alpha-Neup5Ac-(2--3)-beta-D-Galp-(1--4)-[alpha-L-Fucp-(1--3)]-D-GlcpNAc and Reperfusion-Injury

Topics: Antibodies, Monoclonal; Arteriosclerosis; Arthritis; Burns; Humans; Immunoglobulins; Inflammation; Integrins; Intercellular Adhesion Molecule-1; Leukocytes; Oligosaccharides; Reperfusion Injury; Selectins; Sialyl Lewis X Antigen

Arrhythmia during ischemia and reperfusion is still an intriguing problem in cardiovascular medicine. Leukocytes infiltrating the ischemic region play an important pathophysiological role. The effects of soluble sialyl-Lewis-X analogues Hoe934553 and Hoe943644, which may inhibit leukocyte-endothelial interaction, were investigated.. Isolated rabbit hearts were perfused with Tyrode solution according to the Langendorff technique. Polymorphic neutrophilic granulocytes (PMN) were isolated from autologous peripheral blood. After 60 min equilibration PMN (n = 7) or vehicle (n = 7) were infused with or without concomitant treatment with Hoe934553 (n = 6) and Hoe943644 (n = 6). Five minutes after the start of the PMN infusion the left descending coronary artery was occluded for 30 min followed by 30 min of reperfusion. Activation and repolarization waves were recorded at 256 sites using a computerized mapping system.. Ventricular fibrillation (VF) in 4/7 PMN-treated hearts was found, while in PMN-free hearts no VF occurred. Treatment with Hoe934553 and Hoe943644 completely prevented VF. PMN largely enhanced the dispersion of action potential duration during reperfusion. This PMN effect was completely prevented by both drugs. Myeloperoxidase assay showed reduced activity in Hoe934553 and Hoe943644 treated hearts.. Sialyl-Lewis-X analogues (Hoe934553, Hoe943644) can antagonize PMN infiltration and PMN-induced VF in the course of ischemia and reperfusion.

Topics: Animals; Arrhythmias, Cardiac; Coronary Circulation; Disease Models, Animal; Electrophysiologic Techniques, Cardiac; Heart Conduction System; Heart Ventricles; Leukocytes; Male; Models, Cardiovascular; Oligosaccharides; Peroxidase; Rabbits; Reperfusion Injury; Sialyl Lewis X Antigen; Time Factors; Ventricular Pressure

We investigated the effects of OJ-R9545, a novel Sialyl Lewis x analogue, on lung ischemia-reperfusion (IR) injury using an in vivo rabbit model.. The left hilum of the lung was clamped for 110 minutes; the lung was then reperfused for 90 minutes. Either OJ-R9545 (10 mg/kg) or vehicle solution was administered from 10 minutes before reperfusion to 60 minutes after reperfusion in the OJ-R (+) and OJ-R (-) group (n = 6 in each group), respectively. The sham group (n = 3) underwent an identical procedure without ischemia.. Arterial oxygen tensions in the OJ-R (+) group were superior to those in the OJ-R (-) group from 30 to 90 minutes after reperfusion (p < 0.05 and p < 0.01). Lung wet/dry weight ratio and myeloperoxidase activity after reperfusion in the OJ-R (+) group were both significantly lower than the corresponding figures in the OJ-R (-) group (p < 0.05). The intrapulmonary leukocytes were significantly reduced in the OJ-R (+) group compared with those in the OJ-R (-) group (p < 0.01).. OJ-R9545 attenuates lung IR injury by preventing leukocyte infiltration into the lung.

Topics: Animals; Chemotaxis, Leukocyte; Male; Oligosaccharides; Peroxidase; Rabbits; Random Allocation; Reperfusion Injury; Sialyl Lewis X Antigen

