First main series of transition elements with atomic numbers from 22 to 29, found in air pollution and detected in the plants from Tajikistan areas

According to several reports, the presence of transition metal elements in the atmosphere was associated with adverse health effects. The purpose of this investigation was to analyze the presence of transition metal particles with atomic numbers 22-29 on some medicinal plants (n = 22) from various regions of the Republic of Tajikistan and their content in the atmosphere. Samples (n = 43) of individual plant organs, such as seeds, flowers, leaves, trunks, and plant roots, were examined for their elemental composition using X-ray fluorescence analysis. Selection of particles contained in the atmosphere was carried out for 24 h/3 days by the aspiration method using fiberglass filters GF 10 in an apparatus installed at an altitude of 864 m on the periphery of the capital. For the analysis of plant samples, measurements were carried out on a SPECTROSCAN MAX-G wave-dispersive X-ray fluorescence spectrometer. For samples containing filtered atmosphere elements, a high-resolution PANanalytical Epsilon 5 high-resolution energy-dispersive spectrometer was used. Eight transition elements from the 1st main series of metals with atomic numbers 22-29, such as titanium, vanadium, chromium, manganese, iron, cobalt nickel, and copper, were found in plant organs, as well as in the atmosphere samples. Our results showed that the distribution of metals on plants varied depending on plants and their organs. We did not find any correlation between the region of plant collection and their absorption of metal elements. The distribution of metals varied in various plant organs. In the atmosphere samples, we found all the metals that were found in plants. In conclusion, medicinal plants can adsorb and accumulate some harmful chemical elements in their organs, are involved in the recirculation of these metals, and contribute air pollution.

Enhanced sensitivity of VEGF detection using catalase-mediated chemiluminescence immunoassay based on CdTe QD/H2O2 system

Background

Since vascular endothelial growth factor (VEGF) is a significant regulator of cancer angiogenesis, it is essential to develop a technology for its sensitive detection. Herein, we sensitized a chemiluminescence (CL) immunoassay through the combination of H₂O₂-sensitive TGA-CdTe quantum dot (QD) as signal transduction, dextran as a cross-linker to prepare enzyme-labeled antigen and the ultrahigh bioactivity of catalase (CAT) as reporter enzyme.

Results

Under the optimized experimental conditions, the chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) method can detect VEGF in the excellent linear range of 2–35,000 pg mL⁻¹, with a detection limit (S/N = 3) of 0.5 pg mL⁻¹ which was approximately ten times lower than the commercial colorimetric immunoassay. This proposed method has been successfully applied to the clinical determination of VEGF in the human serum samples, and the results illustrated an excellent correlation with the conventional ELISA method (R² = 0.997). The suitable recovery rate of the method in the serum ranged from 97 to 107%, with a relative standard deviation of 1.2% to 13.4%.

Conclusions

The novel immunoassay proposes a highly sensitive, specific, and stable method for very low levels detection of VEGF that can be used in the primary diagnosis of tumors. With the well-designed sensing platform, this approach has a broad potential to be applied for quantitative analysis of numerous disease-related protein biomarkers for which antibodies are available.

Reduction of carcinomatosis risk using icodextrin as a carrier solution of intraperitoneal oxaliplatin chemotherapy

There is no standard treatment in patients with high risk metachronous peritoneal carcinomatosis (PC) in colonic cancer, as perforated tumour or synchronous ovarian metastasis. Icodextrin 4% (ICDX), presently used to prevent postoperative abdominal adhesions, could inhibit the coactivation of the tumour cells and the microenvironment cells, associated with the development of PC. The aim of this study was to inhibit the formation of the PC in a murine model mimicking surgical situation using ICDX and intraperitoneal (IP) prophylactic chemotherapy. We created a model of growing PC in mice using cells of murine colonic cancer CT26. Cells and treatments were injected simultaneously. Five groups were created: CT26 (control group), CT26 + ICDX (ICDX group), CT26 + chemotherapy (oxaliplatin and 5FU) (chemo group), CT26 + chemotherapy + ICDX (ICDX chemo group), ICDX (toxicity group). At day 15, PC was evaluated with rodents PCI. In the chemo group, PCI was significantly lower than in the control group (3.2 versus 8.4, p = 0.02). ICDX had a synergetic effect on PC with chemotherapy; indeed PCI in ICDX chemo group was lower than in chemo group (1.4 versus 3.2, p = 0.04). There was no morbidity linked to ICDX in toxicity group. Safety of ICDX needs to be verified, particularly on colonic anastomosis before ICDX associated to IP chemotherapy could be used as a preventive treatment of PC in high risk patients. This prophylactic treatment is easy to use and would be administrated at the end of a curative surgery for a colonic cancer.

PO-23 - Expression of heparanase in cancer as biomarker of malignancies: overexpression in an aggressive, poor survival gastric cancer "gastric signet ring cell carcinoma" compared with that of other gastric cancers

INTRODUCTION

Gastric signet ring cell carcinoma (GSRC) is a distinct entity among of other gastric cancer. With unknown etiopathology, their incidence is increasing and it presents a low sensitivity to chemotherapy.

AIM

Here, we studied the expression of the heparanase (HPA) in cancer tissues from GSRC patients and several cancer cell lines. HPA is an endo-β-D-glucuronidase, capable of cleaving the lateral chains of heparan sulfate on cell surfaces and the extracellular matrix at acidic pH. Apart from its well-characterized enzyme activity, HPA also has independent enzymatic functions, such as up-regulation of vascular endothelial growth factor (VEGF) -A and VEGF-C and activation of intracellular signaling pathways involved in, survival, migration and proliferation of tumor cells. It can also induce an hypercoagulability by a non-enzymatic manner.

MATERIALS AND METHODS

HPA was tested in several cancer cell lines from ovaries (OVCAR-3, SKOV-3), breast (MDAMB231, MCF7) colon (LS-174), lung (A549), uterus (HELA) and gastric (adenocarcinoma (AGS) and GSRC (KATO-III) using several techniques such as RT-PCR, Q-PCR, immunocytochemistry, flow cytometry and degradation of Fondaparinux at pH 5, evaluated by its anti Xa activity evaluated by Factor Xa amidolytic activity. The amount of HPA mRNA in the biopsy simples of gastric adenocarcinoma (n=10) and GSRC (n=11) in tumors and their environment were analyzed.

