Search

Objective: This study aimed to ascertain the serum levels of selectins (E, L, P) and platelet‐endothelial adhesion molecule‐1 (PECAM‐1) in preschool children with autism spectrum disorder (ASD) and to establish a comparison with the levels observed in healthy controls. Methods: The study included 34 children aged 2–7 years diagnosed with ASD (ASD group) and 34 randomly selected healthy children matched for age and sex to the ASD group. The children were free of any genetic or physical disease, clinically active infection, or medication use. The sociodemographic data form was completed by all parents. The Childhood Autism Rating Scale (CARS) and the Autism Behavior Checklist (ABC) were administered to the patient group, and the Aberrant Behavior Checklist (AbBC) was completed by the families of all children. Serum selectin (E, L, P) and PECAM‐1 levels were measured using enzyme‐linked immunosorbent assay (ELISA) kits. Results: The results showed that the levels of both L‐selectin (p = 0.007) and PECAM‐1 (p = 0.019) were significantly lower in the ASD group than in the control group. No significant difference was observed between the groups concerning E‐selectin and P‐selectin levels (p > 0.05). It was observed that P‐selectin variables were statistically significant in predicting the presence of ASD (p = 0.019). A remarkable inverse correlation was found between the AbBC irritability subscale score and L‐selectin (r = −0.296, p = 0.014) and PECAM‐1 (r = −0.276, p = 0. 023); the AbBC Lethargy‐Social Withdrawal subscale score and E‐Selectin (r = −0.239, p = 0.049), L‐Selectin (r = −0.297, p = 0.014) and PECAM‐1 (r = −0.264, p = 0.029); L‐Selectin levels and the AbBC stereotypic behavior subscale (r = −0.248, p = 0.042). No statistically significant relationship was observed between selectins (E, L, P) and PECAM‐1 levels and CARS scale, ABC subscale or total scores and age variables (p > 0.05). Conclusions: These study results suggest that L‐selectin, P‐selectin and PECAM‐1 may play a role in the pathophysiology of ASD. [ABSTRACT FROM AUTHOR]

Introduction: The impact of activated blood and endothelial cells on the thrombosis in myeloproliferative neoplasms (MPN) has not yet been clarified. We prospectively analyzed correlation between circulating leukocyte‐platelet aggregates and soluble selectins to thrombosis occurrence in MPN, in the context of standard and cardiovascular risk factors, and different clinical and biological characteristics. Methods: Flow cytometric analysis of neutrophil‐platelet (Neu‐Plt) and monocyte‐platelet (Mo‐Plt) aggregates in peripheral blood, as well as quantification of soluble E‐/L‐/P‐selectins by enzyme immunoassay, was performed on 95 newly diagnosed MPN patients. Results: During the follow‐up, thrombosis occurred in 12.6% MPN patients (arterial 9.4%, venous 3.2%), with a mean time of 39 months. The overall incidence rate of main thrombotic events was 4.36 per 100 patient‐years. The incidence of arterial hypertension (HTA) was significantly higher in patients with thrombosis, compared to those without thrombosis (P <.05). The level of soluble P‐selectin was significantly higher in patients with thrombosis compared to those without thrombosis (346.89 ng/mL vs 286.39 ng/mL, P =.034). The mean level of Neu‐Plt (26.7% vs 22.4%) and Mo‐Plt (17.8% vs 12.3%) aggregates did not differ significantly between the groups with and without thrombosis. A multivariate COX proportional hazard regression model confirmed an independent predictive significance of Mo‐Plt aggregates (HR = 1.561, 95% CI: 1.007‐2.420, P =.046), as well as the cumulative effect of Mo‐Plt aggregates and HTA (HR = 1.975, 95%CI: 1.215‐3.212, P =.006) for thrombosis occurrence. Conclusion: Monocyte‐platelet aggregates represent an independent risk factor for thrombosis occurrence, further on supported by HTA. [ABSTRACT FROM AUTHOR]

CD22, a member of Siglec family of sialic acid binding proteins, has restricted expression on B cells. Antibody‐based agents targeting CD22 or CD20 on B lymphoma and leukemia cells exhibit clinical efficacy for treating these malignancies, but also attack normal B cells leading to immune deficiency. Here, we report a chemoenzymatic glycocalyx editing strategy to introduce high‐affinity and specific CD22 ligands onto NK‐92MI and cytokine‐induced natural killer cells to achieve tumor‐specific CD22 targeting. These CD22‐ligand modified cells exhibited significantly enhanced tumor cell binding and killing in vitro without harming healthy B cells. For effective lymphoma cell killing in vivo, we further functionalized CD22 ligand‐modified NK‐92MI cells with the E‐selectin ligand sialyl Lewis X to promote trafficking to bone marrow. The dual‐functionalized cells resulted in the efficient suppression of B lymphoma in a xenograft model. Our results suggest that natural killer cells modified with glycan ligands to CD22 and selectins promote both targeted killing of B lymphoma cells and improved trafficking to sites where the cancer cells reside, respectively. [ABSTRACT FROM AUTHOR]

CD24 is a highly glycosylated protein with a small protein core that is linked to the plasma membrane via a glycosyl‐phosphatidylinositol anchor. CD24 is primarily expressed by immune cells but is often overexpressed in human tumors. In cancer, CD24 is a regulator of cell migration, invasion and proliferation. Its expression is associated with poor prognosis and it is used as cancer stemness marker. Recently, CD24 on tumor cells was identified as a phagocytic inhibitor ("do not eat me" signal) having a suppressive role in tumor immunity via binding to Siglec‐10 on macrophages. This finding is reminiscent of the demonstration that soluble CD24‐Fc can dampen the immune system in autoimmune disease. In the present review, we summarize recent progress on the role of the CD24‐Siglec‐10 binding axis at the interface between tumor cells and the immune system, and the role of CD24 genetic polymorphisms in cancer. We describe the specific function of cytoplasmic CD24 and discuss the presence of CD24 on tumor‐released extracellular vesicles. Finally, we evaluate the potential of CD24‐based immunotherapy. [ABSTRACT FROM AUTHOR]

Two studies evaluated the effects of renal and hepatic impairment on pharmacokinetics and safety of rivipansel (NCT02813798, NCT02871570). A single intravenous 840‐mg rivipansel dose was administered to subjects with renal impairment or normal renal function in study 1005 and subjects with moderate hepatic impairment or normal hepatic function in study 1006. Plasma (both studies) and urine (study 1005) samples were collected for 96 hours postdose. All subjects in studies 1005 (n = 28) and 1006 (n = 16) completed all study procedures. Rivipansel exposure (AUCinf) was 47%, 124%, and 437% higher and total clearance 30%, 57%, and 82% lower in the mild, moderate, and severe renal impairment groups, respectively, than in the normal renal function group. Overall rivipansel exposure was 20% lower and total clearance 31% higher in the moderate hepatic impairment group than in the normal hepatic function group. Ten treatment‐emergent adverse events occurred in studies 1005 and 1006; no event was considered treatment related. As expected, clearance of rivipansel decreased with increasing renal impairment. The difference observed between rivipansel pharmacokinetics in subjects with moderate hepatic impairment and subjects with normal hepatic function was not considered clinically significant. Single doses of rivipansel were well tolerated in subjects with either renal or hepatic impairment. [ABSTRACT FROM AUTHOR]

Background: Porto-sinusoidal vascular disorder (PSVD) is characterised by lesions involving portal veins and sinusoids in absence of cirrhosis with an unclear pathophysiology. However, its association with immunodeficiency, bowel disorders and abdominal bacterial infections supports the role of altered intestinal permeability and gut-derived endotoxins. The study aimed at assessing the association between serological markers of increased intestinal permeability, pro-aggregating/procoagulant state and liver injury in PSVD and portal hypertension., Methods: Thirty-three patients with biopsy-proven PSVD and portal hypertension and 33 healthy subjects were submitted to a venous blood sampling for the measurement of zonulin and lipopolysaccharides (LPS) as markers of intestinal permeability, of s-Glycoprotein VI, sP-selectin, ADAMTS13 and von Willebrand factor (vWF), as markers of platelet aggregation and microvascular inflammation, factor VIII and F1 + 2 as markers of hypercoagulability. In 17 PSVD patients, histomorphological and immunohistochemical study on liver biopsies was performed., Results: Compared with controls, PSVD patients had higher levels of LPS, zonulin, vWF, factor VIII and sP-selectin, F1 + 2. ADAMTS13 was reduced. Serum LPS correlated with zonulin, sP-selectin, FVIII and vWF. At histological analysis, PSVD specimens had increased LPS localisation, toll-like receptor-4(TLR4)-positive macrophages and platelet number compared with samples from healthy liver donors. TLR4+ macrophage number correlated with portal inflammation and fibrosis. Sinusoid dilation and capillarisation were observed. PSVD biopsies showed signs of biliary damage and reduced ductular reaction without alteration in Sox9+ cell population., Conclusions: PSVD patients display an altered intestinal permeability and endotoxemia correlated to a pro-aggregating/procoagulant state; histologically, PSVD was associated with increased TLR4+ cell involvement and platelet clumps within sinusoids. Our study suggests that LPS-TLR4 pathway could contribute to the pathophysiological basis of PSVD with portal hypertension., (© 2023 John Wiley & Sons Ltd.)

