Novel purification of vitronectin from human plasma by heparin affinity chromatography

The glycoprotein vitronectin (also called S-protein, serum spreading factor, or epibolin) promotes spreading of a variety of cultured cells, inhibits the cytotoxicity of membrane attack complex C5b-9, and modulates thrombin-antithrombin III activity. We developed a strikingly simple method to purify vitronectin from human plasma by heparin affinity chromatography. Serum was obtained from plasma by adding calcium and then centrifuging. The heparin-binding activity of vitronectin in human serum was activated with 8 M urea. The activated vitronectin specifically bound to heparin-Sepharose in 8 M urea and was eluted with 0.5 M NaCl containing 8 M urea. This procedure resulted in an approximately 250-fold purification of vitronectin with a 15-30% recovery; 3-6 mg of pure vitronectin were obtained from 100 ml human plasma within 2 days. The purified vitronectin preparations promoted spreading of BHK fibroblastic cells on substrates with a half-maximal activity at only 0.1 microgram/ml. This new method is very simple, rapid, inexpensive, and flexible. It could probably be readily scaled up for commercial applications.

Reduced uptake of oxidized low density lipoproteins in monocyte-derived macrophages from CD36-deficient subjects

To clarify the physiological roles of CD36 as an oxidized low density lipoprotein (OxLDL) receptor, we analyzed the monocyte-derived macrophages from normal and two CD36-deficient subjects, since we identified the molecular abnormalities (Kashiwagi, H., Y. Tomiyama, Y. Kosugi, M. Shiraga, R. H. Lipsky, Y. Kanayama, Y. Kurata, and Y. Matsuzawa 1994. Blood. 83:3545-3552; and Kashiwagi, H., Y. Tomiyama, S. Honda, S. Kosugi, M. Shiraga, N. Nagao, S. Sekiguchi, Y. Kanayama, Y. Kurata, and Y. Matsuzawa. 1995. J. Clin. Invest. 95:1040-1046). Scatchard analysis of 125I-OxLDL binding showed a linear plot and the maximum binding was lower by approximately 40% in the macrophages from subjects with CD36 deficiency than those from normal controls. Competition studies showed that the uptake of 125I-OxLDL was suppressed by OKM5, an antibody against CD36, by 53% in normal control macrophages, but not in the CD36-deficient macrophages. After incubation with OxLDL for 24 h, cholesteryl ester mass accumulation was reduced by approximately 40% in the macrophages from CD36-deficient subjects than those from normal controls. These results suggest that CD36 is one of the physiological receptors for OxLDL. Since specific binding of OxLDL was only reduced by approximately 40% in spite of the complete deficiency of CD36, several other receptors also may have some role in OxLDL uptake. Further studies will be needed to assess the quantitative role of CD36 in foam cell formation in vivo.

Benefits of adjuvant radiotherapy after radical resection of locally advanced main hepatic duct carcinoma

PURPOSE

The objective of this study was to determine the benefits of adjuvant radiotherapy after radical resection of locally advanced main hepatic duct carcinoma (Klatskin tumor).

METHODS AND MATERIALS

We conducted a retrospective review of 63 patients who underwent surgical resection of Stage IVA Klatskin tumor. Of the 63 patients, 47 had microscopic tumor residue (RT1). Twenty-eight of the 47 patients with RT1 were treated by adjuvant radiotherapy and the remaining 19 patients were treated exclusively by surgical resection. Seventeen of the 28 patients with RT1 were treated by both intraoperative radiotherapy (IORT) and postoperative radiotherapy (PORT); of the remaining 11 patients with RT1, 6 underwent resection and IORT, and 5 underwent resection and PORT.

RESULTS

The major complication and 30-day operative death rates were significantly lower in the radiation group (9.5% and 0.0%, respectively) than in the resection alone group (28.5% and 9.5%, respectively). Of the eight 5-year survivors with RT1, 6 had adjuvant radiotherapy and the remaining 2 had resection alone. Adjuvant radiotherapy for patients with RT1 yielded significantly (p = 0.0141) higher 5-year survival rates (33.9%) than in the resection alone group (13.5 %). The best 5-year survival rate (39.2 %) was found in patients who underwent a combination of IORT and PORT after resection. The local-regional control rate was significantly higher in the adjuvant radiation group than in the resection alone group (79.2% vs. 31.2%).