RESULTS

HPA gene is expressed in all cancer cell lines, but its level varies depending on the tumor cell line. In biopsies of gastric cancer, the HPA gene is more expressed in the tumor regions (p=0.0002) and tumor environment (p=0.015) in GSRC than in gastric adenocarcinoma. B) The activity of HPA, evaluated by degradation of Fondaparinux at pH 5, 1) in the supernatants of 10(6) cancer cells: the residual activity of Fondaparinux after 2 hours incubation at 37°C with OVCAR-3 supernatant was of 70% of control value, and of 80% with KATO-III cell supernatants. 2) in patient's plasmas, this technique cannot be used because the site of degradation of fondaparinux by heparanase is masked by AT present in plasma.

CONCLUSIONS

Heparanase was found in in many cancer cell lines and its level depends on origin of tumor cells and on its aggressivity. Taking into account the pro-metastatic functions, proangiogenic and procoagulant activity of HPA and its overexpression in gastric signet ring cell carcinoma of poor prognosis and its cell line, HPA can be considered as a biomarker of malignancy and as a therapeutic target in GSRC patients.

Co-purification of arrestin like proteins with alpha-enolase from bovine myocardial tissues and the possible role in heart diseases as an autoantigen

AIM

Previously, we reported that visual arrestin co-purified with glycolytic enzymes. The aim of this study was to analyze the co-purification of arrestin like proteins (ALP) in bovine cardiac tissues with enolases.

METHODS

The soluble extract of bovine myocardial tissues from different regions such as left and right atriums and ventricles of the bovine heart (n = 3) was analyzed by ACA-34 gel filtration, immuno-affinity column, SDS-PAGE, ELISA, western blot and a sandwich immune assay for quantification of ALP and sequence analysis.

RESULTS

We observed that; 1) The cardiac muscle contained a 50 kDa ALP at a concentration of 751 pg/mg of soluble protein extract, 2) ALP purified, by immunoaffinity, contained alpha-enolase of 48 kDa confirmed by protein sequence analysis; 3) Cardiomyocyte cells exposed to anti arrestin and anti enolase monoclonal antibodies showed decreased proliferation in vitro, 4) High level of autoantibodies were detected by ELISA (3.57% for arrestin and 9.12% for α-enolase) in serum of patients with infarcted heart disease.

CONCLUSION

We suggest a possible interaction between ALP and alpha-enolases yielding a complex that may be involved in the induction of cardiac autoimmune diseases.

Down Regulation of ackA-pta Pathway in Escherichia coli BL21 (DE3): A Step Toward Optimized Recombinant Protein Expression System

Background:

One of the most important problems in production of recombinant protein is to attain over-expression of the target gene and high cell density. In such conditions, the secondary metabolites of bacteria become toxic for the medium and cause cells to die. One of these aforementioned metabolites is acetate, which enormously accumulated in the medium, so that both cell and protein yields are affected.

Objectives:

To overcome this problem, several strategies applied. In this research we used antisense RNA strategy, where the transcription of phosphotransacetylase (PTA) and acetate kinase (ACK), two acetate pathway key enzymes, could be controlled, which led to reduced acetate production.

Materials and Methods:

In order to achieve this, recombinant plasmid harboring antisense sequences targeting both of pta and ackA was assembled, after transfecting to the cells, its effects on the cell growth and acetate accumulation in the minimal media was assessed and compared with the control, the plasmid without antisense cassette, in presence and absence of IPTG in Escherichia coli BL21 (DE3).

Results:

It was observed that the mentioned strategy partially affect the growth and amount of excreted acetate in comparison with the control. In addition it was found that high down-regulation of the acetate production pathway reduces the growth rate of E. coli BL21 (DE3).

Conclusions:

The study principally proved the importance of this strategy in acetate excretion control.

Lymphatic and nerve distribution throughout the parametrium

BACKGROUND

Our objective was to concomitantly assess distribution of lymphatic and nerve structures in the parametrium.

METHODS

Twenty hemipelvises from ten fresh cadavers were dissected to differentiate between, three different parts of the parametrium: the lateral parametrium, the proximal and the distal part of the posterior parametrium. Histologic and immunofluorescence analyses of nerve and lymphatic structures were performed using NSE and LYVE-1 staining, respectively. The percentage of structures was independently scored as 0 (0%), 1 (1-20%), 2 (20-50%), 3 (50-80%), 4 (>80%).

RESULTS

The lateral parametrium and the proximal part of the posterior parametrium contained both nerve (scored 2.25 and 2.50, respectively) and lymphatic (scored 2.50 and 2.00, respectively) structures. The distal part of the posterior parametrium also contained numerous nerve structures (scored 2.00) but lymphatic structures were rare (scored 0.88). No difference in nerve distribution was found according to the parts of parametrium while a significantly lower distribution of lymphatic vessels was observed in the distal part of the posterior parametrium (p=0.03).

CONCLUSION

The distal part of the posterior parametrium is of high nerve density and low lymphatic density raising the issue as to whether it should be removed during radical hysterectomy.

Investigation in vitro Expression of CatSper Sub Fragment followed by Production of Polyclonal Antibody: Potential Candidate for The Next Generation of Non Hormonal Contraceptive

OBJECTIVE

CatSper is a voltage-sensitive calcium channel that is specifically expressed in the testis and it has a significant role in sperm performance. CatSper (1-4) ion channel subunit genes, causes sperm cell hyperactivation and male fertility. In this study, we have explored targeting of the extracellular loop as an approach for the generation of antibodies with the potential ability to block the ion channel and applicable method to the next generation of non-hormonal contraceptive.