The role of the sialyl Lewis(x) (sLe(x))-decorated version of soluble complement receptor type 1 (sCR1) in moderating skeletal muscle reperfusion injury, by antagonizing neutrophil endothelial selectin interaction and complement activation, is examined. Mice underwent 2 h of hindlimb ischemia and 3 h of reperfusion. Permeability index (PI) was assessed by extravasation of 125I-labeled albumin. Neutrophil depletion and complement inhibition with sCR1 reduced permeability by 72% (PI 0.81 +/- 0.10) compared with a 42% decrease (PI 1.53 +/- 0.08) observed in neutropenic mice, indicating that part of the complement-mediated injury is neutrophil independent. sCR1sLe(x) treatment reduced PI by 70% (PI 0.86 +/- 0.06), an additional 20% decrease compared with sCR1 treatment (PI 1.32 +/- 0.08). Treatment with sCR1sLe(x) 0.5 and 1 h after reperfusion reduced permeability by 63% (PI 0.09 +/- 0.07) and 52% (PI 1.24 +/- 0.09), respectively, compared with the respective decreases of 41% (PI 1.41 +/- 0.10) and 32% (PI 1.61 +/- 0.07) after sCR1 treatment. Muscle immunohistochemistry stained for sCR1 only on the vascular endothelium of sCR1sLe(x)-treated mice. In conclusion, sCR1sLe(x) is more effective than sCR1 in moderating skeletal muscle reperfusion injury.

Topics: Animals; Cell Membrane Permeability; Complement Activation; Complement Inactivator Proteins; Hindlimb; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Neutrophils; Oligosaccharides; Receptors, Complement; Recombinant Proteins; Reperfusion Injury; Sialyl Lewis X Antigen

Sinusoidal endothelial cell (SEC) apoptosis is a central feature of reperfusion injury in liver transplantation. Platelet sequestration occurs after transplantation with possible deleterious effects. We tested the hypothesis that platelets mediate SEC apoptosis.. Livers were perfused after 24 hours of cold preservation in University of Wisconsin solution in an isolated perfused rat liver model. The perfusate contained isolated syngeneic red blood cells and purified platelets. Effects of inhibiting platelet adhesion on SEC apoptosis was tested using sialyl Lewis-X oligosaccharide (sLe(x)), a natural ligand of selectin adhesion molecules. Reperfusion injury was assessed by established markers of injury. Apoptosis was determined by TUNEL and electron microscopy.. A third of the circulating platelets was rapidly sequestered in the liver after reperfusion. This was associated with increased graft injury. Single platelets were adherent to sinusoidal lining without morphological or dynamic evidence of impairment of microcirculation. TUNEL staining revealed a 6-fold increase in the number of apoptotic SECs at 1 hour of reperfusion. No hepatocyte death or evidence of necrosis was detected up to 3 hours of reperfusion. Addition of sLe(x) inhibited adhesion and significantly reduced SEC apoptosis.. Platelets cause SEC apoptosis upon reperfusion of liver grafts. Prevention of adhesion is protective.

Topics: Animals; Apoptosis; Binding, Competitive; Blood Platelets; Endothelium; Lewis Blood Group Antigens; Liver; Oligosaccharides; Perfusion; Platelet Adhesiveness; Rats; Rats, Wistar; Reperfusion Injury; Selectins; Sialyl Lewis X Antigen

Glycoprotein adhesion receptors such as selectins contribute to tissue injury in stroke. Ischemic neurons strongly expressed C1q, which may target them for complement-mediated attack or C1qRp-mediated clearance. A hybrid molecule was used to simultaneously inhibit both complement activation and selectin-mediated adhesion. The extracellular domain of soluble complement receptor-1 (sCR1) was sialyl Lewis x glycosylated (sCR1sLex) to inhibit complement activation and endothelial-platelet-leukocyte interactions. sCR1 and sCR1sLex colocalized to ischemic cerebral microvessels and C1q-expressing neurons, inhibited neutrophil and platelet accumulation, and reduced cerebral infarct volumes. Additional benefit was conferred by sialyl Lewis x glycosylation of the unmodified parent sCR1 molecule.

Topics: Animals; Blood Platelets; Cell Adhesion; Cerebral Cortex; Cerebral Infarction; Cerebrovascular Circulation; Cerebrovascular Disorders; Complement Activation; Complement C1q; Glycosylation; Humans; Ischemic Attack, Transient; Leukocytes; Mice; Neurons; Neuroprotective Agents; Neutrophils; Oligosaccharides; Platelet Adhesiveness; Receptors, Complement; Reperfusion Injury; Selectins; Sialyl Lewis X Antigen; Time Factors

