Showing papers on "E-selectin published in 2004"
TL;DR: A unique pharmacological mechanism of Andro’s protective anti-inflammatory actions is revealed, which suppressed the activation of NF-κB in stimulated endothelial cells and abrogated the cytokine- and endotoxin-induced peritoneal deposition of neutrophils, attenuated septic shock, and prevented allergic lung inflammation in vivo.
Abstract: NF-kappaB is a central transcriptional factor and a pleiotropic regulator of many genes involved in immunological responses. During the screening of a plant extract library of traditional Chinese herbal medicines, we found that NF-kappaB activity was potently inhibited by andrographolide (Andro), an abundant component of the plant Andrographis that has been commonly used as a folk remedy for alleviation of inflammatory disorders in Asia for millennia. Mechanistically, it formed a covalent adduct with reduced cysteine (62) of p50, thus blocking the binding of NF-kappaB oligonucleotide to nuclear proteins. Andro suppressed the activation of NF-kappaB in stimulated endothelial cells, which reduced the expression of cell adhesion molecule E-selectin and prevented E-selectin-mediated leukocyte adhesion under flow. It also abrogated the cytokine- and endotoxin-induced peritoneal deposition of neutrophils, attenuated septic shock, and prevented allergic lung inflammation in vivo. Notably, it had no suppressive effect on IkappaBalpha degradation, p50 and p65 nuclear translocation, or cell growth rates. Our results thus reveal a unique pharmacological mechanism of Andro's protective anti-inflammatory actions.
351 citations
TL;DR: Results are consistent with the hypothesis that intermittent perfusion of the placenta, secondary to reduced trophoblast invasion, causes increased secretion of TNF-alpha, and that this contributes to the activation of maternal endothelial cells that characterizes preeclampsia.
Abstract: Preeclampsia is a hypertensive complication of human pregnancy characterized by generalized maternal endothelial cell activation. Circulating pro-inflammatory cytokines derived from the placenta are thought to play a key role. We recently demonstrated that hypoxia-reoxygenation (H/R) of placental tissues in vitro causes equivalent oxidative stress to that seen in preeclampsia. Our aim was to determine whether H/R also increases production of tumor necrosis factor-α (TNF-α), and whether conditioned media from samples exposed to H/R causes activation of human umbilical vein endothelial cells (HUVECs). Concentrations of mRNA encoding TNF-α were significantly higher in placental tissues subjected to H/R compared to hypoxic or normoxic controls. Although there was no difference in the concentrations of TNF-α protein in tissue homogenates, levels of TNF-α protein in the medium were significantly higher after H/R compared to controls, indicating increased secretion. Furthermore, conditioned medium from samples subjected to H/R caused increased expression of E-selectin by HUVECs, and the addition of anti-TNF-α antibodies significantly reduced that activation. These results are consistent with our hypothesis that intermittent perfusion of the placenta, secondary to reduced trophoblast invasion, causes increased secretion of TNF-α, and that this contributes to the activation of maternal endothelial cells that characterizes preeclampsia.
205 citations
TL;DR: The findings suggest that shear stress plays differential roles in modulating the TNF-&agr;–induced expressions of ICAM-1 versus VCAM- 1 and E-selectin genes in ECs.
Abstract: Objective— Vascular endothelial cells (ECs) are subjected to shear stress and cytokine stimulation. We studied the interplay between shear stress and cytokine in modulating the expression of adhesion molecule genes in ECs.
Methods and Results— Shear stress (20 dynes/cm2) was applied to ECs prior to and/or following the addition of tumor necrosis factor (TNF)-α. Shear stress increased the TNF-α–induced expression of intercellular adhesion molecule-1 (ICAM-1) at both mRNA and surface protein levels, but decreased the TNF-α–induced expression of vascular adhesion molecule-1 (VCAM-1) and E-selectin. Transfection studies using promoter reporter gene constructs of ICAM-1, VCAM-1, and E-selectin demonstrated that these shear stress modulations of gene expression occur at the transcriptional levels. After 24-hour preshearing followed by 1 hour of static incubation, the effect of preshearing on TNF-α–induced ICAM-1 mRNA expression vanished. The recovery of the TNF-α–induced VCAM-1 and E-selectin mRNA expressions following preshearing, however, required a static incubation time of >6 hours (complete recovery at 24 hours). Pre- and postshearing caused a reduction in the nuclear factor-κB-DNA binding activity induced by TNF-α in the EC nucleus.
Conclusions— Our findings suggest that shear stress plays differential roles in modulating the TNF-α–induced expressions of ICAM-1 versus VCAM-1 and E-selectin genes in ECs.