MATERIALS AND METHODS

In this experimental study, a small extracellular fragment of CatSper1 channel was cloned in pET-32a and pEGFP-N1 plasmids. Then, subsequent methods were performed to evaluate production of antibody: 1) pEGFP-N1/CatSper was used as a DNA vaccine to immunize Balb/c mice, 2) The purified protein of pET-32a/CatSper was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) and western- blot, and 3) The serum of Balb/-c mice was used as an antibody in ELISA and western-blot. The statistical analysis was performed using the Mann Whitney test.

RESULTS

The results showed that vaccination of the experimental group with DNA vaccine caused to produce antibody with (p<0.05) unlike the control group. This antibody extracted from Balb/c serum could recognize the antigen, and it may be used potentially as a male contraception to prevent sperm motility.

CONCLUSION

CatSpers are the promising targets to develop male contraceptive because they are designed highly specific for sperm; although, no antagonists of these channels have been reported in the literature to date. As results showed, this antibody can be used in male for blocking CatSper channel and it has the potential ability to use as a contraceptive.

Generation of a novel high-affinity monoclonal antibody with conformational recognition epitope on human IgM

As IgM is the first isotype of antibody which appears in blood after initial exposure to a foreign antigen in the pattern of primary response, detection, and quantification of this molecule in blood seems invaluable. To approach these goals, generation, and characterization of a highly specific mAb (monoclonal antibody) against human IgM were investigated. Human IgM immunoglobulins were used to immunize Balb/c mice. Spleen cells taken from the immunized animals were fused with SP2/O myeloma cells using PEG (polyethylene glycol, MW 1450) as fusogen. The hybridomas were cultured in HAT containing medium and supernatants from the growing hybrids were screened by enzyme-linked immunosorbent assay (ELISA) using plates coated with pure human IgM and the positive wells were then cloned at limiting dilutions. The best clone designated as MAN-1, was injected intraperitoneally to some Pristane-injected mice. Anti-IgM mAb was purified from the animals' ascitic fluid by protein-G sepharose followed by DEAE-cellulose ion exchange chromatography. MAN-1 interacted with human IgM with a very high specificity and affinity. The purity of the sample was tested by SDS-PAGE and the affinity constant was measured (K(a) = 3.5 x 10(9)M(-1). Immunoblotting and competitive ELISA were done and the results showed that the harvested antibody recognizes a conformational epitope on the mu chain of human IgM and there was no cross-reactivity with other subclasses of immunoglobulins. Furthermore, isotyping test was done and the results showed the subclass of the obtained mAb which was IgG(1)kappa.

Angiogenic activity in sera of patients with systemic lupus erythematosus

Angiogenesis plays a critical role in the pathogenesis of several connective tissue diseases. There is, however, relatively little information available on the role of angiogenesis in systemic lupus erythematosus (SLE). The aim of this study was to investigate the angiogenic activity in sera of patients with SLE and to determine the association between angiogenic activity and clinical complications. Sera from 66 Tunisian females with SLE and from 32 healthy blood donors were studied for their angiogenic activity using the in-vitro tube formation test on Matrigel. Samples were divided into five groups according to their angiogenic activity, which was scored from 0 (no angiogenesis) to 4 (high angiogenic activity). Samples from each group were then tested randomly to assess serum concentration of vascular endothelial growth factor (VEGF). No correlation was found between angiogenic activity scores and serum VEGF levels. Considering angiogenesis assessment in-vitro, sera of patients with SLE showed a much higher angiogenic activity than healthy controls since a high angiogenic score (score 4) is present in 43.9% of patients and in 6.3% of controls ( P < 0.0002). This high angiogenic activity is not correlated with disease activity; however, SLE patients with anti-dsDNA antibodies and those with nephritis showed higher angiogenic activity compared with patients without these complications since score 4 is found in 50.9% and 67.9% versus 9.1% ( P = 0.017) and 26.3% ( P < 0.001), respectively. In conclusion, our study showed that high serum angiogenic activity in SLE was not correlated with the VEGF levels. We suggest the use of the ‘in-vitro’ tube formation test as a better tool to study the angiogenic potential of sera. We found that in patients with SLE, serum angiogenic activity is increased compared with healthy controls. This high angiogenic activity is associated with renal complications and with the presence of anti-dsDNA antibodies. These findings suggest an involvement of angiogenesis disturbance in the pathogenesis of SLE.

Analysis of endothelial protein C receptor functionality on living cells'

Activated protein C (APC) is a major control system of blood coagulation. APC prevents coagulation pathway by degrading Va and VIIIa plasma's coagulation factors. Protein C activation requires its binding to specific endothelial cell receptor (EPCR). APC binding to EPCR also activates a wide range of defense mechanisms (anti-inflammatory, antiapoptosis...). EPCR expression by cells can be detected by various methods, including immunoanalysis and molecular biology. However, no assays evaluate its functionality. A method, inspired of a standard fibrinoformation time assay, was developed to estimate EPCR ability to bind APC on living cell surface in vitro. Endothelial cells were incubated with APC and fibrinoformation on cells was followed by spectrophotometry (plasma absorbance increases with fibrin polymerization). Membrane-bound EPCR retain APC, thus prolonging fibrinoformation time in a dose-dependent manner. Control was realized with EPCR-negative cells. This new method can be used on any cell type to study the expression of other coagulation receptors.

Vasculogenic mimicry of acute leukemic bone marrow stromal cells

Angiogenesis is thought to be involved in the development of acute leukemia (AL). We investigated whether bone marrow stromal cells (BMSCs) derived from stem cells might be responsible for the increase in microvascular density (MVD), and compared 13 bone marrow samples from AL patients with 23 samples from patients in complete remission (controls). We demonstrated that AL-derived BMSC secreted more insulin growth factor-1 (IGF-1) and SDF-1alpha than controls. In addition, in contrast to normal adherent BMSCs, adherent BMSCs derived from CD133+/CD34+ stem cells from AL patients were able to form capillary-like structures ('vasculogenic mimicry') on Matrigel. The increase in vasculogenic mimicry occurred through PI3 kinase and rho GTPase pathway as inhibitors of these signaling pathways (wortmannin and GGTI-298, respectively) were able to reduce or prevent capillary tube formation. In normal BMSC, addition of exogenous IGF-1 generated capillary-like tubes through the same pathway as observed spontaneously in AL-derived BMSC. The involvement of IGF-1 in the mimicry process was confirmed by the addition of a neutralizing antibody against IGF-1R or a IGF-1R pathway inhibitor (picropodophyllin). In conclusion, AL-derived BMSC present functional abnormalities that may explain the increase in MVD in the bone marrow of AL patients.

