Leukoregulin, a T-cell derived cytokine, upregulates stromelysin-1 gene expression in human dermal fibroblasts: evidence for the role of AP-1 in transcriptional activation.
Leukoregulin (LR), a product of activated T-cells, has been recently shown to modulate the metabolism of extracellular matrix components in human skin fibroblast cultures (Mauviel et al., J Cell Biol 113:1455-1462, 1991). In this study we focused our attention on the effects of LR on the expression of stromelysin-1 gene. This matrix metalloprotease has a broad spectrum of degradative activity and it is also required for maximal activation of interstitial collagenase. Incubation of skin fibroblast cultures with LR resulted in a dose- and time-dependent elevation of stromelysin-1 mRNA levels, the maximum enhancement being up to approximately sevenfold. This effect was abolished by cycloheximide, suggesting a requirement for ongoing protein synthesis. Transient cell transfections with a promoter/reporter gene construct containing 1.3 kb of 5' flanking DNA of the human stromelysin-1 gene linked to the chloramphenicol acetyl transferase (CAT) gene, indicated enhancement of promoter activity by LR. This enhancement was abolished by a single base substitution in the AP-1 binding site of the promoter. Furthermore, gel mobility shift assays demonstrated enhanced AP-1 binding activity in nuclear extracts from cells incubated with LR. However, LR did not alter the activity of a construct containing three AP-1 sequences in front of the thymidine kinase promoter linked to the CAT gene. These results collectively suggest that activation of stromelysin-1 gene expression by LR is mediated by AP-1 regulatory elements which are necessary, but not sufficient, for gene response.
Mauviel
A
A
Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Kähäri
V M
VM
Kurkinen
M
M
Evans
C H
CH
Uitto
J
J
D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D008222:Lymphokines / Q000494:pharmacology*; D019278:Matrix Metalloproteinase 3; D008666:Metalloendopeptidases / Q000235:genetics*; D008969:Molecular Sequence Data; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics; D012867:Skin / Q000187:drug effects / Q000201:enzymology*; D014158:Transcription, Genetic; D014162:Transfection; D015854:Up-Regulation
D008222:Lymphokines; D016755:Proto-Oncogene Proteins c-jun; C044162:leukoregulin; D015500:Chloramphenicol O-Acetyltransferase; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3