen type IV.
abstract: Transforming growth factor-beta1 (TGF-beta1) is well recognized as a potent mediator of both fibrillar (collagen type I) and basement membrane (collagen type IV) production. However, tissue injury is characterized by the concomitant expression of many cytokines and/or growth factors in addition to TGF-beta1, and the ultimate extent of extracellular-matrix (ECM) deposition may reflect the interacting effects of TGF-beta1 and these other cytokines and/or growth factors. We, therefore, sought to determine whether other cytokines and/or growth factors, known to be produced after tissue injury, are capable either alone or in combination with TGF-beta1 of modulating collagen gene expression. Collagen type I and collagen type IV gene expression was assessed in NIH-3T3 cells, a murine fibroblast-like cell line that responds to TGF-beta1, with increases in both collagen type I and collagen type IV production. TGF-beta1 coordinately induced production of collagen type IV messenger ribonucleic acid (mRNA) to a level 3.8-fold above its baseline value (p < 0.001) and collagen type I mRNA to a level 2.6-fold above its baseline value (p < 0.001). Of the other cytokines and/or growth factors tested, only epidermal growth factor (EGF) had significant effects on collagen mRNA expression. We report the novel observation that EGF significantly induced collagen type IV mRNA (3.0-fold; p < 0.001) but did not alter collagen type I mRNA expression. Platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and insulin-like growth factor-1 (IGF-1) did not alter the expression of mRNA for collagen type IV or collagen type I. Addition of TGF-beta1 to cytokine- and/or growth factor-treated cells increased both collagen type IV and collagen type I mRNA levels. However, collagen type IV mRNA levels were similar in cultures given TGF-beta1 alone and cultures given TGF-beta1 with other cytokines and/or growth factors; there were no additive, synergistic, or antagonistic effects after coadministration of TGF-beta1 and other cytokines and/or growth factors. With regard to collagen type I mRNA expression, all cytokines and/or growth factors tested, with the exception of TNF-alpha, had no effect on collagen type I mRNA levels in TGF-beta1-treated cultures. Importantly, TNF-alpha antagonized the stimulatory effect of TGF-beta1 on collagen type I mRNA levels. These observations support a dominant role for TGF-beta1 in stimulating coordinate expression of collagen type I and collagen type IV mRNAs by NIH-3T3 cells; EGF and TNF-alpha are capable of inducing divergent expression of the genes for these two types of collagen.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Grande
authors.forename: D C
authors.initials: DC
authors.lastname: Melder
authors.forename: A R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005786:Gene Expression Regulation; D007375:Interleukin-1 / Q000494:pharmacology; D051379:Mice; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013002:Somatomedins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014746:Vimentin / Q000032:analysis
chemical_list: D007375:Interleukin-1; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D013002:Somatomedins; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D014746:Vimentin; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor; D003094:Collagen