Premium
Induction of MMP‐1 (collagenase‐1) by relaxin in fibrocartilaginous cells requires both the AP‐1 and PEA‐3 promoter sites
Author(s) -
Kapila S,
Xie Y,
Wang W
Publication year - 2009
Publication title -
orthodontics and craniofacial research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 55
eISSN - 1601-6343
pISSN - 1601-6335
DOI - 10.1111/j.1601-6343.2009.01451.x
Subject(s) - relaxin , microbiology and biotechnology , promoter , transfection , collagenase , reporter gene , transcription (linguistics) , biology , chloramphenicol acetyltransferase , chemistry , gene , gene expression , hormone , biochemistry , enzyme , linguistics , philosophy
Structured Abstract Authors – Kapila S, Xie Y, Wang W Objectives – Relaxin induces the matrix metalloproteinase MMP‐1 (collagenase‐1) in TMJ fibrocartilaginous cells, and this response is potentiated by β‐estradiol. We identified the MMP‐1 promoter sites and transcription factors that are induced by relaxin with or without β‐estradiol in fibrocartilaginous cells. Material and Methods – Early passage cells were transiently transfected with the pBLCAT2 plasmid containing specific segments of the human MMP‐1 promoter regulating the chloramphenicol acyl transferase (CAT) gene and co‐transfected with a plasmid containing the β‐galactosidase gene. The cells were cultured in serum‐free medium alone or medium containing 0.1 ng/ml relaxin, or 20 ng/ml β‐estradiol or both hormones, and lysates assayed for CAT and β‐galactosidase activity. Results – Cells transfected with the −1200/−42 or −139/−42 bp MMP‐1 promoter‐reporter constructs showed 1.5‐fold and 3‐fold induction of CAT by relaxin in the absence or presence of β‐estradiol, respectively. Relaxin failed to induce CAT in the absence of the −137/−69 region of the MMP‐1 promoter, which contains the AP‐1‐and PEA3‐binding sites. Using wild type or mutated minimal AP‐1 and PEA‐3 promoters we found that both these promoter sites are essential for the induction of MMP‐1 by relaxin. The mRNAs for transcription factors c‐fos and c‐jun, which together form the AP‐1 heterodimer, and Ets‐1 that modulates the PEA‐3 site, were upregulated by relaxin or β‐estradiol plus relaxin. Conclusion – These studies show that both the AP‐1 and PEA‐3 promoter sites are necessary for the induction of MMP‐1 by relaxin in fibrocartilaginous cells.