Regulation of Human Interstitial Collagenase (Matrix Metalloproteinase‐1) Promoter Activity by Fibroblast Growth Factor

Abstract

Basic fibroblast growth factor (bFGF) is a pleiotropic factor that is implicated in tissue remodeling. The growth factor is capable of up-regulating the expression of the interstitial collagenase (matrix metalloproteinase-1 or MMP-1) gene. In this study, the full-length human MMP-1 promoter, spanning 4.3 kb, was sequenced and the regulatory control of its activity by bFGF was examined in NIH3T3 fibroblasts. Several regulatory sequences, including five activator protein-1 (AP-l), five activator protein-2 (AP-2), five glucocorticoid-response elements and multiple ets/polyoma enhancer-binding 3 elements, were identified. Deletion constructs were prepared and transiently transfected into fibroblast cultures incubated with and without bFGF. The results showed that bFGF enhanced the activity of the deletion promoter fragments and the full-length MMP-1 promoter by sixfold or more in the cell cultures. Stimulation of the MMP-1 promoter activity by bFGF was reflected in substantial increase of the collagenase mRNA levels. A bFGF-responsive element appeared to be the AP-1 consensus sequence. Mutation of the first AP-1 site resulted in major reduction of the basal level of the MMP-1 promoter activity, supporting the notion that the AP-1 consensus sequence is essential for the constitutive expression of the MMP-1 gene. Furthermore, bFGF induction of the activity of the promoter constructs containing a mutant AP-1 site was essentially absent, suggesting that the regulatory element is necessary for the induction of the promoter activity by the growth factor. Thus, bFGF up-regulates MMP-1 gene expression in NIH3T3 fibroblasts via induction of its promoter activity that is dependent on an AP-1 consensus sequence.Keywords: basic fibroblast-growth factor; interstitial collagenase; promoter activity ; activator protein-1.Degradation of collagen is an integral aspect of tissue remodeling which occurs in pathologic and physiologic conditions, such as wound repair, angiogenesis, and embryonic development. At the cellular level, dissolution of collagen in the extracellular matrix is thought to facilitate cellular migration [l]. Various cytokines, growth factors, inflammatory mediators, and phorbol esters have been shown to stimulate enzymatic degradation of collagen [2, 31.The major matrix metalloproteinase that is involved in the degradation of collagens, specifically types I, 11, 111, V, VII, and X collagens, is the interstitial collagenase, known as MMP-1 [2, 31. Many cell types, such as keratinocytes, fibroblasts, monocytes/macrophages, chondrocytes, as well as vascular endothelial and smooth muscle cells secrete MMP-1. The activity of MMP-1 is stringently regulated, either at the promoter level, or The induction of the MMP-1 gene expression via stimulation of its promoter activity involves transcription factors. Activator protein, known more commonly as AP-1, is a well-characterized dimeric complex composed of products encoded by the fos and jun proto-oncogenes. AP-1 regulates expression of the stromelysin and collagenase genes [...

p53 Down-regulates Human Matrix Metalloproteinase-1 (Collagenase-1) Gene Expression

“…Because etoposide induces both AP-1 and NFb (52), two positive regulators of hMMP-1 expression, it is not surprising to see hMMP-1 induction by etoposide in Saos-2 cells. Lack of hMMP-1 induction by etoposide in U2-OS cells, however, implies that etoposide-activated p53 executes a suppressive activity, thus diminishing the Ap-1/NFb effect (11,13,15,16).…”

“…Because etoposide induces both AP-1 and NFb (52), two positive regulators of hMMP-1 expression, it is not surprising to see hMMP-1 induction by etoposide in Saos-2 cells. Lack of hMMP-1 induction by etoposide in U2-OS cells, however, implies that etoposide-activated p53 executes a suppressive activity, thus diminishing the Ap-1/NFb effect (11,13,15,16).During the preparation of this manuscript, Aupperle et al (53) reported that the growth rate, invasiveness, and resistance to apoptosis induced by reactive oxygen species in rheumatoid and normal fibroblast-like synoviacyte increased significantly after endogenous p53 protein was inactivated with virus 18 E6 protein. However, no effect on collagenase mRNA accumulation was observed.…”

“…The activity of MMP-1 is stringently regulated at three levels: the promoter, the activation of proenzyme, and the inhibition of active enzyme. The activator protein-1 (AP-1) binding sites found in the promoters of human collagenase have been shown to be critical to the expression of human collagenase (13)(14)(15)(16).…”

Transcriptional regulation of the human bone sialoprotein gene by fibroblast growth factor 2

“…AP1 mediates signaling of the FGF, but not activin, receptor during mesoderm induction, and AP1/Jun is a key signaling molecule in the development of posterior structure (45). FGF2 increases the transcription of matrix metalloproteinase 1 in NIH3T3 fibroblasts via AP1 (46), and induces binding of nuclear proteins from osteoblast-like ROS17/2.8 cells to consensus AP1 (10). These findings indicate that AP1 may be a crucial response element for FGF2-induced transcription.…”

Transforming growth factor-α activates pancreatic stellate cells and may be involved in matrix metalloproteinase-1 upregulation

“…The pcDNA3.1 vector containing a 2.2-kb fragment of the MMP-1 promoter (derived from pCLCAT3 (ref. 19))/luciferase construct (derived from pGL3) and pRL-SV40 plasmid were used for measuring MMP-1 promoter activity in this study.…”