CONCLUSION

Our data clearly suggest the improved prognosis of patients with locally advanced Klatskin tumor by integrated adjuvant radiotherapy with IORT and PORT to complete gross tumor resection with acceptable treatment mortality and morbidity.

Affinity modulation of platelet integrin alphaIIbbeta3 by beta3-endonexin, a selective binding partner of the beta3 integrin cytoplasmic tail

Platelet agonists increase the affinity state of integrin alphaIIbbeta3, a prerequisite for fibrinogen binding and platelet aggregation. This process may be triggered by a regulatory molecule(s) that binds to the integrin cytoplasmic tails, causing a structural change in the receptor. beta3-Endonexin is a novel 111-amino acid protein that binds selectively to the beta3 tail. Since beta3-endonexin is present in platelets, we asked whether it can affect alphaIIbbeta3 function. When beta3-endonexin was fused to green fluorescent protein (GFP) and transfected into CHO cells, it was found in both the cytoplasm and the nucleus and could be detected on Western blots of cell lysates. PAC1, a fibrinogen-mimetic mAb, was used to monitor alphaIIbbeta3 affinity state in transfected cells by flow cytometry. Cells transfected with GFP and alphaIIbbeta3 bound little or no PAC1. However, those transfected with GFP/beta3-endonexin and alphaIIbbeta3 bound PAC1 specifically in an energy-dependent fashion, and they underwent fibrinogen-dependent aggregation. GFP/beta3-endonexin did not affect levels of surface expression of alphaIIbbeta3 nor did it modulate the affinity of an alphaIIbbeta3 mutant that is defective in binding to beta3-endonexin. Affinity modulation of alphaIIbbeta3 by GFP/beta3-endonexin was inhibited by coexpression of either a monomeric beta3 cytoplasmic tail chimera or an activated form of H-Ras. These results demonstrate that beta3-endonexin can modulate the affinity state of alphaIIbbeta3 in a manner that is structurally specific and subject to metabolic regulation. By analogy, the adhesive function of platelets may be regulated by such protein-protein interactions at the level of the cytoplasmic tails of alphaIIbbeta3.

Induction of Th17 cells in the tumor microenvironment improves survival in a murine model of pancreatic cancer

An important mechanism by which pancreatic cancer avoids antitumor immunity is by recruiting regulatory T cells (Tregs) to the tumor microenvironment. Recent studies suggest that suppressor Tregs and effector Th17 cells share a common lineage and differentiate based on the presence of certain cytokines in the microenvironment. Because IL-6 in the presence of TGF-β has been shown to inhibit Treg development and induce Th17 cells, we hypothesized that altering the tumor cytokine environment could induce Th17 and reverse tumor-associated immune suppression. Pan02 murine pancreatic tumor cells that secrete TGF-β were transduced with the gene encoding IL-6. C57BL/6 mice were injected s.c. with wild-type (WT), empty vector (EV), or IL-6-transduced Pan02 cells (IL-6 Pan02) to investigate the impact of IL-6 secretion in the tumor microenvironment. Mice bearing IL-6 Pan02 tumors demonstrated significant delay in tumor growth and better overall median survival compared with mice bearing WT or EV Pan02 tumors. Immunohistochemical analysis demonstrated an increase in Th17 cells (CD4(+)IL-23R(+) cells and CD4(+)IL-17(+) cells) in tumors of the IL-6 Pan02 group compared with WT or EV Pan02 tumors. The upregulation of IL-17-secreting CD4(+) tumor-infiltrating lymphocytes was substantiated at the cellular level by flow cytometry and ELISPOT assay and mRNA level for retinoic acid-related orphan receptor γt and IL-23R by RT-PCR. Thus, the addition of IL-6 to the tumor microenvironment skews the balance toward Th17 cells in a murine model of pancreatic cancer. The delayed tumor growth and improved survival suggests that induction of Th17 in the tumor microenvironment produces an antitumor effect.

Selective sigma-2 ligands preferentially bind to pancreatic adenocarcinomas: applications in diagnostic imaging and therapy

BACKGROUND

Resistance to modern adjuvant treatment is in part due to the failure of programmed cell death. Therefore the molecules that execute the apoptotic program are potential targets for the development of anti-cancer therapeutics. The sigma-2 receptor has been found to be over-expressed in some types of malignant tumors, and, recently, small molecule ligands to the sigma-2 receptor were found to induce cancer cell apoptosis.

