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Li W, Huang S, Wen H, Luo Y, Cheng J, Jia Z, Han P, Xue W. Fluorescent recognition and selective detection of nitrite ions with carbon quantum dots. Anal Bioanal Chem 2020; 412:993-1002. [PMID: 31932861 DOI: 10.1007/s00216-019-02325-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/08/2019] [Accepted: 12/03/2019] [Indexed: 01/07/2023]
Abstract
The nitrite ion (NO2-) is a vital inorganic species that occurs both in natural ecological systems and human bodies. The high concentration of NO2- can be harmful for animal and human health. It is important to develop a simple, sensitive, reliable, and economic methodology to precisely monitor NO2- in various environmental and biological fields. Thus, a novel nitrite biosensor based on carbon quantum dots (PA-CDs) has been constructed and prepared via a high-efficiency, one-pot hydrothermal route using primary arylamines (PA) such as m-phenylenediamine. The device exhibits bright green fluorescence and a high quantum yield of 20.1% in water. In addition, the PA-CDs also possess two broad linear ranges: 0.05-1.0 μM and 1.0-50 μM with a low detection limit of 7.1 nM. The classical diazo reaction is firstly integrated into the PA-CD system by primary arylamines, which endows the system with high sensitivity and specific selectivity towards nitrite. Importantly, the nanosensor can detect NO2- in environmental water and serum samples with high fluorescence recoveries, demonstrating its feasibility in practical applications. This work broadens a new method to fabricate novel nanosensors and provides a prospective application for fluorescent carbon quantum dots (CDs). Graphical abstract.
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Affiliation(s)
- Wenshuai Li
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Saipeng Huang
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China.
| | - Huiyun Wen
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Yane Luo
- College of Food Science and Technology, Northwest University, Xi'an, 710069, China
| | - Jiewei Cheng
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Zhao Jia
- Shangluo University, Shangluo, 726000, Shaanxi, China
| | - Pu Han
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Weiming Xue
- School of Chemical Engineering, Northwest University, Xi'an, 710069, Shaanxi, China.
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2
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Schattner M. Platelet TLR4 at the crossroads of thrombosis and the innate immune response. J Leukoc Biol 2018; 105:873-880. [DOI: 10.1002/jlb.mr0618-213r] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 11/02/2018] [Accepted: 11/19/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Mirta Schattner
- Laboratory of Experimental ThrombosisInstitute of Experimental Medicine (IMEX‐CONICET‐National Academy of Medicine) Buenos Aires Argentina
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3
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D'Atri LP, Etulain J, Rivadeneyra L, Lapponi MJ, Centurion M, Cheng K, Yin H, Schattner M. Expression and functionality of Toll-like receptor 3 in the megakaryocytic lineage. J Thromb Haemost 2015; 13:839-50. [PMID: 25594115 PMCID: PMC4424134 DOI: 10.1111/jth.12842] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 01/04/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND In addition to their key role in hemostasis, platelets and megakaryocytes regulate immune and inflammatory responses, in part through their expression of Toll-like receptors (TLRs). Among the TLRs, TLR3 recognizes dsRNA associated with viral infection. Thrombocytopenia is a frequent complication of viral infection. However, the expression and functionality of TLR3 in megakaryocytes and platelets is not yet well understood. OBJECTIVE To study the expression and functionality of TLR3 in the megakaryocytic lineage. METHODS AND RESULTS RT-PCR, flow cytometric and immunofluorescence assays showed that TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets. Immunoblotting assays showed that stimulation of megakaryocytes with two synthetic agonists of TLR3, Poly(I:C) and Poly(A:U), activated the nuclear factor-κB (NF-κB), phosphoinositide 3-kinase (PI3K)/Akt, extracellular signal-related kinase (ERK)1/2 and p38 pathways. TLR3-megakaryocyte activation resulted in reduced platelet production in vitro and interferon-β release through the PI3K-Akt and NF-κB signaling pathways. TLR3 ligands potentiated the aggregation mediated by classic platelet agonists. This effect was also observed for ATP release, but not for P-selectin or CD40L membrane exposure, indicating that TLR3 activation was not involved in α-granule release. In addition, TLR3 agonists induced activation of the NF-κB, PI3K-Akt and ERK1/2 pathways in platelets. Reductions in platelet production and platelet fibrinogen binding mediated by Poly(I:C) or Poly(A:U) were prevented by the presence of an inhibitor of the TLR3-dsRNA complex. CONCLUSIONS Our findings indicate that functional TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets, and suggest a potential role for this receptor in the megakaryopoiesis/thrombopoiesis alterations that occur in viral infections.
