scholarly journals Vitronectin (S protein) augments the functional activity of monocyte receptors for IgG and complement C3b

Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 86-93
Author(s):  
CJ Parker ◽  
RN Frame ◽  
MR Elstad
Keyword(s):  
Cell Attachment ◽  
Attachment Site ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Tenfold Increase ◽  
Letter Code ◽  
Single Letter Code ◽  
Arginine Glycine Aspartic Acid ◽  
Dose Dependent Increase ◽  
Dose Dependent

An arginine-glycine-aspartic acid sequence (RGD in the single letter code for amino acids) is present in the cell attachment site of both vitronectin and fibronectin. Inasmuch as fibronectin and synthetic peptides containing RGD enhance ingestion of opsonized particles by monocytes, we investigated the effects of vitronectin on phagocytosis by monocytes of sheep erythrocytes bearing IgG (EA) or complement C3b (EC3b). Peripheral blood monocytes were isolated by countercurrent elutriation and allowed to adhere to slides that had been coated with either vitronectin or fibronectin. Next, EA or EC3b were incubated with the adherent monocytes, and phagocytosis was subsequently quantified. Vitronectin caused the same dose dependent increase in phagocytosis as fibronectin. The augmentation of phagocytosis of EA induced by vitronectin could be inhibited by the F(ab')2 fragments of anti- vitronectin IgG but not by preimmune F(ab')2. The maximum phagocytosis of EA induced by vitronectin could not be enhanced by the addition of fibronectin, suggesting that vitronectin and fibronectin act on the same population of monocytes and that the two proteins stimulate the same mechanism through which the enhanced phagocytosis is mediated. Fibronectin and vitronectin caused a tenfold increase in the attachment of EC3b to monocytes, but phagocytosis was augmented minimally. These studies demonstrate that vitronectin modulates interactions between monocytes and opsonized particles.

scholarly journals Vitronectin (S protein) augments the functional activity of monocyte receptors for IgG and complement C3b

Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 86-93 ◽  
Author(s):  
CJ Parker ◽  
RN Frame ◽  
MR Elstad
Keyword(s):  
Cell Attachment ◽  
Attachment Site ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Tenfold Increase ◽  
Letter Code ◽  
Single Letter Code ◽  
Arginine Glycine Aspartic Acid ◽  
Dose Dependent Increase ◽  
Dose Dependent

Abstract An arginine-glycine-aspartic acid sequence (RGD in the single letter code for amino acids) is present in the cell attachment site of both vitronectin and fibronectin. Inasmuch as fibronectin and synthetic peptides containing RGD enhance ingestion of opsonized particles by monocytes, we investigated the effects of vitronectin on phagocytosis by monocytes of sheep erythrocytes bearing IgG (EA) or complement C3b (EC3b). Peripheral blood monocytes were isolated by countercurrent elutriation and allowed to adhere to slides that had been coated with either vitronectin or fibronectin. Next, EA or EC3b were incubated with the adherent monocytes, and phagocytosis was subsequently quantified. Vitronectin caused the same dose dependent increase in phagocytosis as fibronectin. The augmentation of phagocytosis of EA induced by vitronectin could be inhibited by the F(ab')2 fragments of anti- vitronectin IgG but not by preimmune F(ab')2. The maximum phagocytosis of EA induced by vitronectin could not be enhanced by the addition of fibronectin, suggesting that vitronectin and fibronectin act on the same population of monocytes and that the two proteins stimulate the same mechanism through which the enhanced phagocytosis is mediated. Fibronectin and vitronectin caused a tenfold increase in the attachment of EC3b to monocytes, but phagocytosis was augmented minimally. These studies demonstrate that vitronectin modulates interactions between monocytes and opsonized particles.

Increased Expression of u-PA and u-PAR on Monocytes by LDL and Lp(a) Lipoproteins – Consequences for Plasmin Generation and Monocyte Adhesion

1999 ◽  
Vol 81 (04) ◽  
pp. 594-560 ◽  
Author(s):  
Florence Ganné ◽  
Marc Vasse ◽  
Jean-Louis Beaudeu ◽  
Jacqueline Peynet ◽  
Arnaud François ◽  
...  
Keyword(s):  
Fold Increase ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Atheromatous Plaque ◽  
Monocyte Adhesion ◽  
Blood Monocytes ◽  
Proteolytic Cascade ◽  
Ecm Degradation ◽  
Dose Dependent Increase ◽  
Dose Dependent

