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Plasmin activates pro-matrix metalloproteinase-2 with a membrane-type 1 matrix metalloproteinase-dependent mechanism
Sara Monea1, Kaisa Lehti, Jorma Keski-Oja
1Department of Surgery, S.A. Localio Laboratory for General Surgery Research, New York, New York, USA.
Abstract:
Membrane-type 1 matrix metalloproteinase (MT1-MMP) has been implicated as a physiological activator of progelatinase A (MMP-2). We previously reported that plasmin treatment of cells results in proMMP-2 activation and increased type IV collagen degradation. Here, we analyzed the role of MT1-MMP in plasmin activation of MMP-2 using HT-1080 cells transfected with MT1-MMP sense or antisense cDNA. Control, vector-transfected cells that expressed endogenous MT1-MMP, and antisense cDNA transfectants with very low levels of MT1-MMP did not activate proMMP-2. Conversely, cells transfected with sense MT1-MMP cDNA expressed high MT1-MMP levels and processed proMMP-2 to 68/66-kDa intermediate activation products. Control cells and MT1-MMP transfectants had much higher levels of cell-associated MMP-2 than antisense cDNA transfectants. Addition of plasmin(ogen) to control or MT1-MMP-transfected cells generated active, 62-kDa MMP-2, but was ineffective with antisense cDNA transfectants. The effect of plasmin(ogen) was prevented by inhibitors of plasmin, but not by metalloproteinase inhibitors, implicating plasmin as a mechanism for proMMP-2 activation independent of the activity of MT1-MMP or other MMPs. Plasmin-mediated activation of proMMP-2 did not result from processing of proMT1-MMP and did not correlate with alpha(v)beta(3) integrin or TIMP-2 levels. Thus, plasmin can activate proMMP-2 only in the presence of MT1-MMP; however, this process does not require the catalytic activity of MT1-MMP.
Insights
Membrane-type 1 matrix metalloproteinase (MT1-MMP) is crucial for plasmin-mediated activation of progelatinase A (MMP-2). This activation requires MT1-MMP but not its catalytic activity, highlighting a novel role for MT1-MMP in MMP-2 processing.
Area of Science:
- Biochemistry
- Cell Biology
- Enzymology
Background:
- Membrane-type 1 matrix metalloproteinase (MT1-MMP) is known to activate progelatinase A (MMP-2).
- Plasmin treatment of cells previously shown to activate proMMP-2 and degrade type IV collagen.
Purpose of the Study:
- To investigate the specific role of MT1-MMP in plasmin-induced MMP-2 activation.
- To elucidate the mechanism by which plasmin activates proMMP-2 in the presence of MT1-MMP.
Main Methods:
- Utilized HT-1080 cells transfected with MT1-MMP sense or antisense cDNA.
- Assessed proMMP-2 activation and MMP-2 levels under various conditions, including plasmin(ogen) treatment and inhibition.
- Quantified MT1-MMP, alpha(v)beta(3) integrin, and TIMP-2 levels.
Main Results:
- Cells expressing high MT1-MMP (sense cDNA) processed proMMP-2, while those with low MT1-MMP (antisense cDNA) did not.
- Plasmin(ogen) effectively activated proMMP-2 in control and MT1-MMP-transfected cells, but not in antisense transfectants.
- Plasmin-mediated activation was inhibited by plasmin inhibitors, not metalloproteinase inhibitors, and did not require MT1-MMP catalytic activity.
Conclusions:
- Plasmin is a key enzyme for proMMP-2 activation, and its activity is dependent on the presence of MT1-MMP.
- MT1-MMP facilitates plasmin-mediated MMP-2 activation independently of its catalytic function.
- This suggests a non-catalytic role for MT1-MMP in regulating MMP-2 activity, potentially impacting extracellular matrix degradation.