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Matrix metalloproteinases cleave tissue factor pathway inhibitor. Effects on coagulation
1Departments of Pediatrics, Medicine, and Cell Biology and Physiology, Washington University School of Medicine, St. Louis Children's Hospital and Barnes-Jewish Hospital, St. Louis, Missouri 63110, USA. belaaouaja@msnotes.wustl.edu
Abstract:
The capacity of inflammatory cell-derived matrix metalloproteinases (MMPs) to cleave tissue factor pathway inhibitor (TFPI) and alter its activity was investigated. MMP-7 (matrilysin) rapidly cleaved TFPI to a major 35-kDa product. In contrast, MMP-1 (collagenase-1), MMP-9 (gelatinase B), and MMP-12 (macrophage elastase) cleaved TFPI into several fragments including the 35-kDa band. However, rates of cleavage were most rapid for MMP-7 and MMP-9. NH(2)-terminal amino acid sequencing revealed that MMP-12 cleaved TFPI at Lys(20)-Leu(21)(close to Kunitz I domain and producing a 35-kDa band), Arg(83)-Ile(84) (between Kunitz I and II domains), and Ser(174)-Thr(175) (between Kunitz II and III domains). MMP-7 and MMP-9 cleaved TFPI at Lys(20)-Leu(21) with additional COOH-terminal processing. These MMPs did not cleave tissue factor (TF), factor VII, and factor Xa. Proteolytic cleavage by MMP-1, MMP-7, MMP-9, and MMP-12 resulted in considerable loss of TFPI activity. These observations indicate specific cleavage of TFPI by MMPs, which broadens their substrate profile. Co-localization of MMPs, TF, and TFPI in atherosclerotic tissues suggests that release of MMPs from inflammatory cell leukocytes may effect TF-mediated coagulation.
Insights
Matrix metalloproteinases (MMPs) from inflammatory cells cleave tissue factor pathway inhibitor (TFPI), reducing its activity. Specific MMPs like MMP-7 and MMP-9 rapidly degrade TFPI, impacting coagulation pathways.
Area of Science:
- Biochemistry
- Molecular Biology
- Immunology
Background:
- Matrix metalloproteinases (MMPs) are enzymes involved in tissue remodeling and inflammation.
- Tissue factor pathway inhibitor (TFPI) is a key regulator of the coagulation cascade.
- The interaction between MMPs and TFPI is not fully understood.
Purpose of the Study:
- To investigate the capacity of inflammatory cell-derived MMPs to cleave TFPI.
- To determine the effect of MMP-mediated cleavage on TFPI activity.
- To explore the implications of these interactions in atherosclerotic diseases.
Main Methods:
- In vitro cleavage assays using purified MMPs (MMP-1, MMP-7, MMP-9, MMP-12) and TFPI.
- Analysis of cleavage products using NH(2)-terminal amino acid sequencing.
- Assessment of TFPI activity following proteolytic cleavage.
Main Results:
- MMP-7 and MMP-9 rapidly cleaved TFPI, primarily generating a 35-kDa product.
- MMP-1, MMP-9, and MMP-12 also cleaved TFPI into multiple fragments.
- Cleavage sites were identified, particularly near the Kunitz domains.
- Proteolytic cleavage by these MMPs significantly reduced TFPI activity.
- MMPs did not cleave key coagulation factors like tissue factor (TF), factor VII, or factor Xa.
Conclusions:
- MMPs specifically cleave TFPI, expanding their known substrate profile.
- MMP-mediated degradation of TFPI leads to a loss of anticoagulant activity.
- The co-localization of MMPs, TF, and TFPI in atherosclerotic lesions suggests a role for MMPs in modulating TF-mediated coagulation in disease.