RESULTS

The sigma-2 receptor was expressed at high levels in both human and murine pancreas cancer cell lines, with minimal or limited expression in normal tissues, including: brain, kidney, liver, lung, pancreas and spleen. Micro-PET imaging was used to demonstrate that the sigma-2 receptor was preferentially expressed in tumor as opposed to normal tissues in pancreas tumor allograft-bearing mice. Two structurally distinct sigma-2 receptor ligands, SV119 and WC26, were found to induce apoptosis to mice and human pancreatic cancer cells in vitro and in vivo. Sigma-2 receptor ligands induced apoptosis in a dose dependent fashion in all pancreatic cell lines tested. At the highest dose tested (10 muM), all sigma-2 receptor ligands induced 10-20% apoptosis in all pancreatic cancer cell lines tested (p < 0.05). In pancreas tumor allograft-bearing mice, a single bolus dose of WC26 caused approximately 50% apoptosis in the tumor compared to no appreciable apoptosis in tumor-bearing, vehicle-injected control animals (p < 0.0001). WC26 significantly slowed tumor growth after a 5 day treatment compared to vehicle-injected control animals (p < 0.0001) and blood chemistry panels suggested that there is minimal peripheral toxicity.

CONCLUSION

We demonstrate a novel therapeutic strategy that induces a significant increase in pancreas cancer cell death. This strategy highlights a new potential target for the treatment of pancreas cancer, which has little in the way of effective treatments.

Radical resection of hilar bile duct carcinoma and predictors of survival

BACKGROUND

Patients with carcinoma of the main hepatic duct have a poor prognosis. This study attempted to identify clinicopathological predictors of survival after resection.

METHODS

A retrospective review was performed of 114 patients who presented with hepatic ductal carcinoma between 1976 and 1998. Of the 114 patients, 98 had a radical resection, three underwent palliative resection and 13 were not treated surgically. Forty-six patients with stage IVA disease had microscopic tumour residue after resection. Of these, 28 patients were treated with radiotherapy and the remaining 18 had resection alone.

RESULTS

The overall operative morbidity and mortality rates were 14 and 4 per cent respectively. The overall 5-year survival rate after resection was 28 per cent. Nineteen patients survived for more than 5 years, including ten with stage IVA disease. The main prognostic factors were performance status; jaundice; tumour location; gross appearance; histological grade; T, N and M categories in tumour node metastasis (TNM) classification; TNM stage; and residual tumour. Adjuvant radiotherapy, tumour extension into the hepatic ducts, histological grade, N and residual tumour were independent predictive factors by multivariate Cox analysis.

CONCLUSION

This study suggests that radical resection provides the best survival rate for patients with hilar bile duct carcinoma. For patients with stage IVA disease, following complete gross resection radiotherapy improved treatment outcome.

Molecular basis of CD36 deficiency. Evidence that a 478C-->T substitution (proline90-->serine) in CD36 cDNA accounts for CD36 deficiency

CD36 deficiency is divided into two subgroups: neither platelets nor monocytes express CD36 (type I deficiency), and monocytes express CD36 in spite of the lack of platelet CD36 (type II deficiency). We have already demonstrated that a 478C-->T substitution (proline90-->serine) in platelet CD36 cDNA predominates in type II deficiency (Kashiwagi, H., S. Honda, Y. Tomiyama, H. Mizutani, H. Take, Y. Honda, S. Kosugi, Y. Kanayama, Y. Kurata, and Y. Matsuzawa. 1993. Thromb. Haemostasis. 69:481-484). In this study, we revealed that monocyte CD36 cDNA from two type II deficient subjects was heterozygous for C478 and T478 form, while platelet CD36 cDNA of these subjects consisted of only T478 form. In a type I deficient subject, both platelet and monocyte CD36 cDNA showed only T478 form. Expression assay using C478 or T478 form of CD36 cDNA transfected cells revealed that there was an 81-kD precursor form of CD36, and that the maturation of the 81-kD precursor form to the 88-kD mature form of CD36 was markedly impaired by the substitution. The mutated precursor form of CD36 was subsequently degraded in the cytoplasm. These results indicate that the 478C-->T substitution directly leads to CD36 deficiency via defects in posttranslational modification, and that this substitution is the major defects underlying CD36 deficiency.