Anti-plasminogen monoclonal antibody (MC2B8) inhibites angiogenesis

Angiogenesis is a complex process during which of new blood vessels are produced from the preexisting blood vessels. Formation and growth of new vessels play an important role in the physiologic process (embryonic growth, tissue repair) and pathologic process (tumor growth, inflammation) for surviving of the tissues. In fact, the development of tumors is depended upon new vessel formation through which the tumor is provided with nutrient and oxygen. In this research, the role ofplasminogen conformation with MC2B8 mAb (an antibody directed against C-terminal part of plasminogen) in clot lysis and angiogenesis is observed. In experimental model of angiogenesis, beads, covered with endothelial cells of bone marrow capillaries, are the source of endothelial cells. It coated in three-dimensional structure to be provided through fibrin gel. Different titers of monoclonal antibody (30-480 microg mL(-1)) MC2B8 were added in fibrin gel. 3-5 days after culturing of endothelial cells, growth and migration was seen as the result of capillary formation MC2B8 mAb delayed clot lysis and inhibited angiogenesis at the concentration of 240 microg mL(-1). Present findings suggest that these effects on capillary tube formation and clot lysis caused blockage or conformational changes in plasminogen epitopes involved in angiogenesis and fibrinolysis.

Expression of extracellular matrix proteins fibulin-1 and fibulin-2 by human corneal fibroblasts

PURPOSE

The fibulins are a family of extracellular matrix (ECM) molecules that regulate the organ shape along with other growth factors and stromal cells. We report here the in vitro expression of ECM proteins fibulin-1 and fibulin-2 by human corneal fibroblasts. The ability of fibulin-1 to modulate cell motility was investigated.

METHODS

Fibulin-1 and fibulin-2 mRNA and proteins expression were analyzed in primary and immortalized human corneal fibroblasts (CHN) respectively by gene array, RT-PCR, and immunocytochemistry. The motility and adhesion of the cells transfected with fibulin-1 siRNA were analyzed on tissue culture polystyrene coated with Matrigel or ECM secreted by those fibroblasts.

RESULTS

(1) The microarray analysis shows the expression of fibulin-1, fibulin-2, and their binding partners (i.e., fibronectin, nidogen-1, aggrecan, fibrilin-1, endostatin, and laminin alpha-2 chain). Interestingly, a matrix metalloprotease, ADAMTS-1, for which fibulin-1 acts as a cofactor, was also detected in CHN. (2) The synthesis by CHN of fibulin-1 and 2 mRNA and proteins was confirmed respectively by RT-PCR and immunocytochemistry. (3) Transfection of CHN by fibulin-1 siRNA has no effect on cell adhesion but increases cell migration compared with that of the control cells. This observation suggests an important role of fibulin-1 on cell motility.

CONCLUSIONS

The expression of fibulins and that of their binding partners by human corneal fibroblasts indicate the important role of these proteins in the organization of supramolecular ECM structures of cornea. The variation of their expression and the structural changes of fibulins remain to be determined in corneal pathology.

The effect of wild type P53 gene transfer on growth properties and tumorigenicity of PANC-1 tumor cell line

BACKGROUND

The p53 protein function is essential for the maintenance of the nontumorigenic cell phenotype. Pancreatic tumor cells show a very high frequency of p53 mutation. To determine if restoration of wild type p53 function can be used to eliminate the tumorigenic phenotype in these cells, pancreatic tumor cell lines, PANC-1 and HTB80, differing in p53 status were stably transfected with exogenous wild type p53 gene.

METHODS

The transfection was performed using Polybrene/DMSO-Assisted Gene Transfer method. The wild type p53 gene integration into genomic DNA was detected by Southern blot and PCR. Furthermore, the expression of wild type p53 protein was detected in selected clones by immunohistochemistry and Western blot.

RESULTS

While HTB80 cell line failed to produce a stable p53 expressing clone, the PANC-1 cells produced stable lines. Following characterization of clones, the growth rate and tumorigenicity of PANC-1 wild type p53 clones were compared to the control cells. Our data showed that the expression of wild type p53 decreased the growth rate of PANC-1 cells. It was also observed that the expression of wild type p53 in PANC-1 cells suppressed its potential for tumor formation in nude mice, completely, while the parental line leads to the formation of a relatively large tumor.

CONCLUSION

Our results suggest that gene therapy based on restoration of wild type p53 protein function in pancreatic tumor cells with high amount of mutant p53 is a feasible option in pancreatic cancer treatment.

Malignant hematopoietic cells induce an increased expression of VEGFR-1 and VEGFR-3 on bone marrow endothelial cells via AKT and mTOR signalling pathways

Angiogenesis plays a significant role in a variety of malignant hematologic diseases, and it is recognized that it has prognostic value. However, the cellular mechanisms by which malignant hematologic cells induce angiogenesis are not well understood. In order to investigate the role of cells from B-cell chronic lymphocytic leukemia (B-CLL) and multiple myeloma (MM) in angiogenesis on human bone marrow endothelial cells (HBMEC), we analyzed the impact of factors secreted by B-CLL cells and by MM cells on HBMEC capillary tube formation on matrigel. It was found that, in addition to the secretion of angiogenic factors VEGF and b-FGF by B-CLL and MM cells, MM cells (but not B-CLL cells) induced a dramatic increase in expression of VEGFR-1 and VEGFR-3 on human bone marrow endothelial cells (HBMEC). It would seem that this increase in VEGFR-3 occurred via the ERK and mTOR pathways, since their respective inhibitors U0126, LY294002 or rapamycin were responsible for a decrease of VEGFR-3. In response to MM cells-increased VEGF receptors on HBMEC, endothelial cell migration was enhanced in a wound artificially produced in a semi-confluent HBMEC culture, a phenomenon which was also down-regulated by the same inhibitors that reversed the increase in VEGF receptors. The present study suggests that, in addition to the classic angiogenic pathway, another mechanism related to an increased expression of VEGFRs on HBMEC might exist in malignant hematopoietic angiogenesis.