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Affiliation(s)
- L P D'Atri
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine, CONICET-National Academy of Medicine, Buenos Aires, Argentina
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4
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Casarin AL, Lopes-Pires ME, Morganti RP, Antunes E, Marcondes S. Reactive oxygen and nitrogen species modulate the ex-vivo effects of LPS on platelet adhesion to fibrinogen. Life Sci 2011; 89:773-8. [PMID: 21958470 DOI: 10.1016/j.lfs.2011.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 08/04/2011] [Accepted: 08/27/2011] [Indexed: 11/24/2022]
Abstract
AIMS Excessive production of nitric oxide (NO) and reactive oxygen species (ROS) in sepsis modulates different cell functions. Since the sepsis severity is associated with the degree of platelet activation, we decided to investigate the role of systemic generation of NO and ROS in modulating the platelet adhesion of lipopolysaccharide (LPS)-treated rats. MAIN METHODS Platelet adhesion was evaluated using fibrinogen-coated 96-well microtiter plates. Cyclic GMP levels were measured using enzyme immunoassay kit. KEY FINDINGS Treatment of rats with LPS significantly increased spontaneous platelet adhesion, but reduced the thrombin-activated platelet adhesion when compared with control rats. Chronic treatment of rats with the NO synthase inhibitor L-NAME (20 mg/rat/day, 7 days) prior to LPS injection normalized the increased adhesion in non-activated platelets, but failed to affect the adhesion in thrombin-activated platelets. The cGMP levels were modified neither in non-activated nor in thrombin-activated platelets of LPS-treated rats when compared with control rats. The incubation of non-activated platelets with the O2- scavenger PEG-SOD reversed the stimulatory effect of LPS on spontaneous adhesion, but had no effect in stimulated-platelet adhesion of non-treated or LPS-treated groups. Moreover, pretreatment of rats with the antioxidant N-acetylcysteine (NAC; 150 mg/kg) prevented the increase of non-activated platelet adhesion, and significantly reduced the inhibitory effect of LPS on thrombin-stimulated adhesion. SIGNIFICANCE Our findings suggest that in LPS-treated rats, NO plays an important modulatory role only in non-stimulated platelet adhesion through cGMP-independent mechanisms, while ROS, directly or by affecting the redox state of the animals, modulates both non-activated and thrombin-activated platelet adhesion.
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Affiliation(s)
- André Luis Casarin
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas (SP), Brazil
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5
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Dong HP, Chunag IC, Wang DC, Huang LJ, Lee CI, Tsai JH, Yang RC. Lipopolysaccharide-stimulated leukocytes contribute to platelet aggregative dysfunction, which is attenuated by catalase in rats. Kaohsiung J Med Sci 2011; 26:584-92. [PMID: 21126711 DOI: 10.1016/s1607-551x(10)70090-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 05/21/2010] [Indexed: 10/18/2022] Open
Abstract
Endotoxemia causes several hematological dysfunctions, including platelet degranulation or disseminated intravascular coagulation, which lead to thrombotic and hemorrhagic events. Here, we tested the hypothesis that bacterial lipopolysaccharide (LPS)-stimulated leukocytes contribute to platelet aggregative dysfunction, and this function is attenuated by antioxidants. Platelet-rich plasma (PRP) was prepared from whole blood of normal and endotoxemic rats. The ability of platelet aggregation was measured by an aggregometer. LPS (50-100 μg/mL) was incubated with PRP, whole blood and PRP with polymorphonuclear leukocytes (PMNs) for 30 minutes, 60 minutes and 90 minutes, and platelet aggregation was detected. LPS-induced platelet aggregative dysfunction was undetectable in intact PRP which was isolated from normal whole blood, whereas it was detected in PRP isolated from endotoxemic rats and LPS-treated whole blood. Moreover, the effect of LPS-induced platelet aggregative dysfunction on intact PRP was observed when the PMNs were added. LPS-induced platelet aggregative dysfunction was significantly attenuated by catalase alone and in combination with N(G)-nitro-L-arginine methyl ester, but not by N(G)-nitro-L-arginine methyl ester alone. These results indicate that LPS-stimulated PMNs modulate platelet aggregation during LPS treatment and the effects are reversed by antioxidants. PMNs serve as an approach to understand LPS-induced platelet aggregative dysfunction during endotoxemia. During this process, the generation of reactive oxygen species, hydrogen peroxide especially, from LPS-stimulated PMNs could be an important potential factor in LPS-induced platelet aggregative dysfunction. Catalase contributes to the prevention of platelet dysfunction during LPS-induced sepsis.
