Quantitative real-time reverse transcription polymerase chain reaction analysis of a novel tissue factor splice variant in select human solid tumors.
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Publications and source records attributed to W Kisiel.
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Five known thymol derivatives were isolated from roots of Arnica montana transformed with Agrobacterium rhizogenes LBA 9402. The compounds were characterized by spectral methods. The pattern of thymol derivatives in light-grown hairy roots was slightly different from that in dark-grown ones. This is the first report on the presence of thymol derivatives in hairy roots of the plant.
Lactucin (1) and its derivatives lactucopicrin (2) and 11beta,13-dihydrolactucin (3), which are characteristic bitter sesquiterpene lactones of Lactuca virosa and Cichorium intybus, were evaluated for analgesic and sedative properties in mice. The compounds showed analgesic effects at doses of 15 and 30 mg/kg in the hot plate test similar to that of ibuprofen, used as a standard drug, at a dose of 30 mg/kg. The analgesic activities of the compounds at a dose of 30 mg/kg in the tail-flick test were comparable to that of ibuprofen given at a dose of 60 mg/kg. Lactucopicrin appeared to be the most potent analgetic of the three tested compounds. Lactucin and lactucopicrin, but not 11beta,13-dihydrolactucin, also showed sedative properties in the spontaneous locomotor activity test.
Three new and one known furofuran lignans--syringaresinol derivatives--along with the known phenylpropanoids cichoriin and syringin were isolated from a callus tissue of Cichorium intybus. The compounds were characterised by spectral methods. This is the first report on the presence of furofuran lignans in Cichorium species.
Cichoriin-6'-p-hydroxyphenyl acetate, a new natural product, was isolated from chicory leaves.
Human tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor that inhibits plasmin, trypsin, chymotrypsin, cathepsin G, and plasma kallikrein but not urokinase-type plasminogen activator, tissue plasminogen activator, or thrombin. Preliminary findings in our laboratory suggested that the expression of TFPI-2 is downregulated or lost during tumor progression in human gliomas. To investigate the role of TFPI-2 in the invasiveness of brain tumors, we stably transfected the human high-grade glioma cell line SNB19 and the human low-grade glioma cell line Hs683 with a vector capable of expressing a transcript complementary to the full-length TFPI-2 mRNA in either sense (0.7 kb) or antisense (1 kb) orientations. Parental cells and stably transfected cell lines were analysed for TFPI-2 protein by Western blotting and for TFPI-2 mRNA by Northern blotting. The levels of TFPI-2 protein and mRNA were higher in the sense clones (SNB19) and decreased in the antisense (Hs683) clones than in the corresponding parental and vector controls. In spheroid and matrigel invasion assays, the SNB19 parental cells were highly invasive, but the sense-transfected SNB-19 clones were much less invasive; the antisense-transfected Hs683 clones were more invasive than their parental and vector controls. After intracerebral injection in mice, the sense-transfected SNB19 clones were less able to form tumors than were their parental and vector controls, and the antisense-Hs683 clones but not the parental or vector controls formed small tumors. This is the first study to demonstrate that down- or upregulation of TFPI-2 plays a significant role in the invasive behavior of human gliomas.
Blood clotting factor VIIa is involved in the first step of the blood coagulation cascade, as a membrane-associated enzyme in complex with tissue factor (TF). Factor VIIa is also an important therapeutic agent for hemophilia where its function may include TF-independent as well as TF-dependent mechanisms. This study compared the activity of wild type factor VIIa (WT-VIIa) with that of a mutant with elevated affinity for membrane (P10Q/Q32E, QE-VIIa). Phospholipid and cell-based assays showed the mutant to have up to 40-fold higher function than WT-VIIa in both TF-dependent and TF-independent reactions. Tissue factor-dependent reactions displayed the maximum enhancement when binding had reached equilibrium in competition with another TF-binding protein. In liposome-based assays, the association rate of WT-VIIa with TF occurred at a physical maximum and could not be improved by site-directed mutagenesis. A practical consequence was identical function of WT-VIIa and QE-VIIa in assays that depended entirely on assembly kinetics. Thus, factor VIIa mutants provided unique reagents for probing the mechanism of factor VIIa action. They may also offer superior agents for therapy.