A novel monoclonal antibody with catalytic activity against beta human chorionic gonadotropin

In this study, we report for the first time, production of monoclonal antibody (MAb) against beta human chorionic gonadotropin (hCG) with proteolytic activity. MAb "7D9" was raised in Balb/C mice using purified human chorionic gonadotropin. Immunoblot analysis and enzyme-linked immunoabsorbent assay (ELISA) showed that this MAb reacts with beta hCG. The epitope for this antibody appears to be located in the C-terminal of beta chain as suggested by the absence of cross-reaction with other glycoprotein hormones such as FSH, TSH and LH. Our data reveal that this MAb is very unstable and has autodegradation characteristics. Zymogram analyses also show that 7D9 MAb has a high level of hydrolytic activity against different substrates such as casein and gelatin. This proteolytic activity can be inhibited by EDTA. These findings demonstrate the proteolytic character of 7D9 MAb and consequently explain its instability.

Identification of arrestin-like proteins in a human megakaryocytic cell line (HEL cells)

Proteins of the arrestin family contribute to the regulation of G-protein-mediated signal transduction in a number of tissues, possibly by a desensitization of the appropriate receptor(s). In this study we demonstrate the presence of arrestin-related proteins in a megakaryoblast-like cell line (HEL). Mouse monoclonal and rabbit polyclonal antibodies were prepared against visual arrestin, against a synthetic peptide'GFLGELTSSEVATEVPFRLM' (a pathogenic sequence corresponding to residues 340 to 359 of human visual arrestin), and against the peptide 'VDTNLIEFDTNDDDIV' that represents an aminoacid sequence present in beta -arrestins 1 and 2 but absent from visual arrestin. In Western blots, all of these antibodies revealed a 48-kDa protein in HEL cell extract. Using a beta-arrestin specific primer, RT-PCR of RNA from HEL cells confirmed the presence of beta-arrestin mRNA, with a predicted 480 bp having 98.8% homology with beta-arrestin. These results suggest that arrestin-family proteins may be involved in the desensitization of G-protein mediated receptors in platelets.

Stromal cells extracted from ovarian cancer express functional multi drugs resistance proteins: ATP bindig casset and Major vault protein

2072

Background: Stromal cells play a central role for the growth of tumor cells. The functional contribution of these cells in cancer therapy is poorly understood. Here we studied the presenceofthe proteins ABC (ATP binding Cassette) and MVP (Major vault protein) implicated in the multi drugs resistance (MDR) phenomena in stromal cells isolated from ascitis of patients with ovarian carcinoma. Methods: Stromal cells were extracted from ascitis of patients with ovarian carcinoma. The expression of MDR proteins as p-gp (Permeability-glycoprotein), BCRP (breast cancer resistance protein) and MRPs (multidrug related proteins) as well as LRP (lung resistance protein that is a MVP) was studied by two different technique (immunocytochemistry and flow cytometry) using specific antibodies against these proteins. The functionality of the pumps or efflux, was studied by incorporation of fluorescent probes, Rhodamine 123 and JC1, substrate for p-gp, calcéine-AM substrate for p-gp and MRPs and at last Mitoxantrone substratum of BCRP, in the presence of specific inhibitors: as the cyclosporine HAS, the GG918 and the MK571 for the pumps Pgp, BCRP and MRPs respectively. Then the expression of the genes was assessed by RT-PCR. Results: 1) The expression of the proteins ABC is confirmed by immunocytochemistry and by flow cytometry. The Pgp and LRP proteins were strongly expressed and they are functional, the MRP-1, 2, 3 and BCRP proteins are weakly expressed and the MRP-5 protein is not detected. 2) The RNAm corresponding to all of these proteins is found by RT-PCR in the stromal cells. Conclusions: All of these results suggest that the MDR proteins are present on the cells surface of the tumour cell microenvironnement. The functionality of these proteins allows supposing their implication in the phenomena of multi drugs resistance to chemotherapy. The interaction between cancer cells and stromal cells should be targeted during specific chemotherapy.

No significant financial relationships to disclose.

Albumin nanoparticles for the intravitreal delivery of anticytomegaloviral drugs

Albumin nanoparticles (NP) were proved to be effective and safe carriers for delivering anticytomegaloviral compounds in the vitreous. NP improved the antiviral activity of both ganciclovir and the phosphodiester oligonucleotide analog to formivirsen. NP appeared to be fusogenic carriers able to target the nucleus of cells. In addition, these drug carriers were well tolerated when administered by the intravitreal route and did not induce autoimmune reactions.

In vivo induction of endothelial apoptosis leads to vessel thrombosis and endothelial denudation: a clue to the understanding of the mechanisms of thrombotic plaque erosion

BACKGROUND

The mechanisms of thrombosis on plaque erosion are poorly understood. We examined the potential role of endothelial apoptosis in endothelial erosion and vessel thrombosis.

METHODS AND RESULTS

Segments of New Zealand White rabbit femoral arteries were temporarily isolated in vivo. One artery was incubated with staurosporin for 30 minutes, whereas the contralateral artery was incubated with saline and served as control. Three days later, thrombosis was evaluated angiographically and histologically. TUNEL score in the endothelial layer was significantly increased in staurosporin-treated arteries compared with controls (2.43+/-0.30 versus 0.93+/-0.44, respectively; P=0.001). Large areas of endothelial denudation were detectable in staurosporin-treated vessels, whereas endothelium integrity was almost preserved in the saline group. Vessel thrombosis occurred in 58% of staurosporin-treated arteries (7 of 12) but in only 8% of saline-treated segments (P<0.01). Immunoreactivities for tissue factor, platelets, and fibrin were detectable within the thrombus. Addition of ZVAD-fmk (0.1 mmol/L) significantly reduced the occurrence of thrombosis (1 of 7 arteries or 14%, P=0.04). These results were confirmed in balloon-injured atheromatous arteries.

