Characterization of the cellular binding site for the urinary trypsin inhibitor

Ulinastatin inhibits the metastasis of nasopharyngeal carcinoma by involving uPA/uPAR signaling

Distant metastasis is the primary reason for treatment failure in patients with nasopharyngeal carcinoma (NPC). In this study, we investigated the effect of ulinastatin (UTI) on NPC metastasis and its underlying mechanism. Highly-metastatic NPC cell lines S18 and 58F were treated with UTI and the effect on cell proliferation, migration, and invasion were determined by MTS and Transwell assays. S18 cells with luciferase-expressing (S18-1C3) were injected into the left hind footpad of nude mice to establish a model of spontaneous metastasis from the footpad to popliteal lymph node (LN). The luciferase messenger RNA (mRNA) was measured by quantitative polymerase chain reaction (qPCR), and the metastasis inhibition rate was calculated. Key molecular members of the UTI-related uPA, uPAR, and JAT/STAT3 signaling pathways were detected by qPCR and immunoblotting. UTI suppressed the migration and infiltration of S18 and 5-8F cells and suppressed the metastasis of S18 cells in vivo without affecting cell proliferation. uPAR expression decreased from 24 to 48 h after UTI treatment. The antimetastatic effect of UTI is partly due to the suppression of uPA and uPAR. UTI partially suppresses NPC metastasis by downregulating the expression of uPA and uPAR.

The synergistic effect of propofol and ulinastatin suppressed the viability of the human lung adenocarcinoma epithelial A549 cell line

Ulinastatin and propofol (PPF) are recognized for their anticancer properties. The aim of the present study was to evaluate the synergistic antitumor effect of PPF followed by ulinastatin against A549 cells. In MTT assays, PPF (10, 20 and 30 µM) followed by 200 U/ml ulinastatin was more effective at inhibiting A549 cell viability compared with PPF (10, 20 and 30 µM) or 200 U/ml ulinastatin. PPF (10, 20 and 30 µM) followed by 200 U/ml ulinastatin treatments synergistically increased the number of S cells and synergistically reduced the number of G2/M cells associated with PPF stimulation in a dose-dependent manner. Western blot analysis demonstrated that the antitumor effect of PPF followed by 200 U/ml ulinastatin treatments were associated with the downregulated expression of extracellular signal-regulated kinase 1 and 2 phosphorylation (p-ERK1/2) and matrix metalloproteinases 2 (MMP-2). In conclusion, these data demonstrated that PPF (20 and 30 µM) followed by 200 U/ml ulinastatin treatments synergistically stimulated a significant proportion of A549 cells in S phase. Furthermore, the combination synergistically reduced a significant proportion of A549 cells in G2/M phase and synergistically suppressed the viability of A549 cells, which was possibly related regulation of the expression of p-ERK1/2 and MMP-2 in A549 cells.

Proteome analysis of sheep B lymphocytes in the course of bovine leukemia virus-induced leukemia

Presented are the results of a study of the expression pattern of different proteins in the course of bovine leukemia virus-induced leukemia in experimental sheep and I discuss how the obtained data may be useful in gaining a better understanding of the pathogenesis of the disease, diagnosis, and for the selection of possible therapeutic targets. In cattle, the disease is characterized by life-long persistent lymphocytosis leading to leukemia/lymphoma in about 5% of infected animals. In sheep, as opposed to cattle, the course of the disease is always fatal and clinical symptoms usually occur within a three-year period after infection. For this reason, sheep are an excellent experimental model of retrovirus-induced leukemia. This model can be useful for human pathology, as bovine leukemia virus is closely related to human T-lymphotropic virus type 1. The data presented here provide novel insights into the molecular mechanisms of the bovine leukemia virus-induced tumorigenic process and indicate the potential marker proteins both for monitoring progression of the disease and as possible targets of pharmacological intervention. A study of the proteome of B lymphocytes from four leukemic sheep revealed 11 proteins with altered expression. Among them, cytoskeleton and intermediate filament proteins were the most abundant, although proteins belonging to the other functional groups, i.e. enzymes, regulatory proteins, and transcription factors, were also present. It was found that trypsin inhibitor, platelet factor 4, thrombospondin 1, vasodilator-stimulated phosphoprotein, fibrinogen alpha chain, zyxin, filamin-A, and vitamin D-binding protein were downregulated, whereas cleavage and polyadenylation specificity factor subunit 5, non-POU domain-containing octamer-binding protein and small glutamine-rich tetratricopeptide repeat-containing protein alpha were upregulated. Discussed are the possible mechanisms of their altered expression and its significance in the bovine leukemia virus-induced leukemogenic process. Impact statement The submitted manuscript provides new data on the molecular mechanisms of BLV-induced tumorigenic process indicating the potential marker proteins both for monitoring the progression of the disease and as possible targets of pharmacological intervention. This is to my knowledge the first study of the proteome of the transformed lymphocytes in the course of bovine leukemia virus-induced leukemia in susceptible animals. BLV can be considered as useful model for related human pathogen - HTLV-1, another member of the deltaretrovirus genus evolutionary closely related to BLV. Information gathered in this study can be useful to speculate on possible shared mechanisms of deltaretrovirus-induced carcinogenesis.

Protective effect of ulinastatin in patients with non-small cell lung cancer after radiation therapy: a randomized, placebo-controlled study

Radiation-induced lung injury (RILI) is a frequent, sometimes life-threatening complication of radiation therapy for the treatment of lung cancer. The anti-inflammatory role of ulinastatin has been well documented, and the potential application of ulinastatin in management of acute lung injury has been suggested in multiple animal studies. In this article, we described a double-blind, randomized, placebo-controlled study in patients with non-small cell lung cancer. A total of 120 patients were randomized into two groups: the trial group was treated with ulinastatin for 3 days prior to and for the first 7 days of radiation therapy and the control group was treated with placebo for 10 days following the same schedule. The results from follow-up studies showed that the incidence and grade of RILI were significantly lower in the trial group than in the control group. Reduction in pulmonary function from baseline was significantly smaller in the trial group than that in the control group. Production of serum TGF-β1, TNF-α and IL-6 decreased significantly in the trial group promptly following radiation therapy. However, no difference in survival or tumour response rate was found between the two groups. The results indicated that ulinastatin exerted a protective effect on radiation-induced lung injury. Treatment with ulinastatin could be an effective management strategy and greatly improve the clinical efficacy of radiation therapy for patients with lung cancer.

Effect of ulinastatin on the expression and distribution of high mobility group box 1 in human colon carcinoma cells in vitro

The aim of the present study was to investigate the in vitro effects of ulinastatin (UTI) on the proliferation, invasion, apoptosis, expression and distribution of high mobility group box 1 (HMGB1) and the expression of nuclear factor κB (NF‑κB) in human colon carcinoma LoVo cells. The cells were divided into control (untreated), UTI1 (400 U/ml UTI), UTI2 (800 U/ml UTI) and UTI3 (1,600 U/ml UTI) groups. The cell proliferation, invasion, apoptosis and the gene and protein expression of HMGB1 and NF‑κB were detected using a tetrazolium assay, Transwell cell invasion assays, a caspase‑3 activity assay, western blot analysis and reverse transcription quantitative polymerase chain reaction, respectively. The distribution of HMGB1 was detected using immunofluorescence. LoVo cell proilferation decreased the most in the UTI3 group followed, in order, by the UTI2, UTI1 and control groups. UTI inhibited invasion in LoVo cells and the inhibitory effect was enhanced as the UTI concentration increased. The activity of caspase‑3 increased the least in the control group followed, in order, by the UTI1, UTI2 and UTI3 groups. UTI inhibited the expression of HMGB1 and NF‑κB, and decreased the cytoplasmic distribution of HMGB1. Thus, UTI inhibited LoVo cell proliferation and induced LoVo cell apoptosis, the mechanism of which may be associated with a decreased in the expression of HMGB1 and NF‑κB, and the cytoplasmic distribution of HMGB1.

