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Pasterk L, Philipose S, Eller K, Marsche G, Heinemann A, Schuligoi R. The EP3 Agonist Sulprostone Enhances Platelet Adhesion But Not Thrombus Formation Under Flow Conditions. Pharmacology 2015; 96:137-43. [PMID: 26228833 DOI: 10.1159/000437143] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 06/23/2015] [Indexed: 11/19/2022]
Abstract
Platelets express the EP2, EP3 and EP4 receptors. Prostaglandin (PG) E2 has a biphasic effect on platelets. Low concentrations of PGE2 enhance platelet aggregation through the activation of the EP3 receptors, while at high concentrations it attenuates aggregation via the EP4 receptor. Consequently, EP3 receptor inhibition was shown to inhibit artherothrombosis, but had no influence on bleeding time in vivo. In this study, we investigated the role of the EP3 receptor in adhesion and thrombus formation under flow conditions in vitro. The EP3 agonist sulprostone caused an increase in the adhesion of washed platelets to fibrinogen as well as to collagen under low shear stress, an effect that was blocked by the EP3 antagonist L-798106. In contrast, when whole blood was perfused over collagen-coated surfaces, sulprostone did not enhance binding and thrombus formation of platelets on collagen; at high concentrations it even attenuated this response. We conclude that in more physiological models of thrombus formation, the role for EP3 receptors is limited, indirectly suggesting that the primary action of PGE2 in haemostasis might be an inhibitory one.
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Affiliation(s)
- Lisa Pasterk
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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2
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Sreckovic I, Birner-Gruenberger R, Obrist B, Stojakovic T, Scharnagl H, Holzer M, Scholler M, Philipose S, Marsche G, Lang U, Desoye G, Wadsack C. Distinct composition of human fetal HDL attenuates its anti-oxidative capacity. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:737-46. [PMID: 23321267 DOI: 10.1016/j.bbalip.2012.12.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 12/17/2012] [Accepted: 12/28/2012] [Indexed: 12/12/2022]
Abstract
In human high-density lipoprotein (HDL) represents the major cholesterol carrying lipoprotein class in cord blood, while cholesterol is mainly carried by low-density lipoprotein in maternal serum. Additionally, to carrying cholesterol, HDL also associates with a range of proteins as cargo. We tested the hypothesis that fetal HDL carries proteins qualitatively and quantitatively different from maternal HDL. These differences then contribute to distinct HDL functionality in both circulations. Shotgun proteomics and biochemical analyses were used to assess composition/function of fetal and maternal HDL isolated from uncomplicated human pregnancies at term of gestation. The pattern of analyzed proteins that were statistically elevated in fetal HDL (apoE, proteins involved in coagulation, transport processes) suggests a particle characteristic for the light HDL2 sub-fraction. In contrast, proteins that were enriched in maternal HDL (apoL, apoF, PON1, apoD, apoCs) have been described almost exclusively in the dense HDL3 fraction and relevant to its anti-oxidative function and role in innate immunity. Strikingly, PON1 mass and activity were 5-fold lower (p<0.01) in the fetus, which was accompanied by attenuation of anti-oxidant capacity of fetal HDL. Despite almost equal quantity of CETP in maternal and fetal HDL, its enzymatic activity was 55% lower (p<0.001) in the fetal circulation, whereas LCAT activity was not altered. These findings indicate that maternally derived HDL differs from fetal HDL with respect to its proteome, size and function. Absence of apoA-1, apoL and PON1 on fetal HDL is associated with decreased anti-oxidative properties together with deficiency in innate immunity collectively indicating distinct HDLs in fetuses.
