Human tissue factor pathway inhibitor-2 does not bind or inhibit activated matrix metalloproteinase-1

Tissue Factor Pathway Inhibitor-2 Gene Polymorphisms Associate With Coronary Atherosclerosis in Chinese Population

Tissue factor pathway inhibitor-2 (TFPI-2) may play critical roles in the pathogenesis of atherosclerosis. In this study, we aimed to investigate the association between TFPI-2 gene polymorphisms and coronary atherosclerosis.Four hundred and seven patients with coronary atherosclerosis and 306 individuals with normal coronary artery were enrolled in the present study. Nine single-nucleotide polymorphisms (SNPs) (rs3763473, rs59805398, rs60215632, rs59999573, rs59740167, rs34489123, rs4517, rs4264, and rs4271) were detected with polymerase chain reaction-direct sequencing method. Severity of coronary atherosclerosis was assessed by Gensini score. After the baseline investigation, patients with coronary atherosclerosis were followed up for incidence of cardiovascular events (CVEs).Eight SNPs were in accordance with the Hardy-Weinberg equilibrium, and 8 haplotypes were constructed based on rs59999573, rs59740167, and rs34489123 after linkage disequilibrium and haplotype analysis. Two SNPs (rs59805398 and rs34489123) and 5 haplotypes correlated with coronary atherosclerosis even after adjustment by Gensini score. At follow-up (median 53 months, range 1-60 months), 85 patients experienced CVE. However, there was no strong association between the gene polymorphisms and the occurrence of CVE.Tissue factor pathway inhibitor-2 gene polymorphisms were associated with coronary atherosclerosis in the Chinese population, suggesting that the information about TFPI-2 gene polymorphisms was useful for assessing the risk of developing coronary atherosclerosis, but there was not enough evidence showing it could predict occurrence of CVE.

Tissue factor pathway inhibitor-2 is induced by fluid shear stress in vascular smooth muscle cells and affects cell proliferation and survival

OBJECTIVE

Vascular smooth muscle cells (SMCs) are exposed to fluid shear stress (FSS) after interventional procedures such as balloon-angioplasty. Whereas the effects of hemodynamic forces on endothelial cells are explored in detail, the influence of FSS on smooth muscle cell function is poorly characterized. Here, we investigated the effect of FSS on SMC gene expression and function.

METHODS

Laminar FSS of arterial level (14 dynes/cm(2)) was applied to SMC cultures for 24 hours in a parallel-plate flow chamber. The effect of FSS on gene expression was first screened with microarray technology, and results further verified by real time polymerase chain reaction (RT-PCR) and immunoblotting. Tissue factor pathway inhibitor-2 (TFPI-2) and caspase-3 protein expression was studied in the rat carotid artery after balloon-injury, and the effect of TFPI-2 on SMC DNA synthesis and apoptosis was examined in vitro.

RESULTS

Microarrays identified TFPI-2 as one of the most differentially expressed gene by FSS in cultured SMCs (P < .001). Gene set enrichment analysis revealed significant regulation of genes linked to proliferation, apoptosis, and cell cycle regulation. TFPI-2 induction was confirmed by RT-PCR and immunoblotting demonstrating a more than 400-fold (P < .001) increase in TFPI-2 mRNA in SMCs exposed to FSS compared with static controls, and a consistent protein upregulation. Functionally, SMC proliferation was decreased by FSS (P < .001), and recombinant TFPI-2 was found to inhibit SMC proliferation (P < .001) and induce SMC apoptosis as indicated by activation of caspase-3 (P < .01). In vivo, TFPI-2 expression was found to be upregulated 5, 10, and 20 hours (P < .01) after rat carotid balloon injury, and immunohistochemistry demonstrated TFPI-2 protein in FSS-exposed luminal SMCs, co-localized with caspase-3 in the rat carotid neointima.

CONCLUSION

FSS influenced gene expression associated with cell growth and apoptosis in cultured SMCs and strongly induced expression of TFPI-2 mRNA and protein. TFPI-2 was expressed in luminal, FSS-exposed SMCs together with caspase-3 in the rat carotid neointima after balloon injury. Functionally, TFPI-2 may play a role in vessel wall repair by regulating SMC proliferation and survival. Further studies are needed to elucidate the mechanisms by which TFPI-2 controls SMC function.

