Upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in renal tissue in severe dengue in humans: Effects on endothelial activation/dysfunction.

INTRODUCTION: Dengue is an important mosquito-borne disease in tropical and subtropical regions. Adhesion molecules have not been systematically characterized in the renal tissue of patients with severe dengue (SD). The objective of this study was to detect viral antigens in samples from patients that evolved with SD, correlating with the expression of ICAM-1, VCAM-1, VE-cadherin, and E-selectin to contribute to a better understanding of the pathophysiology of SD. METHODS: Kidney specimens from patients with SD were selected according to clinical and laboratorial data and submitted to histological and immunohistochemistry analysis. A semiquantitative evaluation was performed considering positive immunostaining in 20 glomeruli. RESULTS: Viral antigens were mainly detected in distal tubules. The intense immunostaining of VCAM-1 and ICAM-1 was observed. The expression of E-selectin was discrete, and VE-cadherin expression varied from mild to moderate. VCAM-1 was slightly intense in the glomerular capsule; the expression of ICAM-1 was diffuse. E-selectin was diffuse, and VE-cadherin varied from mild to moderate. The most frequent histological findings were glomerular congestion, mild glomerulitis, acute renal injury, and glomerular atrophy. CONCLUSIONS: The results appear to demonstrate an imbalance between vascular endothelial permeability regulating events in renal lesions in SD. The increase in the expression of ICAM-1 and VCAM-1 is an in-situ indicator of higher permeability with a consequent influx of cells favoring the inflammation of the endothelium. These molecules are important in the pathophysiology of the disease and provide the possibility of developing new markers for the evaluation, clinical follow-up, and therapeutic response of patients with SD.

Upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in renal tissue in severe dengue in humans: Effects on endothelial activation/dysfunction

Abstract INTRODUCTION: Dengue is an important mosquito-borne disease in tropical and subtropical regions. Adhesion molecules have not been systematically characterized in the renal tissue of patients with severe dengue (SD). The objective of this study was to detect viral antigens in samples from patients that evolved with SD, correlating with the expression of ICAM-1, VCAM-1, VE-cadherin, and E-selectin to contribute to a better understanding of the pathophysiology of SD. METHODS: Kidney specimens from patients with SD were selected according to clinical and laboratorial data and submitted to histological and immunohistochemistry analysis. A semiquantitative evaluation was performed considering positive immunostaining in 20 glomeruli. RESULTS: Viral antigens were mainly detected in distal tubules. The intense immunostaining of VCAM-1 and ICAM-1 was observed. The expression of E-selectin was discrete, and VE-cadherin expression varied from mild to moderate. VCAM-1 was slightly intense in the glomerular capsule; the expression of ICAM-1 was diffuse. E-selectin was diffuse, and VE-cadherin varied from mild to moderate. The most frequent histological findings were glomerular congestion, mild glomerulitis, acute renal injury, and glomerular atrophy. CONCLUSIONS: The results appear to demonstrate an imbalance between vascular endothelial permeability regulating events in renal lesions in SD. The increase in the expression of ICAM-1 and VCAM-1 is an in-situ indicator of higher permeability with a consequent influx of cells favoring the inflammation of the endothelium. These molecules are important in the pathophysiology of the disease and provide the possibility of developing new markers for the evaluation, clinical follow-up, and therapeutic response of patients with SD.

Effect of exercise intensity on circulating microparticles in men and women.