Human type-2 tissue factor pathway inhibitor (TFPI-2), also known as placental protein 5, is a 32 kDa serine proteinase inhibitor consisting of three tandemly arranged Kunitz-type inhibitor domains homologous to tissue factor pathway inhibitor. TFPI-2 strongly inhibits a wide variety of serine proteinases including trypsin, chymotrypsin, plasmin, kallikrein and blood coagulation factor XIa. In this study, we have isolated and characterized a genomic clone from an artificial chromosome genomic library that encodes the entire human TFPI-2 gene. The human TFPI-2 gene spans approximately 7 kb and consists of five exons and four introns. Each Kunitz-type domain is encoded by a single exon, similar to that observed for murine TFPI-2 and other Kunitz-type proteinase inhibitors. A total of 535 bp of the 3'-flanking region contain two probable polyadenylation sites (AATAAA) at +4297 and +4314. A single transcription initiation site was identified by oligo-capping and reverse transcription-PCR analysis. Transient transfection of reporter plasmids containing segments of the 5'-flanking region into human transformed bone marrow endothelial cells and glioblastoma cells identified an 85 bp region (-224 to -139) sufficient for transcription of the human TFPI-2 gene.
The isolation and structure elucidation of a new lactucopicrin derivative from Cichorium intybus is described, together with the revised structures of several sesquiterpene lactones previously isolated from Cichorium species. The known eudesmanolide magnolialide and the known guaianolide ixerisoside D, reported for the first time from the plant material, along with the previously known chicory sesquiterpene lactones have been also isolated and identified.
Degradation of ECM, particularly interstitial collagen, promotes plaque instability, rendering atheroma prone to rupture. Previous studies implicated matrix metalloproteinases (MMPs) in these processes, suggesting that dysregulated MMP activity, probably due to imbalance with endogenous inhibitors, promotes complications of atherosclerosis. We report here that the serine proteinase inhibitor tissue factor pathway inhibitor-2 (TFPI-2) can function as an MMP inhibitor. TFPI-2 diminished the ability of the interstitial collagenases MMP-1 and MMP-13 to degrade triple-helical collagen, the primary load-bearing molecule of the ECM within human atheroma. In addition, TFPI-2 also reduced the activity of the gelatinases MMP-2 and MMP-9. In contrast to the "classical" tissue inhibitors of MMPs (TIMPs), TFPI-2 expression in situ correlated inversely with MMP levels in human atheroma. TFPI-2 colocalized primarily with smooth muscle cells in the normal media as well as the plaque's fibrous cap. Conversely, the macrophage-enriched shoulder region, the prototypical site of matrix degradation and plaque rupture, stained only weakly for TFPI-2 but intensely for gelatinases and interstitial collagenases. Evidently, human mononuclear phagocytes, an abundant source of MMPs within human atheroma, lost their ability to express this inhibitor during differentiation in vitro. These findings establish a new, anti-inflammatory function of TFPI-2 of potential pathophysiological significance for human diseases, including atherosclerosis.
Although hyperhomocysteinemia (HHcy) is a well-known risk factor for the development of cardiovascular disease, the underlying molecular mechanisms are not fully elucidated. Here we show that induction of HHcy in apoE-null mice by a diet enriched in methionine but depleted in folate and vitamins B6 and B12 increased atherosclerotic lesion area and complexity, and enhanced expression of receptor for advanced glycation end products (RAGE), VCAM-1, tissue factor, and MMP-9 in the vasculature. These homocysteine-mediated (HC-mediated) effects were significantly suppressed, in parallel with decreased levels of plasma HC, upon dietary supplementation with folate and vitamins B6/B12. These findings implicate HHcy in atherosclerotic plaque progression and stability, and they suggest that dietary enrichment in vitamins essential for the metabolism of HC may impart protective effects in the vasculature.
Blood coagulation is activated commonly in pancreatic carcinoma but the role of the tumor cell in this activation is undefined. Immunohistochemical procedures were applied to fixed sections of 22 cases of resected adenocarcinoma of the pancreas to determine the presence of components of coagulation and fibrinolysis pathways in situ. Tumor cell bodies stained for tissue factor: prothrombin: and factors VII, VIIIc, IX, X, XII, and subunit "a" of factor XIII. Fibrinogen existed throughout the tumor stroma, and tumor cells were surrounded by fibrin. Staining for tissue factor pathway inhibitor, and plasminogen activators was minimal and inconsistent. Plasminogen activator inhibitors -1, -2, and -3 were present in the tumor stroma, and on tumor cells and vascular endothelium. Extravascular coagulation activation exists associated with pancreatic carcinoma cells in situ that is apparently unopposed by naturally occurring inhibitors or the plasminogen activator-plasmin system. We postulate that such local coagulation activation may regulate growth of this malignancy. These findings provide a rationale for testing agents that modulate the blood coagulation/fibrinolytic system (that inhibit tumor growth in other settings) in pancreatic carcinoma.