CONCLUSIONS

In vivo induction of endothelial apoptosis leads to both vessel thrombosis and endothelial denudation. Endothelial apoptosis may be a critical step in the transition from a stable endothelialized plaque to plaque erosion and thrombosis.

Aldosterone signaling modifies capillary formation by human bone marrow endothelial cells

We investigated the regulation of the epithelial sodium channel (ENaC) in human bone marrow endothelial cells (HBMEC) responding to mineralocorticoid hormones and other accessory effectors. The message for both the mineralocorticoid receptor (MCR) and the alpha subunit of ENaC was expressed in HBMEC as predicted bands of 838 and 521 bp, respectively. In Western blots, the MCR of about 107 kDa was localized primarily in the cytoplasmic compartment but migrated to the nucleus when cell cultures were exposed to exogenous aldosterone. On the other hand, the alphaENaC was revealed as a membrane-bound protein of approximately 82 kDa, whose abundance increased after aldosterone treatment. Confocal microscopy confirmed the presence of both the MCR and ENaC as nucleocytoplasmic and membrane-bound proteins, respectively, and both colocalized with tubulin in situ. On Matrigel, the mineralocorticoid aldosterone, by itself, did not influence capillary formation by HBMEC, but the diuretic amiloride reduced the organization of HBMEC into capillary-like networks; curiously, aldosterone further exacerbated this inhibitory effect of amiloride. On the fibrin matrix, aldosterone had no influence at all on the length of the newly formed capillaries, but the capillary diameter was highly increased over the control. Aldosterone-mediated capillary swelling was totally reversed by amiloride, which, by itself, also inhibited capillary elongation by HBMEC. Thus, cell signaling by mineralocorticoid hormones in HBMEC appears to proceed in a manner very similar to that in the epithelial cell, thereby leading to an increase in the endothelial cell volume, which may underline the hypertensive state and which may also modify angiogenesis.

Mineralocorticoid hormones exert dramatic effects on pluripotent human stem cell progeny

The authors studied mineralocorticoid receptor (MCR)-mediated effects of steroids on CD34(+) progenitor cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed the presence of mRNA for both the MCR and the alpha subunit of the epithelial sodium channel, a member of the amiloride-sensitive sodium channel (ASSC) superfamily, in human CD41(+) megacaryoblastic cells derived from cultured bone marrow CD34(+) isolates, as well as in the human erythromegakaryoblastic leukemia (HEL) cell line. Immunofluorescence also revealed the presence of both the MCR and ASSC in circulating CD34(+) and medullar CD41(+) megacaryoblastic cells, the former as a nucleocytoplasmic protein and the latter as a membrane-bound protein, as expected from earlier studies using MCR-specific targets. In a selective medium, the formation of erythrocyte burst-forming units, and of the granulocyte-macrophage colony-forming units, by circulating CD34(+) cells was influenced by the agonists deoxycorticosterone and aldosterone, as well as by the antagonists RU 26752 and ZK 91587, targeted for the MCR. The multiplication of the leukemic HEL progeny, derived from CD41(+) cells, was similarly altered by these steroids targeted for the MCR. In contrast, in the optimal growth medium, the multiplication, and colony formation by bone marrow CD34(+) progenitor cells were not altered by either aldosterone or ZK 91587. These and other studies reveal that the receptor-mediated action of mineralocorticoids may influence the functional maturation of the hematopoietic progenitor lineage, contrary to the classical notion where the mineralotropic effect would be a unique feature of the epithelial cell.

Efficacy of dendrimer-mediated angiostatin and TIMP-2 gene delivery on inhibition of tumor growth and angiogenesis: in vitro and in vivo studies

Gene transfer is an attractive approach to fight cancer by targeting cancer cells or their vasculature. Our study reports the inhibition of tumor growth and angiogenesis by a nonviral method using dendrimers associated with 36-mer anionic oligomers (ON36) for delivering angiostatin (Kringle 1-3) and tissue inhibitor of metalloproteinase (TIMP)-2 genes. The optimal concentrations of dendrimers and ON36 for an efficient green fluorescent protein (GFP) plasmid delivery in endothelial cells (HMEC-1) and cancer cells (MDA-MB-435) were first chosen. Then the efficacy of transfection was determined by testing angiostatin and TIMP-2 secretion by Western blot and the biologic effects were evaluated. Angiostatin gene transfer markedly reduced in vitro (i) HMEC-1 but not MDA-MB-435 proliferation; (ii) HMEC-1 and MDA-MB-435 wound healing reparation; and (iii) capillary tube formation. TIMP-2 gene transfer did not affect cell proliferation but strongly inhibited (i) wound healing of HMEC-1 and MDA-MB-435 cells; and (ii) capillary tube formation. Supernatants of transfected-MDA-MB-435 cells also inhibited the formation of angiogenic networks on Matrigel, indicating a paracrine effect. In vivo, intratumoral angiostatin or TIMP-2 gene delivery using dendrimers associated with ON36 effectively inhibited tumor growth by 71% and 84%, respectively. Combined gene transfer resulted in 96% inhibition of tumor growth. Tumor-associated vascularization was also greatly reduced. These findings provide a basis for the further development of nonviral delivery of genes to fight cancer.