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Affiliation(s)
- Huei-Ping Dong
- Department of Physical Therapy, Foo-Yin University, Kaohsiung, Taiwan
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6
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Morganti RP, Cardoso MHM, Pereira FG, Lorand-Metze I, De Nucci G, Marcondes S, Antunes E. Mechanisms underlying the inhibitory effects of lipopolysaccharide on human platelet adhesion. Platelets 2010; 21:260-9. [PMID: 20218907 DOI: 10.3109/09537101003637240] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Alterations in platelet aggregation in septic conditions are well established. However, little is known about the effects of lipopolysaccharide (LPS) on platelet adhesion. We have therefore investigated the effects of LPS in human platelet adhesion, using an in vitro model of platelet adhesion to fibrinogen-coated wells. Microtiter plates were coated with human fibrinogen, after which washed platelets (6 x 10(8) platelets/ml) were allowed to adhere. Adherent platelets were quantified through measurement of acid phosphatase activity. Calcium mobilization in Fura2-AM-loaded platelets was monitored with a spectrofluorimeter. Platelet flow cytometry in thrombin-stimulated platelets was performed using monoclonal mouse anti-platelet GPIIb/IIIa antibody (PAC-1). Prior incubation of washed platelets with LPS (0.01-300 microg/ml) for 5 to 60 min concentration- and time-dependently inhibited non-activated platelet adhesion. In thrombin-activated (50 mU/ml) platelets, LPS inhibited the adhesion to a significantly lesser extent than non-activated platelets. Cyclohexamide, superoxide dismutase polyethylene glycol (PEG-SOD) or catalase polyethylene glycol did not affect the LPS responses. No alterations in cyclic GMP levels were seen after platelet incubation with LPS, except with the highest concentration employed (300 microg/ml) where an increase of 36% (P < 0.05) was observed. Thrombin increased by 7.5-fold the internal Ca(2+) platelet levels, an effect markedly inhibited by LPS. Thrombin induced concentration-dependent platelet GPIIb/IIIa activation, but LPS failed to affect the activation state of this membrane glycoprotein. In conclusion, LPS inhibits human platelet adhesion to fibrinogen by mechanisms involving blockade of external Ca(2+), independently of cGMP generation and activation of GPIIb/IIIa complex.
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Affiliation(s)
- Rafael P Morganti
- Department of Pharmacology, State University of Campinas (UNICAMP), Campinas (SP), Brazil
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7
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Gursel O, Atay AA, Kurekci AE, Avcu F, Nevruz O, Senses Z, Ozturk E, Hasimi A, Ozcan O. Platelet aggregation in children with Helicobacter pylori infection. Clin Appl Thromb Hemost 2009; 16:637-42. [PMID: 19633022 DOI: 10.1177/1076029609339747] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study was performed to investigate the platelet aggregation alterations in platelet-rich plasma (PRP) samples of children with Helicobacter pylori (H pylori) infection. Platelet aggregation induced by adenosine diphosphate (ADP), collagen, ristocetin, or epinephrine was studied with photometric aggregometry in 30 patients before and after eradication therapy and in a control group including 15 children. The pretreatment mean maximum aggregation values and slope were significantly lower (P < .0001) in the study group at 10 μmol/L concentrations of ADP (ADP-like defect). The maximum aggregation values and slope revealed no significant differences (P > 0.05) between the study group after therapy and the control group. We concluded that H pylori infection may cause dysfunction of platelets in children and can be reversed by H pylori eradication therapy. Further studies should be carried out to determine the mechanisms of platelet dysfunction in children with H pylori infection.
