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Jan Mersmann,
Reinhard Berkels, Paula Zacharowski,
Nguyen Tran,
Alexander Koch,
Kazuma Iekushi,
Stefanie Dimmeler,
Tiago F Granja,
Olaf Boehm,
William C Claycomb,
Kai Zacharowski
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ABSTRACT: To test whether preconditioning with a toll-like receptor (TLR) 2 agonist protects against myocardial ischemia and reperfusion by interfering with chemokine CXCL1 release from cardiomyocytes.
C3H mice were challenged with vehicle or synthetic TLR2 agonist Pam3Cys-Ser-Lys4 (Pam3CSK4; 1 mg/kg) 24 hrs before myocardial ischemia (20 mins) and reperfusion (2 hrs or 24 hrs). Infarct size, troponin T release, and leukocyte recruitment were quantified. In murine cardiomyocytes (HL-1), we studied the expression/activation profile of TLR2 in response to stimulation with Pam3CSK4 (0.01-1 mg/mL). Furthermore, we studied the chemokine ligand 1 (CXCL1) response to Pam3CSK4 and ischemia/reperfusion in vivo and in vitro.
University hospital research laboratory.
Anesthetized male mice and murine cardiomyocytes.
Preconditioning by Pam3CSK4 reduced infarct size and troponin T release. This was accompanied by a decreased recruitment of leukocytes into the ischemic area and an improved cardiac function. In HL-1 cells, TLR2 activation amplified the expression of the receptor in a time-dependent manner and led to CXCL1 release in a concentration-dependent manner. Preconditioning by Pam3CSK4 impaired CXCL1 release in response to a second inflammatory stimulus in vivo and in vitro.
Preconditioning by TLR2 agonist Pam3CSK4 reduces myocardial infarct size after myocardial ischemia/reperfusion. One of the mechanisms involved is a diminished chemokine release from cardiomyocytes, which subsequently limits leukocyte infiltration.
Critical care medicine 03/2010; 38(3):903-9. · 6.37 Impact Factor
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ABSTRACT: Inflammation is the host's defense mechanism to infection or trauma including surgical procedures. In the clinic, non-infectious inflammation plays an important part in cardiology (e.g. Percutaneous transluminal coronary angioplasty, PTCA), intensive care medicine (e.g. polytrauma), cardiac (e.g. extracorporeal circulation) and vascular surgery (e.g. reperfusion injury). An imbalance of the inflammatory response can cause an acute condition like sepsis or long-term Cardiovascular disease (CVD), both of which are leading killers in the Western world. Alterations in coagulation, innate immunity and endothelial function represent key aspects in the mechanism of inflammation and are the link between the pathogenesis of these two diseases. Studying inflammatory pathways or targeting specific mediators during inflammation may help to develop strategies to improve the clinical outcome of patients undergoing major surgery, where postoperative inflammation plays a crucial role.
Frontiers in Bioscience 02/2009; 14:2970-82. · 3.52 Impact Factor
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ABSTRACT: The peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a regulator of anti-inflammatory genes. One of its agonists, rosiglitazone-widely used in the treatment of type 2 diabetes mellitus-has recently been reported to increase the risk for myocardial infarction. In contrast, various studies provide evidence for a rosiglitazone-induced cardioprotection in different models of acute myocardial I/R. Here, we report that this protection can still be observed after 28 days of reperfusion in a murine model even when treatment commenced after the period of ischemia (reperfusion therapy). In vitro, cells from the rat cardiomyoblast cell line H9c2(2-1) are protected against oxidative stress by incubation with rosiglitazone, which can be abrogated by dexamethasone or cycloheximide. The antioxidant enzyme heme oxygenase 1 is up-regulated in these cells after rosiglitazone treatment. Our data provide further evidence that rosiglitazone exerts protective effects during myocardial I/R and might contribute to the reevaluation of the approved drug rosiglitazone.
