Objective: 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.
Design: 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.
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.
View Article and Find Full Text PDFObjective: Apoptosis of cardiomyocytes has been suggested to contribute to outcome following myocardial ischaemia and reperfusion (MI/R). Caspase inhibitors were developed as potential therapeutics for MI/R. However, various reports using the broad-spectrum caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.
View Article and Find Full Text PDFObjective: Preconditioning with bacterial wall fragments lipopolysaccharide (LPS) or lipoteichoic acid (LTA) reduce myocardial infarct size after ischaemia and reperfusion (I/R) in rats. Preconditioning with LTA reduces neutrophil accumulation during reperfusion and thereby ameliorates one of myocardial reperfusion injury's most important mechanisms. In this study, we use an ex vivo model of regional myocardial I/R to investigate LTA versus LPS induced preconditioning in a system devoid of leukocytes.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFObjective: Pretreatment with low-dose lipopolysaccharide protects cells/organs against a subsequent lethal Gram-negative (lipopolysaccharide tolerance) or Gram-positive (cross tolerance) stimulus. We determined whether this occurs in the rat lung. The involvement of inducible nitric oxide synthase and heme oxygenase-1 was evaluated.
View Article and Find Full Text PDFObjective: The fibrin-derived peptide Bbeta15-42 has been shown to reduce infarct size in rodent models of ischemia-reperfusion injury. To increase its potential for translation into the clinic, we studied the effects of Bbeta15-42 in pigs, whose coronary anatomy is similar to that of humans. In addition, we evaluated the pharmacokinetics and safety of Bbeta15-42 in several species, including humans.
View Article and Find Full Text PDFMany compounds have been shown to prevent reperfusion injury in various animal models, although to date, translation into clinic has revealed several obstacles. Therefore, the National Heart, Lung, and Blood Institute convened a working group to discuss reasons for such failure. As a result, the concept of adequately powered, blinded, randomized studies for preclinical development of a compound has been urged.
View Article and Find Full Text PDFContext: Sepsis is a leading cause of death in the Western world and can be associated with failure of the hypothalamic-pituitary-adrenal axis. A coordinated response of the adrenal and immune system is of vital importance for survival during sepsis. Within the immune response, Toll-like receptors (TLRs) play a crucial role by recognizing pathogen-associated molecules such as bacterial DNA.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFSepsis and septic shock are leading killers in the noncoronary intensive care unit, and they remain worldwide health concerns. The initial host defense against bacterial infections involves Toll-like receptors (TLRs), which detect and respond to microbial ligands. In addition, a coordinated response of the adrenal and immune systems is crucial for survival during severe inflammation.
View Article and Find Full Text PDFDuring 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.
View Article and Find Full Text PDFIn the event of a myocardial infarction, current interventions aim to reopen the occluded vessel to reduce myocardial damage and injury. Although reperfusion is essential for tissue salvage, it can cause further damage and the onset of inflammation. We show a novel anti-inflammatory effect of a fibrin-derived peptide, Bbeta15-42.
View Article and Find Full Text PDFNon-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.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2004
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.
View Article and Find Full Text PDFObjective: 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 15 N-nitroflurbiprofen (100 mg).