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Affiliation(s)
- Orhan Gursel
- Department of Pediatric Hematology, Gulhane Military Medical Academy, Ankara, Turkey.
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Zhang G, Han J, Welch EJ, Ye RD, Voyno-Yasenetskaya TA, Malik AB, Du X, Li Z. Lipopolysaccharide stimulates platelet secretion and potentiates platelet aggregation via TLR4/MyD88 and the cGMP-dependent protein kinase pathway. THE JOURNAL OF IMMUNOLOGY 2009; 182:7997-8004. [PMID: 19494325 DOI: 10.4049/jimmunol.0802884] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Bacterial LPS induces rapid thrombocytopenia, hypotension, and sepsis. Although growing evidence suggests that platelet activation plays a critical role in LPS-induced thrombocytopenia and tissue damage, the mechanism of LPS-mediated platelet activation is unclear. In this study, we show that LPS stimulates platelet secretion of dense and alpha granules as indicated by ATP release and P-selectin expression, and thus enhances platelet activation induced by low concentrations of platelet agonists. Platelets express components of the LPS receptor-signaling complex, including TLR (TLR4), CD14, MD2, and MyD88, and the effect of LPS on platelet activation was abolished by an anti-TLR4-blocking Ab or TLR4 knockout, suggesting that the effect of LPS on platelet aggregation requires the TLR4 pathway. Furthermore, LPS-potentiated thrombin- and collagen-induced platelet aggregation and FeCl(3)-induced thrombus formation were abolished in MyD88 knockout mice. LPS also induced cGMP elevation and the stimulatory effect of LPS on platelet aggregation was abolished by inhibitors of NO synthase and the cGMP-dependent protein kinase (PKG). LPS-induced cGMP elevation was inhibited by an anti-TLR4 Ab or by TLR4 deficiency, suggesting that activation of the cGMP/protein kinase G pathway by LPS involves the TLR4 pathway. Taken together, our data indicate that LPS stimulates platelet secretion and potentiates platelet aggregation through a TLR4/MyD88- and cGMP/PKG-dependent pathway.
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Affiliation(s)
- Guoying Zhang
- Department of Pharmacology, University of Illinois, Chicago, IL 60612, USA
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Abstract
Endotoxemia caused by bacterial lipopolysaccharides (LPS) deleteriously affects many aspects of hemostasis. Much of this effect is well characterized as being secondary to the LPS-mediated inflammatory response, but direct effects of LPS on coagulation factors may also contribute to disregulation of the hemostatic process. Spectrophotometric assays were used to investigate the effects of LPS from different bacteria on thrombin and plasmin activities. We found that enzymatic activity of purified thrombin, but not plasmin, decreases in the presence of endotoxin. LPS-mediated inhibition of thrombin activity can be reversed by plasma gelsolin and recombinant endotoxin-neutralizing protein. Preincubation of thrombin with LPS before platelet activation results in inhibition of aggregation and secretion. Additionally, a decrease of elastic shear moduli of fibrin gels was observed when their formation was induced with thrombin preincubated with LPS or when LPS was present in fibrinogen solutions during fibrin gel formation. When added to platelet-rich plasma, after activation with collagen, LPS-inhibited thrombin activity. LPS-mediated inhibition of thrombin activity may contribute to the hemostasis dysfunctions observed during endotoxemia.