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Affiliation(s)
- Ivana Sreckovic
- Department of Obstetrics and Gynecology, Medical University of Graz, Austria
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Philipose S, Kónya V, Lazarević M, Pasterk LM, Marsche G, Frank S, Peskar BA, Heinemann Á, Schuligoi R. Laropiprant attenuates EP3and TP prostanoid receptor-mediated thrombus formation. BMC Pharmacol Toxicol 2012. [PMCID: PMC3506277 DOI: 10.1186/2050-6511-13-s1-a14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Philipose S, Konya V, Lazarevic M, Pasterk LM, Marsche G, Frank S, Peskar BA, Heinemann A, Schuligoi R. Laropiprant attenuates EP3 and TP prostanoid receptor-mediated thrombus formation. PLoS One 2012; 7:e40222. [PMID: 22870195 PMCID: PMC3411562 DOI: 10.1371/journal.pone.0040222] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 06/02/2012] [Indexed: 11/24/2022] Open
Abstract
The use of the lipid lowering agent niacin is hampered by a frequent flush response which is largely mediated by prostaglandin (PG) D2. Therefore, concomitant administration of the D-type prostanoid (DP) receptor antagonist laropiprant has been proposed to be a useful approach in preventing niacin-induced flush. However, antagonizing PGD2, which is a potent inhibitor of platelet aggregation, might pose the risk of atherothrombotic events in cardiovascular disease. In fact, we found that in vitro treatment of platelets with laropiprant prevented the inhibitory effects of PGD2 on platelet function, i.e. platelet aggregation, Ca2+ flux, P-selectin expression, activation of glycoprotein IIb/IIIa and thrombus formation. In contrast, laropiprant did not prevent the inhibitory effects of acetylsalicylic acid or niacin on thrombus formation. At higher concentrations, laropiprant by itself attenuated platelet activation induced by thromboxane (TP) and E-type prostanoid (EP)-3 receptor stimulation, as demonstrated in assays of platelet aggregation, Ca2+ flux, P-selectin expression, and activation of glycoprotein IIb/IIIa. Inhibition of platelet function exerted by EP4 or I-type prostanoid (IP) receptors was not affected by laropiprant. These in vitro data suggest that niacin/laropiprant for the treatment of dyslipidemias might have a beneficial profile with respect to platelet function and thrombotic events in vascular disease.
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Affiliation(s)
- Sonia Philipose
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Viktoria Konya
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Mirjana Lazarevic
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Lisa M. Pasterk
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Gunther Marsche
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Sasa Frank
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Bernhard A. Peskar
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Akos Heinemann
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Rufina Schuligoi
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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Konya V, Üllen A, Kampitsch N, Theiler A, Philipose S, Parzmair GP, Marsche G, Peskar BA, Schuligoi R, Sattler W, Heinemann A. Endothelial E-type prostanoid 4 receptors promote barrier function and inhibit neutrophil trafficking. J Allergy Clin Immunol 2012; 131:532-40.e1-2. [PMID: 22704539 DOI: 10.1016/j.jaci.2012.05.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 04/19/2012] [Accepted: 05/04/2012] [Indexed: 01/13/2023]
Abstract
BACKGROUND Increased vascular permeability is a fundamental characteristic of inflammation. Substances that are released during inflammation, such as prostaglandin (PG) E(2), can counteract vascular leakage, thereby hampering tissue damage. OBJECTIVE In this study we investigated the role of PGE(2) and its receptors in the barrier function of human pulmonary microvascular endothelial cells and in neutrophil trafficking. METHODS Endothelial barrier function was determined based on electrical impedance measurements. Neutrophil recruitment was assessed based on adhesion and transendothelial migration. Morphologic alterations are shown by using immunofluorescence microscopy. RESULTS We observed that activation of E-type prostanoid (EP) 4 receptor by PGE(2) or an EP4-selective agonist (ONO AE1-329) enhanced the barrier function of human microvascular lung endothelial cells. EP4 receptor activation prompted similar responses in pulmonary artery and coronary artery endothelial cells. These effects were reversed by an EP4 antagonist (ONO AE3-208), as well as by blocking actin polymerization with cytochalasin B. The EP4 receptor-induced increase in barrier function was independent of the classical cyclic AMP/protein kinase A signaling machinery, endothelial nitric oxide synthase, and Rac1. Most importantly, EP4 receptor stimulation showed potent anti-inflammatory activities by (1) facilitating wound healing of pulmonary microvascular endothelial monolayers, (2) preventing junctional and cytoskeletal reorganization of activated endothelial cells, and (3) impairing neutrophil adhesion to endothelial cells and transendothelial migration. The latter effects could be partially attributed to reduced E-selectin expression after EP4 receptor stimulation. CONCLUSION These data indicate that EP4 agonists as anti-inflammatory agents represent a potential therapy for diseases with increased vascular permeability and neutrophil extravasation.