Introduction. Inflammation is widely recognized to play an important role in cancer progression and is related to thrombosis. Soluble P-selectin (sP-selectin) is one of several biomarkers that may be predictive of thrombosis in cancer. This study aimed to investigate the correlation between monocyte count and sP-selectin in various stages of nasopharyngeal carcinoma. Methods. Fifty-five patients with nasopharyngeal carcinoma were divided into three groups according to nodal and distant metastasis (group of stages I-IVA, IVB, and IVC). Monocyte count was calculated from routine peripheral blood examination, while sP-selectin level was measured using commercial ELISA kit. Results. The monocyte count of subjects in groups IVB and IVC was significantly higher compared to group I-IVA (707/μL versus 528/μL, p=0.022; 841/μL versus 528/μL, p=0.005). Plasma levels of sP-selectin in group IVC were higher than group I-IVA (59.5 ng/mL versus 41.97 ng/mL, p=0.001) and group IVB (59.5 ng/mL versus 45.53 ng/mL, p=0.007). In subjects with high monocyte count (>665/μL), there was moderate correlation between monocyte count and sP-selectin (r=0.436, p=0.022). Conclusion. Advanced stages of nasopharyngeal carcinoma had higher levels of monocyte count and sP-selectin compared to earlier stages. Monocyte count was correlated with sP-selectin especially in high monocyte count subgroup. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The aim of this study was to examine the effect of TXL, a Chinese medicine prescription, on cerebral microcirculatory disturbances after pMCAO in mice using TPLSM and further explore the underlying mechanisms. Methods: Adlut male C57BL/6J mice were subjected to pMCAO and orally administered with TXL (3.0, 1.5 and 0.75 g/kg/d) at 1, 3, and 21 hours after pMCAO. The following parameters were examined at 6 and 24 hours after pMCAO: neurological deficits, infarct volume, BBB permeability, cerebral microvessel structure, brain microcirculation (TPLSM imaging), vasoactive factors, and adhesion molecules. Results: TXL improved neurological deficits, reduced infarct volume, attenuated BBB disruption, protected cerebral microvessel structure, increased cerebral capillary flow velocity and volume flux, and inhibited leukocyte–endothelial cell interactions at 6 or 24 hours after pMCAO. The therapeutic efficacy was exerted in a dose‐dependent manner. Further study revealed that TXL (high dose) regulated the expression of PGI2, TXA2, and ET‐1, and suppressed ICAM‐1 and P‐selectin. Conclusions: TXL alleviates cerebral microcirculatory disturbances against ischemic injury by modulating endothelial function and inhibiting leukocyte–endothelial cell interactions. These effects are associated with regulating the expression of PGI2, TXA2, and ET‐1, and suppressing ICAM‐1 and P‐selectin expression. [ABSTRACT FROM AUTHOR]

Introduction. Impaired maternal immune tolerance resulting in systemic inflammation plays a pivotal role in the pathogenesis of preeclampsia. Phenotypical changes of monocytes and neutrophil granulocytes have already been studied in preeclampsia, and some studies also included T lymphocyte activation markers; however, the results are controversial and a comprehensive analysis of activation markers is lacking. The characteristics of cellular adhesion molecules in preeclampsia are yet to be described. Material and Methods. Peripheral blood samples of 18 preeclamptic patients and 20 healthy pregnant women in the third trimester were evaluated using flow cytometry to characterize the cell surface expression of T lymphocyte activation markers and selectins. Results. We found an elevated ratio of HLA-DR and CD122-, CD62E-, and CD62L-expressing cells among the CD4+ T lymphocytes in PE in comparison to healthy pregnancy. No alterations were found in the prevalence of CD69-, CD25-, and CD62P-expressing lymphocytes and CD11c-expressing monocytes. Conclusions. Our findings support the role of activated T lymphocytes and specific cell adhesion molecules in the pathogenesis of preeclampsia. [ABSTRACT FROM AUTHOR]

Novel polymeric cell adhesion inhibitors were developed in which the selectin tetrasaccharide sialyl-LewisX (SLeX) is multivalently presented on a biocompatible poly(2-hydroxypropyl)methacrylamide (PHPMA) backbone either alone (P1) or in combination with O-sulfated tyramine side chains (P2). For comparison, corresponding polymeric glycomimetics were prepared in which the crucial 'single carbohydrate' substructures fucose, galactose, and sialic acid side chains were randomly linked to the PHPMA backbone (P3 or P4 (O-sulfated tyramine)). All polymers have an identical degree of polymerization, as they are derived from the same precursor polymer. Binding assays to selectins, to activated endothelial cells, and to macrophages show that polyHPMA with SLeX is an excellent binder to E-, L-, and P-selectins. However, mimetic P4 can also achieve close to comparable binding affinities in in vitro measurements and surprisingly, it also significantly inhibits the migration of macrophages; this provides new perspectives for the therapy of severe inflammatory diseases. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations and binding free energy calculations were employed to examine the interaction between E-selectin and six structurally related oligosaccharides including the physiological ligand sialyl Lewis x. Molecular dynamics simulations revealed that sialyl Lewis x and its mimics share a common binding region and similar interactions with E-selectin involving the formation of hydrogen bonds with Glu80, Asn82, Asn83, Arg97, Asn105, Asp106, and Glu107 residues and electrostatic contacts with Ca2+ and the positively charged Lys111 and Lys 113 residues. Regarding binding free energy calculations, the performance of the rigorous but computationally expensive pathway methods TI, BAR, and MBAR was compared to the less rigorous but faster end-point methods MM/ PBSA and MM/ GBSA aimed at identifying a suitable approach to deal with the very subtle binding free energy differences within the ligands under study. All methods succeeded in predicting increased binding affinities for sialyl Lewis x analogs compared to the native ligand with absolute errors <1 kcal/mol. The best correlation with experimental data was obtained by TI ( r2 = 0.84), followed by MBAR ( r2 = 0.80), BAR ( r2 = 0.73), MM/ PBSA ( r2 = 0.73) and MM/ GBSA ( r2 = 0.47). These results provide valuable information to increase understanding about E-selectin-oligosaccharide interactions and conduct further research aimed at designing novel ligands targeting this protein. [ABSTRACT FROM AUTHOR]

Introduction Despite similar residual factor VIII activity, patients with haemophilia A ( HA) show significant interindividual variability with regard to bleeding frequency and severity, suggesting that additional factors modulate thrombin generation and fibrin deposition. Protein disulphide isomerase ( PDI) is an abundant oxidoreductase that exerts pleiotropic effects in primary and secondary haemostasis and contributes to thrombosis and vascular inflammation. Aim We conducted a pilot study to explore a potential role of platelet PDI in patients with HA. Methods Expression and release of platelet PDI were studied by flow cytometry and enzyme-linked immunosorbent assay, respectively. Results Compared to healthy male controls ( n = 12), patients with HA ( n = 24) showed significantly increased expression of PDI antigen on ADP- or TRAP-6-, but not on buffer-treated platelets, a finding that could not be explained by enhanced platelet activation, as indicated by expression of the α-granule protein, CD62P (P-selectin). While platelet agonists did not affect PDI secretion in healthy male controls, increased levels of PDI antigen were found in supernatants of TRAP-6-treated platelets from patients with HA. Importantly, in two patients with exceedingly high TRAP-6-induced PDI release over baseline, findings were consistent when platelets were isolated and stimulated on a separate occasion. No obvious association was found between platelet PDI and bleeding phenotype in this patient cohort. Conclusion Agonist-induced expression and release of platelet PDI were increased in patients with HA. Larger studies are needed to clarify if variations in this platelet response contribute to the diversity in bleeding frequency and severity among patients with congenital factor VIII deficiency. [ABSTRACT FROM AUTHOR]

Endothelial activation is pivotal in the development and escalation of sepsis. Central to endothelial activation is the endothelial up-regulation of cellular adhesion molecules ( CAMs) including E-selectin, ICAM-1, VCAM-1, and PECAM-1. Shed CAMs are also found in circulating soluble forms ( sCAMs). We investigated whether sCAMs can be used as biomarkers for the differentiation between septic and non-septic patients. Furthermore, we investigated lymphocyte and monocyte expression of LFA-1 ( CD11a/ CD18) and VLA-4 ( CD49d/ CD29) ligands for ICAM-1 and VCAM-1, respectively. Twenty-one septic and 15 critically ill non-septic patients were included. All patients had an APACHE II score above 13 at ICU admission. Fifteen healthy volunteers served as controls. Flow cytometry was used to estimate levels of sE-selectin, sICAM-1, sVCAM-1, sPECAM-1, and the cellular expression of CD11a and CD49d. Levels of sE-selectin, sICAM-1 and sPECAM-1 were higher in the septic patients compared with the non-septic patients and controls at admission and during the observation period. Lymphocyte and monocyte expression of CD11a and CD49d was suppressed or unaltered in the septic patients compared with the non-septic patients and controls. Levels of sE-selectin, sICAM-1, and sPECAM-1 were able to discriminate between septic and non-septic patients, indicating that sCAMs may be potential diagnostic biomarkers of sepsis. [ABSTRACT FROM AUTHOR]