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Affiliation(s)
- Robert Bucki
- Department of Physiology and the Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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10
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Hsiao G, Wang Y, Tzu NH, Fong TH, Shen MY, Lin KH, Chou DS, Sheu JR. Inhibitory effects of lycopene on in vitro platelet activation and in vivo prevention of thrombus formation. ACTA ACUST UNITED AC 2005; 146:216-26. [PMID: 16194683 DOI: 10.1016/j.lab.2005.03.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Revised: 03/16/2005] [Accepted: 03/22/2005] [Indexed: 11/21/2022]
Abstract
Lycopene is a natural carotenoid antioxidant that is present in tomatoes and tomato products. The pharmacologic function of lycopene in platelets is not yet understood. Therefore, in this study we sought to systematically examine the effects of lycopene in the prevention of platelet aggregation and thrombus formation. We found that lycopene concentration-dependently (2-12 micromol/L) inhibited platelet aggregation in human platelets stimulated by agonists. Lycopene (6 and 12 micromol/L) inhibited phosphoinositide breakdown in platelets labeled with tritiated inositol, intracellular Ca+2 mobilization in Fura-2 AM-loaded platelets, and thromboxane B2 formation stimulated by collagen. In addition, lycopene (6 and 12 micromol/L) significantly increased the formations of cyclic GMP and nitrate but not cyclic AMP in human platelets. Rapid phosphorylation of a protein of 47,000 Da (P47), a marker of protein kinase C activation, was triggered by PDBu (60 nmol/L). This phosphorylation was markedly inhibited by lycopene (12 micromol/L) in phosphorus-32-labeled platelets. In an in vivo study, thrombus formation was induced by irradiation of mesenteric venules in mice pretreated with fluorescein sodium. Lycopene (5, 10, and 20 mg/kg) significantly prolonged the latency period for the induction of platelet-plug formation in mesenteric venules. These results indicate that the antiplatelet activity of lycopene may involve the following pathways: (1) Lycopene may inhibit the activation of phospholipase C, followed by inhibition of phosphoinositide breakdown and thromboxane B2 formation, thereby leading to inhibition of intracellular Ca+2 mobilization. (2) Lycopene also activated the formations of cyclic GMP/nitrate in human platelets, resulting in the inhibition of platelet aggregation. The results may imply that tomato-based foods are especially beneficial in the prevention of platelet aggregation and thrombosis.
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Affiliation(s)
- George Hsiao
- Graduate Institute of Pharmacology, Taipei Medical University, Taipei, Taiwan
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11
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Dong HP, Chen HW, Hsu C, Chiu HY, Lin LC, Yang RC. PREVIOUS HEAT SHOCK TREATMENT ATTENUATES LIPOPOLYSACCHARIDE-INDUCED HYPORESPONSIVENESS OF PLATELETS IN RATS. Shock 2005; 24:239-44. [PMID: 16135963 DOI: 10.1097/01.shk.0000174019.10311.80] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Several studies demonstrated that previous heat shock treatment caused expression of heat shock proteins (HSPs) and reduced organ dysfunction and mortality in experimentally induced severe sepsis. However, the protective mechanism on platelet function remains unclear. The aim of this study was to investigate the effect of heat shock treatment on platelet aggregation ex vivo in endotoxin-induced rats with sepsis. Rats of the heated group were heated by whole-body hyperthermia 18 h before lipopolysaccharide (LPS) injection. Blood samples were obtained from the carotid artery 90 min after LPS injection. Platelet aggregation ability was measured by aggregometer. Results revealed that platelet aggregation ex vivo was significantly inhibited in LPS-induced rats in a manner of dose dependence. Previous heat shock treatment caused overexpression of HSPs and significantly attenuated the LPS-induced platelet hyporesponsiveness. This attenuation disappeared in accordance with absence of HSP72 at 7 days after heat shock treatment. Aggregation of normal platelets was also inhibited by incubating with plasma obtained from endotoxemic rats but not from preheated endotoxemic rats. Furthermore, no significant hyporesponsiveness was found in endotoxemic platelets in addition to preheated endotoxemic plasma. The addition of H2O2 scavenger catalase diminished the platelet hyporesponsiveness significantly only in nonheated endotoxemic rats. Moreover, the plasma nitrite and nitrate levels were significantly attenuated in preheated endotoxemic rats. These results revealed that previous heat shock treatment might attenuate LPS-induced hyporesponsiveness of platelets by changing the plasma components possibly through altering H2O2 and nitric oxide concentrations.