SummaryMonocyte-derived foam cells figure prominently in rupture-prone regions of atherosclerotic plaque. As urokinase/urokinase-receptor (u-PA/u-PAR) is the trigger of a proteolytic cascade responsible for ECM degradation, we have examined the effect of atherogenic lipoproteins on monocyte surface expression of u-PAR and u-PA. Peripheral blood monocytes, isolated from 10 healthy volunteers, were incubated with 10 to 200 µg/ml of native or oxidised (ox-) atherogenous lipoproteins for 18 h and cell surface expression of u-PA and u-PAR was analysed by flow cytometry. Both LDL and Lp(a) induced a dose-dependent increase in u-PA (1.6-fold increase with 200 μg/ml of ox-LDL) and u-PAR [1.7-fold increase with 200 μg/ml of ox-Lp(a)]. There is a great variability of the response among the donors, some of them remaining non-responders (absence of increase of u-PA or u-PAR) even at 200 μg/ml of lipoproteins. In positive responders, enhanced u-PA/u-PAR is associated with a significant increase of plasmin generation (1.9-fold increase with 200 μg/ml of ox-LDL), as determined by an amidolytic assay. Furthermore, monocyte adhesion to vitronectin and fibrinogen was significantly enhanced by the lipoproteins [respectively 2-fold and 1.7-fold increase with 200 μg/ml of ox-Lp(a)], due to the increase of u-PAR and ICAM-1, which are receptors for vitronectin and fibrinogen. These data suggest that atherogenous lipoproteins could contribute to the development of atheromatous plaque by increasing monocyte adhesion and trigger plaque weakening by inducing ECM degradation.

The Lipopolysaccharide Mutant Re-LPS Is a Useful Tool for Detecting LPS Contamination in Rheumatoid Synovial Cell Cultures

Pathobiology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Hiroki Kohno ◽  
Kazuhisa Ouhara ◽  
Sho Mokuda ◽  
Tadahiro Tokunaga ◽  
Tomohiro Sugimoto ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Synovial Cell ◽  
Polymyxin B ◽  
Heat Inactivation ◽  
Synovial Cells ◽  
Toll Like Receptor ◽  
Blood Monocytes ◽  
Wild Type ◽  
Peripheral Blood Monocytes ◽  
Dose Dependent

<b><i>Introduction:</i></b> Lipopolysaccharide (LPS) contamination of commercially available proteins has seriously impeded research on citrullinated fibrinogen (cit-Fb) in rheumatoid synovial cells (RSCs). <b><i>Methods:</i></b> RSCs obtained from 4 rheumatoid arthritis patients who underwent full knee arthroplasty were cultured, stimulated with cit-Fb, and cytokine expression levels were measured. We then evaluated polymyxin-B (PMB), heat inactivation, and rough (R)-type LPS mutants for rapid detection of LPS contamination. <b><i>Results:</i></b> cit-Fb induced expression of <i>CXCL10</i> and <i>IFNB</i> in RSCs via the toll-like receptor. PMB inhibited cit-Fb-mediated CXCL10 gene expression but not protein expression induced by 20 μg/mL cit-Fb. Heat inactivation did not affect LPS-mediated <i>CXCL10</i> or <i>IL-6</i> induction; however, cit-Fb-mediated <i>CXCL10</i>expression was inhibited. Wild-type LPS from <i>Escherichia coli</i> (WT-LPS) strongly induces <i>CXCL10</i> expression, but induction by Ra-LPS was weak, and induction by Rc- and Re-LPS was minimal. Re-LPS suppression of WT-LPS-mediated <i>CXCL10</i> induction in RSCs and peripheral blood monocytes (PBMs) was dose dependent. Furthermore, Re-LPS completely suppressed cit-Fb-mediated <i>CXCL10</i> induction in RSCs and PBMs. <b><i>Conclusion:</i></b> To easily identify LPS contamination during routine experiments, our results suggest that Re-LPS is a better tool for rapid detection of LPS contamination compared to PMB and heat treatment.

Characterization of Monocyte-Associated Factor V

1993 ◽  
Vol 70 (02) ◽  
pp. 273-280 ◽  
Author(s):  
Janos Kappelmayer ◽  
Satya P Kunapuli ◽  
Edward G Wyshock ◽  
Robert W Colman
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Peripheral Blood ◽  
De Novo ◽  
Factor V ◽  
Blood Monocytes ◽  
De Novo Synthesis ◽  
Hep G2 ◽  
Hep G2 Cells ◽  
Peripheral Blood Monocytes