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Affiliation(s)
- Viktoria Konya
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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Mashta A, Mishra P, Philipose S, Tamilzhalagan S, Mahmud H, Bhaskar S, Upadhyay P. Diagnosis of tuberculosis: the experience at a specialized diagnostic laboratory. J Negat Results Biomed 2011; 10:16. [PMID: 22093248 PMCID: PMC3228662 DOI: 10.1186/1477-5751-10-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 11/18/2011] [Indexed: 11/10/2022] Open
Abstract
This work describes the experience at a tuberculosis clinical laboratory where relatively new TB diagnosis technologies; nucleic acid detection of two target strands, IS6110 and devR, by PCR and microscopic observation drug susceptibility (MODS) were used. The LJ culture was the gold standard. This evaluation was done from August 2007 to July 2009 on 463 sputum samples of tuberculosis suspects at a specialized tuberculosis clinic in Delhi, India.None of the tests we evaluated can accurately detect the presence or absence of Mycobacterium tuberculosis in all the samples and smear microscopy was found to be the most reliable assay in this study.The PCR assay could detect down to 2 pg of H37Rv DNA. Sensitivity, specificity was 0.40, 0.60 and 0.19, 0.81 for smear positive (n = 228) and negative samples (n = 235) respectively. In the MODS assay, sensitivity, specificity of 0.48, 0.52 and 0.38, 0.76 was observed for smear positive and negative samples. Sputum smear microscopy had sensitivity of 0.77 and specificity of 0.70.
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Affiliation(s)
- Anita Mashta
- Product Development Cell, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Konya V, Philipose S, Bálint Z, Olschewski A, Marsche G, Sturm EM, Schicho R, Peskar BA, Schuligoi R, Heinemann A. Interaction of eosinophils with endothelial cells is modulated by prostaglandin EP4 receptors. Eur J Immunol 2011; 41:2379-89. [PMID: 21681739 DOI: 10.1002/eji.201141460] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 04/18/2011] [Accepted: 05/18/2011] [Indexed: 01/21/2023]
Abstract
Eosinophil extravasation across the endothelium is a key feature of allergic inflammation. Here, we investigated the role of PGE(2) and its receptor, E-type prostanoid receptor (EP)-4, in the regulation of eosinophil interaction with human pulmonary microvascular endothelial cells. PGE(2) and the EP4 receptor agonist ONO AE1-329 significantly reduced eotaxin-induced eosinophil adhesion to fibronectin, and formation of filamentous actin and gelsolin-rich adhesive structures. These inhibitory effects were reversed by a selective EP4 receptor antagonist, ONO AE3-208. PGE(2) and the EP4 agonist prevented the activation and cell-surface clustering of β2 integrins, and L-selectin shedding of eosinophils. Under physiological flow conditions, eosinophils that were treated with the EP4 agonist showed reduced adhesion to endothelial monolayers upon stimulation with eotaxin, as well as after TNF-α-induced activation of the endothelial cells. Selective activation of EP1, EP2, and EP3 receptors did not alter eosinophil adhesion to endothelial cells, whereas the EP4 antagonist prevented PGE(2) from decreasing eosinophil adhesion. Finally, eosinophil transmigration across thrombin- and TNF-α-activated endothelial cells was effectively reduced by the EP4 agonist. These data suggest that PGE(2) -EP4 signaling might be protective against allergic responses by inhibiting the interaction of eosinophils with the endothelium and might hence be a useful therapeutic option for controlling inappropriate eosinophil infiltration.