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Affiliation(s)
- Huei-Ping Dong
- Department of Physiology, Kaohsiung Medical University, Kaohsiung City, Taiwan
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12
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Kuckleburg CJ, Sylte MJ, Inzana TJ, Corbeil LB, Darien BJ, Czuprynski CJ. Bovine platelets activated by Haemophilus somnus and its LOS induce apoptosis in bovine endothelial cells. Microb Pathog 2005; 38:23-32. [PMID: 15652292 DOI: 10.1016/j.micpath.2004.10.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 10/26/2004] [Accepted: 10/28/2004] [Indexed: 11/19/2022]
Abstract
Haemophilus somnus is a bacterial pathogen that causes respiratory disease and vasculitis in cattle. Thrombotic meningoencephalitis (TME) and other severe forms of H. somnus-mediated vascular disease are characterized histopathologically by vasculitis, thrombosis, and infiltration of polymorphonuclear cells. It has been reported previously that activated human platelets express CD40L, FasL and P-selectin (CD62P). We hypothesized that if these surface markers are up-regulated on bovine platelets after in vitro exposure to H. somnus and its lipooligosaccharide (LOS), they might contribute to endothelial cell damage. Using flow cytometry, we demonstrated low baseline expression of these molecules by bovine platelets and increased expression following in vitro stimulation with ADP, H. somnus or H. somnus LOS. H. somnus stimulated platelets were capable of causing apoptosis in endothelial cells as measured by Hoechst-33342 staining and caspase-3 activity. If these events occur in vivo, they might promote vascular damage and endothelial cell apoptosis, leading to the development of vasculitis and thrombosis that characterize bovine H. somnus infection.
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Affiliation(s)
- Christopher J Kuckleburg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive West, Madison, WI 53706, USA
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Totsuka E, Murata A, Nishimura A, Umehara M, Nara M, Ono H, Nozaki T, Takiguchi M, Wajima N, Takahashi K, Seino K, Narumi S, Hakamada K, Sasaki M. Attenuation of canine warm ischemic small bowel injury by novel combination of nitric oxide donor, FK409, and cytokine suppressive anti-inflammatory agent FR167653. Transplant Proc 2004; 36:1988-90. [PMID: 15518720 DOI: 10.1016/j.transproceed.2004.08.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Organ ischemia-reperfusion injury is caused by two consecutive steps, microcirculatory disturbance and neutrophil-endothelial cell interactions, which are caused by inflammatory cytokines. We examined the hypothesis that combination therapy with a donor (FK409) of nitric oxide, one of the potent mediators with diverse roles as a vosodilator and a platelet inhibitor, together with the cytokine suppressor agent (FR167653) attenuates warm ischemic injury in canine small bowel. Small bowel ischemia was initiated by clamping the superior mesenteric artery and vein. Animals were divided into two groups: a control group (n = 5) subjected to 2-hour small bowel ischemia only, and a combination therapy group (FK/FR group, n = 5) that received FK409 (300 mcg/kg/h) plus FR167653 (1 mg/kg/h) intravenously before and after the ischemic event. We evaluated animal survival, small bowel tissue blood flow, and enzyme release from the small bowel. All controls died from severe acidosis within 2 days and all the FK/FR animals survived 7 days (P < .05). The FK/FR group recovered more than 70% of blood flow immediately after the revascularization, while the flow was less than 40% among the controls. Serum creatine phosphokinase values in the control group after reperfusion were significantly higher than those in the FK/FR group. In conclusion improvement of the microcirculation by FK409 and inhibition of cytokine release by FR167653 together attenuated warm ischemic small bowel injury.
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Affiliation(s)
- E Totsuka
- Second Department of Surgery, Hirosaki University School of Medicine, Hirosaki, Japan.