NEW FINDINGS: What is the central question of this study? What is the effect of exercise intensity on circulating microparticle populations in young, healthy men and women? What is the main finding and its importance? Acute, moderate-intensity continuous exercise and high-intensity interval exercise altered distinct microparticle populations during and after exercise in addition to a sex-specific response in CD62E+ microparticles. The microparticles studied contribute to cardiovascular disease progression, regulate vascular function and facilitate new blood vessel formation. Thus, characterizing the impact of intensity on exercise-induced microparticle responses advances our understanding of potential mechanisms underlying the beneficial vascular adaptations to exercise. ABSTRACT: Circulating microparticles (MPs) are biological vectors of information within the cardiovascular system that elicit both deleterious and beneficial effects on the vasculature. Acute exercise has been shown to alter MP concentrations, probably through a shear stress-dependent mechanism, but evidence is limited. Therefore, we investigated the effect of exercise intensity on plasma levels of CD34+ and CD62E+ MPs in young, healthy men and women. Blood samples were collected before, during and after two energy-matched bouts of acute treadmill exercise: interval exercise (10 × 1 min intervals at ∼95% of maximal oxygen uptake V̇O2max) and continuous exercise (65% V̇O2max). Continuous exercise, but not interval exercise, reduced CD62E+ MP concentrations in men and women by 18% immediately after exercise (from 914.5 ± 589.6 to 754.4 ± 390.5 MPs µl-1 ; P < 0.05), suggesting that mechanisms underlying exercise-induced CD62E+ MP dynamics are intensity dependent. Furthermore, continuous exercise reduced CD62E+ MPs in women by 19% (from 1030.6 ± 688.1 to 829.9 ± 435.4 MPs µl-1 ; P < 0.05), but not in men. Although interval exercise did not alter CD62E+ MPs per se, the concentrations after interval exercise were higher than those observed after continuous exercise (P < 0.05). Conversely, CD34+ MPs did not fluctuate in response to short-duration acute continuous or interval exercise in men or women. Our results suggest that exercise-induced MP alterations are intensity dependent and sex specific and impact MP populations differentially.

Skap2 is required for ß2 integrin-mediated neutrophil recruitment and functions.

Integrin activation is required for neutrophil functions. Impaired integrin activation on neutrophils is the hallmark of leukocyte adhesion deficiency (LAD) syndrome in humans, characterized by impaired leukocyte recruitment and recurrent infections. The Src kinase-associated phosphoprotein 2 (Skap2) is involved in integrin functions in different leukocyte subtypes. However, the role of Skap2 in ß2 integrin activation and neutrophil recruitment is unknown. In this study, we demonstrate the crucial role of Skap2 in regulating actin polymerization and binding of talin-1 and kindlin-3 to the ß2 integrin cytoplasmic domain, thereby being indispensable for ß2 integrin activation and neutrophil recruitment. The direct interaction of Skap2 with the Wiskott-Aldrich syndrome protein via its SH3 domain is critical for integrin activation and neutrophil recruitment in vivo. Furthermore, Skap2 regulates integrin-mediated outside-in signaling events and neutrophil functions. Thus, Skap2 is essential to activate the ß2 integrins, and loss of Skap2 function is sufficient to cause a LAD-like phenotype in mice.

The effect of soluble E-selectin on tumor progression and metastasis.

BACKGROUND: Distant metastasis resulting from vascular dissemination of cancer cells is the primary cause of mortality from breast cancer. We have previously reported that E-selectin expression on the endothelial cell surface mediates shear-resistant adhesion and migration of circulating cancer cells via interaction with CD44. As a result of shedding, soluble E-selectin (sE-selectin) from the activated endothelium is present in the serum. In this study, we aimed to understand the role of sE-selectin in tumor progression and metastasis. METHODS: We investigated the effect of sE-selectin on shear-resistant adhesion and migration of metastatic breast cancer cells and leukocytes in vitro and in vivo. RESULTS: We found that sE-selectin promoted migration and shear-resistant adhesion of CD44(+) (/high) breast cancer cell lines (MDA-MB-231 and MDA-MB-468) to non-activated human microvessel endothelial cells (ES-HMVECs), but not of CD44(-/low) breast cancer cell lines (MCF-7 and T-47D). This endothelial E-selectin independent, sE-selectin-mediated shear-resistant adhesion was also observed in a leukocyte cell line (HL-60) as well as human peripheral blood mononuclear cells (PBMCs). Additionally, the incubation of MDA-MB-231 cells with sE-selectin triggered FAK phosphorylation and shear-resistant adhesion of sE-selectin-treated cells resulted in increased endothelial permeabilization. However, CD44 knockdown in MDA-MB-231 and HL-60 cells resulted in a significant reduction of sE-selectin-mediated shear-resistant adhesion to non-activated HMVECs, suggesting the involvement of CD44/FAK. Moreover, functional blockade of ICAM-1 in non-activated HMVECs resulted in a marked reduction of sE-selectin-mediated shear-resistant adhesion. Finally, the pre-incubation of CD44(+) 4 T1 murine breast cancer cells with sE-selectin augmented infiltration into the lung in E-selectin K/O mice and infusion of human PBMCs pre-incubated with sE-selectin stimulated MDA-MB-231 xenografted breast tumor growth in NSG mice. CONCLUSIONS: Our data suggest that circulating sE-selectin stimulates a broad range of circulating cells via CD44 and mediates pleiotropic effects that promote migration and shear-resistant adhesion in an endothelial E-selectin independent fashion, in turn accelerating tissue infiltration of leukocytes and cancer cells.