Diagnostic value of tests for reticulated platelets, plasma glycocalicin, and thrombopoietin levels for discriminating between hyperdestructive and hypoplastic thrombocytopenia

We measured reticulated platelets (RPs) and plasma glycocalicin (GC) and thrombopoietin (TPO) levels simultaneously in 107 thrombocytopenic patients to clarify the diagnostic value of these tests for discriminating hyperdestructive from hypoplastic thrombocytopenia. The percentage of RPs and GC index (plasma GC level normalized for the individual platelet count) were markedly elevated in patients with idiopathic thrombocytopenic purpura (ITP) but normal or slightly elevated in patients with aplastic anemia (AA) or chemotherapy-induced thrombocytopenia (ChemoT). For RP percentage for diagnosing hyperdestructive thrombocytopenia the sensitivity and specificity were excellent but were lower for the GC index. Absolute RP counts and plasma GC levels were markedly decreased and plasma TPO levels markedly elevated in patients with AA or ChemoT, but absolute RP counts and plasma GC levels were moderately decreased and plasma TPO levels only slightly elevated in patients with ITP. The sensitivity and specificity of plasma TPO levels for diagnosing hypoplastic thrombocytopenia were excellent. Using the RP percentage and plasma TPO levels in combination improved specificities. Simultaneous measurement of RP percentage and plasma TPO level may help discriminate thrombocytopenia of unknown cause in routine hematologic practice.

Establishment of surgically induced chronic acid reflux esophagitis in rats

BACKGROUND

The purpose of the study was to establish an animal model of chronic acid reflux esophagitis which could be used for further investigations of the pathophysiology of reflux esophagitis.

METHODS

Esophagitis was produced by ligating the transitional region between the forestomach and the glandular portion with a 2-0 silk thread and covering the duodenum near the pylorus ring with a small piece of an 18Fr Nélaton catheter. The histologic features of the esophagus were examined, and the survival rate of these animals was investigated. Moreover, the effects of lansoprazole on this model was studied.

RESULTS

The 3-week survival rate was 90%, and esophagitis was noted in all rats. Esophagitis was found 2 or 3 cm above the esophagogastric junction in most cases and at 4.0+/-2.3 sites per animal. Histopathologically, there were increased thickness of the esophageal epithelium, elongation of the lamina propria papillae, which extended upward into the epithelium, marked inflammatory cell infiltration, interruption of the lamina muscularis mucosae, and increase of collagen fibers in the lamina propria and submucosa. These signs were in accord with the histologic features of typical chronic esophagitis. No signs of esophagitis were observed, except in one animal, in the rats given 1 mg/kg/day of lansoprazole.

CONCLUSIONS

This experimental rat model is considered useful as a model of chronic acid-type esophagitis for the evaluation of the pathophysiology of reflux esophagitis and the evaluation of drug efficacy.

Impaired platelet function in a patient with P2Y12 deficiency caused by a mutation in the translation initiation codon

In this study, we have identified a patient (OSP-1) with a congenital P2Y12 deficiency showing a mild bleeding tendency from her childhood and examined the role of P2Y12 in platelet function. At low concentrations of agonists OSP-1 platelets showed an impaired aggregation to several kinds of stimuli, whereas at high concentrations they showed a specifically impaired platelet aggregation to adenosine diphosphate (ADP). ADP normally induced platelet shape change and failed to inhibit PGE1-stimulated cAMP accumulation in OSP-1 platelets. Molecular genetic analysis revealed that OSP-1 was a homozygous for a mutation in the translation initiation codon (ATG to AGG) in the P2Y12 gene. Heterologous cell expression of wild-type or mutant P2Y12 confirmed that the mutation was responsible for the deficiency in P2Y12. OSP-1 platelets showed a markedly impaired platelet spreading onto immobilized fibrinogen. Real-time observations of thrombogenesis under a high shear rate (2000 s(-1)) revealed that thrombi over collagen were small and loosely packed and most of the aggregates were unable to resist against high shear stress in OSP-1. Our data suggest that secretion of endogenous ADP and subsequent P2Y12-mediated signaling are critical for platelet aggregation, platelet spreading, and as a consequence, for stabilization of thrombus.

Sigma-2 receptor ligands potentiate conventional chemotherapies and improve survival in models of pancreatic adenocarcinoma

BACKGROUND

We have previously reported that the sigma-2 receptor is highly expressed in pancreas cancer. Furthermore, we have demonstrated that sigma-2 receptor specific ligands induce apoptosis in a dose-dependent fashion. Here, we examined whether sigma-2 receptor ligands potentiate conventional chemotherapies such as gemcitabine and paclitaxel.