We have previously shown that human liver myofibroblasts promote in vitro invasion of human hepatocellular carcinoma (HCC) cells through a hepatocyte growth factor (HGF)/urokinase/plasmin-dependent mechanism. In this study, we demonstrate that myofibroblasts synthesize the serine proteinase inhibitor tissue factor pathway inhibitor-2 (TFPI-2). Despite the fact that recombinant TFPI-2 readily inhibits plasmin, we show that it potentiates HGF-induced invasion of HCC cells and is capable of inducing invasion on its own. Furthermore, HCC cells stably transfected with a TFPI-2 expression vector became spontaneously invasive. HCC cells express tissue factor and specifically factor VII. Addition of an antibody to factor VII abolished the pro-invasive effect of TFPI-2. We suggest that TFPI-2 induces invasion following binding to a tissue factor-factor VIIa complex preformed on HCC cells. Our data thus demonstrate an original mechanism of cell invasion that may be specific for liver tumor cells.
We report the expression of tissue factor pathway inhibitor-2 (TFPI-2) (also known as PP-5, placental protein-5; MSPI, matrix-associated serine protease inhibitor) in E. coli as a 25-kDa nonglycosylated protein with a glycine substituted for aspartic acid at the amino terminus. High-level expression of TFPI-2 was obtained with pRE1 expression vector under the transcriptional and translational controls of the lambdaP(L) promoter and lambdacII ribosome-binding site, respectively, with ATG initiation codon. TFPI-2 was produced as inclusion bodies and accounted for 25-30% of the total E. coli proteins. The inclusion bodies containing TFPI-2 were solubilized with urea, sulfitolyzed, purified, and refolded through a disulfide interchange reaction. The refolded E. coli TFPI-2 inhibited plasmin with an inhibition constant (K(i)) of 5 nM that is similar with the TFPI-2 expressed in a mammalian system. The refolded E. coli TFPI-2 bound heparin and also inhibited plasmin, regardless of whether the enzyme was in the fluid phase or was bound to the membranes of HT-1080 fibrosarcoma cells. In addition, refolded E. coli TFPI-2 inhibited radiolabeled matrix degradation and Matrigel matrix invasion by HT-1080 fibrosarcoma cells and B16-F10 melanoma cells. Together, our results suggest that glycosylation is not essential for antiprotease, antitumor, and matrix-binding activities of TFPI-2. Based on these collective data, we conclude that a biologically active nonglycosylated TFPI-2 can be produced in E. coli and that the protein can be produced in high-enough quantities to conduct in vivo studies for determination of the role of this inhibitor in tumor invasion and metastasis.
Interleukin-1beta-converting enzyme (ICE, caspase-1) regulates key steps in inflammation and immunity, by activating the proinflammatory cytokines interleukin (IL-)1beta and IL-18, or mediating apoptotic processes. We recently provided evidence for the regulation of caspase-1 activity via an endogenous inhibitor expressed by human vascular smooth muscle cells (SMCs) (Schönbeck, U., M. Herzberg, A. Petersen, C. Wohlenberg, J. Gerdes, H.-D. Flad, and H. Loppnow. 1997. J. Exp. Med. 185:1287-1294). However, the molecular identity of this endogenous inhibitor remained undefined. We report here that the serine proteinase inhibitor (serpin) PI-9 accounts for the endogenous caspase-1 inhibitory activity in human SMCs and prevents processing of the enzyme's natural substrates, IL-1beta and IL-18 precursor. Treatment of SMC lysates with anti-PI-9 antibody abrogated the caspase-1 inhibitory activity and coprecipitated the enzyme, demonstrating protein-protein interaction. Furthermore, PI-9 antisense oligonucleotides coordinately reduced PI-9 expression and promoted IL-1beta release. Since SMCs comprise the majority of cells in the vascular wall, and because IL-1 is implicated in atherogenesis, we tested the biological validity of our in vitro findings within human atheroma in situ. The unaffected arterial wall contains abundant and homogeneously distributed PI-9. In human atherosclerotic lesions, however, PI-9 expression correlated inversely with immunoreactive IL-1beta, supporting a potential role of the endogenous caspase-1 inhibitor in this chronic inflammatory disease. Thus, our results provide new insights into the regulation of this enzyme involved in immune and inflammatory processes of chronic inflammatory diseases, and point to an endogenous antiinflammatory action of PI-9, dysregulated in a prevalent human disease.