Inflammation is a common process associated with numerous vascular pathologies. We hypothesized that targeting the inflamed endothelium by coupling a peptide with high affinity for P-selectin to the surface of dexamethasone-loaded lipid nanoemulsions will highly increase their specific binding to activated endothelial cells (EC) and reduce the cell activation. We developed and characterized dexamethasone-loaded lipid nanoemulsions directed towards P-selectin (PLN-Dex) and monitored their anti-inflammatory effects in vitro using cultured EC (EA.hy926 cells) and in vivo using a mouse model of acute inflammation [lipopolysaccharides (LPS) intravenously administered in C57BL/6 mice]. We found that PLN-Dex bound specifically to the surface of activated EC are efficiently internalized by EC and reduced the expression of proinflammatory genes, thus preventing the monocyte adhesion and transmigration to/through activated EC. Given intravenously in mice with acute inflammation, PLN-Dex accumulated at a significant high level in the lungs (compared to nontargeted nanoemulsions) and significantly reduced mRNA expression level of key proinflammatory cytokines such as IL-1β, IL-6, and MCP-1. In conclusion, the newly developed nanoformulation, PLN-Dex, is functional in vitro and in vivo, reducing selectively the endothelium activation and the consequent monocyte infiltration and diminishing significantly the lungs’ inflammation, in a mouse model of acute inflammation. [ABSTRACT FROM AUTHOR]

Background Clopidogrel is commonly prescribed to cats with perceived increased risk of thromboembolic events, but little information exists regarding its antiplatelet effects. Objective To determine effects of clopidogrel on platelet responsiveness in cats with or without the A31P mutation in the MYBPC3 gene. A secondary aim was to characterize variability in feline platelet responses to clopidogrel. Animals Fourteen healthy cats from a Maine Coon/outbred mixed Domestic cat colony: 8 cats homozygous for A31P mutation in the MYPBC3 gene and 6 wild-type cats without the A31P mutation. Methods Ex vivo study. All cats received clopidogrel (18.75 mg PO q24h) for 14 days. Before and after clopidogrel treatment, adenosine diphosphate ( ADP)-induced P-selectin expression was evaluated. ADP- and thrombin-induced platelet aggregation was measured by optical aggregometry ( OA). Platelet pVASP and ADP receptor response index ( ARRI) were measured by Western blot analysis. Results Platelet activation from cats with the A31P mutation was significantly ( P = .0095) increased [35.55% (18.58-48.55) to 58.90% (24.85-69.90)], in response to ADP. Clopidogrel treatment attenuated ADP-induced P-selectin expression and platelet aggregation. ADP- and PGE1-treated platelets had a similar level of pVASP as PGE1-treated platelets after clopidogrel treatment. Clopidogrel administration resulted in significantly lower ARRI [24.13% (12.46-35.50) to 11.30% (−7.383 to 23.27)] ( P = .017). Two of 13 cats were nonresponders based on OA and flow cytometry. Conclusion and Clinical Importance Clopidogrel is effective at attenuating platelet activation and aggregation in some cats. Cats with A31P mutation had increased platelet activation relative to the variable response seen in wild-type cats. [ABSTRACT FROM AUTHOR]

Objective: There are few reports on the migration of CLA+ T cells through E-selectin in cutaneous lichen planus, with only one study on oral lichen planus (OLP). This study aimed to analyze CLA expression and assess whether there is a correlation with E-selectin (CD62E) in OLP lesions.Material and Methods: Biopsies were performed on 11 patients including two areas: one without clinical and histopathological features of OLP [perilesional group (PLG)] and the other with clinical and histopathological features of OLP [OLP group (OLPG)]. The specimens obtained were divided into two: One was fixed in formalin for routine analysis (H&E), and the other was frozen for CD3, CD4, CD8, CLA, and CD62E immunofluorescence markers.Results: More CD4+ (median 1409, range 860-2519), CD8+ (median 1568, range 654-3258), and CLA+ T cells (median 958, range 453-2198) and higher CD62E expression (median 37, range 27-85) were identified in OLPG (P = 0.003; P = 0.003; P = 0.004; P = 0.003, respectively) than those in PLG. The median prevalence analysis was also significantly higher for CLA+CD8+ T cells in OLPG (OLPG = 39.4%, range 18.4-64.2; PLG = 29.4%, range 12.1-47.1) (P = 0.026). None of the correlations between CD3+ or CLA+ T cells and CD62E in OLPG and in PLG were significant.Conclusion: The significant presence of CLA+ T cells and E-selectin expressions in the OLPG suggests their involvement in the etiopathogenesis of OLP; however, only a weak correlation between CLA+ T cells and E-selectin was observed. [ABSTRACT FROM AUTHOR]

Vascular injury is a serious complication of sepsis due to the gram-negative bacterium Neisseria meningitidis. One of the critical early steps in initiating this injury is via the interaction of leucocytes, particularly neutrophils, with adhesion molecules expressed on inflamed endothelium. We have previously demonstrated that both lipopolysaccharide (LPS) and non-LPS components of meningococci can induce very high levels of expression of the vascular endothelial cell adhesion molecule E-selectin, which is critical for early tethering and capture of neutrophils onto endothelium under flow. Using an LPS-deficient strain of meningococcus, we showed that very high levels of expression can be induced in primary endothelial cells, even in the context of weak activation of the major host signal transduction factor [nuclear factor-B (NF-B)]. In this study, we show that the particular propensity for N. meningitidis to induce high levels of expression is regulated at a transcriptional level, and demonstrate a significant role for phosphorylation of the ATF2 transcription factor, likely via mitogen-activated protein (MAP) kinases, on the activity of the E-selectin promoter. Furthermore, inhibition of E-selectin expression in response to the lpxA- strain by a p38 inhibitor indicates a significant role of a p38-dependent MAPK signalling pathway in ATF2 activation. Collectively, these data highlight the role that LPS and other bacterial components have in modulating endothelial function and their involvement in the pathogenesis of meningococcal sepsis. Better understanding of these multiple mechanisms induced by complex stimuli such as bacteria, and the specific inflammatory pathways they activate, may lead to improved, focused interventions in both meningococcal and potentially bacterial sepsis more generally. [ABSTRACT FROM AUTHOR]

P- and E-selectins are expressed on the surface of endothelial cells and may contribute to neutrophil recruitment following injurious lengthening contractions of skeletal muscle. Blunting neutrophil, but not macrophage, accumulation after lengthening contractions may provide a therapeutic benefit as neutrophils exacerbate damage to muscle fibers, while macrophages promote repair. In this study, we tested the hypothesis that P- and E-selectins contribute to neutrophil, but not macrophage, accumulation in muscles after contraction- induced injury, and that reducing neutrophil accumulation by blocking the selectins would be sufficient to reduce damage to muscle fibers. To test our hypothesis, we treated mice with antibodies to block P- and E-selectin function and assessed leukocyte accumulation and damage in muscles 2 days after lengthening contractions. Treatment with P/E-selectin blocking antibodies reduced neutrophil content by about half in muscles subjected to lengthening contractions. In spite of the reduction in neutrophil accumulation, we did not detect a decrease in damage 2 days after lengthening contractions. We conclude that P- and/or E-selectin contribute to the neutrophil accumulation associated with contraction-induced muscle damage and that only a portion of the neutrophils that typically accumulate following injurious lengthening contractions is sufficient to induce muscle fiber damage and force deficits. Thus, therapeutic interventions based on blocking the selectins or other adhesion proteins will have to reduce neutrophil numbers by more than 50% in order to provide a benefit. [ABSTRACT FROM AUTHOR]