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Sheu JR, Fong TH, Liu CM, Shen MY, Chen TL, Chang Y, Lu MS, Hsiao G. Expression of matrix metalloproteinase-9 in human platelets: regulation of platelet activation in in vitro and in vivo studies. Br J Pharmacol 2004; 143:193-201. [PMID: 15289295 PMCID: PMC1575278 DOI: 10.1038/sj.bjp.0705917] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
1. The aim of this study was to identify the presence of matrix metalloproteinase-9 (MMP-9) in human platelets and systematically examine its inhibitory mechanisms of platelet activation. 2. In this study, we report on an efficient method for the quantitative analysis of pro-MMP-9 in human platelets using capillary zone electrophoresis (CZE). To elucidate subcellular localization of MMP-9 in human platelets, we investigated intraplatelet MMP-9 by immunogold labeling and visualized it using electron microscopy. In an in vivo thrombotic study, platelet thrombus formation was induced by irradiation of mesenteric venules with filtered light in mice pretreated with fluorescein sodium. 3. MMP-9-gold labeling was observed on the plasma membrane, alpha-granules, open canalicular system, and within the cytoplasma both in resting and activated platelets. Furthermore, activated MMP-9 concentration-dependently (15-90 ng ml(-1)) inhibited platelet aggregation stimulated by agonists. Activated MMP-9 (21 and 90 ng ml(-1)) inhibited phosphoinositide breakdown, intracellular Ca(2+) mobilization, and thromboxane A(2) formation in human platelets stimulated by collagen (1 microg ml(-1)). In addition, activated MMP-9 (21 and 90 ng ml(-1)) significantly increased the formation of nitric oxide/cyclic GMP. 4. Rapid phosphorylation of a platelet protein of Mr 47,000 (P47), a marker of protein kinase C activation, was triggered by phorbol-12, 13-dibutyrate (PDBu) (60 nm). This phosphorylation was markedly inhibited by activated MMP-9 (21 and 90 ng ml(-1)). Activated MMP-9 (1 microg g(-1)) significantly prolonged the latency period of inducing platelet plug formation in mesenteric venules. 5. These results indicate that the antiplatelet activity of activated MMP-9 may be involved in the following pathways. (1) Activated MMP-9 may inhibit the activation of phospholipase C, followed by inhibition of phosphoinositide breakdown, protein kinase C activation, and thromboxane A(2) formation, thereby leading to inhibition of intracellular Ca(2+) mobilization. (2) Activated MMP-9 also activated the formation of nitric oxide/cyclic GMP, resulting in inhibition of platelet aggregation. These results strongly indicate that MMP-9 is a potent inhibitor of aggregation. It may play an important role as a negative feedback regulator during platelet activation.
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Affiliation(s)
- Joen R Sheu
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei 110, Taiwan.
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15
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Cranshaw JH, Evans TW, Mitchell JA. Characterization of the effects of isoprostanes on platelet aggregation in human whole blood. Br J Pharmacol 2001; 132:1699-706. [PMID: 11309241 PMCID: PMC1572736 DOI: 10.1038/sj.bjp.0704019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We tested the effects of 11 commercially-available isoprostanes on platelet aggregation directly or when triggered by the thromboxane receptor agonist U46619 or collagen in healthy human citrated blood using a whole blood aggregometer. None of the isoprostanes tested triggered aggregation alone, nor facilitated aggregation by a sub-threshold dose of U46619 or collagen. Five isoprostanes inhibited aggregation (rank order of potency 8-iso PGE(1)>8-iso PGE(2)>8-iso PGF(2alpha)>8-iso PGF(3alpha)>8-iso-13,14-dihydro-15-keto PGF(2alpha)). Blood incubated with LPS to induce a gross inflammatory response exhibited a time dependent (2 - 12 h) reduction in aggregation to U46619 but maintained a consistent response to collagen. Under these conditions, as in control blood, none of the isoprostanes tested induced aggregation. In fact, the inhibitory actions of isoprostanes on U46619-induced aggregation were enhanced in blood treated with LPS. L-NAME inhibited aggregation induced by U46619 in fresh blood and in blood treated with LPS. In the presence of L-NAME, (with or without LPS) none of the isoprostanes tested induced aggregation but retained their inhibitory action. Thus, in human whole blood the action of 8-iso PGE(1), 8-iso PGE(2), 8-iso PGF(2alpha), 8-iso PGF(3alpha), and 8-iso-13,14-dihydro-15-keto PGF(2alpha) is antiaggregatory. Moreover, this inhibitory capacity is still apparent and may be enhanced in blood subjected to inflammatory stimulation.