Shock 08/2008; 30(1):64-8. · 2.85 Impact Factor
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ABSTRACT: The occlusion of a coronary artery leads to ischemia of the myocardium, while permanent occlusion results in cell death and myocardial dysfunction. Early restoration of blood flow is the only means to reduce or prevent myocardial necrosis, but-paradoxically-reperfusion itself contributes to injury of the heart. In animal models, this phenomenon is well described, and there are many different unrelated approaches to reduce reperfusion injury. In humans, however, pharmacological interventions have so far failed to reduce myocardial reperfusion injury. We summarize the pathogenesis of reperfusion injury, detailing the role of fibrin(ogen) and its derivatives. Moreover, we introduce a new concept for fibrin derivatives as potential targets for reperfusion therapy.
Journal of Molecular Medicine 07/2006; 84(6):469-77. · 4.67 Impact Factor
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ABSTRACT: During Gram-negative sepsis, lipopolysaccharide (LPS) activates toll-like receptor (TLR) 4 and induces complex responses of immune system and haemostasis. In the present study we investigated whether thrombelastography is suitable to monitor the LPS-induced activation of coagulation. Whole blood samples from healthy volunteers were incubated with LPS for various incubation periods (0-5 hrs), thereafter rotation thrombelastography was performed. Incubation of whole blood (>or=3 h) with LPS markedly reduced clotting time; after 5 hrs the variable was reduced from 459+/-39 sec to 80+/-20 sec while the other thrombelastography variables (angle alpha, clot formation time, maximal clot formation) remained unaltered. EC(50) of the LPS effect on whole blood clotting time was 18 microg/ml. In isolated leukocytes, diluted in platelet poor plasma, far lower LPS-concentrations were effective: 10 ng/ml LPS reduced clotting time from 439+/-68 sec to 200+/-56 sec. Experiments with the protein synthesis inhibitor cycloheximide and active site-inhibited factor VIIa revealed that LPS exerts its effects via the synthesis of tissue factor. Addition of tissue factor to whole blood samples revealed that a concentration of 100 fmol/l can be detected using thrombelastography. In whole blood samples the tissue factor concentration induced by LPS amounted up to 12 pmol/l. In summary, thrombelastography proved to be a sensitive and reliable tool for the determination of LPS-induced tissue factor mediated activation of haemostasis in whole blood samples.
Thrombosis and Haemostasis 04/2006; 95(3):557-61. · 5.04 Impact Factor
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ABSTRACT: Non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat the condition of rheumatoid arthritis, where levels of prostaglandin E2 (PGE2) and granulocyte macrophage-colony stimulating factor (GM-CSF) are elevated in the synovial fluid. NO-NSAIDs are a new class of cyclooxygenase (COX)-inhibitors developed by coupling a nitric oxide (NO)-donating moiety to conventional NSAIDs. We show that, in cytokine-treated synoviocytes (from non-rheumatic patients), NO-naproxen and NO-flurbiprofen like their parent compounds concentration-dependently reduce the levels of PGE2 (an index of COX-2 activity), with a corresponding rise in the release of GM-CSF. Unlike acetylsalicylic acid (ASA), NO-ASA reduces the levels of PGE2, without increasing GM-CSF release, although cell viability is reduced at the highest concentration (1 mM). The effects of NSAIDs and NO-NSAIDs on GM-CSF release were attributable to the PGE2 mediated cyclic (c) AMP pathway because PGE2 reversed the effects of COX blockade. Second, phosphodiesterase inhibitors 3-isobutyl-1-methylxanthine (IBMX) and Ro-201724 (both of which elevate cAMP levels) decreased GM-CSF release, in the presence of PGE2. Finally, neither sodium nitroprusside nor zaprinast (both of which elevate cGMP levels) affected GM-CSF or PGE2 release. Our findings demonstrate that GM-CSF is regulated by NSAIDs and NO-NSAIDs via inhibition of COX and appears to be mediated via the cAMP pathway. NO-ASA is the exception, because it does not increase GM-CSF release, although at millimolar concentrations cell viability is reduced.