Background: HNA-3a antibodies induce severe transfusion-related acute lung injury (TRALI) in which neutrophils play a major role. As neutrophil passage through the pulmonary microvasculature is a critical step in the pathogenesis of TRALI, we investigated the impact of HNA-3a antibodies on two important factors that could impair granulocyte passage through lung capillaries: the elasticity of neutrophils and the expression and activation of adhesion molecules.Study Design and Methods: The impact of HNA-3a antibodies on the elasticity of neutrophils was investigated using atomic force microscopy (AFM). Neutrophils were settled on poly-2-hydroxyethyl-methacrylate-coated glass slides before treatment with anti-HNA-3a plasma samples, control plasma, or control plasma containing formyl-methionyl-leucyl-phenylalanine (fMLP). Elasticity measurements were carried out in a temperature-controlled perfusion chamber using an atomic force microscopy (AFM) device. The impact of HNA-3a antibodies on the surface expression of total CD11b, activation of CD11b, and L-selectin (CD62L) shedding was investigated by flow cytometry. The functional impact of HNA-3a antibodies on neutrophil adhesion was assessed using fibrinogen-coated plates.Results: HNA-3a antibodies induced stiffening of neutrophils (+24%-40%; p < 0.05) to a similar extent as fMLP. This effect was blocked by treatment of neutrophils with cytochalasin D. While total surface expression of CD11b and L-selectin on neutrophils was largely unaffected, HNA-3a antibodies induced alloantigen-specific activation of CD11b (+72%-107%; p < 0.05) and increased adhesion of neutrophils to fibrinogen.Conclusion: Accumulation of neutrophils in the pulmonary microvasculature during severe TRALI is likely mediated by increased rigidity and CD11b-mediated adhesion of neutrophils leading to retention of neutrophils. [ABSTRACT FROM AUTHOR]

Background: Recent genome-wide association studies in Caucasians suggested that an association exists between the ABO gene locus and soluble levels of P-selectin (sP-selectin). However, it is unclear if the relationship corresponds to the phenotypic expression of ABO groups or is present in different ethnic groups. The aim of this study was to verify this observation at both genotypic and phenotypic levels in a healthy Chinese population.Study Design and Methods: The ABO blood groups were determined by both phenotypes and genotypes in 440 healthy Chinese Han volunteers, while P-selectin levels were evaluated for sP-selectin and total platelet P-selectin (pP-selectin).Results: ABO phenotyping and quantitative analysis of individual sP-selectin plasma levels were combined to demonstrate that individuals phenotypically expressing the A antigen have approximately 20% lower sP-selectin plasma levels than those carrying the B or O phenotype (p < 0.0001), but that no difference exists between A and AB and between B and O phenotypes. Genotyping data revealed that the presence of the A gene could be attributed to the observed difference in phenotype comparison, with no difference between A/A, A/B, and A/O genotypes. There were also no associations between ABO blood groups, either phenotypes or genotypes, and pP-selectin levels.Conclusion: This study demonstrated an association between sP-selectin levels and ABO groups in a Chinese Han population, implicating its generalizability to other ethnic groups. This finding will improve the understanding of the mechanism of ABO blood group-associated diseases. [ABSTRACT FROM AUTHOR]

Porphyromonas gingivalis, an important periodontal pathogen, has been proved to actively invade cells, induce endothelial cell activation, and promote development of atherosclerosis. Innate immune surveillance, which includes the activity of nucleotide-binding oligomerization domain ( NOD)-like receptors ( NLRs) and Toll-like receptors ( TLRs), are essential for the control of microbial infections; however, the roles of receptor families in P. gingivalis infections remain unclear. Here, we examined the roles of NLRs and TLRs in endothelial cell activation caused by P. gingivalis. Live P. gingivalis and whole cell sonicates were used to stimulate endothelial cells, and both showed upregulation of E-selectin as well as NOD1, NOD2, and TLR2. In addition, silencing of these genes in endothelial cells infected with P. gingivalis led to a reduction in E-selectin expression. Porphyromonas gingivalis also induced nuclear factor-κB ( NF-κB) and P38 mitogen-activated protein kinase ( MAPK) activity in endothelial cells, whereas small interfering RNA targeting NOD1 significantly reduced these signals. Moreover, inhibition of either NOD2 or TLR2 inhibited NF-κB significantly, but had only a weak inhibitory effect on P38 MAPK signaling. Direct inhibition of NF-κB and P38 MAPK significantly attenuated E-selectin expression induced by P. gingivalis in endothelial cells. Taken together, these findings suggest that NOD1, NOD2, and TLR2 play important, non-redundant roles in endothelial cell activation following P. gingivalis infection. [ABSTRACT FROM AUTHOR]

Objective Recent studies show that sublingual microcirculation is altered in patients resuscitated from CA. The objective of this study was to investigate whether the cerebral microcirculation is disturbed in the early post-resuscitation period. Methods Male Sprague-Dawley rats were randomized to either 10 minutes of CA or uninterrupted circulation, and observed to 120 or 360 minutes after ROSC. At 120 and 360 minutes, cerebral microcirculation was evaluated by SDF microscopy through a craniectomy. Plasma samples were analyzed for endothelial adhesion molecules and inflammatory markers, and brains were fixated for histological analysis. Results Cerebral microcirculation, evaluated by TVD, PVD, PPV, and MFI did not differ between groups ( p > 0.16). Plasma samples drawn 360 minutes after ROSC displayed a significant increase in sE-selectin, sL-selectin, sI-CAM1, IL-1 β, IL-6, IL-10, and elastase compared to controls. In the CA animals, sE-selectin and elastase increased between 120 and 360 minutes after resuscitation ( p < 0.007). Histological analysis revealed neuronal death in hippocampus layer CA1 360 min after resuscitation. Conclusion When evaluated by SDF, the cerebral microcirculation appears unaffected in the early post- CA period despite hypotension, systemic inflammation, endothelial activation, and neuronal injury. [ABSTRACT FROM AUTHOR]

Background Following pig-to-primate kidney transplantation, endothelial cell activation and xenogenic activation of the recipient's coagulation eventually leading to organ dysfunction and microthrombosis can be observed. In this study, we examined the effect of a TNF-receptor fusion protein ( TNF- RFP) on endothelial cell activation and coagulopathy utilizing an appropriate ex vivo perfusion system. Methods Using an ex vivo perfusion circuit based on C1-Inhibitor (C1-Inh) and low-dose heparin administration, we have analyzed consumptive coagulopathy following contact of human blood with porcine endothelium. Porcine kidneys were recovered following in situ cold perfusion with Histidine-tryptophan-ketoglutarate (HTK) organ preservation solution and were immediately connected to a perfusion circuit utilizing freshly drawn pooled porcine or human AB blood. The experiments were performed in three individual groups: autologous perfusion (n = 5), xenogenic perfusion without any further pharmacological intervention (n = 10), or with addition of TNF- RFP (n = 5). After perfusion, tissue samples were obtained for real-time PCR and immunohistological analyses. Endothelial cell activation was assessed by measuring the expression levels of E-selectin, ICAM-1, and VCAM-1. Results Kidney survival during organ perfusion with human blood, C1-Inh, and heparin, but without any further pharmacological intervention was 126 ± 78 min. Coagulopathy was observed with significantly elevated concentrations of D-dimer and thrombin-antithrombin complex ( TAT), resulting in the formation of multiple microthrombi. Endothelial cell activation was pronounced, as shown by increased expression of E-selectin and VCAM-1. In contrast, pharmacological intervention with TNF- RFP prolonged organ survival to 240 ± 0 min (max. perfusion time; no difference to autologous control). Formation of microthrombi was slightly reduced, although not significantly, if compared to the xenogenic control. D-dimer and TAT were elevated at similar levels to the xenogenic control experiments. In contrast, endothelial cell activation, as shown by real-time PCR, was significantly reduced in the TNF- RFP group. Conclusion We conclude that although coagulopathy was not affected, TNF- RFP is able to suppress inflammation occurring after xenoperfusion in this ex vivo perfusion model. [ABSTRACT FROM AUTHOR]

Cancer metastasis involves multistep adhesive interactions between tumor cells (TCs) and endothelial cells (ECs), but the molecular mechanisms of intercellular communication in the tumor microenvironment remain elusive. Using static and flow coculture systems in conjunction with flow cytometry, we discovered that certain receptors on the ECs are up- regulated on melanoma cell adhesion. Direct contact but not separate coculture between human umbilical endothelial cells (HUVECs) and a human melanoma cell line (Lu1205) increased intercellular adhesion molecule 1 (ICAM-1) and E-selectin expression on HUVECs by 3- and 1.5-fold, respectively, compared with HUVECs alone. The nonmetastatic cell line WM35 failed to promote ICAM-1 expression changes in HUVECs on contact. Enzyme-linked immunosorbent assay (ELISA) revealed that EC-TC contact has a synergistic effect on the expression of the cytokines interleukin (IL)-8, IL-6, and growth-related oncogene α (Gro-α). By using E-selectin cross-linking and beads coated with CD44 immunopurified from Lu1205 cells, we showed that CD44/selectin ligation was responsible for the ICAM-1 up-regulation on HUVECs. Protein kinase Cα (PKC-α) activation was found to be the downstream target of the CD44/selectin-initiated signaling, as ICAM-1 elevation was inhibited by siRNA targeting PKCα or a dominant negative form of PKCα (PKCα DN). Western blot analysis and electrophoretic mobility shift assays (EMSAs) showed that TC-EC contact mediated p38 phosphorylation and binding of the transcription factor SP-1 to its regulation site. In conclusion, CD44/selectin binding signals ICAM-1 up-regulation on the EC surface through a PKCα-p38-SP-1 pathway, which further enhances melanoma cell adhesion to ECs during metastasis. [ABSTRACT FROM AUTHOR]