202 citations
TL;DR: EGCG and to a lesser extent ECG prevented the induction of VCAM-1 expression in a concentration-dependent manner after stimulation with TNF-alpha, whereas EC and EGC were without effect.
189 citations
TL;DR: Investigation of the effects of constantly high and intermittently high glucose on nitrotyrosine formation and adhesion molecule and interleukin expression in human umbilical vein endothelial cells found that oscillating glucose was more effective in triggering the generation of nitrosative stress and inducing the expression of adhesion molecules and IL‐6 than stable high glucose.
180 citations
TL;DR: The flavones inhibited nuclear translocation and DNA binding activity of the NF-kappa B-containing binding site in the promoter region of the CAM genes in TNF-alpha-activated HUVEC, which may hamper initial atherosclerotic events involving endothelial CAM induction.
Abstract: Flavones have been classified as anti-atherogenic agents that inhibit monocyte adhesion to stimulated endothelium, possibly by blocking induction of cell adhesion molecules (CAM). This anti-atherogenic feature of these flavonoids appears to be related to their chemical structures. Flavones may interfere with key signaling events involved in endothelial cell activation by inflammatory mediators. This study examined the effects of flavones on the induction of CAM and the translocation and DNA binding of nuclear factor-kappa B (NF-kappa B) in TNF-alpha-activated human umbilical vein endothelial cells (HUVEC). The effects of flavones, luteolin and apigenin, on adhesion of THP-1 monocytes to the TNF-alpha-activated HUVEC, protein expression and mRNA levels of vascular cell adhesion molecule-1 (VCAM-1), intracellular cell adhesion molecule-1 (ICAM-1) and E-selectin, and nuclear appearance and DNA binding activity of NF-kappa B were determined. Flavanols, flavonols, and flavanones were used for comparison. TNF-alpha significantly induced HUVEC protein expression of VCAM-1, ICAM-1, and E-selectin with increasing mRNA levels. Luteolin and apigenin inhibited the TNF-alpha-induced upregulation of THP-1 adhesion and VCAM-1 expression; these inhibitory effects were dose-dependent. The flavones at doses of > or =25 micromol/L almost completely abolished the increased CAM protein and mRNA regardless of their anti-oxidative activity. With the exception of the flavonol quercetin, flavonoids had no such effect; quercetin substantially attenuated the CAM induction. The flavones inhibited nuclear translocation and DNA binding activity of the NF-kappa B-containing binding site in the promoter region of the CAM genes in TNF-alpha-activated HUVEC. The inhibition of endothelial CAM induction by flavones is mediated by their interference with the NF-kappa B-dependent transcription pathway. Thus, the flavones may hamper initial atherosclerotic events involving endothelial CAM induction.
140 citations
TL;DR: It is demonstrated for the first time that human bone-metastatic prostate tumor cells roll on human BMECs under physiological flow conditions, and the importance of both glycoprotein(s) and glycosphingolipid structures displaying sialyl Lewis X epitopes as potential E-selectin ligand expression is established.
Abstract: Prostate tumor cells preferentially adhere to bone marrow endothelial cells (BMECs) compared with endothelial linings from other tissue microvessels, implicating the importance of BMEC adhesion in the predilection of prostate tumor metastasis to bone. E (endothelial)-selectin, which functions as an initiator of leukocyte adhesion to target tissue endothelium, is constitutively expressed on BMECs, suggesting that prostate tumor cells could use this adhesive mechanism to initiate their migration into bone. In this report, we demonstrate for the first time that human bone-metastatic prostate tumor cells roll on human BMECs under physiological flow conditions. We show that these dynamic adhesive interactions are dependent on the expression of BMEC E-selectin and sialylated glycoconjugates on bone-metastatic prostate tumor cells. We also establish the importance of both glycoprotein(s) and glycosphingolipid structures displaying sialyl Lewis X epitopes as potential E-selectin ligands on bone-metastatic prostate tumor cells. Coexpression of sialylated glycoproteins and glycolipids on bone-metastatic prostate tumor cells triggers robust E-selectin binding activity, which is identical to that observed on human hematopoietic progenitor cells. By Western blot analysis, we identify candidate E-selectin glycoprotein ligand(s); distinct sialyl Lewis X (or HECA-452 antigen)-bearing membrane proteins were resolved at M r 130,000 and M r 220,000 as well as others ranging from M r 100,000 to M r 220,000. Immunohistochemical analysis of HECA-452 antigen expression on normal prostate tissue and on low- and high-grade prostate adenocarcinoma shows that HECA-452 antigen expression is directly associated with prostate tumor progression and may indicate acquisition of E-selectin ligand expression. These findings provide novel insight into potential adhesive mechanisms promoting hematogenous dissemination of prostate tumor cells into bone.