European Journal of Pharmacology 02/2005; 508(1-3):7-13. · 2.52 Impact Factor
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Stefan R Bornstein, Paula Zacharowski,
Ralf R Schumann,
Andreas Barthel,
Nguyen Tran,
Claudia Papewalis,
Valeria Rettori,
Samuel M McCann,
Klaus Schulze-Osthoff,
Werner A Scherbaum,
Jörg Tarnow,
Kai Zacharowski
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ABSTRACT: Septicemia is one of the major health concerns worldwide, and rapid activation of adrenal steroid release is a key event in the organism's first line of defense during this form of severe illness. The family of Toll-like receptors (TLRs) is critical in the early immune response upon bacterial infection, and TLR polymorphisms are frequent in humans. Here, we demonstrate that TLR-2 deficiency in mice is associated with reduced plasma corticosterone levels and marked cellular alterations in adrenocortical tissue. TLR-2-deficient mice have an impaired adrenal corticosterone release after inflammatory stress induced by bacterial cell wall compounds. This defect appears to be mediated by a decrease in systemic and intraadrenal cytokine expression, including IL-1, tumor necrosis factor alpha, and IL-6. Our data demonstrate a link between the innate immune system and the endocrine stress response. The critical role of TLR-2 in adrenal glucocorticoid regulation needs to be considered in patients with inflammatory disease.
Proceedings of the National Academy of Sciences 12/2004; 101(47):16695-700. · 9.68 Impact Factor
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ABSTRACT: Objective: Nitric oxide–donating nonsteroidal anti-inflammatory drugs (NO-NSAIDs) are a new class of cyclooxygenase (COX) inhibitors. To investigate whether these drugs actually release nitric oxide (NO), we labeled the nitroxy group of nitroflurbiprofen with nitrogen 15 to determine the metabolic fate of this compound in humans.Method: Six healthy volunteers who fasted were given an oral dose of 15N-nitroflurbiprofen (100 mg). Samples of blood, urine, and gastric headspace gas were taken over a 24-hour period to determine the levels of nitroflurbiprofen, flurbiprofen, total nitrate/nitrite, 15N-nitrate/nitrite, COX activity, and gastric NO. In a crossover study (1 week apart), a further 6 healthy volunteers who fasted were given an oral dose of nitroflurbiprofen (100 mg) or flurbiprofen (65 mg) and levels of gastric NO were determined.Results: Nitroflurbiprofen was undetectable in the systemic circulation. Levels of 15N-nitrate/nitrite (5.2% 1.5% enrichment) and flurbiprofen (2.4 0.7 g/mL) peaked at 4 hours in the plasma and gradually decreased thereafter. In unstimulated blood, the plasma levels of thromboxane B2 (COX-1 activity) were 2 to 3 ng/mL, and after calcium ionophore stimulation, large amounts of thromboxane B2 were produced (112 31 ng/mL). Prostaglandin E2 was undetectable in unstimulated blood. After lipopolysaccharide stimulation, the plasma levels of prostaglandin E2 increased to 15 4 ng/mL. The metabolite flurbiprofen inhibited plasma COX-1 activity for the duration of the study period (maximum inhibition at 4 hours), whereas COX-2 activity recovered after 6 hours. In the crossover study, levels of gastric NO were higher in subjects given nitroflurbiprofen, when compared with those given flurbiprofen. (The area under the curve for gastric NO was 435 107 ppm h versus 305 94 ppm h [95% confidence interval of the difference, 89-172 ppm h; P < .001]).Conclusion: Nitroflurbiprofen was undetectable in the systemic circulation, suggesting metabolism to 15N-nitrate/nitrite and flurbiprofen in the presystemic circulation. Levels of gastric NO were significantly higher after ingestion of nitroflurbiprofen than flurbiprofen.
Clinical Pharmacology & Therapeutics 09/2004; 76(4):350-358. · 6.04 Impact Factor