Protective effects of urinary trypsin inhibitor on vascular permeability following subarachnoid hemorrhage in a rat model

AIMS

Inflammation and apoptosis play important roles in increasing vascular permeability following subarachnoid hemorrhage (SAH). The objective of this study was to evaluate whether urinary trypsin inhibitor (UTI), a serine protease inhibitor, attenuates vascular permeability by its antiinflammatory and antiapoptotic effects after experimental SAH.

METHODS

Subarachnoid hemorrhage models were established in adult male Sprague-Dawley rats by endovascular perforation. UTI was administered by intraperitoneal injection immediately following SAH. Brain edema was assessed by magnetic resonance imaging (MRI) at 24 h after SAH. Neurological deficits, brain water content, vascular permeability, malondialdehyde (MDA) concentration, and myeloperoxidase (MPO) activity were evaluated. Immunohistochemical staining and Western blot were used to explore the underlying protective mechanism of UTI.

RESULTS

Urinary trypsin inhibitor 50,000 U/kg significantly attenuated brain edema and neurological deficits and reduced vascular permeability at 24 h after SAH. MDA concentration and MPO activity in hippocampus were significantly decreased with UTI treatment. Furthermore, the levels of phosphorylated JNK, NF-κB (p65), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and proapoptotic protein p53, caspase-3 were elevated in the microvascular endothelial cells of the hippocampus after SAH, which were alleviated with UTI treatment.

CONCLUSION

Urinary trypsin inhibitor reduced vascular permeability after SAH through its antiinflammatory and antiapptotic effects via blocking the activity of JNK, NF-κB, and p53.

Protective effect of urinary trypsin inhibitor on the development of radiation-induced lung fibrosis in mice

This study aimed to analyze whether Ulinastatin, a urinary trypsin inhibitor (UTI), inhibits the TGF-beta signaling pathway and lung fibrosis induced by thoracic irradiation in a lung injury mouse model. The thoraces of 9-week-old female fibrosis-sensitive C57BL/6 mice were irradiated with a single X-ray dose of 12 Gy or 24 Gy. UTI was administrated intraperitoneally at a dose of 200,000 units/kg concurrently with radiation (concurrent UTI) or daily during the post-irradiation period for 8-14 days (post-RT UTI). Mice were sacrificed at 16 weeks after irradiation to assess the histological grade of lung fibrosis and immunohistochemical TGF-beta expression. Survival rates of mice given 24 Gy to the whole lung +/- UTI were also compared. Post-RT UTI reduced the score of lung fibrosis in mice, but concurrent UTI had no beneficial effects in irradiated mice. The fibrosis score in post-RT UTI mice was 3.2 +/- 1.0, which was significantly smaller than that of irradiated mice without UTI treatment (RT alone; 6.0 +/- 1.3; p < 0.01). The rates of TGF-beta positive cells in post-RT UTI and the RT alone mice were 0.18 +/- 0.03 and 0.23 +/- 0.04, respectively (p < 0.01). There was a significantly positive correlation between the fibrosis score and the TGF-beta positive rate (R(2) = 0.26, p < 0.01). The survival rate at 30 weeks for post-RT UTI mice was significantly better than that of RT alone mice (33% vs. 10%, p < 0.05). The administration of post-RT UTI suppressed TGF-beta expression and radiation-induced lung fibrosis, which resulted in significant survival prolongation of the irradiated mice.

The presence of tryptase-positive and bikunin-negative mast cells in psoriatic skin lesions

Human mast cells are well known to produce a serine protease, tryptase, which appears to play a pathogenic role in various skin inflammations. It was previously reported that a rat homologue of bikunin may inhibit tryptase activity. Various type of cells (i.e. keratinocytes) are able to produce this protein inhibitor, it still remains unclear if bikunin is present in dermal inflammatory milieu, in which mast cells, through secretion of tryptase, play an inflammatory role. Therefore, the purpose of the present study was to exploit expression and production of bikunin in dermis and dermal constituents. We first compared the dermal mast cells in psoriatic lesions with those in lesional skin of atopic dermatitis or of chronic eczema by use of immunoelectron microscopy and immunohistochemical analyses using antibodies to bikunin and tryptase. Then, we tested what kinds of cytokines may regulate the de novo synthesis of bikunin. To do so, RNA was extracted from a human mastocytic cell line, HMC-1, reverse-transcribed, and semiquantitative RT-PCR was performed using primers specific for bikunin. With immunoelectron microscopy, bikunin was found to localize on the cell membrane, while tryptase was in the secretary granules of the mast cells. In psoriatic lesions, around 70% of dermal mast cells were positive for both tryptase and bikunin, and the remaining was mostly positive for tryptase, but the expression of bikunin was under the detection limit of the experimental setting. This observation was seen in only psoriatic lesions, even in almost cured lesions, while in atopic dermatitis or chronic eczema only mast cells doubly positive for bikunin and tryptase were seen. In HMC-1, bikunin was constitutively expressed at an mRNA level, which was upregulated by stimulation with interleukine-4, but was suppressed by interferon-gamma. Bearing in mind the concept that in psoriasis local cytokine milieu is shifted toward a Th1 pattern (predominant secretion of interferon-gamma), tryptase-positive, bikunin-negative mast cells may be induced.

Bikunin down-regulates heterodimerization between CD44 and growth factor receptors and subsequently suppresses agonist-mediated signaling

We provided evidence previously that bikunin, a Kunitz-type protease inhibitor, can disrupt dimerization of CD44 proteins, which may result in suppression of receptor-mediated MAP kinase signaling. However, to what extent dimerization may alter ligand-induced signaling has not been documented. Given the recent recognition that some growth factor receptors can form heterodimers with CD44, the present study was undertaken to determine whether the CD44 and growth factor receptors (e.g., EGFR, FGFR, HGFR, VEGFR, TGF-betaRI, or TGF-betaRII) can form heterodimers in cancer cells and, if so, to investigate the potential functional consequences of such heterodimerization. We also examined whether bikunin can abrogate these heterodimerizations and inhibit CD44/growth factor-dependent signaling. Here, we show direct evidence for heterodimerization of CD44-FGFR and CD44-TGF-betaRI in human chondrosarcoma HCS-2/8 cells, CD44-EGFR complex in human glioma U87MG cells, and CD44-TGF-betaRI heterodimer in human ovarian cancer HRA cells. Coupling of CD44 and growth factor receptor may be selective, depending on a cell type. Bikunin does not alter the ligand binding, whereas functionally reduces heterodimerization between CD44 and growth factor receptors. The disruption of heterodimerization substantially reduces receptor-induced tyrosine phosphorylation and ERK1/2 activation. Taken together, our data suggest that bikunin-mediated suppression of heterodimerization between CD44 and growth factors may inhibit the agonist-promoted activation of the signaling pathway.