SummaryWe demonstrate that in addition to possessing binding sites for intact factor V (FV), unstimulated peripheral blood monocytes also express activated factor V (FVa) on their surfaces. FVa was identified on the monocyte surface by monoclonal antibody B38 recognizing FVa light chain and by human oligoclonal antibodies H1 (to FVa light chain) and H2 (to FVa heavy chain) using immunofluorescence microscopy and flow cytometry. On Western blots, partially cleaved FV could be identified as a 220 kDa band in lysates of monocytes. In addition to surface expression of FVa, monocytes also contain intracellular FV as detected only after permeabilization by Triton X-100 by monoclonal antibody B10 directed specifically to the Cl domain not present in FVa. We sought to determine whether the presence of FV in peripheral blood monocytes is a result of de novo synthesis.Using in situ hybridization, no FV mRNA could be detected in monocytes, while in parallel control studies, factor V mRNA was detectable in Hep G2 cells and CD18 mRNA in monocytes. In addition, using reverse transcriptase and the polymerase chain reaction, no FV mRNA was detected in mononuclear cells or in U937 cells, but mRNA for factor V was present in Hep G2 cells using the same techniques. These data suggest that FV is present in human monocytes, presumably acquired by binding of plasma FV, and that the presence of this critical coagulation factor is not due to de novo synthesis.

LH-RH TEST IN 100 PATIENTS WITH OVARIAN INSUFFICIENCY

1974 ◽  
Vol 75 (3) ◽  
pp. 428-434 ◽  
Author(s):  
P.-J. Czygan ◽  
M. Breckwoldt ◽  
F. Lehmann ◽  
R. Langefeld ◽  
G. Bettendorf
Keyword(s):  
Intravenous Injection ◽  
Functional State ◽  
Clear Correlation ◽  
Normal Range ◽  
Ovarian Insufficiency ◽  
Lh Rh ◽  
Dose Dependent Increase ◽  
Dose Dependent

ABSTRACT The effect of synthetic LH-RH was studied in 100 patients with various types of ovarian insufficiency by following up the FSH- and LH-levels in plasma. LH-RH was administered in doses of 12.5, 25 and 100 μg as a rapid intravenous injection. The patients were classified according to the endocrine state of the pituitary as evidenced by the urinary gonadotrophin levels. A clear correlation between the functional state of the pituitary and its responsiveness to exogenous LH-RH was demonstrated. Most of the patients with undetectable low urinary gonadotrophin levels failed to respond. The majority of patients with gonadotrophin excretion in the normal range and those with elevated levels reacted with a dose dependent increase in circulating LH. The amount of liberated FSH however was related to the injected dose only in patients with high gonadotrophic excretion. The present study indicates that synthetic LH-RH provides a useful tool in the evaluation of the pitutiary function particularly in patients with low and with undetectable gonadotrophin excretion. The data presented in this paper also demonstrate that the functional state of the pituitary is clearly reflected by the urinary gonadotrophin levels.

Evaluation of the Laxative activity of Saponin Enriched Hydroethanolic Pericarp extract of Sapindus emarginatus in Animal models

2020 ◽  
Vol 16 ◽  
Author(s):  
Lalitha Vivekanandan ◽  
Roxanne Gekonge Mandere ◽  
Sivakumar Thangavel
Keyword(s):  
Animal Models ◽  
Gravimetric Analysis ◽  
Triterpene Saponins ◽  
Laxative Effect ◽  
Saponin Content ◽  
The Family ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Efficacious Drug

Background: Constipation is a common, predominant, chronic gastrointestinal functional disorder. The drugs available to treat constipation are limited because of their side effects in long term use. So we need of efficacious drug to treat constipation. Sapindus emarginatus Vahl belongs to the family Sapindaceae, commonly known as soapnut. Traditionally used for the antipruritic, antifertility, constipation, and anti-inflammatory agents. Objective: The present study was undertaken to evaluate the laxative activity of hydroethanolic pericarp extract of Sapindus emarginatus (HESE) in animal models. Methods: The saponin content in extract was measured by gravimetric analysis. The laxative activity of hydroethanolic pericarp extract of Sapindus emarginatus is evaluated by the weight of feces matter, charcoal meal hyperperistalsis test, and loperamide induced constipation model. Results: The saponin content of the soapnut pericarp was 13.48 % and the extract was found to be 11.92 %. The results obtained from these models showed a significant dose-dependent increase in fecal weight, peristalsis index, and moisture content compared to control animals. Conclusion: The present study concluded that the oral administration of HESE showed a significant laxative activity by using different animal models. The presence of triterpene saponins is responsible for this activity. Further studies are needed to confirm their mechanism behind the laxative effect. The administration of extract was found to be a valid candidate in constipation therapy.

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