Adaptive immune responses of legumin nanoparticles

Legumin is one of the main storage proteins in the pea seeds (Pisum sativum L.) and the molecules of this protein have the capacity of binding together to form nanoparticles after aggregation and chemical cross-linkage with glutaraldehyde. The aim of this work was to study the adaptive immune response of legumin nanoparticles in rats. Following intradermal immunisation with the native protein legumin and legumin nanoparticles of about 250 nm, the humoral and cell-mediated immune responses were analysed in rats. The humoral responses against legumin and legumin nanoparticles were examined by western blot and ELISA analysis. Both techniques clearly showed that sera from rats immunised with legumin strongly expressed antibodies against this protein. On the contrary, serum samples from rats inoculated with legumin nanoparticles did not contain detectable amounts of antibodies. These results may be explained by a reduction on the antigenic epitopes of the protein induced by the glutaraldehyde used during the cross-linking step. Concerning the cell-mediated response, neither legumin nor legumin nanoparticles stimulated an immunogenic response. This absence of response of spleen lymphocytes for legumin and legumin nanoparticles may be explained by a cytostatic effect of legumin which was corroborated by the evaluation of the middle phase of cell apoptose. In fact, both legumin and legumin nanoparticles are potent inductors of a cytostatic phenomenon and showed a significant increase of the chromatin condensation (p < 0.05) as compared with control.

[Thalidomide inhibits the angiogenic activity of culture supernatants of multiple myeloma cell line]

OBJECTIVE

To investigate the pro-angiogenic effects of several multiple myeloma (MM) cell line culture supernatants on human bone marrow endothelial cell (HBMEC) proliferation, migration, and capillary formation, and the anti-angiogenic effects of thalidomide.

METHODS

HBMEC was cultured in the presence of MM cell lines (IM9, XG1, U266 and MOLP-5) supernatants. Proliferation and migration of HBMEC were determined, capillary-like tubule formation of HBMEC was examined in fibrin and Matrigel. The inhibiting effect of thalidomide was investigated by adding it into myeloma cell line culture supernatants. Vascular endothelial growth factor (VEGF) was measured by ELISA.

RESULTS

(1) MM cell lines culture supernatants promoted HBMEC proliferation and migration. (2) In fibrin and Matrigel, capillary-like tubule network formation promoted by the supernatants. (3) All of these effects could be inhibited by thalidomide. (4) This effect was not related to VEGF in the supernatants.

CONCLUSIONS

MM cell line promote proliferation, migration and tubule formation by secreting VEGF or other several cytokines. Thalidomide can inhibit these effects.

The blockade of mineralocorticoid hormone signaling provokes dramatic teratogenesis in cultured rat embryos

Although the administration of adrenocortical hormones to pregnant rats provokes only limited effect on the growth and development of the fetus, the direct influence of these steroids on cultured embryos has never been studied. The disruption of cell signaling by ZK 91587, which specifically occupies the mineralocorticoid receptor, resulted within 2 days in significant and pronounced adverse effects on the total length, the somite number, the embryo curvature, the communication between vitelline and umbilical blood vessels in the allantoid, and the vascularization of the vitelline sac, in 244-hour Wistar rat embryos in culture. The average score of 16 organs declined in a dose-dependent manner, following exposure to ZK 91587, and this was totally reversed by 10 microM aldosterone which, by itself, did not at all influence the embryonic development. The organogenesis was inhibited in the order: hind limb > fore limb > optic stalk > brain > olfactory pit > otic vesicle. ZK 91587 was completely ineffective in embryos that had attained the age of 260 hours. Similar, but less dramatic, results were obtained with the mineralocorticoid antagonist RU 26752, and with the antiglucocorticoid RU 38486. Sprague-Dawley rat embryos responded in a manner similar to the Wistar conceptuses. Thus, steroid receptor-mediated cell signaling is of critical importance to the growth and development of cultured rat embryos, which form a new model system to unravel adrenocortical hormone action.

The role of platelet factor 4 in platelet aggregation induced by the antibodies implicated in heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a severe side effect of heparin treatment. Recent studies using immunological methods demonstrated that antibodies contained in plasma, or in purified total immunoglobulin (Ig)G from patients suffering HIT, recognize as target antigen the complex heparin/platelet factor (PF4). In the present study, the role of PF4 in in-vitro platelet aggregation induced by purified total IgG or platelet-poor plasma from patients suffering HIT was investigated. In order to demonstrate the functional role of PF4, an anti-PF4 antibody that specifically blocked PF4 was used. In an experimental system composed of washed platelet suspension, incubation of F(ab')2 fragments (0.125 microg/ml) of the polyclonal anti-PF4 antibody resulted in complete inhibition of platelet aggregation triggered by purified total IgG from patients suffering HIT and heparin. In platelet-rich plasma, a significantly higher concentration (4.25 microg/ml) of the anti-PF4 F(ab')2 was required to inhibit platelet aggregation induced by HIT-PPP and heparin. Intermediate concentrations of the anti-PF4 antibody partially inhibited platelet aggregation. In plasma milieu, the concentration of PF4 was about five-fold higher in comparison with that measured in the purified system. The intensity of platelet aggregation depended on the concentration of HIT-IgG. Platelet aggregation was abolished in the presence of high concentrations of heparin (superior or equal to 10 IU/ml). The present study shows that PF4 is essential for platelet aggregation triggered by the antibodies related to HIT in the presence of heparin. The concentration of PF4 that is available to bind with heparin or with the HIT-related antibodies is critical for platelet aggregation induced by HIT antibodies.

Distribution of albumin nanoparticles in animals induced with the experimental allergic encephalomyelitis

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease characterised by a disruption of the blood-brain barrier (BBB), demyelination and a relevant inflammatory reaction with an intense infiltration of macrophages. These neurological disorders are similar to those observed in the multiple sclerosis (MS) disease. The use of different liposomes and adeno-associated virus has been proposed for improving the treatment of this pathogenesis. The aim of this work was to evaluate the potential and capacity of albumin nanoparticles to reach the central nervous system (CNS) in EAE-induced rats. For this purpose, the distribution of biotinylated nanoparticles within the CNS was studied. Albumin carriers were mainly found in the lumbar portion of the spinal cord, overlying the meningeal and perivascular areas. The optic chiasma, iris and the area of the Purkinje cells of the cerebellum revealed also an intense presence of these carriers. Finally, immunohistochemical studies also revealed that circulating macrophages (ED1), which migrate to damaged sites, and resident activated microglial cells (OX42) were involved in the distribution of albumin nanoparticles. In summary, the use of nanoparticles may be useful for the design of new pharmaceutical dosage forms able to target the lesions associated with alterations of the BBB.