Expression and characterization of Kunitz domain 3 and C-terminal of human tissue factor pathway inhibitor-2

Human tissue factor pathway inhibitor-2 (hTFPI-2) is a serine protease inhibitor and its inhibitory activity is enhanced by heparin. The Kunitz domain 3 and Cterminal of hTFPI-2 (hTFPI-2/KD3C), which has the activity toward heparin calcium, have been successfully expressed in Pichia pastoris and purified by SPSepharose and heparin-Sepharose chromatography. The Fourier transformed infrared spectroscopy (FTIR), Raman spectroscopy, and circular dichroism (CD) experiment results implied that hTFPI-2/KD3C contained small contents of alpha-helix and beta-strand, but large amounts of random coil and two kinds of disulfide bonds, gauche-gauche-gauche (ggg) and trans-gauchetrans (tgt). The interaction of hTFPI-2/KD3C with heparin calcium was investigated by CD. It was found that heparin calcium induced b-strands in hTFPI-2/ KD3C to different extents depending on the ratio of hTFPI-2/KD3C and heparin calcium.

Progress in matrix metalloproteinase research

Matrix metalloproteinases (MMPs) are now acknowledged as key players in the regulation of both cell-cell and cell-extracellular matrix interactions. They are involved in modifying matrix structure, growth factor availability and the function of cell surface signalling systems, with consequent effects on cellular differentiation, proliferation and apoptosis. They play central roles in morphogenesis, wound healing, tissue repair and remodelling in response to injury and in the progression of diseases such as arthritis, cancer and cardiovascular disease. Because of their wide spectrum of activities and expression sites, the elucidation of their potential as drug targets in disease or as important features of the repair process will be dependent upon careful analysis of their role in different cellular locations and at different disease stages. Novel approaches to the specific regulation of individual MMPs in different contexts are also being developed.

Tissue Factor Pathway Inhibitor-2 Is Upregulated by Vascular Endothelial Growth Factor and Suppresses Growth Factor-Induced Proliferation of Endothelial Cells

Objective— The purpose of this study is to investigate the expression and regulation of type-2 tissue factor pathway inhibitor (TFPI-2) in endothelial cells, as well as the regulation of human endothelial cell (EC) function by TFPI-2.

Methods and Results— Real-time polymerase chain reaction (PCR) and Western blot analysis revealed that vascular endothelial growth factor (VEGF) induced both time- and dose-dependent increase in TFPI-2 mRNA and protein expression in endothelial cells. TFPI-2 mRNA expression was also significantly upregulated by IL-1β, and modestly increased by both tumor necrosis factor (TNF)-α and fibroblast growth factor (FGF)-2, but not placental growth factor (PlGF). VEGF upregulation of TFPI-2 was dramatically reduced by inhibition of the MEK pathway. Administration of TFPI-2 protein suppressed both VEGF and FGF-2 stimulation of EC proliferation in a dose-dependent manner. A recombinant preparation of the first Kunitz-type domain of TFPI-2 (KD1) did not suppress growth factor stimulation of EC proliferation, suggesting a mechanism distinct from the proteinase inhibitory activity of TFPI-2. Exogenously added TFPI-2 protein suppressed VEGF-induced EC migration in 2 different assays. Recombinant wt-KD1 or the R24K mutant of KD1, but not the R24Q mutant, dramatically suppressed VEGF-induced EC migration. TFPI-2 protein, but not recombinant KD1, blocked VEGF-induced activation of both Akt and ERK1/2 in ECs. At higher doses, TFPI-2 protein blocked VEGFR2 activation.

Conclusion— Our data suggest that VEGF-upregulation of TFPI-2 expression in endothelial cells may represent a mechanism for negative feedback regulation and modulation of its pro-angiogenic action on endothelial cells. TFPI-2, or derivatives of TFPI-2, may be novel therapeutics for treatment of angiogenic disease processes.