Suppression of urokinase expression and invasion by a soybean Kunitz trypsin inhibitor are mediated through inhibition of Src-dependent signaling pathways

A soybean Kunitz trypsin inhibitor (KTI) interacts with cells as a negative modulator of the invasive cells. Using complementary pharmacological and genetic approaches, we provide novel findings regarding mechanisms by which KTI inhibits signaling pathways in ovarian cancer cells leading to invasion. Transforming growth factor-beta1 (TGF-beta1) directly activates Src kinase, which in turn activates ERK-phosphatidylinositol 3-kinase/Akt, the downstream targets of Src, for urokinase-type plasminogen activator (uPA) up-regulation in human ovarian cancer HRA cells. Preincubation of the HRA cells with KTI reduced the ability of TGF-beta1 to trigger the uPA expression at the gene level and at the protein level. To further elucidate the mechanism of the KTI-dependent suppressive effect of TGF-beta1-induced uPA expression and invasion, we investigated which signaling pathway transduced by KTI is responsible for this inhibitory effect. Here, we show that 1) KTI suppressed TGF-beta1-induced phosphorylation of Src, ERK1/2, and Akt by 40-60%; 2) KTI was insensitive to suppress the phosphorylation of ERK1/2 and Akt in the constitutively active (CA)-c-Src (Y529F) cells; 3) uPA expression was up-regulated in TGF-beta1-stimulated HRA cells and in unstimulated Y529F cells; 4) the addition of KTI reduced the TGF-beta1-induced increase of uPA gene and protein expression in the wild-type c-Src-transfected cells (in contrast, KTI could not inhibit uPA expression in the Y529F cells); and 5) CA-c-Src transfection resulted in a 2-fold increase in invasiveness, whereas KTI did not reduce invasion of the Y529F cells. Using additional complementary genetic approaches (CA-MEK1, CA-Akt, or kinase-dead-Akt), we conclude that KTI may suppress uPA expression and promotion of invasion possibly through one or more upstream targets of Src.

Tumor Suppressor Activity and Epigenetic Inactivation of Hepatocyte Growth Factor Activator Inhibitor Type 2/SPINT2 in Papillary and Clear Cell Renal Cell Carcinoma

Following treatment with a demethylating agent, 5 of 11 renal cell carcinoma (RCC) cell lines showed increased expression of hepatocyte growth factor (HGF) activator inhibitor type 2 (HAI-2/SPINT2/Bikunin), a Kunitz-type protease inhibitor that regulates HGF activity. As activating mutations in the MET proto-oncogene (the HGF receptor) cause familial RCC, we investigated whether HAI-2/SPINT2 might act as a RCC tumor suppressor gene. We found that transcriptional silencing of HAI-2 in RCC cell lines was associated with promoter region methylation and HAI-2/SPINT2 protein expression was down-regulated in 30% of sporadic RCC. Furthermore, methylation-specific PCR analysis revealed promoter region methylation in 30% (19 of 64) of clear cell RCC and 40% (15 of 38) of papillary RCC, whereas mutation analysis (in 39 RCC cell lines and primary tumors) revealed a missense substitution (P111S) in one RCC cell line. Restoration of HAI-2/SPINT2 expression in a RCC cell line reduced in vitro colony formation, but the P111S mutant had no significant effect. Increased cell motility associated with HAI-2/SPINT2 inactivation was abrogated by treatment with extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) and phospholipase C-gamma inhibitors, but not by an inhibitor of atypical protein kinase C. These findings are consistent with frequent epigenetic inactivation of HAI-2/SPINT2, causing loss of RCC tumor suppressor activity and implicate abnormalities of the MET pathway in clear cell and papillary sporadic RCC. This information provides opportunities to develop novel targeted approaches to the treatment of RCC.

Attenuation of graft ischemia-reperfusion injury by urinary trypsin inhibitor in mouse intestinal transplantation

AIM: Ischemia/reperfusion (I/R) injury is one of the major obstacles for intestinal transplantation (ITx). Urinary trypsin inhibitor (Ulinastatin, UTI) suppresses proteases and stabilizes lysosomal membranes. We supposed that Ulinastatin would diminish I/R injury of intestinal graft.

METHODS: UTI- treated group and untreated control group were investigated by histological assessment at 1.5, 4, 24, and 72 h after ITx. Myeloperoxidase (MPO) activity was used as the activity of neutrophils, and malondialdehyde (MDA) was used as an index of lipid peroxidation. TNFα and i-NOS mRNA expression in graft tissue were measured by semi-quantitative RT-PCR. CD11b⁺ Gr1⁺ cells in graft lamina propria were analyzed by flow cytometry.

RESULTS: Histological scores of the graft showed that the tissue injury was markedly attenuated by UTI treatment at different time points after ITx, with reduced MPO and MDA value in the grafts. The expression of TNFα and i-NOS mRNA was profoundly inhibited, while the infiltration of CD11b⁺ Gr1⁺ cells into the intestinal graft was decreased in UTI group.

CONCLUSION: Urinary trypsin inhibitor attenuates I/R injury in mouse intestinal transplantation by reducing monocytes infiltration and down-regulation of TNFα and i-NOS mRNA expression.

Overexpression of a hybrid gene consisting of the amino-terminal fragment of urokinase and carboxyl-terminal domain of bikunin suppresses invasion and migration of human ovarian cancer cellsin vitro

A Kunitz-type protease inhibitor, bikunin, is known to suppress the invasion and metastasis of cancer cells. HI8, a carboxyl-terminal domain of bikunin, is an active site of this glycoprotein. To increase its affinity for cancer cells, we constructed a chimeric gene, ATF-HI8, and investigated the anti-invasive and anti-migratory activity of ATF-HI8 on ovarian cancer cells. ATF-HI8-expressing plasmid and ATF-expressing plasmid were introduced into the highly invasive and metastatic ovarian cancer cell line HRA. The properties of the established cell line (HRA/ATF-HI8) were compared to those of the HRA/ATF and the HRA/luciferase (HRA/LUC, control) cell lines in terms of cell proliferation, invasion and migration. As a result, (i) there were no differences in cell proliferation between HRA/ATF-HI8 and HRA/LUC; (ii) the invasion and migration of HRA/ATF-HI8 cells were significantly inhibited compared to those of HRA/LUC cells; (iii) the migration, but not the invasion, of HRA/ATF cells was significantly inhibited compared to that of HRA/LUC. These results indicate that the overexpression of ATF-HI8 inhibits the invasion and migration of ovarian cancer cells without affecting cell proliferation and suggest that HI8 is involved in the anti-invasive and the anti-migratory activities, and the addition of ATF brought about the increase in the anti-migratory activity of HI8. The above findings suggest the applicability of therapeutic strategies targeting the inhibition of peritoneal invasion and dissemination of ovarian cancer by the use of the chimeric gene ATF-HI8.

Cytokine-induced gene expression at the crossroads of innate immunity, inflammation and fertility: TSG-6 and PTX3/TSG-14

Two cytokine-inducible gene products, important in inflammation and infection, also play essential roles in female fertility. One of these is the product of tumor necrosis factor (TNF)-stimulated gene 6 (TSG-6), alternatively termed TNFAIP6 (for TNF-alpha-induced protein 6), originally cloned from diploid human fibroblasts stimulated with TNF. The second is pentraxin 3 (PTX3), also termed TSG-14, originally isolated from TNF-stimulated human fibroblasts and from interleukin-1 (IL-1)-stimulated vascular endothelial cells. TSG-6, which specifically binds to hyaluronan (HA) and to inter-alpha-inhibitor (I alpha I), shows potent anti-inflammatory activity in acute and chronic inflammation, notably in several models of autoimmune arthritis. PTX3 was shown to play an important role in resistance to fungal infection with Aspergillus fumigatus. Both TSG-6 and PTX3 are synthesized in the ovary prior to ovulation, where they become components of an expanding viscoelastic matrix that surrounds the oocyte before its release from the follicle at the ovarian surface. Female mice with a targeted disruption of either the TSG-6 or PTX3 gene show severe defects in fertility.