Mineralocorticoid receptor-mediated signaling regulates the ion gated sodium channel in vascular endothelial cells and requires an intact cytoskeleton

The PCR analysis followed by sequence alignment showed that both the mineralocorticoid receptor (MCR) and the epithelial sodium channel (ENaC) genes were expressed in the human vascular endothelial cell line (ECV). The growth and multiplication of the ECV in culture were influenced by both aldosterone and the MCR-specific antagonist ZK 91587. Following double labelled immunofluorescence recorded by confocal microscopy, both the MCR and the ENaC were found to colocalize with the tubulin filaments in ECV cells in situ; no association was observed with cellular actin. ZK 91587 not only eliminated the basal expression, but it also impaired the transactivation of the ENaC gene by aldosterone. The disruption of actin and tubulin by cytochalasin D and colchicine, respectively, resulted in the total elimination of ENaC induction by aldosterone. These studies suggest that (i) the transcriptional regulation of the ENaC gene by the MCR-mediated signalling is not restricted to epithelial cells and requires cytoskeleton integrity in ECV cells in situ, (ii) tubulin may form a new and novel mediator in cell regulation, and (iii) the vascular tone may actually be regulated via transactivation of the ion gated sodium channel in the endothelial cell of the blood vessels under direct, receptor-mediated action of aldosterone.

Epithelial sodium channel and the mineralocorticoid receptor in cultured rat Müller glial cells

Müller glial cells are the major non-neuronal cells of the retina. They are involved in retinal function and exert a profound influence on the function of retinal neurons. We present an in vitro study of the localization of the mineralocorticoid receptor (MCR) and of the epithelial sodium channel (ENaC) in rat Müller glial cells isolated from rat retina, using respectively, a polyclonal antiserum raised against the rat purified MCR, and a rabbit polyclonal antibody against the 14-amino acid (aa) peptide QGLGKGDKREEQGL, which corresponds to the N-terminal region (44-58aa) of the alpha-subunit of the ENaC. In an immunocytochemical study using anti-MCR and anti-ENaC antibodies, the MCR was detected as a protein present in the cytoplasm and in the nucleus, whereas ENaC was detected as a membrane-bound protein. Reverse transcription-polymerase chain reaction (RT-PCR) analysis using specific primers, 5'-CTGCCTTTATGGATGATGGT-3' (sense), 5'-GTTCAGCTCGAAGAAGA-3' (antisense) for ENaC and 5'-AGGCTACCACAGTCTCCCTG-3' (sense) and 5'-GCAGTGTAAAATCTCCAGTC-3' (antisense) for MCR, showed expression of the ENaC and MCR genes in Müller cells. The presence of ENaC and MCR was detected as the predicted bands of 520 bp and 843 bp, respectively. In both cases, 100% identity was observed between the sequences of rat Müller cell (RMC) PCR products and rat kidney. Interestingly, the basal levels of ENaC were increased in vitro by the MCR-specific hormone, aldosterone. Thus, our results strongly suggest that the Müller glial cells may play a role in the regulation of extracellular Na+ concentration, which could be regulated by steroid-mediated sodium uptake.

Mineralocorticoid hormone signaling regulates the 'epithelial sodium channel' in fibroblasts from human cornea

We investigated the regulation of sodium absorption by steroid hormones in embryologically diverse cells from the human eye. A cell extract from human corneal fibroblasts was positive for both the epithelial sodium channel (ENaC) and the mineralocorticoid receptor (MCR) as 82- to 85-kD and 102-kD bands, respectively, by the Western blot technique. In fluorescent, confocal and electron microscopy, the MCR was revealed as a nucleocytoplasmic protein, whereas the ENaC was almost exclusively membrane bound; both appeared aligned along actin filaments of corneal keratocytes, and both were widely colocalized in various cell types of human cornea in situ. Following reverse transcription and amplification of total RNA isolated from corneal fibroblasts, the ENaC and MCR genes in the PCR product were evident as predicted bands of 520 and 843 bp, respectively, whose sequence exhibited 100% identity with those from known human sources. The multiplication of corneal fibroblasts was influenced by both the MCR-specific antagonist RU 26752 and the natural hormone aldosterone, and these steroids also stimulated protein phosphorylation. In quantitative PCR, both the basal and aldosterone-induced levels of ENaC were diminished by the MCR-specific antagonist ZK 91587. Consequently, the ocular sodium channel appears to be regulated by steroid signalling in cells of diverse embryological origins, contrary to the existing notions where (a) this process would be limited exclusively to the epithelial cells and (b) ocular sodium transport would be regulated via the Na(+)-K(+)-ATPase in the basolateral membrane.

Fibrinogen Alès: a homozygous case of dysfibrinogenemia (gamma-Asp(330)-->Val) characterized by a defective fibrin polymerization site "a"

Congenital homozygous dysfibrinogenemia was diagnosed in a man with a history of 2 thrombotic strokes before age 30. His hemostatic profile was characterized by a dramatically prolonged plasma thrombin clotting time, and no clotting was observed with reptilase. Complete clotting of the abnormal fibrinogen occurred after a prolonged incubation of plasma with thrombin. The release of fibrinopeptides A and B by thrombin and of fibrinopeptide A by reptilase were both normal. Thrombin-induced fibrin polymerization was impaired, and no polymerization occurred with reptilase. The polymerization defect was characterized by a defective site "a," resulting in an absence of interaction between sites A and a, indicated by the lack of fragment D(1) (or fibrinogen) binding to normal fibrin monomers depleted in fibrinopeptide A only (Des-AA fm). By SDS-PAGE, the defect was detected on the gamma-chain and in its fragment D(1). The molecular defect determined by analysis of genomic DNA showed a single base change (A-->T) in exon VIII of the gamma-chain. The resulting change in the amino acid structure is gamma 330 aspartic acid (GAT) --> valine (GTT). It is concluded that the residue gamma-Asp(330) is essential for the normal functioning of the polymerization site a on the fibrinogen gamma-chain.