Leucocyte trafficking is vital for the immune defence. In adults, early tethering and rolling interactions between leucocytes and endothelial cells are mediated by P-, E- and L-selectins and their ligands. In contrast, the role of selectins in migration of mononuclear cells during fetal development in humans remains unknown. We studied the functions of endothelial E- and P-selectins and their counter-receptors during human ontogeny. Immunohistochemical stainings showed that P-selectin is expressed in megakaryocytes and endothelial cells starting from gestational weeks 7 and 11, respectively. Endothelial E-selectin appeared latest, at week 32. Real-time imaging using in vitro flow chamber assays showed that cord blood mononuclear leucocytes used E-, P- and L-selectin and PSGL-1 to roll on and adhere to endothelium under physiological shear stress. These data show that selectins are synthesized and functional before birth in humans and have the potential to mediate the emigration of mononuclear cells and inflammatory responses. [ABSTRACT FROM AUTHOR]

Background Recent studies showed that Mirasol pathogen reduction treatment ( PRT) leads to increased P-selectin expression and increased oxygen and glucose consumption in resting platelets ( PLTs). This study investigates the effect of PRT on PLT activation. Study Design and Methods Untreated or Mirasol-treated PLTs were analyzed at different time points during storage. Microaggregation upon stimulation with phorbol myristate acetate ( PMA), convulxin, and ristocetin was measured. Alpha granule contents and release upon thrombin stimulation were assessed by flow cytometry and Western blotting. PLT spreading was determined on collagen-coated glass slides. Results Mirasol PRT led to spontaneous aggregation (hyperreactivity), as measured by flow cytometry in the absence of agonist throughout storage time. PMA-induced aggregation was significantly higher in Mirasol PRT PLTs compared to controls. Aggregation in response to convulxin and ristocetin was significantly lower and directly influenced by storage time after Mirasol PRT, compared to untreated stored PLT concentrates. Despite the reported hyperreactivity of resting PLTs, PLT activation with thrombin on Day 8 after Mirasol PRT resulted in less P-selectin-positive PLTs. Furthermore, platelet factor 4 (PF4) secretion was reduced upon thrombin stimulation on Day 8 after PRT compared to controls. Significantly decreased spreading of Mirasol PRT PLTs over collagen-coated slides was observed directly after PRT and persisted throughout storage. Conclusion Mirasol PRT leads to hyperreactive PLTs, probably caused by continuous basal degranulation through storage time. This results in a reduction in the degranulation capacity upon acute stimulation, which influences PLT spreading, but not overtly microaggregation. The clinical relevance needs to be investigated. [ABSTRACT FROM AUTHOR]

Human multipotent mesenchymal stromal/stem cells ( MSCs) have been shown to exert immunomodulatory properties that have great potential in therapies for various inflammatory and autoimmune disorders. However, intravenous delivery of these cells is followed by massive cell entrapment in the lungs and insufficient homing to target tissues or organs. In targeting to tissues, MSCs and other therapeutic cells employ similar mechanisms as leucocytes, including a cascade of rolling and adhesion steps mediated by selectins, integrins and their ligands. However, the mechanisms of MSCs homing are not well understood. We discovered that P-selectin (CD62P) binds to umbilical cord blood (UCB)-derived MSCs independently of the previously known sialyl Lewis x ( sLex)-containing ligands such as P-selectin glycoprotein ligand-1 (PSGL-1, CD162). By biochemical assays, we identified galectin-1 as a novel ligand for P-selectin. Galectin-1 has previously been shown to be a key mediator of the immunosuppressive effects of human MSCs. We conclude that this novel interaction is likely to play a major role in the immunomodulatory targeting of human UCB-derived MSCs. [ABSTRACT FROM AUTHOR]

Thrombocytopenia is associated with bleeding risk. However, in thrombocytopenic patients, platelet count does not correlate with bleeding risk and other factors are thus likely to contribute to this risk. This review presents currently available platelet-related markers available on automated haematology analysers and commonly used methods for testing platelet function. The test principles, advantages and disadvantages of each test are described. We also evaluate the current literature regarding the clinical utility of the test for prediction of bleeding in thrombocytopenia in haematological and oncological diseases. We find that several platelet-related markers are available, but information about the clinical utility in thrombocytopenia is limited. Studies support that mean platelet volume ( MPV) can aid diagnosing the cause of thrombocytopenia and low MPV may be associated with bleeding in thrombocytopenia. Flow cytometry, platelet aggregometry and platelet secretion tests are used to diagnose specific platelet function defects. The flow cytometric activation marker P-selectin and surface coverage by the Cone-and-Plate[let] analyser predict bleeding in selected thrombocytopenic populations. To fully uncover the clinical utility of platelet-related tests, information about the prevalence of platelet function defects in thrombocytopenic conditions is required. Finally, knowledge of the performance in thrombocytopenic samples from patients is essential. [ABSTRACT FROM AUTHOR]

Introduction.The acute coronary syndrome (ACS) is a complex disease where genetic and environmental factors are involved. Eselectin gene is a candidate for ACS progression due to its contribution in the inflammatory process and endothelial function. The rs5361 (561A>C) polymorphism in the E-selectin gene has been linked to changes in gene expression, affinity for its receptor, and plasmatic levels; therefore it is associated with an increased risk of cardiovascular disease. The aim of this study was to determine the association of the rs5361 polymorphism with ACS and to measure serum levels of soluble E-selectin (sE-selectin). Materials andMethods. 283 ACS patients and 205 healthy subjects (HS) fromWesternMexico were included. The polymerase chain reactionrestriction fragment length polymorphism was used to determine the rs5361 polymorphism.The sE-selectin levels were measured by enzyme-linked immunosorbent assay. Results. Neither genotype nor allele frequencies of the rs5361 polymorphism showed statistical differences between groups.ThesE-selectin levels were significantly higher in ACS patients compared to HS (54.58 versus 40.41 ng/ml, P = 0.02).The C allele had no effect on sE-selectin levels. Conclusions.The rs5361 E-selectin gene polymorphism is not a susceptibility marker for ACS inWestern Mexico population. However, sE-selectin may be a biological marker of ACS. [ABSTRACT FROM AUTHOR]

Objective Recent evidence has suggested the importance of an aberrantly activated monocyte system in amyotrophic lateral sclerosis ( ALS) pathogenesis. However, the roles of each monocyte subset, namely CD14+ CD16− classical monocytes, CD14dim CD16+ non-classical monocytes and CD14+ CD16+ intermediate monocytes, in ALS remain unknown. We aimed to clarify the alterations in the monocyte subset proportions and the surface marker expressions on each monocyte subset in ALS. Methods Blood samples were collected from 19 ALS patients and 28 healthy controls ( HC). The surface expressions of CCR2, CX3 CR1, CD64 and CD62 L were measured in the three monocyte subsets (classical, non-classical and intermediate) by flow cytometry. Results The percentages of CCR2 and CD62 L on CD14+ CD16− classical monocytes were significantly lower in ALS patients than in HC ( P = 0.0012 and P = 0.0296, respectively). No differences were found in CX3 CR1 and CD64 on each monocyte subset. The percentage of intermediate monocytes showed a significant negative correlation with the revised ALS functional rating scale score ( r = −0.631, P = 0.0038). Conclusions Reductions in chemotaxis- and adhesion-related molecules on classical inflammatory monocytes are present in ALS, further suggesting the involvement of an aberrant innate immune system in ALS pathogenesis. [ABSTRACT FROM AUTHOR]

The cell plasma membrane is tightly coupled with the vital processes of apoptosis and activation. In the current study, we investigated exposure of the apoptosis marker phosphatidylserine ( PS) and activation marker P-selectin ( CD62) on the plasma membrane of anucleate platelets. We found that, depending on triggering stimuli, the plasma membrane of human platelets may exist in four states with predominant exposure of (i) PS but not CD62 (75·9 ± 2·8% of total cells), (ii) CD62 but not PS (86·2 ± 1·3%), (iii) both PS and CD62 (89·6 ± 1·0%) or (iv) neither PS nor CD62 (87·9-97·5%), when platelets were treated at optimal conditions with pro-apoptotic BH3 mimetic ABT-737, thrombin, calcium ionophore A23187 or control diluents, respectively. The dynamics of PS exposure induced by ABT-737 is a slow temperature-dependent process requiring 90 min treatment at 37°C rather than at room temperature for obtaining high levels of PS exposure. In contrast, thrombin-induced CD62 exposure and A23187-induced PS and CD62 exposure showed fast temperature-independent dynamics. This model of selective and concurrent stimulation of PS and/or CD62 transition to the platelet surface provides an experimental horizon for elucidating the roles of plasma membrane markers of platelet apoptosis and activation in platelet clearance. [ABSTRACT FROM AUTHOR]