METHODS

Mouse (Panc-02) and human (CFPAC-1, Panc-1, AsPC-1) pancreas cancer cell lines were used in this study. Apoptosis was determined by FACS or immunohistochemical analysis after TUNEL and Caspase-3 staining. Combination therapy with the sigma-2 ligand SV119 and the conventional chemotherapies gemcitabine and paclitaxel was evaluated in an allogenic animal model of pancreas cancer.

RESULTS

SV119, gemcitabine, and paclitaxel induced apoptosis in a dose-dependent fashion in all pancreas cancer cell lines tested. Combinations demonstrated increases in apoptosis. Mice were treated with SV119 (1 mg/day) which was administered in combination with paclitaxel (300 microg/day) over 7 days to mice with established tumors. A survival benefit was observed with combination therapy (p = 0.0002). Every other day treatment of SV119 (1 mg/day) in combination with weekly treatment of gemcitabine (1.5 mg/week) for 2 weeks also showed a survival benefit (p = 0.046). Animals tolerated the combination therapy and no gross toxicity was noted in serum biochemistry data or on necropsy.

CONCLUSION

SV119 augments tumoricidal activity of paclitaxel and gemcitabine without major side effects. These results highlight the potential utility of the sigma-2 ligand as an adjuvant treatment in pancreas cancer.

1q23 gain is associated with progressive neuroblastoma resistant to aggressive treatment

Neuroblastoma is one of the most common malignant tumors of childhood and is characterized by regressive and progressive disease. Genetic factors that define progression of neuroblastomas are still unknown. We performed comparative genomic hybridization (CGH) on 27 neuroblastomas and dual-color fluorescence in situ hybridization (FISH) to identify genetic aberrations associated with progressive neuroblastoma showing resistance to aggressive treatment. 17q21-q25 gains and MYCN amplification were associated with stage 4 neuroblastomas; however, these genetic aberrations had no significant relation to the progression of stage 4 neuroblastomas. A novel chromosomal gain at 1q21-q25 was found in 8 of 16 cases (50%) of stage 4 neuroblastoma. Gain of 1q21-q25 was observed in all of the progressive cases (8/8), which showed resistance to chemotherapy, including 5 fatal neuroblastomas in stage 4, whereas 1q21-q25 gain was not found in any of the 8 remission cases in stage 4. Survival analysis also showed that 1q21-q25 gain was associated with a poor outcome. High xenotransplantability in nude mice was observed for the tumors with 1q21-q25 gain (4/5; 80%). These data show that 1q21-q25 gain is strongly associated with progression of stage 4 neuroblastoma. Furthermore, by dual-color FISH analysis using cosmid clones, the 1q21-q25 gain was narrowed to increase in DNA copy number on 1q23 in the fatal type of stage 4 neuroblastoma showing this gain. These results suggest that DNA amplification at 1q23 may play a role in the development of progressive neuroblastoma in an advanced stage.

Activation of vitronectin (serum spreading factor) binding of heparin by denaturing agents

Vitronectin (serum spreading factor), a cell-adhesive glycoprotein present in mammalian serum, has previously been the subject of conflicting reports concerning its binding to heparin. Vitronectin purified from human plasma does not bind to heparin under physiological conditions, but it does so after treatment with denaturing agents including 8 M urea or 6 M guanidine-HC1, or heating at 100 degrees C for 5 min. These treatments seem to expose a heparin-binding site in vitronectin; this finding thus resolves the conflicts concerning this function.

TAT-Bim Induces Extensive Apoptosis in Cancer Cells

BACKGROUND

Suppression of apoptosis is central to the development of cancer and is associated with resistance to modern adjuvant treatments. Therefore, molecules and pathways of apoptotic processes are critical targets for the development of anti-cancer therapeutics. Since apoptosis is executed by intracellular proteins, molecular approaches must incorporate a method to deliver the treatment into the tumor cells.

METHODS

We utilized a peptide that contains two domains, a peptide transduction domain derived from the HIV-1 TAT protein and a biological effector domain, the BH3 domain from the pro-apoptotic Bcl-2 family member Bim. We examined whether this construct (TAT-Bim) induced apoptosis in several cancer cell lines (T-cell lymphoma (EL4), pancreatic cancer (Panc-02), and melanoma (B16)) and whether TAT-Bim treatment synergized with radiation. A mutant TAT-Bim peptide with no biologic activity (TAT-Bim-inactive) was used as a control. C57/BL6 mice were challenged with syngeneic cancer cell lines and the effects of intratumoral TAT-Bim injection on tumor growth and host survival were determined.