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Affiliation(s)
- J H Cranshaw
- Unit of Critical Care Medicine, Royal Brompton Hospital, NHLI Division of Imperial College School of Medicine, Sydney Street, London SW3 6NP
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George A, Bang RL, Lari AR, Gang RK. Acute thrombocytopenic crisis following burns complicated by staphylococcal septicaemia. Burns 2001; 27:84-8. [PMID: 11164671 DOI: 10.1016/s0305-4179(00)00065-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pathophysiological changes in a burn patient can at times manifest as severe complications, the management of which can be extremely challenging to the burn surgeon. A case report of an adult male with burns (18% total body surface area) who developed an acute unexpected thrombocytopenia crisis (2x10(9) l(-1)) on day 3 followed by disseminated intravascular coagulation is presented. The various etiological factors and possible mechanisms leading to thrombocytopenia in burns are discussed. Minor burns may present acute major complications in the presence of other thrombocytopenic factors like trauma and sepsis and thrombocytopenia by it self can be a good indicator of sub-clinical infection.
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Affiliation(s)
- A George
- Al-Babtain Centre for Plastic, Reconstructive Surgery & Burns, Ibn-Sina Hospital, Kuwait
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Przyklenk K, Hata K, Whittaker P, Elliott GT. Monophosphoryl lipid A: a novel nitric oxide-mediated therapy to attenuate platelet thrombosis? J Cardiovasc Pharmacol 2000; 35:366-75. [PMID: 10710120 DOI: 10.1097/00005344-200003000-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nitric oxide (NO) is a potent inhibitor of platelet aggregation. However, the benefits of NO-based therapies can be confounded by concomitant hypotension. Monophosphoryl lipid A (MLA) is a nontoxic derivative of endotoxin that purportedly increases nitric oxide synthase (NOS) activity and, presumably, NO production, yet has a hemodynamically benign profile. Thus our aims were to determine whether (a) MLA attenuates in vivo platelet aggregation in damaged and stenotic canine coronary arteries by a NO-mediated mechanism but without reductions in arterial pressure; and (b) the platelet inhibitory effects are manifest in vitro. To address the first aim, anesthetized dogs underwent coronary injury + stenosis, resulting in cyclic variations in coronary blood flow (CFVs) caused by the formation/dislodgement of platelet-rich thrombi. In protocol I, dogs received MLA (100 microg/kg + 40 microg/kg/h) or vehicle beginning 15 min before stenosis. Protocol II was identical, except the NOS inhibitor aminoguanidine was coadministered with MLA/vehicle. Coronary patency was assessed throughout the initial 3 h after injury + stenosis. Infusion of MLA did not result in hypotension. However, in protocol I, the median nadir of the CFVs was higher (2.1 vs. 0.8 ml/min; p < 0.05), median duration of total thrombotic occlusion tended to be reduced (0 vs. 10.4 min; p = 0.1), and mean flow-time area, expressed as a percentage of baseline flow, was increased (53 +/- 9% vs. 33 +/- 3%; p < 0.05) in MLA-treated versus vehicle-treated dogs. In contrast, in protocol II, vessel patency was comparable in both groups. Finally, whole blood impedance aggregometry (protocol HI) revealed a significant reduction in the in vitro platelet aggregation in blood samples receiving exogenous MLA, which was blocked by coadministration of exogenous aminoguanidine. Thus MLA attenuates platelet-mediated thrombosis in both damaged and stenotic canine coronary arteries and in vitro, possibly by an NO-mediated mechanism, but without concomitant hypotension.
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Affiliation(s)
- K Przyklenk
- Heart Institute, Good Samaritan Hospital, and Department of Medicine, University of Southern California, Los Angeles 90017-2395, USA.
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