The ORF3 protein of hepatitis E virus interacts with liver-specific alpha1-microglobulin and its precursor alpha1-microglobulin/bikunin precursor (AMBP) and expedites their export from the hepatocyte

Hepatitis E virus (HEV), a plus-stranded RNA virus contains three open reading frames. Of these, ORF1 encodes the viral nonstructural polyprotein; ORF2 encodes the major capsid protein and ORF3 codes for a phosphoprotein of undefined function. Using the yeast two-hybrid system to screen a human cDNA liver library we have isolated, an N-terminal deleted protein, alpha(1) -microglobulin/bikunin precursor (AMBP) that specifically interacts with the ORF3 protein of HEV. Independently cloned, full-length AMBP was obtained and tested positive for interaction with ORF3 using a variety of in vivo and in vitro techniques. AMBP, a liver-specific precursor protein codes for two different unrelated proteins alpha(1)-microglobulin (alpha(1)m) and bikunin. alpha(1) m individually interacted with ORF3. The above findings were validated by COS-1 cell immunoprecipitation, His(6) pull-down experiments, and co-localization experiments followed by fluorescence resonance energy transfer analysis. Human liver cells showing co-localization of ORF3 with endogenously expressing alpha(1) m showed a distinct disappearance of the protein from the Golgi compartment, suggesting that ORF3 enhances the secretion of alpha(1)m out of the hepatocyte. Using drugs to block the secretory pathway, we showed that alpha m was not degraded in the presence of ORF3. Finally, (1)pulse labeling of alpha(1)m showed that its secretion was expedited out of the liver cell at faster rates in the presence of the ORF3 protein. Hence, ORF3 has a direct biological role in enhancing alpha(1)m export from the hepatocyte.

Reduced bikunin gene expression as a factor of poor prognosis in ovarian carcinoma

BACKGROUND

In previous studies, the authors showed that various types of cultured tumor cells treated with exogenous bikunin protein or ovarian carcinoma cells transfected with bikunin cDNA have low invasiveness and diminished metastatic potential. This study was carried out to clarify the relation between the expression of individual bikunin mRNA and tumor progression.

METHODS

Forty-one newly diagnosed ovarian carcinomas were investigated using a semiquantitative reverse transcriptase-polymerase chain reaction.

RESULTS

The authors found that 24 patients had tumors that overexpressed bikunin and that gene expression was reduced in the tumors of the remaining 17 individuals. Bikunin mRNA expression was independent of age, surgical stage, tumor size, degree of differentiation, histologic subtype, and serum CA 125 levels. There was a significant correlation between low expression of bikunin mRNA and lymph node status (P=0.035) or peritoneal status (P=0.042). Multivariate analysis indicated that bikunin was an independent prognostic marker (P=0.013; hazard ratio, 2.30; 95 % confidence interval, 1.13-4.19), even after controlling for lymph node metastasis and the degree of peritoneal dissemination. In addition, low expression was a significant predictor for poor prognosis compared with high expression (2-year survival rate; 75.0 % vs. 47.1 %, respectively; P<0.05).

CONCLUSIONS

The data suggest that low bikunin mRNA expression by ovarian carcinoma cells may be associated with poor prognosis. It is conceivable that testing for bikunin mRNA may identify patients with ovarian carcinoma who are at high risk for early disease recurrence and a poor prognosis.

The protease inhibitor bikunin, a novel anti-metastatic agent

Bikunin is a Kunitz-type protease inhibitor predominantly found in human amniotic fluid. In cancers, administration of bikunin may block tumor cell invasion by a direct inhibition of tumor cell-associated plasmin activity as well as by inhibiting urokinase-type plasminogen activator (uPA) expression at the gene and protein levels, possibly through suppression of CD44 dimerization and/or the MAP kinase signaling cascade. Treatment of cancer patients with bikunin may be beneficial in the adjuvant setting to delay the onset of metastasis development and/or in combination with cytotoxic agents to improve treatment efficacy in patients with advanced ovarian cancer.

Suppression of invasion and peritoneal carcinomatosis of ovarian cancer cell line by overexpression of bikunin

Bikunin (bik), a Kunitz-type protease inhibitor, also known as urinary trypsin inhibitor, is proposed as a main participant in the inhibition of tumor cell invasion and metastasis, possibly through the direct inhibition of cell-associated plasmin activity and suppression of urokinase-type plasminogen activator (uPA) mRNA expression. In the present study, we transfected the human ovarian carcinoma cell line HRA, highly invasive cells, with an expression vector harboring a cDNA encoding for human bik. Our study was designed to investigate the effect of bik overexpression and changes in tumor cell phenotype and invasiveness in the stably transfected clones. Bik gene transfection of HRA gave the following results: 1) transfection of HRA with the bik cDNA resulted in 5 variants stably expressing functional bik; 2) bik(+) clones exhibited a significantly reduced uPA mRNA expression as compared to the parental cells; 3) bikunin negatively regulates the ERK1/2 activity; 4) secretion-blocking treatments of bik(+) clones abrogated bik-mediated suppression of ERK1/2 activation and uPA expression; 5) the regulation of invasion seen in the HRA cells is mainly mediated by the uPA-plasmin-MMP-2 system; 6) transfection of HRA with the bik gene significantly reduced invasion, but not proliferation, adhesion, or migration relative to the parental cells; and 7) animals with bik(+) clones induced reduced peritoneal dissemination and long term survival. We conclude that transfection of HRA cells with the bik cDNA constitutively suppresses ERK1/2 activation, which results in inhibition of uPA expression and subsequently reduces dissemination of bik(+) clones.

Kunitz-type protease inhibitor bikunin disrupts phorbol ester-induced oligomerization of CD44 variant isoforms containing epitope v9 and subsequently suppresses expression of urokinase-type plasminogen activator in human chondrosarcoma cells

We previously found that bikunin (bik), a Kunitz-type protease inhibitor, suppresses phorbol ester (PMA)-stimulated expression of urokinase-type plasminogen activator (uPA). In the present study, we tried to answer this mechanism using human chondrosarcoma HCS-2/8 cells. Our results showed the following novel findings: (a) the standard form of CD44 (CD44s; 85 kDa) is expressed in both unstimulated and PMA-stimulated cells, while CD44v isoforms containing epitope v9 (110 kDa) are strongly up-regulated in response to treatment with PMA; (b) CD44v isoforms containing epitope v9 present on the same cell exclusively form aggregates in stimulated cells; (c) induction of uPA mRNA expression could be achieved by using a second cross-linker antibody to cross-link Fab monomers of anti-CD44; (d) co-treatment of stimulated cells with anti-CD44 mAb alone or anti-CD44v9 mAb alone suppresses PMA-induced clustering of CD44, which results in inhibition of uPA overexpression; (e) bikunin efficiently disrupts PMA-induced clustering of CD44, but does not prevent PMA-induced up-regulation of CD44v isoforms containing epitope v9; and (f) after exposure to bik, approximately 150-kDa band is mainly detected with immunoprecipitation and this band is shown to be a heterodimer composed of the 110-kDa v9-containing CD44v isoforms and a 45-kDa bik receptor (bik-R). In conclusion, we provide, for the first time, evidence that the bik-R can physically interact with the CD44v isoforms containing epitope v9 and function as a repressor to down-regulate PMA-stimulated uPA expression, at least in part, by preventing clustering of CD44v isoforms containing epitope v9.