Deregulation of Soluble Adhesion Molecules in Resistant Hypertension and Its Role in Cardiovascular Remodeling.

BACKGROUND: Resistant hypertension (RHTN) and target organ damage are linked to increased inflammatory biomarkers, which may regulate adhesion molecules, such as intracellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1); and the platelet (P-selectin) and endothelial (E-selectin) selectins. We investigated a previously unknown relationship between soluble P-selectin (sP-selectin), E-selectin (sE-selectin), ICAM-1 (sICAM-1) and VCAM-1 (sVCAM-1) with RHTN and target organ damage. METHODS AND RESULTS: We included 110 subjects diagnosed for true RHTN and 112 mild-moderate hypertensive (HTN) patients. Blood pressure parameters, pulse wave velocity and left ventricular mass index (LVMI) were measured. Adhesion molecules were measured on ELISA. Both sP-selectin and sE-selectin were increased; in contrast, sICAM-1 was reduced in RHTN compared with HTN patients, while similar sVCAM-1 was noted in the groups. sP-selectin and sVCAM-1 were elevated in the presence of arterial stiffness (sP-selectin: 104±47 vs. 89±45 ng/ml, P<0.05; sVCAM-1: 1,189±411 vs. 1,060±412 ng/ml, P<0.05) and cardiac hypertrophy (sP-selectin: 105±51 vs. 88±43 ng/ml, P<0.05; sVCAM-1: 1,170±433 vs. 1,040±383 ng/ml, P<0.05) in all HTN patients. sP-selectin was associated with target organ damage after adjustment for age and BP. Apart from potential confounders, sE-selectin was a significant indicator of RHTN. CONCLUSIONS: The adhesion molecule sP-selectin plays a role in cardiovascular damage, and sE-selectin in resistance to antihypertensive therapy. (Circ J 2016; 80: 1196-1201).

Inhibition of E-selectin expression on the surface of endothelial cells inhibits hepatocellular carcinoma growth by preventing tumor angiogenesis.

PURPOSE: Interactions between endothelial and tumor cells via E-selectin and sialyl Lewis x (sLex) have been suggested to play a significant role in the development of metastasis and tumor growth. In this work, we tested whether inhibition of E-selectin expression on the surface of endothelial cells might impair endothelial/tumor cells interactions and tumor growth of hepatocarcinoma cells in vitro and in vivo. METHODS: We used HepG2 cells that highly express sLex antigens and HuH7 cells that do not express sLex. Inhibition of E-selectin expression on the surface of endothelial cells was obtained by using cimetidine and amiloride treatment. RESULTS: Cimetidine and amiloride inhibited, respectively, by 20 and 64 % E-selectin expression by activated endothelial cells and significantly subsequent adhesion of HepG2 cells to activated endothelial cells. Subcutaneous injection of cimetidine or amiloride resulted in a significant inhibition of HepG2 cells tumor growth in nu/nu mice but not of HuH7 cells. Thus, cimetidine and amiloride administration led to an inhibition of 57 and 75 % of HepG2 tumor growth in vivo, respectively. This effect was associated with an inhibition of vasculogenesis as demonstrated by anti-CD31 immunostaining. CONCLUSION: Inhibition of E-selectin expression allows an anti-tumoral effect on sLex-expressing HCC tumors in vivo. This suggests that interactions between HCC cells and endothelial cells through sLex antigens and E-selectin might be a target for treatment of HCC. Further studies might evaluate the clinical impact of cimetidine and amiloride in the treatment of HCC patients alone or in combination with other anti-tumoral agents.