Background Endothelial damage/dysfunction may contribute to a prothrombotic state in patients with atrial fibrillation (AF) and the increased risk of thromboembolism and cardiovascular events. Raised plasma von Willebrand factor ( vWf), an established marker of endothelial damage/dysfunction, has been associated with stroke and vascular events, at least in a clinical trial population. Soluble E-selectin ( sE-sel) is another biomarker of endothelial activation/dysfunction, with more limited data on prognostic outcomes in AF. Objective To assess the relationship between the levels of vWf, sE-sel and clinical adverse outcomes (including stroke, MI and all-cause mortality) in a 'real-world' community cohort of patients with AF. Methods We studied 423 patients (mean age 72·7 ± 8·4 years, 55·6% male) with nonvalvular AF, with a median follow-up of 19 (9-31) months. Plasma vWf and sE-sel levels were measured using enzyme-linked immunosorbent assay (ELISA). Results There were 94 clinical adverse events (22·2%) observed during a median follow-up of 19 months. Patients with clinical events had significantly higher vWf ( P < 0·001) and sE-sel levels at baseline ( P < 0·001) compared with those who were event free. Kaplan-Meir analyses demonstrated that more clinical adverse events occurred in the upper tertile of vWf [upper vs. lowest tertile, RR 3·8, 95% CI (2·63-5·57), P < 0·001; upper vs. middle tertile, RR 10·5, 95% CI (5·33-20·60), P < 0·001]. Similarly, the highest tertile of sE-sel was associated with more adverse events [upper vs. lowest tertile, RR 3·7, 95% CI (2·51-5·31), P < 0·001; upper vs. middle tertile, RR 6·5, 95% CI (3·56-11·91), P < 0·001]. Conclusion High plasma vWf and soluble E-selectin levels are associated with an increased risk of clinical adverse events (acute myocardial infarction, ischaemic stroke and all-cause mortality) in 'real-world' patients with AF. These soluble biomarkers may potentially aid clinical risk stratification in this common arrhythmia. [ABSTRACT FROM AUTHOR]

Background Platelet (PLT) function in PLT concentrates declines during storage and is further affected by pathogen reduction treatment. Flow cytometric assessment of agonist-induced P-selectin expression can be used to assess PLT function in patients with thrombocytopenia. The aim of this study was to evaluate how this functional test relates to established in vitro measures of PLT function. Study Design and Methods Six units of PLTs in plasma and 6 units of riboflavin and ultraviolet ( Mirasol, Terumo BCT)-treated PLTs in plasma were sampled on Days 2, 6, 8, and 10 after donation. PLT concentration, Annexin 5 A staining, ThromboLUX (LightIntegra) thrombelastography, and P-selectin expression, both in unstimulated PLTs and in response to concentration series of adenosine diphosphate, collagen-related peptide, and thrombin receptor-activating peptide (TRAP), were measured. Results For PLTs in plasma Annexin 5 A expression increased by 0.60% (95% confidence interval [ CI], 0.40%-0.80%) and P-selectin expression increased by 1.2% (95% CI, 0.80%-1.6%) per day. Responsiveness to TRAP simultaneously decreased by 1.3% (95% CI, 0.80%-1.8%) per day. After Mirasol treatment ThromboLUX scores decreased 3.3 points (95% CI, 0.2-6.4 points) from 22 to 19 points, Annexin 5 A expression increased by 4.8% (95% CI, 3.3%-6.2%), and P-selectin expression increased by 13% (95% CI, 10%-16%), all averaged over the entire storage period. Responsiveness to TRAP simultaneously decreased by 19% (95% CI, 17%-21%). Conclusions Our results suggest flow cytometric measurement of agonist-induced P-selectin expression can measure PLT quality decline over the entire range encountered during 10-day storage of both standard PLTs and Mirasol-treated PLTs in plasma. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the biocompatibility of a newly developed long-term wearable artificial pump-lung ( APL) in a clinically relevant ovine animal model. The wearable APL device was implanted in five sheep through left thoracotomy. The device was connected between the right atrium and pulmonary artery and evaluated for 30 days. Three sheep were used as the sham control. Platelet activation was assessed by measuring platelet surface P-selectin ( CD62 P) expression with flow cytometry and plasma soluble P-selectin with an enzyme-linked immunosorbent assay. Thrombotic deposition on the device components and hollow fiber membranes were analyzed with digital imaging and scanning electron microscopy. Surface P-selectin of the APL and sham groups changed significantly over the study period, but without significant differences between the two groups. Soluble P-selectin for the two groups peaked in the first 24 h after the surgery. Soluble P-selectin of the APL group remained slightly elevated over the study period compared to the presurgical baseline value and was slightly higher compared to that of the sham group. Plasma free hemoglobin remained in the normal ranges in all the animals. In spite of the surgery-related alteration in laboratory tests and elevation of platelet activation status, the APL devices in all the animals functioned normally (oxygen transfer and blood pumping) during the 30-day study period. The device flow path and membrane surface were free of gross thrombus. Electron microscopy images showed only scattered thrombi on the fibers (membrane surface and weft). In summary, the APL exhibited excellent biocompatibility. Two forms of platelet activation, surgery-related and device-induced, in the animals implanted with the wearable APL were observed. The limited device-induced platelet activation did not cause gross thrombosis and impair the long-term device performance. [ABSTRACT FROM AUTHOR]

Chondroitin sulfate (CS) is a glycosaminoglycan (GAG) side chain of proteoglycans (PGs) which are widely distributed in the extracellular matrix and at cell surface. CS shows a highly structural diversity in not only molecular weight (MW) but sulfonation pattern. CS has been reported to exert anti-inflammatory activity by having effects on cytokine production by helper T cells. In this study, we focused on the structures of CS chains, especially MW of CS, and investigated effect of the different MW of CS on binding affinity with L-selectin and cytokine production by murine splenocytes. Firstly, we fractionated CS by employing gel filtration chromatography and obtained several CS fractions with different MW. Then the interaction between fractionated CS and L-selectin was analyzed by surface plasmon resonance (SPR). Finally, the influence of MW of CS on cytokine production by murine splenocytes was investigated in vitro. The results showed that interferon-gamma production was significantly increased by mouse splenocytes cocultivated with CS. On the contrary, CS inhibited interleukin 5 production by murine splenocytes depending on MW of the cocultivated CS. These results strongly indicate the existence of the optimal molecular size for an anti-inflammatory effect of CS through cytokine production by murine splenocytes. [ABSTRACT FROM AUTHOR]

Ligands for E-selectin and P-selectin ( E-lig and P-lig) are induced on CD4+ T cells upon differentiation into effector T cells. Glycosyltransferases, especially α 1,3-fucosyltransferase VII ( Fuc T-VII) and core 2 β1,6- N-acetyl-glycosaminyltransferase I ( C2 Glc NAc T-I), are critical for their synthesis. We here analysed the signals that control the expression of E-lig, P-lig and m RNA coding for Fuc T-VII and C2 Glc NAc T-I. In line with previous reports, we found that P-lig expression correlates with the regulation of C2 Glc NAc T-I, whereas E-lig expression can occur at low levels of C2 Glc NAc T-I m RNA but requires high Fuc T-VII m RNA expression. Interestingly, the two enzymes are regulated by different signals. Activation-induced C2 Glc NAc T-I up-regulation under permissive (T helper type 1) conditions was strongly reduced by cyclosporin A ( Cs A), suggesting the involvement of T-cell receptor-dependent, calcineurin/ NFAT-dependent signals in combination with interleukin-12 ( IL-12) -mediated signals in the regulation of C2 Glc NAc T-I. In contrast, expression of Fuc T-VII m RNA was not significantly inhibited by Cs A. Interleukin-4 inhibited the expression of Fuc T-VII but IL-2 and IL-7 were found to support induction of Fuc T-VII and E-lig. E-selectin, P-selectin and their ligands initially appeared to have rather overlapping functions. These findings however, unravel striking differences in the regulation of E-lig and P-lig expression, dictated by the dominance of Fuc T-VII and C2 Glc NAc T-I, respectively, and their dependency on signals from either promiscuous or homeostatic cytokines ( Fuc T-VII) or a strong T-cell receptor signal in combination with inflammatory cytokines in case of C2 Glc NAc T-I. [ABSTRACT FROM AUTHOR]