137 citations
TL;DR: Data show that E-selectin– and chemokine-mediated arrest mechanisms are overlapping in this model and identify CXCR2 as an important neutrophil arrest Chemokine in vivo.
Abstract: The signaling events leading to the activation of integrins and firm arrest of rolling neutrophils in inflamed venules have yet to be elucidated. In vitro assays suggest that both E-selectin and chemokines can trigger arrest of rolling neutrophils, but E-selectin−/− mice have normal levels of adherent neutrophils in inflamed venules. To test whether chemokine-induced neutrophil arrest in vivo can be unmasked by blocking E-selectin, we investigated neutrophil adhesion in inflamed cremaster muscle venules in tumor necrosis factor (TNF)-α–treated CXCR2−/− or wild-type (WT) mice injected with E-selectin blocking monoclonal antibody (mAb) 9A9. To block chemokine receptor signaling, we investigated E-selectin−/− or WT mice treated with pertussis toxin (PTx) intravenously. Neutrophil adhesion was unchanged in CXCR2−/−, E-selectin−/−, PTx-treated WT, or mAb 9A9–treated WT mice. However, TNF-α–induced neutrophil adhesion was almost completely abrogated in E-selectin−/− mice treated with PTx and significantly reduced in CXCR2−/− mice treated with the E-selectin blocking mAb. In thioglycollate-induced peritonitis, PTx treatment blocked neutrophil recruitment into the peritoneum of E-selectin−/− mice, but had only a partial effect in WT animals. These data show that E-selectin– and chemokine-mediated arrest mechanisms are overlapping in this model and identify CXCR2 as an important neutrophil arrest chemokine in vivo.
137 citations
TL;DR: The approach described here can form the basis for further development of adenoviral gene therapy vectors with improved pharmacokinetics and increased efficiency and specificity of therapeutic gene transfer into endothelial cells in disease.
Abstract: To assess the possibilities of retargeting adenovirus to activated endothelial cells, we conjugated bifunctional polyethylene glycol (PEG) onto the adenoviral capsid to inhibit the interaction between viral knob and cox- sackie-adenovirus receptor (CAR). Subsequently, we introduced anv integrin-specific RGD peptide or E-selectin-specific antibody to the other functional group of the PEG molecule for the retargeting of the ad- enovirus to activated endothelial cells. In vitro studies showed that this approach resulted in the elimination of transgene transfer into CAR-positive cells, while at the same time specific transgene transfer to activated endothelial cells was achieved. PEGylated, retargeted adenovirus showed longer persistence in the blood cir- culation with area under plasma concentration-time curve (AUC) values increasing 12-fold compared to un- modified virus. Anti-E-selectin antibody-PEG-adenovirus selectively homed to inflamed skin in mice with a delayed-type hypersensitivity (DTH) inflammation, resulting in local expression of the reporter transgene lu- ciferase. This is the first study showing the benefits of PEGylation on adenovirus behavior upon systemic ad- ministration. The approach described here can form the basis for further development of adenoviral gene therapy vectors with improved pharmacokinetics and increased efficiency and specificity of therapeutic gene transfer into endothelial cells in disease.
135 citations
TL;DR: The data suggest that E-selectin is unique among selectins in its capacity for clustering sialylated ligands and transducing signals leading to neutrophil arrest in shear flow.
Abstract: Two adhesive events critical to efficient recruitment of neutrophils at vascular sites of inflammation are up-regulation of endothelial selectins that bind sialyl Lewis x ligands and activation of β 2 -integrins that support neutrophil arrest by binding ICAM-1. We have previously reported that neutrophils rolling on E-selectin are sufficient for signaling cell arrest through β 2 -integrin binding of ICAM-1 in a process dependent upon ligation of L-selectin and P-selectin glycoprotein ligand 1 (PSGL-1). Unresolved are the spatial and temporal events that occur as E-selectin binds to human neutrophils and dynamically signals the transition from neutrophil rolling to arrest. Here we show that binding of E-selectin to sialyl Lewis x on L-selectin and PSGL-1 drives their colocalization into membrane caps at the trailing edge of neutrophils rolling on HUVECs and on an L-cell monolayer coexpressing E-selectin and ICAM-1. Likewise, binding of recombinant E-selectin to PMNs in suspension also elicited coclustering of L-selectin and PSGL-1 that was signaled via mitogen-activated protein kinase. Binding of recombinant E-selectin signaled activation of β 2 -integrin to high-avidity clusters and elicited efficient neutrophil capture of β 2 -integrin ligands in shear flow. Inhibition of p38 and p42/44 mitogen-activated protein kinase blocked the cocapping of L-selectin and PSGL-1 and the subsequent clustering of high-affinity β 2 -integrin. Taken together, the data suggest that E-selectin is unique among selectins in its capacity for clustering sialylated ligands and transducing signals leading to neutrophil arrest in shear flow.