Treatment with selectin blocking antibodies after lengthening contractions of mouse muscle blunts neutrophil accumulation but does not reduce damage.

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.

Targeting the microenvironment in acute myeloid leukemia.

The bone marrow microenvironment plays a critical role in the development, progression, and relapse of acute myeloid leukemia (AML). Similar to normal hematopoietic stem cells, AML blasts express receptors on their surface, allowing them to interact with specific components of the marrow microenvironment. These interactions contribute to both chemotherapy resistance and disease relapse. Preclinical studies and early phase clinical trials have demonstrated the potential for targeting the tumor-microenvironment interactions in AML. Agents currently under investigation include hypoxia-inducible agents and inhibitors of CXCR4 and adhesion molecules such as VLA-4 and E-selectin.

ACE2 and Ang-(1-7) protect endothelial cell function and prevent early atherosclerosis by inhibiting inflammatory response.

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) is a counter-regulator against ACE by converting angiotensin II (Ang-II) to Ang-(1-7), but the effect of ACE2 and Ang-(1-7) on endothelial cell function and atherosclerotic evolution is unknown. We hypothesized that ACE2 overexpression and Ang-(1-7) may protect endothelial cell function by counterregulation of angiotensin II signaling and inhibition of inflammatory response. METHODS: We used a recombinant adenovirus vector to locally overexpress ACE2 gene (Ad-ACE2) in human endothelial cells in vitro and in apoE-deficient mice in vivo. The Ang II-induced MCP-1, VCAM-1 and E-selectin expression, endothelial cell migration and adhesion of human monocytic cells (U-937) to HUVECs by ACE2 gene transfer were evaluated in vitro. Accelerated atherosclerosis was studied in vivo, and atherosclerosis was induced in apoE-deficient mice which were divided randomly into four groups that received respectively a ACE2 gene transfer, Ad-ACE2, Ad-EGFP, Ad-ACE2 + A779, an Ang-(1-7) receptor antagonist, control group. After a gene transfer for 4 weeks, atherosclerotic pathology was evaluated. RESULTS: ACE2 gene transfer not only promoted HUVECs migration, inhibited adhesion of monocyte to HUVECs and decreased Ang II-induced MCP-1, VCAM-1 and E-selectin protein production in vitro, but also decreased the level of MCP-1, VCAM-1 and interleukin 6 and inhibit atherosclerotic plaque evolution in vivo. Further, administration of A779 increased the level of MCP-1, VCAM-1 and interleukin 6 in vivo and led to further advancements in atherosclerotic extent. CONCLUSIONS: ACE2 and Ang-(1-7) significantly inhibit early atherosclerotic lesion formation via protection of endothelial function and inhibition of inflammatory response.

Cimetidine attenuates vinorelbine-induced phlebitis in mice by militating E-selectin expression.