Aims To determine whether E-selectin deficiency can attenuate brain ischemia in a mouse model of focal cerebral ischemia. Methods E-selectin was determined in spontaneously hypertensive rats ( SHRs) and stroke-prone spontaneously hypertensive rats ( SHR- SPs). E-selectin knockout (Es−/−) mice and wild-type control ( WT) mice underwent permanent distal middle cerebral artery occlusion ( MCAO). Behavioral analyses were performed followed by the measurement of infarct areas. Myeloperoxidase ( MPO) protein was determined by Western blot. IL-6, IL-1β, and TNF-α were detected by ELISA. In situ detection of apoptotic cells was performed by TUNEL staining. Results The brain and serum E-selectin levels were higher in SHR- SPs than in SHRs ( P < 0.05) after salt intake. E-selectin deficiency improved neurological function and reduced infarct area in cerebral ischemic mice. MPO and IL-1β were lower in Es−/− mice than in WT mice. In addition, the number of apoptotic cells in Es−/− mice was significantly less than in WT mice after MCAO. Conclusions E-selectin deficiency presents protective effect on cerebral ischemia. This protective effect is likely achieved by the inhibition of inflammation and apoptosis. [ABSTRACT FROM AUTHOR]

Recent work identified L-asparaginase ( L-ASP) as a putative therapeutic target for ovarian cancer. We suggest that L-ASP, a dysregulator of glycosylation, would interrupt the local microenvironment, affecting the ovarian cancer cell-endothelial cell interaction and thus angiogenesis without cytotoxic effects. Ovarian cancer cell lines and human microvascular endothelial cells ( HMVEC) were exposed to L-ASP at physiologically attainable concentrations and subjected to analyses of endothelial tube formation, invasion, adhesion and the assessment of sialylated proteins involved in matrix-associated and heterotypic cell adhesion. Marked reduction in HMVEC tube formation in vitro, HMVEC and ovarian cancer cell invasion, and heterotypic cell-cell and cell-matrix adhesion was observed ( P < 0.05-0.0001). These effects were associated with reduced binding to ß1integrin, activation of FAK, and cell surface sialyl LewisX ( sLex) expression. No reduction in HMVEC E-selectin expression was seen consistent with the unidirectional inhibitory actions observed. L-ASP concentrations were non-toxic to either ovarian cancer or HMVEC lines in the time frame of the assays. However, early changes of autophagy were observed in both cell types with induction of ATG12, beclin-1, and cleavage of LC-3, indicating cell injury did occur. These data and the known mechanism of action of L-ASP on glycosylation of nascent proteins suggest that L-ASP reduces of ovarian cancer dissemination and progression through modification of its microenvironment. The reduction of ovarian cancer cell surface sLex inhibits interaction with HMVEC and thus HMVEC differentiation into tubes, inhibits interaction with the local matrix reducing invasive behaviour, and causes cell injury initiating autophagy in tumour and vascular cells. [ABSTRACT FROM AUTHOR]

Methylglyoxal ( MG) is a reactive dicarbonyl metabolite formed during glucose, protein and fatty acid metabolism. In hyperglycaemic conditions, increased MG level has been linked to the development of diabetes and its vascular complications at the macrovascular and microvascular levels where inflammation plays a role. To study the mechanism of MG-induced inflammation in vivo, we applied MG locally to healthy mice and used intravital microscopy to investigate the role of endothelial cell adhesion molecules in MG-induced leucocyte recruitment in cremasteric microvasculature. Administration of MG (25 and 50 mg/kg) to the tissue dose-dependently induced leucocyte recruitment at 4·0-5·5 hr, with 84-92% recruited cells being neutrophils. Such MG treatment up-regulated the expression of endothelial cell adhesion molecules P-selectin, E-selectin, intercellular adhesion molecule-1, but not vascular cell adhesion molecule-1. Activation of the nuclear factor-κB signalling pathway contributed to MG-induced up-regulation of these adhesion molecules and leucocyte recruitment. The role of the up-regulated endothelial cell adhesion molecules in MG-induced leucocyte recruitment was determined by applying specific functional blocking antibodies to MG-treated animals and observing changes in leucocyte recruitment parameters. Our data demonstrate that the up-regulation of P-selectin, E-selectin and intercellular adhesion molecule-1 contributes to the increased leucocyte rolling flux, reduced leucocyte rolling velocity, and increased leucocyte adhesion, respectively. Our results reveal the role of endothelial cell adhesion molecules in MG-induced leucocyte recruitment in microvasculature, an inflammatory condition related to diabetic vascular complications. [ABSTRACT FROM AUTHOR]

The ability of leukocytes to navigate through the different body compartments is an essential component for functioning immune defense and surveillance systems. In order to exit the blood circulation, leukocytes follow distinct recruitment steps, including capture of free-flowing leukocytes to, and rolling along, the vessel wall; firm leukocyte arrest on the endothelial lining; and postarrest modifications (spreading and crawling), which prepare the leukocyte for transmigration through the vascular wall. Post-translational glycosylation (including sialylation) has been known for many years to be functionally relevant for selectin ligands and, hence, selectin-mediated capture and rolling. Recently, sialylation by the α2-3 sialyltransferase ST3Gal-IV was identified to significantly influence chemokine-triggered firm leukocyte arrest, expanding the role of α2-3 sialylation from leukocyte rolling to subsequent chemokine-triggered leukocyte arrest. These findings make ST3Gal-IV an interesting drug target for modulating leukocyte trafficking in human disorders, including autoimmune diseases and cancer. [ABSTRACT FROM AUTHOR]

Sialic acids are a diverse family of monosaccharides widely expressed on all cell surfaces of vertebrates and so-called 'higher' invertebrates, and on certain bacteria that interact with vertebrates. This overview surveys examples of biological roles of sialic acids in immunity, with emphasis on an evolutionary perspective. Given the breadth of the subject, the treatment of individual topics is brief. Subjects discussed include biophysical effects regulation of factor H; modulation of leukocyte trafficking via selectins; Siglecs in immune cell activation; sialic acids as ligands for microbes; impact of microbial and endogenous sialidases on immune cell responses; pathogen molecular mimicry of host sialic acids; Siglec recognition of sialylated pathogens; bacteriophage recognition of microbial sialic acids; polysialic acid modulation of immune cells; sialic acids as pathogen decoys or biological masks; modulation of immunity by sialic acid O-acetylation; sialic acids as antigens and xeno-autoantigens; antisialoglycan antibodies in reproductive incompatibility; and sialic-acid-based blood groups. [ABSTRACT FROM AUTHOR]

Background Platelet concentrates ( PC) are prepared by centrifugation of platelet-rich plasma ( PRP) that is prepared by centrifugation of whole blood. The resuspension of the platelet pellet during PC preparation from dogs is difficult because of platelet activation induced by centrifugation. Objectives To investigate the efficacy of adding prostaglandin E1 ( PGE1) to prevent platelet activation during PC preparation from dogs. Animals Fifteen healthy Beagle dogs. Methods Prospective, experimental trial: PGE1 was added to PRP before the high-speed centrifugation during PC preparation. To estimate the effect of this addition, we assessed the platelet aggregability before transfusion, the survival of the platelets after transfusion, and the platelet reactivity after transfusion, which is estimated by the P-selectin expression of the platelets when stimulated by thrombin. Results The difficulty associated with platelet resuspension was resolved by PGE1. PGE1 strongly inhibited platelet aggregation induced by collagen and ADP; however, it recovered after the platelets were resuspended in plasma without PGE1 (mean aggregation ratio; collagen: 10.00-80.80%, ADP: 8.20-53.60%). Survival of the platelets after transfusion was not affected by PGE1 (mean 8.04 and 7.56 days, without and with PGE1), and thrombin-induced P-selectin expression after transfusion in PGE1-treated PC was also well maintained (mean positive ratio 53.7 and 47.9%, before and 24 hours after transfusion). Conclusions and Clinical Importance The addition of PGE1 in PRP before the centrifugation of PRP can improve the preparation efficiency of PC from dogs, while maintaining the therapeutic efficacy of the platelets. [ABSTRACT FROM AUTHOR]

Selectins promote metastasis by mediating specific interactions between selectin ligands on tumor cells and selectin-expressing host cells in the microvasculature. Using affinity chromatography in conjunction with tandem mass spectrometry and bioinformatics tools, we identified mucin 16 (MUC16) as a novel selectin ligand expressed by metastatic pancreatic cancer cells. While up-regulated in many pancreatic cancers, the biological function of sialofucosylated MUC16 has yet to be fully elucidated. To address this, we employed blot rolling and cell-free flow-based adhesion assays using MUC16 immunopurified from pancreatic cancer cells and found that it efficiently binds E- and L- but not P-selectin. The selectin-binding determinants are sialofucosylated structures displayed on O- and N-linked glycans. Silencing MUC16 expression by RNAi markedly reduces pancreatic cancer cell binding to E- and L-selectin under flow. These findings provide a novel integrated perspective on the enhanced metastatic potential associated with MUC16 overexpression and the role of selectins in metastasis. [ABSTRACT FROM AUTHOR]