RESULTS

TAT-Bim was internalized by all cancer cells within two hours. TAT-Bim resulted in apoptosis in a dose dependent fashion in all cell lines and sublethal irradiation augmented the effects of TAT-Bim induced apoptosis. TAT-Bim significantly slowed tumor growth in murine models of pancreatic cancer and melanoma.

CONCLUSION

TAT-Bim exemplifies a strategy for cancer therapy that involves inducing apoptosis by antagonizing the endogenous anti-apoptotic machinery. Small peptide therapeutics, in combination with traditional adjuvant therapies such as radiation, may provide a valuable 'second hit' and drive tumor cells into programmed cell death.

Microsatellite instability in inflamed and neoplastic epithelium in ulcerative colitis

BACKGROUND

Several genetic alterations have been documented in dysplasia and cancer developing in ulcerative colitis (UC). However, the microsatellite instability (MSI) status has rarely been described, especially in the inflamed epithelium of UC.

AIMS

To study MSI status during neoplastic and inflammatory changes in UC.

METHODS

Seventy five surgically resected samples of colorectal mucosa, taken from 16 colectomy specimens of patients with UC were examined: five patients had a long duration with dysplasia or cancer (UC-LD with neoplasm), seven patients had a long duration without neoplastic changes (UC-LD without neoplasm), and four patients had a short duration without neoplastic changes (UC-SD). In addition to MSI status examined by six microsatellite markers, p53 expression was compared among the three groups.

RESULTS

With regard to non-neoplastic inflamed epithelium, MSI in two or more loci (MSI> or =2) was seen more frequently in the UC-LD without neoplasm group than in the UC-SD group (six of 14 v one of 12; p = 0.060), and significantly more often than in the UC-LD with neoplasm group (six of 14 v two of 23; p = 0.016). In the UC-LD without neoplasm group, MSI> or =2 was detected significantly more frequently in patients with severe inflammation than in those with mild inflammation (six of nine v none of five; p = 0.028). With regard to neoplastic epithelium in the UC-LD with neoplasm group, MSI in two or more loci was found in three of 17, and p53 overexpression was seen in 11 of 17 of the neoplastic lesions.

CONCLUSIONS

A high incidence of MSI in long standing UC with severe inflammation probably reflects genomic instability caused by repeated inflammatory stress. Thus, the influence of inflammation should be considered when estimating MSI in UC. It is possible that changes in p53 expression are important in the development of cancer in UC.

Diversities in animal vitronectins. Differences in molecular weight, immunoreactivity and carbohydrate chains

Six animal plasma vitronectins, human, horse, porcine, bovine, rabbit and chicken vitronectins purified by a novel method using two successive heparin affinity columns, showed marked diversity in molecular weight, immunoreactivity and carbohydrate composition. Chicken vitronectin had a distinctly different amino acid composition from the mammalian vitronectins; and bovine vitronectin was the only one to contain N-glycolylneuraminic acid as well as N-acetylneuraminic acid. Binding studies with horseradish peroxidase-labelled lectins indicated that all the vitronectins contained complex-type, sialylated N-linked sugar chains and that only porcine vitronectin had a fucosylated sugar chain. D-Galactosamine determinations and binding studies with horseradish peroxidase-peanut lectin on native and asialovitronectins revealed that the mammalian vitronectins other than human vitronectin contained O-linked sugar chains with sialic acid, chicken vitronectin contained unsialylated chains, and human vitronectin contained neither. The results indicate that diversities in vitronectins are apparent in their molecular weights and glycosylations, especially in the number and structure of O-linked sugar chains.

Interleukin-1 receptor antagonist in patients with active systemic lupus erythematosus. Enhanced production by monocytes and correlation with disease activity

OBJECTIVE

To evaluate the relationship between the serum concentration of interleukin-1 receptor antagonist (IL-1Ra) and systemic lupus erythematosus (SLE) disease activity, and to investigate the expression of IL-1Ra messenger RNA (mRNA) and its production by monocytes from patients with SLE.

METHODS

Serum IL-1Ra was measured by enzyme-linked immunosorbent assay, and expression of IL-1Ra mRNA was determined by Northern blotting.