Plasma and urine levels of urinary trypsin inhibitor in patients with acute and fulminant hepatitis

BACKGROUND AND AIM

Urinary trypsin inhibitor (UTI) is synthesized by hepatocytes and excreted into urine. Plasma and urine UTI levels have been measured to evaluate whether these levels may be useful markers in various pathological conditions. However, there has been no study on plasma and urine UTI levels in patients with acute liver diseases. The aim of the present study was to evaluate plasma and urine UTI levels and their relationship with the severity of hepatic damage in patients with acute liver diseases.

METHODS

Plasma and urine UTI levels were measured by newly developed enzyme-linked immunosorbent assay in 15 patients with acute hepatitis (AH), 12 patients with acute severe hepatitis (ASH) and 10 patients with fulminant hepatitis (FH), as assessed on admission. The serial changes in plasma and urine UTI were also observed in some patients with AH and ASH.

RESULTS

Plasma UTI levels (U/mL, median [25-75th percentile]) were: 11.0, (9.5-16.1) in patients with AH; 7.8 (5.6-11.5) in those with ASH; 6.5 (4.0-9.5) in patients with FH; and 9.7 (7.3-11.0) in normal controls. Plasma UTI levels in patients with FH were significantly lower than in those with AH. Plasma UTI levels showed significant positive correlations with the levels of prothrombin time (PT), hepaplastin test, antithrombin III, alpha2-plasmin inhibitor, plasminogen (Plg) and fibrinogen. After the recovery of liver dysfunction, increased plasma UTI levels in patients with AH were decreased, whereas previously decreased plasma UTI levels in patients with ASH were increased. Urine UTI levels were significantly increased in patients with AH compared with those of normal controls. In patients with ASH and FH, urine UTI levels were increased but not significantly. Urine UTI levels significantly positively correlated with PT and Plg. After the recovery of liver dysfunction, previously increased urine UTI levels in patients with AH were decreased. The correlation between plasma UTI and urine UTI levels was not significant.

CONCLUSIONS

The findings of the present study suggested that the levels of plasma and urine UTI changed in patients with AH and were closely related to the abnormalities of coagulo-fibrinolysis, including PT. Further studies are needed to clarify whether these levels may be useful markers to predict the prognosis of acute hepatitis.

Structure and function analysis of urinary trypsin inhibitor (UTI): identification of binding domains and signaling property of UTI by analysis of truncated proteins

The binding of urinary trypsin inhibitor (UTI) to its binding sites/receptors on tumor cells inhibits cell invasion in a number of experimental systems and that UTI downregulates constitutive and phorbol ester-induced urokinase production by certain tumor cells. To determine whether the carbohydrate moieties and core protein are required for urokinase suppression, we obtained UTI derivatives that contained O-glycoside-linked N-terminal glycopeptide (UTIm1), N-glycoside-linked C-terminal tandem Kunitz domains (UTIm2), UTI lacking O-glycoside (UTIc), asialo UTI (UTIa), UTI lacking N-glycoside (UTIn), purified Kunitz domain II of UTI (HI-8), and recombinant Kunitz domain II of UTI (R-020). The IC(50) of inhibiting binding of (125)I-labeled UTI to cells was indistinguishable for UTIa, UTIn and intact UTI, whereas the IC(50) for inhibiting binding of (125)I-labeled UTI to cells was 2.5-, 25- and 29-fold greater for UTIm1, UTIm2 and UTIc than for native UTI. We next looked at the suppression of the urokinase expression by UTI derivatives. An enzyme-linked immunosorbent assay was carried out to measure secreted and cell-associated urokinase. Intact UTI, UTIa, or UTIn effectively suppressed urokinase expression, but UTIm1, UTIm2, UTIc, HI-8 and R-020 had no significant effect. These data show that UTI requires either the N-terminal extension with the O-linked carbohydrate moiety (chondroitin 4-sulfate sugar side chain; Ala1 to Lys21 residues) or the Kunitz domain I (Lys22 to Arg77 residues) of UTI to bind to cells, but the urokinase expression was inhibited only by the O-glycoside-linked core protein without the N-glycoside side chain.

Characterization of binding properties of urinary trypsin inhibitor to cell-associated binding sites on human chondrosarcoma cell line HCS-2/8

Urinary trypsin inhibitor (UTI) forms membrane complexes with UTI-binding proteins (UTI-BPs) and initiates modulation of urokinase-type plasminogen activator (uPA) expression, which results in UTI-mediated suppression of cell invasiveness. It has been established that suppression of uPA expression and invasiveness by UTI is mediated through inhibition of protein kinase C-dependent signaling pathways and that human chondrosarcoma cell line HCS-2/8 expresses two types of UTI-BPs; a 40-kDa UTI-BP (UTI-BP(40)), which is identical to link protein (LP), and a 45-kDa UTI-BP (UTI-BP(45)). Here we characterize binding properties of UTI-BPs.UTI complexes in the cells. In vitro ligand blot, cell binding and competition assays, and Scatchard analyses demonstrate that both UTI-BP(40) and UTI-BP(45) bind (125)I-UTI. A deglycosylated form of UTI (NG-UTI), from which the chondroitin-sulfate side chain has been removed, binds only to UTI-BP(40). Additional experiments, using various reagents to block binding of (125)I-UTI and NG-UTI to the UTI-BP(40) and UTI-BP(45) confirm that the chondroitin sulfate side chain of UTI is required for its binding to UTI-BP(45). Analysis of binding of (125)I-UTI and NG-UTI to the cells suggests that low affinity binding sites are the UTI-BP(40) (which can bind NG-UTI), and the high affinity sites are the UTI-BP(45). In addition, UTI-induced suppression of phorbol ester stimulated up-regulation of uPA is inhibited by reagents that were shown to prevent binding of UTI to the 40- and 45-kDa proteins. We conclude that UTI must bind to both of the UTI-BPs to suppress uPA up-regulation.

Suppression of urokinase expression and invasiveness by urinary trypsin inhibitor is mediated through inhibition of protein kinase C- and MEK/ERK/c-Jun-dependent signaling pathways

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, interacts with cells as a negative modulator of the invasive cells. Human ovarian cancer cell line, HRA, was treated with phorbol ester (PMA) to evaluate the effect on expression of urokinase-type plasminogen activator (uPA), since the action of uPA has been implicated in matrix degradation and cell motility. Preincubation of the cells with UTI reduced the ability of PMA to trigger the uPA expression at the gene level and at the protein level. UTI-induced down-regulation of PMA-stimulated uPA expression is irreversible and is independent of a cytotoxic effect. Down-regulation of uPA by UTI is mediated by its binding to the cells. We next asked whether the mechanism of inhibition of uPA expression by UTI was due to interference with the protein kinase C second messenger system. An assay for PKC activity demonstrated that UTI does not directly inhibit the catalytic activity of PKC and that PMA translocation of PKC from cytosol to membrane was inhibited by UTI, indicating that UTI inhibits the activation cascade of PKC. PMA could also activate a signaling pathway involving MEK1/ERK2/c-Jun-dependent uPA expression. When cells were preincubated with UTI, we could detect suppression of phosphorylation of these proteins. Like several types of PKC inhibitor, UTI inhibited PMA-stimulated invasiveness. We conclude that UTI markedly suppresses the cell motility possibly through negative regulation of PKC- and MEK/ERK/c-Jun-dependent mechanisms, and that these changes in behavior are correlated with a coordinated down-regulation of uPA which is likely to contribute to the cell invasion processes.