Objective. We hypothesised that the endothelial dysfunction is associated with early glucose dysregulation and/or atherosclerosis risk factors in nondiabetic women with a previous history of gestational diabetes (pGDM). Material/Methods. Anthropometric parameters, glucose regulation (OGTT), insulin resistance (HOMA), lipids, biomarkers of endothelial dysfunction, and inflammation were evaluated in 85 women with pGDM and in 40 controls 2-24 months postpartum. Results. The pGDM group consisted of 67% normoglycemic women (pGDM-N) and 33% with prediabetic state (pGDM-P). The BMI, waist circumference, fasting and 2 h glucose (OGTT), soluble adhesion molecules, tissue plasminogen activator antigen, high sensitivity C-reactive protein, total-, LDL-cholesterol, and triglycerides/HDL-cholesterol ratio were higher in the pGDM women compared with the controls. After adjustment for BMI and fasting glucose, only higher triglycerides, higher TG/HDL and lower HDL-cholesterol were associated with pGDM. The pGDM-P differed from pGDM-N for only higher triglycerides and TG/HDL. The plasma level of sE-selectin was not independently associated with glucose concentration in pGDM group. sE-selectin level correlated with triglycerides, TG/HDL, plasminogen activator inhibitor-1 antigen, and sICAM-1. Conclusions. sE-selectin level correlated with components of metabolic syndrome, but only the atherogenic lipid profile was independently associated with a previous history of GDM in nondiabetic women 2-24 months postpartum. [ABSTRACT FROM AUTHOR]

Cell adhesion molecules play a significant role in cancer progression and metastasis. Cell-cell interactions of cancer cells with endothelium determine the metastatic spread. In addition, direct tumor cell interactions with platelets, leukocytes, and soluble components significantly contribute to cancer cell adhesion, extravasation, and the establishment of metastatic lesions. Clinical evidence indicates that heparin, commonly used for treatment of thromboembolic events in cancer patients, is beneficial for their survival. Preclinical studies confirm that heparin possesses antimetastatic activities that lead to attenuation of metastasis in various animal models. Heparin contains several biological activities that may affect several steps in metastatic cascade. Here we focus on the role of cellular adhesion receptors in the metastatic cascade and discuss evidence for heparin as an inhibitor of cell adhesion. While P- and L-selectin facilitation of cellular contacts during hematogenous metastasis is being accepted as a potential target of heparin, here we propose that heparin may also interfere with integrin activity and thereby affect cancer progression. This review summarizes recent findings about potential mechanisms of tumor cell interactions in the vasculature and antimetastatic activities of heparin. [ABSTRACT FROM AUTHOR]

The aim of this study was to measure P-selectin, E-selectin, and CD-4L levels over time in chronic hemodialysis ( HD) patients. Thirty stable patients with end-stage renal failure undergoing chronic HD were included in the study. Blood samples were obtained before HD for measurement of P-selectin, E-selectin, and CD-40L. Measurements were performed at month 0 ( T0), 3 ( T2), 8 ( T3), and 13 ( T4). The levels of P-selectin, E-selectin, and CD40L were also analyzed according to the occurrence of cardiovascular disease ( CVD) and to CVD-related mortality. The levels of CD40L and P-selectin changed significantly over time, decreasing at month 3 and 6 and returning at the T0 levels at month 13. Conversely, E-selectin levels did not. The levels of CD40L, P-selectin and E-selectin over time did not differ significantly between patients with age ≤65 or >65 years, between patients with or without CVD, or between patients who died or who survived during the follow-up. In end-stage renal failure patients undergoing chronic HD, CD40L and P-selectin, but not E-selectin, showed a transient decrease over time, and the serum levels of these molecules were not associated with CVD or with CVD-related mortality. [ABSTRACT FROM AUTHOR]

Abstract: Members of the protein kinase C (PKC) family of serine/threonine kinases have been implicated in several physiological processes regulating the activation response of platelets. They are involved in processes leading to granule secretion, integrin activation, platelet aggregation and spreading, and procoagulation. The protein kinase C θ (PKCθ) isoform, which was originally identified in T lymphocytes, is also expressed at relatively high levels in platelets, wherein it is involved in the regulation of hemostasis and thrombosis. Recent studies suggest a role for PKCθ in protease-activated receptor (PAR)-, glycoprotein VI (GPVI) receptor- and glycoprotein αIIbβ3 integrin receptor-linked signal transduction pathways. The present review focuses on the latest observations relevant to the role of PKCθ in platelet activation. [Copyright &y& Elsevier]

Abstract: Despite great strides in our knowledge of the genetic and epigenetic changes underlying malignancy, we have limited information on the molecular basis of metastasis. Over 90% of cancer deaths are caused by spread of tumor cells from a primary site to distant organs and tissues, highlighting the pressing need to define the molecular effectors of cancer metastasis. Mounting evidence suggests that circulating tumor cells (CTCs) home to specific tissues by hijacking the normal leukocyte trafficking mechanisms. Cancer cells characteristically express CD44, and there is increasing evidence that hematopoietic cell E-/L-selectin ligand (HCELL), a sialofucosylated glycoform of CD44, serves as the major selectin ligand on cancer cells, allowing interaction of tumor cells with endothelium, leukocytes, and platelets. Here, we review the structural biology of CD44 and of HCELL, and present current data on the function of these molecules in mediating organ-specific homing/metastasis of CTCs. [Copyright &y& Elsevier]

Please cite this paper as: Senchenkov, Khoretonenko, Leskov, Ostanin, and Stokes (2011). P-Selectin Mediates the Microvascular Dysfunction Associated with Persistent Cytomegalovirus Infection in Normocholesterolemic and Hypercholesterolemic Mice. Microcirculation 18( 6), 452-462. Abstract Objective: Cytomegalovirus has been implicated in cardiovascular disease, possibly through the induction of inflammatory processes. P-selectin and L-selectin are adhesion molecules that mediate early microvascular responses to inflammatory stimuli. This study examined the role of these selectins in the microvascular dysfunction that occurs during persistent CMV infection. Methods: C57Bl/6, P- or L-selectin-deficient mice were mock-inoculated or infected with murine CMV, and five weeks later placed on normal diet or high cholesterol diet for six weeks. P-selectin expression was measured or intravital microscopy was performed to determine arteriolar vasodilation and venular blood cell recruitment. Results: P-selectin expression was significantly increased in the heart, lung, and spleen of mCMV-ND, but not mCMV-HC C57Bl/6. mCMV-ND and mCMV-HC exhibited impaired arteriolar function, which was reversed by treatment with an anti-P-selectin antibody, but not L-selectin deficiency. mCMV-HC also showed elevated leukocyte and platelet recruitment. P-selectin inhibition abrogated, whereas L-selectin deficiency partially reduced these responses. Conclusions: We provide the first evidence for P-selectin upregulation by persistent mCMV infection and implicate this adhesion molecule in the associated arteriolar dysfunction. P-selectin, and to a lesser extent L-selectin, mediates the leukocyte and platelet recruitment induced by CMV infection combined with hypercholesterolemia. [ABSTRACT FROM AUTHOR]

Gaber AO, Mulgaonkar S, Kahan BD, Woodle ES, Alloway R, Bajjoka I, Jensik S, Klintmalm GB, Patton PR, Wiseman A, Lipshutz G, Kupiec-Weglinski J, Gaber LW, Katz E, Irish W, Squiers EC, Hemmerich S. YSPSL (rPSGL-Ig) for improvement of early renal allograft function: A double-blind, placebo-controlled, multi-center Phase IIa study. Clin Transplant 2011: 25: 523-533. © 2010 John Wiley & Sons A/S. Abstract: Introduction: Recombinant P-selectin glycoprotein ligand IgG fusion protein, rPSGL-Ig (YSPSL), a fusion protein of human P-selectin ligand and IgG1-Fc, blocks leukocyte adhesion and protects against ischemia reperfusion injury (IRI) in animal models. Patients and Methods: This randomized 15-center, double-blind, 59-patient Ph2a study assessed YSPSL's safety in recipients of deceased-donor kidney allografts and its potential efficacy in improving early graft function. Two doses and two dosing modalities were evaluated. Results: No drug-specific toxicities or increased adverse event rates were noted. Two YSPSL-treated patients died of causes determined as unrelated to study drug. YSPSL did not reduce the incidence of dialysis within the first week post-transplant (41% in treated vs. 20% in placebo patients). Renal function endpoints scored at post-operative days 1 & 2 were also not impacted by YSPSL. However, at day 5, the fraction of patients with serum creatinine above 6 mg/dL was lower in the YSPSL vs. placebo group (26% vs. 55%, p = 0.043). Large variations in the dialysis-delayed graft function (DGF) rates were observed between centers, independently of treatment assignment, indicating subjectivity of this endpoint. Conclusion: In this first Ph2a study in kidney transplantation, YSPSL was safe but did not impact the dialysis-DGF rate. Further studies with more objective efficacy endpoints are required to define the impact of YSPSL on early renal allograft function. [ABSTRACT FROM AUTHOR]