During rejection and reperfusion injury, infiltration of leukocytes into the lung allograft is regulated by adhesion molecules, especially selectins. Sialyl-Lewis X (SLX), an oligosaccharide, is a membrane ligand molecule of P-selectin adhesion receptors. In this study, we investigated the effect of intravenous administration of a synthetic oligosaccharide analog of SLX on rejection and reperfusion injury after rat lung transplantation.. Left lateral, orthotopic, allogeneic lung transplantation was performed between fully incompatible rat strains (Dark Agouti-->Lewis) after an average total ischemic time of 45 minutes. Group A (n = 6) served as control; no immunosuppression was used. In group B (n = 6), rats received 200 micrograms/kg/day SLX intravenously on days 0 to 4. The animals were killed on days 5 and 10, respectively. In groups C and D, syngeneic lung transplantation was performed (Lewis-->Lewis), with an ischemic time of 7 hours. Group C (n = 6) served as untreated controls. Group D rats (n = 6) received a single dose of 20 mg/kg SLX at the end of the ischemic time. The animals were killed on days 2 and 5, respectively.. In group B rats, treated for rejection, a lower grade of rejection (2.7 +/- 0.6 vs 4.0 +/- 0.0, p < 0.05) and fewer infiltrating CD11a-positive leukocytes (6.6 +/- 2.7 vs 18.6 +/- 7.3, p < 0.05) were found histologically compared with group A. In group D rats, treated for reperfusion injury, a significant reduction of reperfusion injury was detected on chest radiograms and by histologic study.. A synthetic oligosaccharide analog of SLX reduces allograft rejection and reperfusion injury by abrogation of P-selectin-dependent leukocyte-endothelial interaction. According to these findings, treatment with oligosaccharides to reduce reperfusion injury and rejection seems to be a promising strategy for clinical lung transplantation.

Topics: Animals; Graft Rejection; Lung; Lung Transplantation; Male; Microcirculation; Oligosaccharides; P-Selectin; Rats; Rats, Inbred Lew; Rats, Inbred Strains; Reperfusion Injury; Sialyl Lewis X Antigen

Cell adhesion plays a central role in the pathogenesis of neutrophil-induced hepatic injury after ischemia and reperfusion. Sialyl Lewis(x) binds to selectins mediating neutrophil adherence to endothelium, thereby facilitating subsequent migration and tissue damage.. We studied the effect of a novel sulfo-derivative of sialyl Lewis(x), GM-1998, on the liver inflammatory response after ischemia and reperfusion. Specifically, we evaluated its impact on three key inflammatory mediators: neutrophil migration, free radicals, and serum cytokines.. Rats were subjected to total hepatic ischemia for 90 min using an extracorporeal portosystemic shunt to avoid splanchnic congestion. GM-1998 was given at a total dose of 20 mg/kg both prior to and after reperfusion. Liver function tests, liver tissue free radicals, and myeloperoxidase (MPO), serum cytokines (IL-1, TNF-alpha), and liver histology were analyzed 4 hr after reperfusion. Additionally, survival was followed for up to 7 days.. Seven-day survival significantly increased from 20% in the control group to 65% in the sulfo-Lewis(x) treated group. Liver function tests and histological damage scores were improved in comparison to controls. We observed significant downregulation of free radicals and neutrophil migration. This compound did not significantly affect serum cytokine levels.. GM-1998 showed a protective effect in an in vivo model of severe liver ischemia and reperfusion by decreasing tissue free radical levels and selectin-mediated neutrophil migration. This protective effect was also reflected in improved liver function tests and histological response leading to better survival. We confirmed the beneficial effect of neutrophil blockade as a key target to prevent damage after the reperfusion phenomenon by using a glycomimetic sulfo-Lewis(x).

Topics: Animals; Anti-Inflammatory Agents; Catalase; Gangliosides; Interleukin-1; Liver; Male; Neutrophils; Oligosaccharides; Peroxidase; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Sialyl Lewis X Antigen; Superoxide Dismutase; Tumor Necrosis Factor-alpha

To define the mechanisms responsible for the lung leukosequestration and injury elicited by intestinal ischemia/reperfusion (I/R).. The effect of 120 minutes of superior mesenteric artery occlusion and 90 minutes of reperfusion on neutrophil deformability, lung neutrophil retention, and pulmonary microvascular permeability was determined.. Compared with control surgery, intestinal I/R resulted in a significant increase in neutrophil stiffness (mean yield pressure [Pyield], 1.533 +/- 0.075 and 2.302 +/- 0.288 cm H2O, respectively) and lung neutrophil content (6.3 +/- 1.4 and 31.5 +/- 6.4 U/g wet weight, respectively). These changes were not affected by inhibition of neutrophil adherence before gut reperfusion. However, the increased lung microvascular permeability elicited by gut I/R (0.111 +/- 0.020 [control surgery] and 0.255 +/- 0.041 [I/R] mL/min/cm H2O/100 g lung tissue) was significantly attenuated by administration of antibodies directed against neutrophil or endothelial determinants of leukocyte adhesion.. The results of this study suggest that intestinal I/R is a potent inflammatory stimulus that elicits an increase in neutrophil stiffness and lung neutrophil retention independent of neutrophil-endothelial cell adhesion. In contrast, the increased lung microvascular permeability elicited by gut I/R is attenuated by strategies that interfere with neutrophil-endothelial cell adhesion.

