Recombinant Human Plasma Gelsolin Stimulates Phagocytosis while Diminishing Excessive Inflammatory Responses in Mice with Pseudomonas aeruginosa Sepsis

Plasma gelsolin (pGSN) is a highly conserved abundant circulating protein, characterized by diverse immunomodulatory activities including macrophage activation and the ability to neutralize pro-inflammatory molecules produced by the host and pathogen. Using a murine model of Gram-negative sepsis initiated by the peritoneal instillation of Pseudomonas aeruginosa Xen 5, we observed a decrease in the tissue uptake of IRDye®800CW 2-deoxyglucose, an indicator of inflammation, and a decrease in bacterial growth from ascitic fluid in mice treated with intravenous recombinant human plasma gelsolin (pGSN) compared to the control vehicle. Pretreatment of the murine macrophage line RAW264.7 with pGSN, followed by addition of Pseudomonas aeruginosa Xen 5, resulted in a dose-dependent increase in the proportion of macrophages with internalized bacteria. This increased uptake was less pronounced when cells were pretreated with pGSN and then centrifuged to remove unbound pGSN before addition of bacteria to macrophages. These observations suggest that recombinant plasma gelsolin can modulate the inflammatory response while at the same time augmenting host antibacterial activity.

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Plasma gelsolin modulates cellular response to sphingosine 1-phosphate

AJP Cell Physiology ◽

10.1152/ajpcell.00051.2010 ◽

2010 ◽

Vol 299 (6) ◽

pp. C1516-C1523 ◽

Cited By ~ 36

Author(s):

Robert Bucki ◽

Alina Kułakowska ◽

Fitzroy J. Byfield ◽

Małgorzata Żendzian-Piotrowska ◽

Marcin Baranowski ◽

...

Keyword(s):

Human Plasma ◽

Cellular Response ◽

Inflammatory Responses ◽

Structural Analog ◽

Bioactive Lipids ◽

High Concentration ◽

Aortic Endothelial Cells ◽

Plasma Gelsolin ◽

Proinflammatory Mediators ◽

Sphingosine 1 Phosphate

Hypogelsolinemia is observed in patients with different states of acute or chronic inflammation such as sepsis, rheumatoid arthritis, and multiple sclerosis. In animal models of sepsis, repletion of plasma gelsolin reduces septic mortality. However, the functions of extracellular gelsolin and the mechanisms leading to its protective nature are poorly understood. Potential mechanisms involve gelsolin's extracellular actin scavenging function or its ability to bind bioactive lipids or proinflammatory mediators, which would limit inflammatory responses and prevent tissue damage. Here we report that human plasma gelsolin binds to sphingosine 1-phosphate (S1P), a pleiotropic cellular agonist involved in various immune responses, and to its synthetic structural analog FTY720P (Gilenya). The fluorescence intensity of a rhodamine B-labeled phosphatidylinositol 4,5-bisphosphate binding peptide derived from gelsolin and the optical density of recombinant human plasma gelsolin (rhpGSN) were found to decrease after the addition of S1P or FTY720P. Gelsolin's ability to depolymerize F-actin also decreased progressively with increasing addition of S1P. Transient increases in phosphorylation of extracellular signal-regulated kinase in bovine aortic endothelial cells (BAECs) after S1P treatment were inhibited by rhpGSN. The ability of S1P to increase F-actin content and the elastic modulus of primary astrocytes and BAECs was also prevented by rhpGSN. Evaluation of S1P and gelsolin levels in cerebrospinal fluid reveals a low concentration of gelsolin and a high concentration of S1P in samples obtained from patients suffering from lymphatic meningitis. These findings suggest that gelsolin-mediated regulation of S1P bioactivity may be important to maintain immunomodulatory balance at inflammatory sites.

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The Effect of Insulin on Adenosine 3′:5′-Monophosphate and Guanosine 3′:5′-Monophosphate Concentrations in Human Plasma

Clinical Science ◽

10.1042/cs0500487 ◽

1976 ◽

Vol 50 (6) ◽

pp. 487-491

Author(s):

K. Siddle ◽

C. J. Davies ◽

K. J. Shetty ◽

R. S. Elkeles

Keyword(s):

Cyclic Amp ◽

Human Plasma ◽

Cyclic Gmp ◽

Cyclic Nucleotide ◽

Human Subjects ◽

Insulin Injection ◽

Initial Concentration ◽

Normal Human ◽

Dose Dependent Increase ◽

Dose Dependent

1. The action of insulin on plasma cyclic nucleotide concentrations in normal human subjects has been studied after intravenous injection, alone and in combination with glucagon. 2. After injection of insulin alone there was an initial small, though not significant, decrease in plasma cyclic AMP at 15 min followed by an increase to more than twice the initial concentration at 30 min. The increase was absent when hypoglycaemia was lessened by infusion of glucose after insulin injection. 3. Injection of insulin caused no significant change in plasma cyclic GMP concentration, whether or not glucose was infused after the hormone. 4. Glucagon (3–300 nmol, 10–1000 μg), caused a dose-dependent increase in plasma cyclic AMP concentration. The rise in plasma cyclic AMP produced by 3 or 30 nmol of glucagon was not significantly modified by simultaneous injection of insulin (44 nmol; 6 units).

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Systemic and local immune response to intraocular AAV vector administration in non-human primates

10.1101/2021.09.13.460058 ◽

2021 ◽

Author(s):

Divya Ail ◽

Duohao Ren ◽

Elena Brazhnikova ◽

Celine Jaillard ◽

Stephane Bertin ◽

...