RESULTS

Serum IL-1Ra concentrations were significantly higher in patients with active SLE compared with normal subjects and patients with other rheumatic diseases, and showed a strong correlation with SLE disease activity. IL-1Ra mRNA expression in freshly isolated monocytes from patients with active SLE was considerably higher than that in normal monocytes. Moreover, monocytes from patients with active SLE produced increased amounts of IL-1Ra in response to adherent IgG, compared with monocytes from normal subjects.

CONCLUSION

A high serum concentration of IL-1Ra is a pathophysiologic feature of active SLE and a good indicator of disease activity. Functional changes of monocytes, such as increased secretion of IL-1Ra in response to adherent IgG and enhanced expression of IL-1Ra mRNA in freshly isolated cells, may be involved in the enhanced IL-1Ra production in active SLE. High concentrations of IL-1Ra in the circulation and possibly in peripheral lymphoid tissues may influence immunologic and inflammatory features of SLE.

Anti-interleukin-6 autoantibodies in rheumatic diseases. Increased frequency in the sera of patients with systemic sclerosis

OBJECTIVE

To investigate the presence and the roles of anti-interleukin-6 (anti-IL-6) autoantibodies in rheumatic diseases, and to further elucidate clinical and pathophysiologic significance of anticytokine autoantibodies.

METHODS

Anti-IL-6 IgG autoantibodies were measured by the 125I-IL-6 binding activity of IgG, which was isolated from serum by protein A-Sepharose.

RESULTS

Nine of 52 sera (17.3%) from patients with systemic sclerosis (SSc) contained anti-IL-6 antibodies, whereas only 1.9% of sera from normal subjects and 0-5% of sera from patients with other rheumatic diseases were positive for the antibodies. Moreover, anti-IL-6 autoantibodies were found predominantly among patients with the limited form of SSc (42.9%), compared with those with the diffuse form (7.9%).

CONCLUSION

Anti-IL-6 IgG autoantibodies were detected in patients with SSc, particularly those with the limited form of the disease, at a significantly increased frequency compared with normal subjects and patients with other rheumatic diseases. These results suggest that the development of anti-IL-6 autoantibodies and IL-6 may have a role in the pathophysiology of SSc.

Use of multifunctional sigma-2 receptor ligand conjugates to trigger cancer-selective cell death signaling

One major challenge in the development of cancer therapeutics is the selective delivery of the drugs to their cellular targets. In the case of pancreatic cancer, the σ-2 receptor is a unique target that triggers apoptosis upon activation. We have previously developed a series of chemical compounds with high affinity for the σ-2 receptor and showed rapid internalization of the ligands. One particular specific ligand of the σ-2 receptor, SV119, binds to pancreatic cancer cells and induces target cell death in vitro and in vivo. In this study, we characterized the ability of SV119 to selectively deliver other death-inducing cargos to augment the cytotoxic properties of SV119 itself. When conjugated to SV119, small molecules that are known to interfere with intracellular prosurvival pathways retained their ability to induce cell death, the efficiency of which was enhanced by the combinatorial effect of SV119 delivered with its small molecule cargo. Our findings define a simple platform technology to increase the tumor-selective delivery of small molecule therapeutics via σ-2 ligands, permitting chemotherapeutic synergy that can optimize efficacy and patient benefit.

Critical role of ADP interaction with P2Y12 receptor in the maintenance of alpha(IIb)beta3 activation: association with Rap1B activation

OBJECTIVE

Platelet integrin alpha(IIb)beta3 plays a crucial role in platelet aggregation, and the affinity of alpha(IIb)beta3 for fibrinogen is dynamically regulated. Employing modified ligand-binding assays, we analyzed the mechanism by which alpha(IIb)beta3 maintains its high-affinity state.