PURPOSE: We investigated E-selectin expression in mice and rabbits with vinorelbine-induced phlebitis and the effect of cimetidine. To find the relationship between E-selectin expression and vinorelbine-induced phlebitis. METHODS: Mouse and rabbit model of vinorelbine-induced phlebitis was established by intravenous infusion of vinorelbine. Pathological observation, molecular-biological determination of E-selectin and protein function of it was evaluated. RESULTS: Grossly, we observed swelling, edema and cord-like vessel changes in mice receiving vinorelbine but only mild edema in mice pretreated with cimetidine. Pathological scoring yielded a total score of 37 for vinorelbine-treated mice and 17 for mice pretreated with cimetidine (P < 0.05). ELISA revealed that rabbits treated with vinorelbine had markedly higher serum contents of E-selectin than normal saline (NS) controls (vinorelbine 1.534 ± 0.449 vs. NS 0.746 ± 0.170 ng/mL, P < 0.05), which was markedly attenuated by cimetidine (cimetidine 0.717 ± 0.468 vs. vinorelbine 1.534 ± 0.449 ng/mL, P < 0.05). Rose Bengal staining assays showed that vinorelbine markedly increased the adhesion rate of neutrophils for endothelial cells (vinorelbine 38.70 ± 8.34% vs. controls 8.93 ± 4.85%, P < 0.01), which, however, was significantly suppressed by cimetidine (9.93 ± 5.91%, P < 0.01 vs. vinorelbine). In E-selectin knockout mice, we found no apparent difference in tail swelling in mice receiving vinorelbine or cimetidine and vinorelbine. CONCLUSIONS: In conclusion, cimetidine attenuates vinorelbine-induced phlebitis in mice probably by suppressing increased expression of E-selectin.

Sirtuin 1 stabilization by HuR represses TNF-α- and glucose-induced E-selectin release and endothelial cell adhesiveness in vitro: relevance to human metabolic syndrome.

Chronic inflammation and hyperglycaemia, typical features of metabolic diseases, trigger endothelial damage and release of E-selectin, a marker of endothelial activation. In the present study, we investigated molecular pathways involved in the regulation of endothelial cell activation induced by tumour necrosis factor-α (TNF-α) and high glucose. In cultured human umbilical vein endothelial cells (HUVECs), we studied the role of HuR, an ELAV (embryonic lethal, abnormal vision, Drosophila) family RNA-binding protein, and Sirtuin 1 (SIRT1) on E-selectin release and cell adhesion at different glucose concentrations. HuR expression and binding to SIRT1 were also analysed ex vivo in peripheral blood mononuclear cells (PBMCs) of subjects with and without the metabolic syndrome (MS), by immunoprecipitation (IP) of the ribonucleoprotein (RNP) complex. We found that SIRT1 overexpression prevented TNF-α- and high-glucose-dependent nuclear factor-κB (NF-κB)-p65 acetylation, E-selectin promoter activity, E-selectin release and adhesion of THP-1 cells to HUVECs. The same was mimicked by HuR overexpression, which binds and stabilizes SIRT1 mRNA. Importantly, in PBMCs of individuals with MS compared with those without, SIRT1 expression was lower, and the ability of HuR to bind SIRT1 mRNA was significantly reduced, while plasma E-selectin was increased. We conclude that post-transcriptional stabilization of SIRT1 by HuR represses inflammation- and hyperglycaemia-induced E-selectin release and endothelial cell activation. Therefore, increasing SIRT1 expression represents a strategy to counter the accelerated vascular disease in metabolic disorders.

Cell adhesion molecules in metastatic neuroblastoma models.

Several cell adhesion molecules (CAMs) including selectins, integrins, cadherins and immunoglobulin-like CAMs are involved in leukocyte adhesion especially at sites of inflammation. In cancer cells, these CAMs have been associated with the growth and metastatic behavior in several malignant entities. In this study adhesion of LAN 1 and SK-N-SH neuroblastoma cells to selectins, hyaluronan and endothelial cells were determined under flow conditions. Furthermore cells were injected subcutaneously into wildtype and selectin deficient scid mice and their growth and metastatic behavior were analyzed. Under shear stress SK-N-SH cells firmly adhered to E-selectin-Fc-fusion protein, hyaluronan and endothelial cells, while LAN 1 cells showed less or hardly any adhesive events by comparison. In the SK-N-SH xenograft model metastasis formation was slightly dependent on the expression of selectins, while LAN 1 cells developed metastases completely independent of selectin expression. The different adhesive and metastatic properties of LAN 1 and SK-N-SH cells are reflected by a different expression profile of several CAMs. The results indicate that endothelial selectins are not essential for metastasis formation of human LAN 1 and SK-N-SH cells. However, other CAMs namely CD44, N-cadherin, NCAM and integrins were upregulated or downregulated, respectively, in SK-N-SH and LAN 1 cells and are potential adhesion molecules involved in the metastatic cascade of these cells.