Topics: Animals; Antibodies, Monoclonal; Antigens, CD; Capillary Permeability; Cell Adhesion; Cell Size; Intercellular Adhesion Molecule-1; Intestinal Mucosa; L-Selectin; Lung; Microcirculation; Neutrophils; Oligosaccharides; Peroxidase; Rats; Reperfusion Injury; Sialyl Lewis X Antigen

Neutrophil adhesion and migration is associated with hepatic ischemia and reperfusion. The role of a Sialyl Lewis(x) (SLe)(x) oligosaccharide, a ligand for selections, was studied in hepatic ischemia and reperfusion injury.. Total hepatic ischemia was produced in rats for 90 minutes using an extracorporeal portosystemic shunt. To assess the role of SLe(x) in hepatic ischemia and reperfusion injury, 25 mg/kg of an SLe(x) analog, CY-1503, was given five minutes before reperfusion or at reperfusion. Biochemical tests of hepatic injury, myeloperoxidase activity in hepatic tissue, and histologic studies, including neutrophil infiltration determined by the naphthol esterase technique, were analyzed six hours after reperfusion.. Significantly improved protection in biochemical hepatic injury tests (aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase) was noted between the ischemic and the SLe(x) treated groups. Myeloperoxidase activity and polymorphonuclear cell infiltration in hepatic tissue were decreased in the SLe(x) groups. Histologic protection from hepatic damage was observed in the treated groups.. The SLe(x) oligosaccharide analog, CY-1503, had an important protective role in hepatic ischemia and reperfusion injury. Modulation of SLe(x) in the neutrophil decreased the adhesion of polymorphonuclear cells and their subsequent migration after hepatic ischemia and reperfusion.

Topics: Animals; Drug Evaluation, Preclinical; Endothelium, Vascular; Ischemia; Lewis Blood Group Antigens; Ligands; Liver; Male; Neutrophils; Oligosaccharides; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Selectins; Sialyl Lewis X Antigen

Restoration of blood flow to ischemic skeletal muscle results in a reperfusion injury characterized by permeability edema in part mediated by neutrophils that adhere via the selectin family of adhesion molecules. Rats underwent 4 h of hindlimb tourniquet ischemia followed by 4 h reperfusion. The role of neutrophils was determined by rendering one group of animals neutropenic before ischemia. In additional experimental groups, selectins were blocked with either a soluble form of the selectin counter-receptor, sialyl-Lewis X (SLX) or a monoclonal antibody directed against P-selectin (PB1.3). Neutrophil depletion resulted in a 36.1% reduction in hindlimb permeability (p < .05). SLX reduced hindlimb permeability index (PI) 23.9% at 1 mg/kg and 36.1% at 10 mg/kg compared to a nonfucosylated oligosaccharide, sialyl-N-acetylactosamine (p < .05). SLX also reduced neutrophil sequestration by 48.6% (p < .05). PB1.3 reduced hindlimb injury by 26.5% (p < .05) but did not reduce leukosequestration. We interpret these data to indicate that ischemia and reperfusion lead to selectin-mediated neutrophil sequestration. The oligosaccharide SLX, while moderately effective in limiting neutrophil sequestration was as effective as neutrophil depletion in reducing hindlimb permeability. The lack of concordance between the ability of SLX and PB1.3 in limiting neutrophil sequestration and permeability indicate mechanisms of action of these two agents that are in addition to the blocking of adhesion.