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Affiliation(s)
- Viktoria Konya
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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Luschnig-Schratl P, Sturm EM, Konya V, Philipose S, Marsche G, Fröhlich E, Samberger C, Lang-Loidolt D, Gattenlöhner S, Lippe IT, Peskar BA, Schuligoi R, Heinemann A. EP4 receptor stimulation down-regulates human eosinophil function. Cell Mol Life Sci 2011; 68:3573-87. [PMID: 21365278 PMCID: PMC3192285 DOI: 10.1007/s00018-011-0642-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 02/07/2011] [Accepted: 02/15/2011] [Indexed: 01/08/2023]
Abstract
Accumulation of eosinophils in tissue is a hallmark of allergic inflammation. Here we observed that a selective agonist of the PGE2 receptor EP4, ONO AE1-329, potently attenuated the chemotaxis of human peripheral blood eosinophils, upregulation of the adhesion molecule CD11b and the production of reactive oxygen species. These effects were accompanied by the inhibition of cytoskeletal rearrangement and Ca2+ mobilization. The involvement of the EP4 receptor was substantiated by a selective EP4 antagonist, which reversed the inhibitory effects of PGE2 and the EP4 agonist. Selective kinase inhibitors revealed that the inhibitory effect of EP4 stimulation on eosinophil migration depended upon activation of PI 3-kinase and PKC, but not cAMP. Finally, we found that EP4 receptors are expressed by human eosinophils, and are also present on infiltrating leukocytes in inflamed human nasal mucosa. These data indicate that EP4 agonists might be a novel therapeutic option in eosinophilic diseases.
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Affiliation(s)
- Petra Luschnig-Schratl
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitaetsplatz 4, 8010 Graz, Austria
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Philipose S, Ofner M, Heinemann Á, Schuligoi R. A biological target for antiplatelet therapy: the prostaglandin E2 receptor EP4. BMC Pharmacol 2010. [PMCID: PMC3016526 DOI: 10.1186/1471-2210-10-s1-a17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Schuligoi R, Sturm E, Luschnig P, Konya V, Philipose S, Sedej M, Waldhoer M, Peskar BA, Heinemann A. CRTH2 and D-type prostanoid receptor antagonists as novel therapeutic agents for inflammatory diseases. Pharmacology 2010; 85:372-82. [PMID: 20559016 DOI: 10.1159/000313836] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 04/13/2010] [Indexed: 11/19/2022]
Abstract
Accumulation of type 2 T helper (Th2) lymphocytes and eosinophils is a hallmark of bronchial asthma and other allergic diseases, and it is believed that these cells play a crucial pathogenic role in allergic inflammation. Thus, Th2 cells and eosinophils are currently considered a major therapeutic target in allergic diseases and asthma. However, drugs that selectively target the accumulation and activation of Th2 cells and eosinophils in tissues are unavailable so far. Prostaglandin (PG)D(2) is a key mediator in various inflammatory diseases including allergy and asthma. It is generated by activated mast cells after allergen exposure and subsequently orchestrates the recruitment of inflammatory cells to the tissue. PGD(2) induces the chemotaxis of Th2 cells, basophils and eosinophils, stimulates cytokine release from these cells and prolongs their survival, and might hence indirectly promote IgE production. PGD(2) mediates its biologic functions via 2 distinct G protein-coupled receptors, D-type prostanoid receptor (DP), and the chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). DP and CRTH2 receptors are currently being considered as highly promising therapeutic targets for combating allergic diseases and asthma. Here, we revisit the roles of PGD(2) receptors in the regulation of eosinophil and Th2 cell function and the efforts towards developing candidate compounds for clinical evaluation.
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Affiliation(s)
- Rufina Schuligoi
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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Kulkarni RD, Philipose S. Effect of sodium bicarbonate on tolerance to orally admininstered iron. Indian J Physiol Pharmacol 1970; 14:53-6. [PMID: 5500719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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