METHODS AND RESULTS

Washed platelets adjusted to 50 x 10(3) microL(-1) were stimulated with 0.2 U mL(-1) thrombin or 5 microm U46619 under static conditions. After the completion of alpha(IIb)beta3 activation and granule secretion, different kinds of antagonists were added to the activated platelets. The activated alpha(IIb)beta3 was then detected by fluorescein isothiocyanate (FITC)-labeled PAC1. The addition of 1 mum AR-C69931MX (a P2Y12 antagonist) or 1 mm A3P5P (a P2Y1 antagonist) disrupted the sustained alpha(IIb)beta3 activation by approximately 92% and approximately 38%, respectively, without inhibiting CD62P or CD63 expression. Dilution of the platelet preparation to 500 microL(-1) also disrupted the sustained alpha(IIb)beta3 activation, and the disruption by such dilution was abrogated by the addition of exogenous adenosine 5'-diphosphate (ADP) in a dose-dependent fashion. The amounts of ADP released from activated platelets determined by high-performance liquid chromatography were compatible with the amounts of exogenous ADP required for the restoration. We next examined the effects of antagonists on protein kinase C (PKC) and Rap1B activation induced by 0.2 U mL(-1) thrombin. Thrombin induced long-lasting PKC and Rap1B activation. AR-C69931MX markedly inhibited Rap1B activation without inhibiting PKC activation.

CONCLUSIONS

Our data indicate that the continuous interaction between released ADP and P2Y12 is critical for the maintenance of alpha(IIb)beta3 activation.

Laparoscopic Heller myotomy and Dor fundoplication for the treatment of achalasia

BACKGROUND

The significance of laparoscopic Heller myotomy and Dor fundoplication (LHD) for the treatment of achalasia in relation to the severity of the lesion has not been sufficiently assessed.

METHODS

Of patients who were diagnosed with achalasia from August 1994 to February 2004, 55 individuals who underwent LHD served as subjects. The therapeutic effects of LHD were assessed in terms of operation time, intraoperative complications, postoperative hospital stay, and symptom improvement in relation to morphologic type (spindle type, Sp; flask type, Fk; and sigmoid type, Sig). Degree of symptomatic improvement was classified into four grades: excellent, good, fair, and poor.

RESULTS

Breakdown of morphologic type was as follows: Sp, n = 29; Fk, n = 18; and Sig, n = 8. Excluding one patient for whom conversion to open surgery was required, median average operation time for 54 patients was 160 min. As to intraoperative complications, esophageal mucosal perforation was seen in nine of the 55 patients (16%); however, conversion to open surgery could be avoided by suturing the affected area. Moreover, intraoperative bleeding of at least 100 g was seen in five of the 55 patients (9%), with one Fk patient requiring conversion to open surgery and transfusion. Median postoperative hospital stay was 8 days. Degree of dysphagia relief was excellent in 45 patients (83%), good in eight patients (15%), and fair in one patient (2%). Excellent improvement was obtained in 90%, 88%, and 50% in Sp, Fk, and Sig patients, respectively. Reflux esophagitis was seen in two patients, and was treated with a proton pump inhibitor.

CONCLUSIONS

The results of the present study suggest that classification of morphologic type is a useful parameter in predicting postoperative outcome in achalasia. In order to achieve excellent symptomatic relief, surgery for achalasia should be recommended for but not limited to Sp and Fk types.

Monoclonal anticardiolipin autoantibodies established from the (New Zealand white x BXSB)F1 mouse model of antiphospholipid syndrome cross-react with oxidized low-density lipoprotein

OBJECTIVE

Autoimmunity-prone (New Zealand white x BXSB)F1 ([NZW x BXSB]F1) mice have been shown to be useful as a model of antiphospholipid syndrome with myocardial infarction. The aim of this study was to examine the cross-reactivity of anticardiolipin antibody (aCL) derived from (NZW x BXSB)F1 mice with oxidized low-density lipoprotein (ox-LDL), which is closely associated with atherosclerosis.

METHODS

Six monoclonal antibodies (MAb) against CL were established from (NZW x BXSB)F1 mice, and reactivity of aCL with ox-LDL was examined by micro-enzyme-linked immunosorbent assay.

RESULTS

Higher titers of anti-ox-LDL autoantibodies were found in adult (NZW x BXSB)F1 mice compared with other autoimmunity-prone mouse strains (P < 0.01) or a control strain (P < 0.005). There was a significant positive correlation between titers of aCL and those of anti-ox-LDL in (NZW x BXSB)F1 mice (r = 0.79, P < 0.001). Of the 6 MAb against CL, 2 clones that showed beta 2-glycoprotein 1-dependent reactivity also cross-reacted with ox-LDL. Binding of monoclonal aCL to solid-phase cardiolipin was inhibited by ox-LDL, but not by native LDL.

CONCLUSION

We confirmed that aCL derived from (NZW x BXSB)F1 mice can cross-react with ox-LDL. This result suggests that aCL, which is closely associated with lupus-associated thrombosis, may also play an important role in atherosclerotic complications in patients with systemic lupus erythematosus.