Keyword(s):

Gene Therapy ◽

Neutralizing Antibodies ◽

Inflammatory Responses ◽

Post Injection ◽

Serum Antibodies ◽

Adeno Associated Virus ◽

Antibody Levels ◽

Dose Dependent Increase ◽

Dose Dependent ◽

Clinical Grading

The positive clinical outcomes in adeno-associated virus (AAV)-mediated retinal gene therapy have often been attributed to the low immunogenicity of AAVs along with the immune-privilege of the eye. However, several recent preclinical studies and clinical trials have shown potential for inflammatory responses to AAV mediated gene therapy. Our current understanding of the factors contributing to intraocular inflammation such as the existence of serum antibodies against AAVs prior to injection and their contribution to increases in antibody levels post-injection is incomplete. The parameters that regulate the generation of new antibodies in response to the AAV capsid or transgene post-injection after intraocular administration are also insufficiently described. In this study we carried out a retrospective analysis of the pre-existing serum antibodies in correlation with changes in antibody levels after intraocular injections of AAV in non-human primates (NHPs). We analyzed NHP serums for the presence of both Binding Antibodies (BABs), as well as a subset of these called Neutralizing Antibodies (NABs) that impede AAV transduction upon binding. We observed significantly higher pre-existing serum BABs against AAV8 compared to other serotypes. We observed a dose-dependent increase in both BABs and NABs in the serums collected post-injection, irrespective of the serotype or the mode of injection. Lastly, we were able to demonstrate a co-relation between the serum BAB levels with clinical grading of inflammation and levels of transgene expression.

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The Nonantibiotic Macrolide EM703 Improves Survival in a Model of Quinolone-Treated Pseudomonas aeruginosa Airway Infection

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02761-16 ◽

2017 ◽

Vol 61 (9) ◽

Cited By ~ 4

Author(s):

Gopinath Kasetty ◽

Ravi K. V. Bhongir ◽

Praveen Papareddy ◽

Heiko Herwald ◽

Arne Egesten

Keyword(s):

Pseudomonas Aeruginosa ◽

Bacterial Resistance ◽

Inflammatory Responses ◽

Lavage Fluid ◽

Macrolide Antibiotics ◽

Chronic Obstructive ◽

Gram Negative ◽

Content Type ◽

Airway Infections ◽

Anti Inflammatory

ABSTRACT Macrolide antibiotics are used as anti-inflammatory agents, e.g., for prevention of exacerbations in chronic obstructive pulmonary disease and cystic fibrosis. Several studies have shown improved outcomes after the addition of macrolides to β-lactam antibiotics for treatment of severe community-acquired pneumonia. However, a beneficial effect of macrolides in treating Gram-negative bacterial airway infections, e.g., those caused by Pseudomonas aeruginosa, remains to be shown. Macrolide antibiotics have significant side effects, in particular, motility-stimulating activity in the gastrointestinal tract and promotion of bacterial resistance. In this study, EM703, a modified macrolide lacking antibiotic and motility-stimulating activities but with retained anti-inflammatory properties, was used as an adjunct treatment for experimental P. aeruginosa lung infection, in combination with a conventional antibiotic. Airway infections in BALB/cJRj mice were induced by nasal instillation of P. aeruginosa; this was followed by treatment with the quinolone levofloxacin in the absence or presence of EM703. Survival, inflammatory responses, and cellular influx to the airways were monitored. Both pretreatment and simultaneous administration of EM703 dramatically improved survival in levofloxacin-treated mice with P. aeruginosa airway infections. In addition, EM703 reduced the levels of proinflammatory cytokines, increased the numbers of leukocytes in bronchoalveolar lavage fluid, and reduced the numbers of neutrophils present in lung tissue. In summary, the findings of this study show that the immunomodulatory properties of the modified macrolide EM703 can be important when treating Gram-negative pneumonia, as exemplified by P. aeruginosa infection in this study.

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

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614531 ◽

1999 ◽

Vol 81 (04) ◽

pp. 594-560 ◽

Cited By ~ 10

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.

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LH-RH TEST IN 100 PATIENTS WITH OVARIAN INSUFFICIENCY

Acta Endocrinologica ◽

10.1530/acta.0.0750428 ◽

1974 ◽

Vol 75 (3) ◽

pp. 428-434 ◽

Cited By ~ 5

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.

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In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

International Journal of Pharmaceutical and Phytopharmacological Research ◽

10.24896/eijppr.2016641 ◽

2016 ◽

Vol 6 (4) ◽

pp. 68

Author(s):

Sushma Vashisht ◽

Manish Pal Singh ◽

Viney Chawla

Keyword(s):

Antibacterial Activity ◽

Methanolic Extract ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Disc Diffusion ◽

Gram Positive ◽

Gram Negative ◽

Shorea Robusta ◽

Dose Dependent ◽

Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

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Faculty Opinions recommendation of Gram-negative bacteremia upon hospital admission: when should Pseudomonas aeruginosa be suspected?

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1148864.605949 ◽

2009 ◽

Author(s):

Gary Garber ◽

Gregory Rose

Keyword(s):

Pseudomonas Aeruginosa ◽

Hospital Admission ◽

Gram Negative ◽

Gram Negative Bacteremia

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

Current Bioactive Compounds ◽

10.2174/1573407216999200924162315 ◽

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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