Fibrin deposition is a salient feature of hypoxemic vasculature and results from induction of tissue factor. Such tissue factor expression in an oxygen deficient environment is driven by the transcription factor Early Growth Response (Egr)-1. Using homozygous null mice for the protein kinase C beta-isoform gene (PKCbeta null), PKCbeta is shown to be upstream of Egr-1 in this oxygen deprivation-mediated pathway for triggering procoagulant events. Whereas wild-type mice exposed to hypoxia (6%) displayed a robust increase in tissue factor transcripts and antigen, and vascular fibrin deposition, PKCbeta null animals showed a markedly blunted response. Consistent with a central role for Egr-1 in hypoxia-induced expression of tissue factor, PKCbeta null mice subjected to oxygen deprivation displayed at most a minor elevation in Egr-1 transcripts, antigen, and intensity of the gel shift band by electrophoretic mobility shift assay, compared with normoxic animals. These data firmly establish PKCbeta as a trigger for events leading to induction of Egr-1 and tissue factor under hypoxic conditions, and provide insight into a biologic cascade whereby oxygen deprivation recruits targets of PKCbeta and Egr-1, thereby amplifying the cellular response.
Immunohistochemistry was applied to AMeX-fixed tissue sections of 12 adenocarcinomas of the stomach (seven intestinal adenocarcinomas and five diffuse carcinomas), 12 adenocarcinomas of the pancreas (nine ductal adenocarcinomas and three signet ring carcinomas), and 12 squamous cell carcinomas of the larynx obtained at surgical resection to examine the possibility of extravascular activation of blood coagulation in cancer tissues by exploring the in loco patterns of distribution of fibrinogen, a final product of blood coagulation, fibrin, and a by-product of coagulation reactions (prothrombin fragment 1+2). Gastric, pancreatic, and laryngeal cancers exhibited fibrinogen antigen in abundance throughout the tumor stroma. Fibrin was detected along the edges of nests of carcinoma cells and at the host-tumor interface. Prothrombin fragment 1+2 was present in the blood vessels in areas of neoangiogenesis at the host-tumor interface (gastric and pancreatic cancer tissues) and on the tumor cell bodies (pancreatic and laryngeal cancer tissues). The presence of prothrombin fragment 1+2 in cancer tissues appears to be a good indicator of coagulation activation and thrombin generation at the tumor burden.
Antibodies to PF4/heparin can be demonstrated in almost all patients with heparin-induced thrombocytopenia/thrombosis (HIT/HITT) and in some persons exposed to heparin who do not have clinical manifestations. The role of anti-PF4/heparin antibodies in the pathogenesis of HIT/HITT has been difficult to establish because the antibodies found in serum are generally polyclonal and polyspecific. To circumvent this problem, we developed a murine monoclonal antibody (mAb) to human (h) PF4/heparin complexes. A monoclonal IgG(2bkappa )antibody (designated KKO) was identified that bound specifically to hPF4/heparin complexes. Maximal binding of KKO to hPF4/heparin complexes occurred at similar molar ratios of PF4:heparin observed for HIT/HITT antibodies. KKO also bound to hPF4 in association with other glycosaminoglycans. Platelet activation by KKO required heparin and was abrogated by blockade of FcgammaRIIA. In the presence of PF4, KKO bound to endothelial cells, but not to CHO cells lacking heparan sulfate proteoglycans. Variants of PF4 complexed to heparin were recognized equally well by KKO and HIT/HITT sera. KKO competes for binding with a subset of HIT/HITT antibodies that are relatively spared by mutations in the 3rd domain of PF4. The nucleotide and predicted amino acid sequences of KKO and RTO, a murine anti-hPF4 mAb that does not require heparin for binding, revealed no obvious relationship in either the heavy- or the light-chain immunoglobulin variable regions. These studies suggest that KKO recapitulates the antigenic and functional specificity of a subset of HIT/HITT antibodies and may, therefore, provide insight into the pathogenesis of thrombocytopenia and thrombosis in affected persons. (Blood. 2000;95:1533-1540)