Suppression of urokinase-type plasminogen activator expression from human ovarian cancer cells by urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, efficiently inhibits tumor cell invasion and metastasis. We examined the effect of UTI on urokinase-type plasminogen activator (uPA) expression in ovarian cancer cell lines, HOC-I and HRA. By Northern blot, Western blot, ELISA, and zymographic analyses, we demonstrated that UTI inhibited the expression of uPA mRNA and protein in these cells in a time- and dose-dependent manner, independent of whether induction was triggered by phorbol ester. Monoclonal antibody 4G12, which inhibits UTI binding to the cells, produced a dose-dependent abrogation in UTI-mediated down-regulation of uPA expression. These data suggest that UTI significantly down-regulates tumor cell uPA mRNA expression and protein secretion, and that UTI binding to the cells is necessary to exert the UTI's action.

Human myometrial cells in culture express specific binding sites for urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI), which is present in amniotic fluid, prevents uterine contractility during pregnancy possibly via specific binding protein mechanisms. To test for the presence of UTI binding sites on the cell surface, we prepared cultured myometrial cells obtained at biopsy from 12 pregnant women and performed binding, competition, and cross-linking experiments using a specific radiolabelled UTI as a ligand. We report for the first time two classes of binding sites of differing affinities. Scatchard analysis at 4 degrees C, using radioiodinated UTI, revealed that UTI binds to 35 000 high affinity binding sites/cell (K(d) = 9.1x10(-9) mol/l) and 450 000 lower affinity binding sites/cell (K(d) = 3.5x10(-7) mol/l) in cultured myometrial cells. It appears to be the low affinity site that is internalized, and this has been identified as a protein of approximately 45 kDa by cross-linking and immunoaffinity labelling studies. Monoclonal antibodies against the NH(2)-terminal fragment of UTI abrogated specific binding of this protein to the cells. Treatment of the cells with hyaluronidase resulted in >80% inhibition of the [(125)I]-labelled UTI binding to the cells. These data show that the UTI binding site, which is hyaluronidase sensitive, is expressed on the surface of human uterine myometrial cells to accumulate the UTI molecule during pregnancy.

Identity of urinary trypsin inhibitor-binding protein to link protein

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, directly binds to some types of cells via cell-associated UTI-binding proteins (UTI-BPs). Here we report that the 40-kDa protein (UTI-BP(40)) was purified from the cultured human chondrosarcoma cell line HCS-2/8 by UTI affinity chromatography. Purified UTI-BP(40) was digested with trypsin, and the amino acid sequences of the peptide fragments were determined. The sequences of six tryptic fragments of UTI-BP(40) were identical to subsequences present in human link protein (LP). Authentic bovine LP and UTI-BP(40) displayed identical electrophoretic and chromatographic behavior. The UTI-binding properties of UTI-BP(40) and LP were indistinguishable. Direct binding and competition studies strongly demonstrated that the NH(2)-terminal fragment is the UTI-binding part of the LP molecule, that the COOH-terminal UTI fragment (HI-8) failed to bind the NH(2)-terminal subdomain of the LP molecule, and that LP and UTI-BP(40) exhibited significant hyaluronic acid binding. These results demonstrate that UTI-BP(40) is identical to LP and that the NH(2)-terminal domain of UTI is involved in the interaction with the NH(2)-terminal fragment of LP, which is bound to hyaluronic acid in the extracellular matrix.

Bikunin, a serine protease inhibitor, is present on the cell boundary of epidermis

Bikunin, which is an inhibitor of serine proteases, is widely distributed in human tissues, including liver, kidney, and mucous membranes of the stomach and colon. The aim of this study was to clarify whether bikunin is expressed in human epidermis and its appendages. Immunoblot analysis using a specific polyclonal antibody to bikunin revealed that a single 43 kDa protein is present in the cell lysate from the human keratinocyte cell line HaCaT. Immunohistochemically, dotted reaction products stained with anti-bikunin antibody were localized on the cell boundary in both basal and spinous cell layers, except on the cell boundary of the basal cells facing the basal membrane. There were no reaction products in the granular-horny cell layers. Reaction products stained with anti-bikunin antibody were also observed on the hair bulb cells and eccrine sweat gland cells, but not on apocrine sweat glands. Also, reaction products were observed on the luminal surface of the renal proximal tubules and in the cytoplasm of these cells. In immunoelectron microscopy, gold particles were observed on the cell membranes close to the desmosomal structures. Reverse transcription-polymerase chain reaction and northern blot analyses showed that mRNA specific for bikunin was expressed in HaCaT cells and human epidermal keratinocytes obtained from suction blisters, and was contained in a commercially available human keratinocyte cDNA preparation. These findings indicate that bikunin is expressed in keratinocytes and may play an important part in regulating keratinocytes in either mitosis or inflammation.

Urinary trypsin inhibitor levels in amniotic fluid of normal human pregnancy: decreased levels observed at parturition

OBJECTIVE

Urinary trypsin inhibitor, a light chain of inter-alpha-trypsin inhibitor, is reported to inhibit uterine contractility during pregnancy. The objective was to measure amniotic fluid urinary trypsin inhibitor levels in women throughout pregnancy.

STUDY DESIGN

We determined levels of urinary trypsin inhibitor in human amniotic fluid (n = 40) by means of Western blot analysis. For quantification, computerized scanning and densitometry were used. Results were analyzed for statistical significance with the Mann-Whitney U test.

RESULTS

During pregnancy, mean amniotic fluid urinary trypsin inhibitor levels (+/-SD) were 1.5 +/- 0.22, 1. 2 +/- 0.18, and 0.58 +/- 0.24 micromol/L at 15 to 22 (n = 10), 30 to 35 (n = 5), and 37 to 40 (n = 10) weeks' gestation, respectively. There was a significant negative correlation of urinary trypsin inhibitor level with gestational age. A significant difference was observed in amniotic fluid urinary trypsin inhibitor levels before and after (0.10 +/- 0.03 micromol/L; n = 15) the onset of labor.

CONCLUSION

Amniotic fluid urinary trypsin inhibitor levels decrease significantly at term. These results support the hypothesis that parturition may occur through the down-regulation of urinary trypsin inhibitor, which may decrease uterine contractility and maintain the uterus in a state of quiescence during pregnancy.

Urinary trypsin inhibitor suppresses vascular smooth muscle contraction by inhibition of Ca2+ influx

Urinary trypsin inhibitor (UTI) and its precursor form inter-alpha trypsin inhibitor (ITI) are present in plasma. To determine the action of UTI on blood vessels, we performed isometric vascular muscle contraction tests, microcirculation studies and measurement of cytosolic free Ca2+ in vascular smooth muscle cells. An isometric vascular muscle contraction test showed that the contractions stimulated by endothelin-1 or norepinephrine were suppressed in the presence of UTI, and that the contractions were not inhibited in the presence of ITI. The microcirculation study showed that the contraction of mesenteric arterioles of WKY rats induced by norepinephrine were inhibited by treatment of UTI, and that they did not alter by treatment of ITI. Pre-incubation of UTI, but not ITI, with vascular smooth muscle cells inhibited the increase of cytosolic free Ca2+ induced by endothelin-1 or norepinephrine. Cell-binding study by biotinylated UTI showed that vascular smooth muscle cells have specific binding site for UTI, but not for ITI. We propose that circulating UTI converted from ITI has a regulatory effect on local vascular tone by regulation of Ca2+ influx into smooth muscle cells.