Topics: Animals; Antibodies, Monoclonal; Capillary Permeability; Cell Adhesion; Lewis X Antigen; Male; Muscle, Skeletal; Oligosaccharides; P-Selectin; Peroxidase; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sialyl Lewis X Antigen

We investigated the role of adhesion molecules in the early phase of reperfusion following cold ischemia. Livers of male Lewis rats were preserved for 0 h (group A) or 24 h in University of Wisconsin (UW) solution without additives (group B) or in UW solution with anti-ICAM-1 antibody (group C) or anti-E-selectin-1, SLe(x) and SLe(a) antibodies (group D). The livers were then reperfused with diluted rat whole blood (DWB; groups A and B). DWB containing anti-ICAM-1 and LFA-1 antibodies (group C) or DWB containing anti-L-selectin, SLe(x) and SLe(a) antibodies (group D). The reperfusion was performed at 37 degrees C for 1 h at 5 cm H2O of perfusion pressure. During reperfusion, hepatic microcirculation was assessed by monitoring portal and peripheral tissue blood flow. Bile production was significantly reduced in group B livers compared with those in group A. Anti-ICAM-1 and LFA-1 antibodies failed to improve hepatic microcirculation, whereas anti-LECAM-1, SLe(x) and SLe(a) antibodies significantly improved the microcirculation. Bile production in group C and D livers was comparable to that in group B livers. Preservation for 24 h significantly increased the release of TNF-alpha from 0.207 to 43.7 pg/g per hour during reperfusion. Monoclonal antibodies to the adhesion molecules did not suppress the release of TNF-alpha in groups C and D. Histological examination demonstrated a lack of leukocyte infiltration or thrombus in hetapic microvessels. The extent of hepatocyte necrosis did not differ among groups B, C, and D. We conclude that the microcirculatory disturbance in the early phase of reperfusion occurs as a result of the tethering of leukocytes through the interaction of the selectin family and their ligands, and that the ICAM-1-LFA-1 pathway is not involved in this step. The lack of improvement in bile production with antibodies to the selectin family and their ligands strongly suggests that other mechanisms participate in the deterioration of hepatic function.

Topics: Adenosine; Allopurinol; Animals; Antibodies, Monoclonal; Antibody Specificity; Bile; CA-19-9 Antigen; Cell Adhesion; Cold Temperature; E-Selectin; Glutathione; Insulin; Intercellular Adhesion Molecule-1; Ischemia; L-Lactate Dehydrogenase; L-Selectin; Leukocytes; Liver; Lymphocyte Function-Associated Antigen-1; Male; Microcirculation; Necrosis; Oligosaccharides; Organ Preservation; Organ Preservation Solutions; Raffinose; Rats; Rats, Inbred Lew; Reperfusion; Reperfusion Injury; Sialyl Lewis X Antigen; Tumor Necrosis Factor-alpha

Ischemia-reperfusion injury in the rabbit ear is neutrophil (PMN)-mediated, and is significantly reduced by anti-adhesion agents directed against beta 2 integrins, P-selectin, or L-selectin. We further examined selectin-mediated adherence in this setting following the administration of soluble sialyl Lewis(x) (SLe(x)), the principal carbohydrate ligand for P-, L-, and E-selectin, at various times following reperfusion. Under constant ambient temperature conditions, the rabbit ear vascular supply was isolated and occluded with an atraumatic vascular clamp for 6 h, then allowed to reperfuse. Animals receiving i.v. SLe(x) (25 mg/kg bolus + 50 mg/kg infusion over 10 h) 1) at the time of reperfusion, 2) 1 h after reperfusion, 3) 4 h after reperfusion, or 4) 12 h after reperfusion were compared with control animals receiving either saline or sialyl lactosamine, an oligosaccharide structurally similar to SLe(x) but not involved in selectin recognition. Tissue injury was assessed by serial measurement of ear edema and by visual determination of ear necrosis over 7 days. Tissue edema and necrosis were significantly reduced in animals treated with SLe(x) immediately upon reperfusion or after a 1-h delay, but not in animals for whom SLe(x) administration was delayed by 4 or 12 h. Furthermore, SLe(x) administration alone had no effect on circulating leukocyte or PMN counts, or PMN expression of CD18 or L-selectin. We conclude that interruption of selectin-mediated adherence with soluble SLe(x) oligosaccharide attenuates reperfusion in the rabbit ear. The observation that SLe(x) is efficacious only if administered in the first hour after reperfusion suggests that the more immediately available P- and L-selectin participate in this PMN adhesion/injury process, whereas E-selectin, with its delayed endothelial expression, does not.

Topics: Amino Sugars; Animals; CD18 Antigens; Ear; L-Selectin; Leukocytes; Lewis Blood Group Antigens; Lewis X Antigen; Oligosaccharides; Rabbits; Reperfusion Injury; Sialyl Lewis X Antigen