Overlapping roles for endothelial selectins in murine hematopoietic stem/progenitor cell homing to bone marrow.

Selectins are carbohydrate-binding adhesion molecules that are critically involved in leukocyte recognition of endothelium. The endothelial selectins have been implicated in homing of hematopoietic stem and progenitor cells (HSPCs) to the bone marrow (BM) during bone marrow transplant (BMT), but the precise roles of individual selectins in this process have never been defined. BMT of lethally irradiated mice lacking both endothelial selectins (E/P KO) with limiting numbers of wild type BM cells rescued significantly fewer E/P KO than WT recipients, but higher numbers of transplanted WT cells rescued E/P KOs in a dose-dependent fashion. Short-term homing assays confirmed a substantial defect in HSPC homing to BM in E/P KO mice. In contrast, BMT of E-selectin null or P-selectin null mice at limiting cell number uniformly rescued greater than 95% of the transplanted animals. Consistent with these functional results, flow cytometric analysis revealed both E-selectin ligands and P-selectin ligands on distinct subsets of HSPC. These results demonstrate overlapping functions for the endothelial selectins in HSPC homing to BM in the setting of BMT, and define a novel aspect of HSPC heterogeneity linked to selectin ligand expression.

Chronic plus binge ethanol feeding synergistically induces neutrophil infiltration and liver injury in mice: a critical role for E-selectin.

UNLABELLED: Chronic plus binge ethanol feeding acts synergistically to induce liver injury in mice, but the mechanisms underlying this phenomenon remain unclear. Here, we show that chronic plus binge ethanol feeding synergistically up-regulated the hepatic expression of interleukin-1ß and tumor necrosis factor alpha and induced neutrophil accumulation in the liver, compared with chronic or binge feeding alone. In vivo depletion of neutrophils through administration of an anti-Ly6G antibody markedly reduced chronic-binge ethanol feeding-induced liver injury. Real-time polymerase chain reaction analyses revealed that hepatic E-selectin expression was up-regulated 10-fold, whereas expression of other neutrophil infiltration-related adhesion molecules (e.g., P-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1) was slightly up- or down-regulated in this chronic-binge model. The genetic deletion of E-selectin prevented chronic-binge ethanol-induced hepatic neutrophil infiltration as well as elevation of serum transaminases without affecting ethanol-induced steatosis. In addition, E-selectin-deficient mice showed reduced hepatic expression of several proinflammatory cytokines, chemokines, and adhesion molecules, compared to wild-type mice, after chronic-binge ethanol feeding. Finally, the expression of E-selectin was highly up-regulated in human alcoholic fatty livers, but not in alcoholic cirrhosis. CONCLUSIONS: Chronic-binge ethanol feeding up-regulates expression of proinflammatory cytokines, followed by the induction of E-selectin. Elevated E-selectin plays an important role in hepatic neutrophil infiltration and injury induced by chronic-binge feeding in mice and may also contribute to the pathogenesis of early stages of human alcoholic liver disease.

Serum levels of lipoprotein(a) and E-selectin are reduced in rheumatoid arthritis patients treated with methotrexate or methotrexate in combination with TNF-α-inhibitor.