Identification of structural domains in inter-alpha-trypsin involved in calcium oxalate crystallization

The urinary glycoprotein that inhibits calcium oxalate (CaOx) crystallization in vitro shows a structural similarity to urinary trypsin inhibitor (UTI; recently termed bikunin), the light chain of inter-alpha-trypsin inhibitor (I alpha I). The functional domains of I alpha I involved in its inhibitory activity of CaOx crystallization have been investigated using isolated intact domains of I alpha I produced from controlled proteolytic digests of the protein. The fragments investigated include the heavy chains of I alpha I, UTI, chondroitinase AC-treated UTI, and the carboxyl-terminal domain of UTI (termed HI-8). The effects of I alpha I and its fragments on the inhibitory activity of CaOx crystallization were evaluated in vitro using CaOx crystal aggregation and growth assays, and seeded crystal generation assay as well as using crystal matrix protein generation assay. UTI, but not the heavy chains of I alpha I, had a discernible effect on CaOx crystallization inhibitory activity. Less requirement of the carbohydrate moiety of UTI is implicated by the observation that chondroitinase AC-treated UTI fragment was also found to inhibit CaOx crystallization with almost the same activity as UTI. HI-8 also efficiently inhibited CaOx crystallization, while I alpha I showed a weak inhibitory activity. The results are almost consistent with a seed crystal generation assay and a crystal adsorption inhibition assay, in which I alpha I or its derivatives inhibits prothrombin fragment 1 (F1) adsorption to CaOx crystals. In conclusion, these results suggest that the part of the I alpha I protein responsible for inhibition of CaOx crystallization is the carboxyl-terminal domain of UTI.

Identification and characterization of the cell-associated binding protein for urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI) inhibits not only tumor cell invasion but also production of experimental and spontaneous metastasis. Cell-binding experiments indicated that human choriocarcinoma SMT-cc1 cells have specific binding sites for UTI on their cell surface. [Kobayashi et al., J. Biol. Chem. 269, 1994, 20,642-20,647]. UTI binding protein (UTIBP) was purified to homogeneity by a combination of UTI-coupled affinity beads, preparative polyacrylamide gel electrophoresis and reverse phase HPLC. This protein is very similar to a truncated form of human cartilage link protein (LP). LP was identified structurally by its apparent molecular mass with and without deglycosylation treatment: Immunologically by the reactivity with anti-UTIBP antibody, and functionally by its ability to bind the NH2-terminal domain of UTI. UTI and UTIBP are distributed uniformly in the cytoplasm and/or over the cell surface of tumor cells and fibroblasts. The level of staining for hyaluronic acid, UTIBP and UTI is much lower in sections digested with hyaluronidase. These results suggest that the cell membrane-derived UTI-associated binding protein is the LP of proteoglycan-hyaluronic acid aggregates, which interacts with hyaluronic acid. Cell-associated LP may play a role in modulating protease activity to the environment close to tumor and fibroblast cell surface.

Urinary trypsin inhibitor reduces the release of histamine from rat peritoneal mast cells

We determined the ability of urinary trypsin inhibitor (UTI), which is a Kunitz-type protease inhibitor present in serum and in urine, to inhibit rat peritoneal mast cell (RPMC) mediator release induced by several stimuli. UTI attenuated the immunoglobulin E-mediated release of both preformed (histamine) and newly formed (leukotriene C4) mediators from RPMCs. Inhibition (21%+/-5%) of the anti-IgE-triggered release of histamine was observed after a 30-minute incubation of RPMCs with UTI (5 micromol/L). To investigate the specificity of the UTI effect, we studied the stimulatory activity of phorbol ester (phorbol 12-myristate 13-acetate (PMA)) or calcium ionophore A23187 in control and UTI-treated mast cells. The efficacy of UTI as an inhibitor was dependent on the nature of the stimulus, because histamine release induced by PMA-mediated or calcium ionophore A23187-mediated processes was not inhibited by UTI. A series of structurally distinct protease inhibitors did not inhibit IgE-induced release of mediators from RPMCs. The Kunitz-type protease inhibitors are important in the regulation of RPMC function. In parallel with the UTI-related decrease in anti-IgE stimulatory activity on mediator release, increased microviscosity of membrane lipids could be observed by two independent experiments on fluorescence polarization with diphenylhexatriene (DPH) and on the fluorescence probe fluorescein isothiocyanate-concanavalin A. UTI reduces mediator release by a mechanism-possibly an interruption of the coupling of receptor and effector systems-because UTI acts as an agent to decrease biologic lipid membrane fluidity.

The crystal structure of bikunin from the inter-alpha-inhibitor complex: a serine protease inhibitor with two Kunitz domains

Bikunin is a serine protease inhibitor found in the blood serum and urine of humans and other animals. Its sequence shows internal repetition, suggesting that it contains two domains that resemble bovine pancreatic trypsin inhibitor (BPTI). A fragment of bikunin has been crystallised, its structure solved and subsequently refined against 2.5 A data. The two BPTI-like domains pack closely together and are related by an approximate 60 degrees rotation combined with a translation. These domains are very similar to each other and other proteins with this fold. The largest variations occur in the loops responsible for protease recognition. The loops of the first domain are unobstructed by the remaining protein. However, the loops of the second domain are close to the first domain and it is possible that protease binding may be affected or, in some cases, abolished by the presence of the first domain. Thus, cleavage of the two domains could alter the substrate specificity of domain II. Bikunin has a hydrophobic patch close to the N terminus of domain I, which is the most likely site for cell-surface receptor binding. In addition, there is a basic patch at one end of domain II that may be responsible for the inhibition of calcium oxalate crystallization in urine.

Urinary trypsin inhibitor suppresses the production of interstitial procollagenase/proMMP-1 and prostromelysin 1/proMMP-3 in human uterine cervical fibroblasts and chorionic cells

The mechanisms by which urinary trypsin inhibitor (UTI) prevents preterm premature rupture of fetal membrane and premature cervical ripening were investigated. We, therefore, examined the effects of UTI on the production of matrix metalloproteinases (MMPs) which closely participate in the breakdown of extracellular matrix in cultured human uterine cervical fibroblasts and human chorionic cells. UTI suppressed specifically the production of interstitial procollagenase/proMMP-1 and prostromelysin 1/proMMP-3 from both cells in a dose-dependent manner (0.32-1.28 microM). This suppression was accompanied by a decrease in steady-state levels of their mRNAs. These results indicate for the first time that UTI down-regulates the production of proMMP-1 and proMMP-3 accompanying with the decrease in the expression of their mRNAs, and therefore UTI actually participates in the maintenance of fetal membranes and/or uterine cervix by overall suppression of MMP production along with the known inhibitory actions towards serine proteinases.

Ulinastatin, a human trypsin inhibitor, inhibits endotoxin-induced thromboxane B2 production in human monocytes

OBJECTIVES

Ulinastatin has an inhibitory effect on certain cytokines produced from lipopolysaccharide (endotoxin)-stimulated human monocytes. However, the effects of ulinastatin on arachidonic acid metabolism in monocytes have not been determined. This study examined the effects of ulinastatin on the arachidonic acid metabolite, thromboxane B2, in response to endotoxin-, phorbol 12-myristate 13-acetate-, or arachidonic acid-stimulated human peripheral blood monocytes.

DESIGN

Controlled, human laboratory investigation of monocyte function in vitro.

SETTING

Research facility of a health science university.

SUBJECTS

Five normal volunteers.

INTERVENTIONS

Mononuclear cells were separated from blood using Histopaque. Monocytes were stimulated with endotoxin (0.1 to 10 micrograms/mL) or other stimulatory agents, which were added simultaneously with or without ulinastatin (25 to 1000 U/mL). None of the compounds in this study altered the cell viability of adherent cellular protein content. Ulinastatin alone did not affect basal thromboxane B2.

