Furin-independent Pathway of Membrane Type 1-Matrix Metalloproteinase Activation in Rabbit Dermal Fibroblasts

Abstract

We investigated the gene expression and intracellular activity of processing protease furin and its involvement in the process of membrane type 1-matrix metalloproteinase (MT1-MMP) activation in rabbit dermal fibroblasts. When the rabbit fibroblasts were treated with concanavalin A (ConA), pro-MMP-2 was converted to an active 62-kDa MMP-2 through the appearance of a 64-kDa intermediate MMP-2. The ConA-induced pro-MMP-2 activation resulted from increasing the gene expression and production of MT1-MMP in the rabbit fibroblasts. Reverse transcriptase-polymerase chain reaction demonstrated that in rabbit dermal fibroblasts furin mRNA was detected and, unlike MT1-MMP, was not increased by ConA. These findings are further supported by the fact that the intracellular furin activity also was constitutively detected and was unchanged by the ConA treatment. Very similar phenomena were also observed in human uterine cervical fibroblasts, which are known to produce MT1-MMP by ConA stimulation. These results suggest that the expression of the furin gene and the intracellular activity are not regulated by ConA. On the other hand, neither a synthetic furin inhibitor, decanoyl-RVKR-CH 2 Cl (25-100 M) nor a furin antisense oligonucleotide (40 M) inhibited the MT1-MMP-mediated pro-MMP-2 activation in ConA-treated rabbit dermal fibroblasts, whereas these compounds interfered with pro-MMP-2 activation in ConA-treated human uterine cervical fibroblasts. Nonetheless, the furin antisense oligonucleotide completely suppressed furin gene expression in both rabbit and human fibroblasts. These results suggest that furin does not participate in the process of MT1-MMP activation induced by ConA in rabbit dermal fibroblasts.

Processing of Integrin αv Subunit by Membrane Type 1 Matrix Metalloproteinase Stimulates Migration of Breast Carcinoma Cells on Vitronectin and Enhances Tyrosine Phosphorylation of Focal Adhesion Kinase

“…To attenuate the effects of MT1-MMP on pro-␣ v , we inhibited the furin pathway of pro-␣ v maturation by incubating glioma and breast carcinoma cells with 100 M dec-RVKR-cmk, a furin inhibitor (44,45). Consistent with our previous report (41), activation of MT1-MMP is not affected by inhibition of furin in breast carcinoma and glioma cells.…”

Furin regulates the intracellular activation and the uptake rate of cell surface-associated MT1-MMP

“…There is evidence that a portion of the cellular MT1-MMP pool is processed by additional PCs and also by autocatalysis directly at the cell surface (Sato et al, 1999;Yana and Weiss, 2000;Rozanov and Strongin, 2003;Deryugina et al, 2004). Inhibition of MT1-MMP activation by furin inhibitors, including a nanomolar range a1-anti-trypsin variant Portland (PDX) inhibitor repressed motility and tumorigenicity of cancer cells (Bassi et al, 2001).…”

Role for Furin in Tumor Necrosis Factor Alpha-Induced Activation of the Matrix Metalloproteinase/Sphingolipid Mitogenic Pathway

“…Activation of pro-MMP2 takes place at the cell surface and involves interactions with active MT1-MMP, which is itself activated through rapid trafficking to the cell surface and proteolytic processing (34,48). MT1-MMP is cleaved at a 108 RRKR cleavage site of its prodomain sequence by proprotein convertases such as furin (42,44). Furin is a Golgi-associated serine proteinase which is synthesized as an inactive enzyme whose activation is spatially and temporally regulated through a multistep autocatalytic pro-cessing of the N-terminal prosegment occurring in the endoplasmic reticulum (ER) and in the acidic trans-Golgi network (TGN) (58).…”