OBJECTIVES: To examine the effect of methotrexate (MTX) with or without tumor necrosis factor alpha (TNF-α)-inhibitors on serum lipoprotein(a) (s-Lp(a)), and to explore a possible relationship between s-Lp(a) and endothelial function (EF) in terms of serum levels of adhesion molecules and reactive hyperaemic index (RHI) in patients with rheumatoid arthritis (RA). METHODS: Serum levels of Lp(a), endothelial adhesion molecules, RHI and inflammatory markers were studied in 64 RA patients, starting with either MTX (n=34) or MTX+TNF-α-inhibitor treatment (n=30) at baseline and after 6 weeks and 6 months. RESULTS: Compared to baseline values, s-Lp(a) was significantly reduced after 6 weeks (p=0.001) and 6 months (p=0.001) in RA patients treated with MTX, and after 6 weeks (p=0.001) in the MTX+TNF-α-inhibitor group. A non-significant reduction was found after 6 months (p=0.102) in the MTX+TNFα-inhibitor group. Serum E-selectin (s-E-selectin) was significantly reduced in both RA treatment groups at both control points. S-Lp(a) correlated positively with s-E-selectin at baseline (p=0.004), and change in s-E-selectin correlated with the change in s-Lp(a) during follow-up (p6weeks= 0.008, p 6months=0.009). No association was found between s-Lp(a) and the other adhesion molecules and RHI. CONCLUSIONS: MTX or MTX combined with a TNFα-inhibitor appears to significantly reduce Lp(a). This finding indicate that s-Lp(a) might be related to systemic inflammation, or that the examined drugs might reduce s-Lp(a) by other mechanisms. Anti-inflammatory treatment might be a novel therapeutic option to decrease s-Lp(a). The associations between s-E-selectin and s-Lp(a) suggest an interaction between these factors, or a common cause.

Differing requirements for CCR4, E-selectin, and α4ß1 for the migration of memory CD4 and activated T cells to dermal inflammation.

CCR4 on T cells is suggested to mediate skin homing in mice. Our objective was to determine the interaction of CCR4, E-selectin ligand (ESL), and α(4)ß(1) on memory and activated T cells in recruitment to dermal inflammation. mAbs to rat CCR4 were developed. CCR4 was on 5-21% of memory CD4 cells, and 20% were also ESL(+). Anti-TCR-activated CD4 and CD8 cells were 40-55% CCR4(+), and ∼75% of both CCR4(+) and CCR4(-) cells were ESL(+). CCR4(+) memory CD4 cells migrated 4- to 7-fold more to dermal inflammation induced by IFN-γ, TNF, TLR agonists, and delayed-type hypersensitivity than CCR4(-) cells. CCR4(+) activated CD4 cells migrated only 5-50% more than CCR4(-) cells to these sites. E-selectin blockade inhibited ∼60% of CCR4(+) activated CD4 cell migration but was less effective on memory cells where α(4)ß(1) was more important. Anti-α(4)ß(1) also inhibited CCR4(-) activated CD4 cells more than CCR4(+) cells. Anti-E-selectin reduced activated CD8 more than CD4 cell migration. These findings modify our understanding of CCR4, ESL, α(4)ß(1), and dermal tropism. There is no strict relationship between CCR4 and ESL for skin homing of CD4 cells, because the activation state and inflammatory stimulus are critical determinants. Dermal homing memory CD4 cells express CCR4 and depend more on α(4)ß(1) than ESL. Activated CD4 cells do not require CCR4, but CCR4(+) cells are more dependent on ESL than on α(4)ß(1), and CCR4(-) cells preferentially use α(4)ß(1). The differentiation from activated to memory CD4 cells increases the dependence on CCR4 for skin homing and decreases the requirement for ESL.

Engineering cellular trafficking via glycosyltransferase-programmed stereosubstitution.

The proximate hurdle for cell trafficking to any anatomic site is the initial attachment of circulating cells to target tissue endothelium with sufficient strength to overcome prevailing forces of blood flow. E-selectin, an endothelial molecule that is inducibly expressed at all sites of inflammation, is a potent effector of this primary braking process. This molecule is a member of a family of C-type lectins known as selectins that bind sialofucosylated glycans displayed on either a protein (i.e., glycoprotein) or lipid (i.e., glycolipid) scaffold. On human cells, the predominant E-selectin ligand is a specialized glycoform of CD44 known as hematopoietic cell E-/L-selectin ligand (HCELL). This review focuses on the biology of HCELL/E-selectin interactions in cell migration, and discusses the utility and applicability of glycosyltransferase-programmed stereosubstitution (GPS) for glycoengineering HCELL expression. Without compromising cell viability or native phenotype, this exoglycosylation technology literally "sweetens" CD44, licensing E-selectin-dependent vascular delivery for all cell-based therapeutics.