MEASUREMENTS AND MAIN RESULTS

Endotoxin induced dose-dependent increases in thromboxane B2 production by the monocytes. Ulinastatin (100 U/mL) maximally decreased endotoxin (1.0 microgram/mL)-stimulated thromboxane B2 production, which was not further suppressed with higher ulinastatin concentrations. Increases in thromboxane B2, stimulated by phorbol myristic acid (10 nM) or arachidonic acid (16 microM), were also suppressed by ulinastatin at 100 to 1000 U/mL.

CONCLUSIONS

These results indicate that ulinastatin may nonspecifically but moderately down-regulate stimulated arachidonic acid metabolism in human monocytes. Therefore, the present results warrant further clinical studies to examine the beneficial effects of ulinastatin in the treatment of patients with sepsis syndrome.

Granulocyte-colony stimulating factor promotes invasion by human lung cancer cell lines in vitro

The effects of exogenous and endogenous granulocyte colony-stimulating factor (G-CSF) on invasion by cancer cells were studied, using lung cancer cell lines that produce G-CSF (NCI-H157) and lines that do not (PC-9 and NCI-H23). The invasive capacity of NCI-H157 cells was 26- to 27-fold higher than that of PC-9 and NCI-H23 cells. The invasiveness of PC-9 cells was stimulated by exogenous G-CSF, while that of NCI-H157 cells was not. Antibodies against G-CSF blocked the stimulation of PC-9 cell invasiveness by exogenous G-CSF. Anti G-CSF antibodies also inhibited invasion by NCI-H157 cells in the absence of exogenous G-CSF. These results suggest that endogenous and exogenous G-CSF both stimulate invasion by lung cancer cells.

Inter-alpha-trypsin inhibitor bound to tumor cells is cleaved into the heavy chains and the light chain on the cell surface

Inter-alpha-trypsin inhibitor (ITI), a human serum protease inhibitor of molecular mass 240 kDa which may release physiological derivatives, has been shown to interact with hyaluronic acid (HA), resulting in pericellular matrix stabilization (Chen, L., Mao, S.J.T., McLean, L. R., Powers, R. W., and Larsen, W. J. (1994) J. Biol. Chem. 269, 28282-28287). The purpose of this study is to determine whether ITI binding to tumor cell surface is mediated by urinary trypsin inhibitor (UTI)-receptor or cell-associated hyaluronic acid (HA). We demonstrated specific complex formation of the heavy (H) chains of ITI with HA. Binding of the H-chains of ITI to immobilized HA was detected and quantified using colorimetric immunoassays. Binding was time-, temperature-, and concentration-dependent. However, UTI and HI-8 (the carboxyl terminus of UTI) failed to bind to immobilized HA. ITI bound to HA remained functional protease inhibiting activity. After incubation of SMT-cc1 cells with purified biotinylated ITI, biotinylated ITI is bound to the cells, dissociated, and gives rise to the H-chains and UTI on the cell surface. The cell surface receptor-bound UTI derived from ITI may be the result of the limited proteolysis on the cell surface. In the cells treated with hyaluronidase, bound H-chains disappeared from the surface of the cells, while most of the cell surface ITI derivatives was present in deglycosylated UTI (28 kDa). It is suggested that the binding of ITI to the cell surface is mediated by HA on the cells. This was confirmed by the fact that the hyaluronidase-treated cells can abolish the ITI binding. The cell surface UTI formation was inhibited by diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride, and eglin C, suggesting that elastase-like enzyme(s) may be responsible for the UTI formation. Preincubation of the cells with UTI did not decrease in exogenously added ITI on the cell surface. A model for cell surface UTI formation is proposed in which ITI binding to cells from serum used for the culture is followed by the limited proteolysis by trace amounts of active serine proteases, to form cell-surface receptor-bound UTI and the H-chains intercalated into cell surface HA. This process is subject to regulation of cell-associated UTI and of stabilization of pericellular matrix.

Evidence for the covalent binding of SHAP, heavy chains of inter-alpha-trypsin inhibitor, to hyaluronan

We previously showed that serum-derived 85-kDa proteins (SHAPs, serum-derived hyaluronan associated proteins) are firmly bound to hyaluronan (HA) synthesized by cultured fibroblasts. SHAPs were then identified to be the heavy chains of inter-alpha-trypsin inhibitor (ITI) (Huang, L., Yoneda, M., and Kimata, K. (1993) J. Biol. Chem. 268, 26725-26730). In this study, the SHAP.HA complex was isolated from pathological synovial fluid from human arthritis patients. The SHAP.HA complex was digested with thermolysin, followed by CsCl gradient centrifugation. The HA-containing fragments thus obtained were further digested with chondroitinase AC II and subjected to TSK gel high performance liquid chromatography (HPLC). Peptide-HA disaccharide-containing fractions (the SHAP.HA binding regions) were further purified by reverse phase HPLC. Major peaks were analyzed by protein sequencing and mass spectrometry (electrospray ionization mass spectrometry and collision induced dissociation-MS/MS). By comparison with the reported C-terminal sequences of the human ITI family, the peptides were found to correspond to tetrapeptides derived from the C termini of heavy chains 1 of and 2 of inter-alpha-trypsin inhibitor (HC1 and HC2), and heavy chain 3 of pre-alpha-trypsin inhibitor (HC3), respectively, and a heptapeptide from HC1. Mass spectrometric analyses suggested that the C-terminal Asp of each heavy chain was esterified to the C6-hydroxyl group of an internal N-acetylglucosamine of HA chain. This report is the first demonstration to give evidence for the covalent binding of proteins to HA.

Inhibitory effect of a conjugate between human urokinase and urinary trypsin inhibitor on tumor cell invasion in vitro

Proteolytic enzymes such as urokinase-type plasminogen activator (uPA), plasmin, and collagenase mediate proteolysis by a variety of tumor cells. uPA secreted by tumor cells can be bound to a cell surface receptor via a growth factor-like domain within the amino-terminal fragment (ATF) of the uPA molecule with high affinity. Urinary trypsin inhibitor (UTI) efficiently inhibits the soluble and the tumor cell-surface receptor-bound plasmin and subsequently reduces tumor cell invasion and the formation of metastasis. The anti-invasive effect is dependent on the anti-plasmin activity of the UTI molecule, domain II in particular. We synthesized a conjugate between ATF of human uPA and a native UTI molecule or domain II of UTI (HI-8). The effect of the conjugates (ATF.UTI or ATF.HI-8) on tumor cell invasion in vitro was investigated. ATF.UTI and ATF.HI-8 bound to U937 cells in a rapid, saturable, dose-dependent, and reversible manner. A large part of receptor-bound ATF-UTI and ATF.HI-8 remains on the cell surface for at least 5 h at 37 degrees C. Inhibition of tumor cell-surface receptor-bound plasmin by ATF.UTI and ATF.HI-8 was markedly enhanced when compared with tumor cells treated either with ATF, UTI, or HI-8. Results of a cell invasion assay showed that ATF.UTI and ATF.HI-8 is very effective at targeting HI-8 specifically to uPA receptor-expressing tumor cells, whereas tumor cells devoid of uPA receptor may be less affected by the conjugates. Our results indicate that cell surface uPA and plasmin activity is essential to the invasive process and that the conjugates exhibit plasmin inhibition to the close environment of the cell surface and subsequently inhibit the tumor cell invasion through Matrigel in an in vitro invasion assay.