135 citations
TL;DR: The data support the view that statins might be clinically useful in protection against E‐selectin mediated metastasis by giving rise to a significant reduction in TNF‐α stimulated adhesion of colon carcinoma cells to HUVEC.
Abstract: E-selectin mediated cell-cell adhesion plays an important role in inflammatory processes and extravasation of tumor cells. Tumor necrosis factor-alpha (TNF-alpha) induces E-selectin gene and protein expression in primary human endothelial cells (HUVEC) and in an endothelial cell line (EA.hy-926). As shown by ELISA and FACS analyses, HMG-CoA reductase inhibitors (e.g., lovastatin) impair the TNF-alpha stimulated increase in E-selectin protein expression. Similar results were obtained for E-selectin mRNA expression and promoter activity, indicating that the effect of lovastatin is based on inhibition of gene expression. The effective inhibitory concentration of lovastatin was in a physiologically relevant range (IC50<0.1 microM). Lovastatin-mediated block of TNF-alpha induced E-selectin expression is due to inhibition of protein geranylgeranylation rather than farnesylation. Down-regulation of Rho signaling by coexpression of dominant-negative Rho mutants (i.e RhoA, RhoB and Rac) impaired TNF-alpha driven E-selectin gene expression, indicating Rho signaling to be essential for transcriptional activation of the E-selectin gene. Inhibition of E-selectin expression by lovastatin gives rise to a significant reduction in TNF-alpha stimulated adhesion of colon carcinoma cells to HUVEC. Furthermore, low concentration of lovastatin (i.e., < or =1 microM) attenuated TNF-alpha induced tumor cell invasion in vitro. The data support the view that statins might be clinically useful in protection against E-selectin mediated metastasis.
TL;DR: Whether a novel contrast agent (Gd‐DTPA‐B(sLeX)A, which contains an sLeX mimetic moiety that enables it to bind to the adhesion molecule E‐selectin) can be used to identify endothelial activation in the brain is determined.
Abstract: MRI is an increasingly important clinical tool, but it is clear that conventional imaging fails to identify the full extent of lesion load in certain conditions, such as multiple sclerosis. The aim of this study was to determine whether a novel contrast agent (Gd-DTPA-B(sLeX)A, which contains an sLeX mimetic moiety that enables it to bind to the adhesion molecule E-selectin) can be used to identify endothelial activation in the brain. Microinjection of the proinflammatory cytokines IL-1beta or TNF-alpha into the striatum of Wistar rats rapidly induces focal adhesion molecule expression on the endothelium in the absence of MRI-visible changes. This phenomenon was used to investigate the potential of Gd-DTPA-B(sLeX)A to reveal MRI-invisible brain pathology. T1-weighted serial images were acquired in anesthetized animals before and after administration of Gd-DTPA-B(sLeX)A, 3-4 hr after cytokine was injected intracerebrally. Both TNF-alpha and IL-1beta up-regulated E-selectin on the brain endothelium, which correlated with increased signal intensity observed after administration of the novel contrast agent. No enhancement was visible with the nonselective contrast agent Gd-DTPA-BMA, indicating that there was no leakage of the agent across the blood-brain barrier (BBB) or nonselective binding to the endothelium. These data demonstrate the potential of such contrast agents for the early detection of brain injury and inflammation.
TL;DR: Co expression and colocalization of E-selectin, chemokine, and ICAM-1 in dermal vessels could serve to recruit T cells to noninflamed human skin, providing the basis for a model of cutaneous immunosurveillance system active in the absence of pathologic inflammation.
Abstract: The success of the cutaneous immune system reflects its ability to rapidly and efficiently recruit leukocytes to areas of trauma and infection. Skin-homing memory T cells expressing cutaneous lymphocyte-associated Ag tether on the walls of postcapillary venules in inflamed skin via interaction with endothelial E-selectin and roll in response to the shear stress imparted by flowing blood. Rolling cells sample the vascular surface for chemoattractant compounds (e.g., thymus- and activation-regulated chemokine/CCL17 interacting with CCR4 on the leukocyte surface) and, if successfully stimulated, progress to firm arrest and transmigration mediated by LFA-1 and vascular ICAM-1. Although it is established that this sequence of events draws T cells into inflamed skin, the mechanisms directing trafficking of T cells to noninflamed skin are less well characterized. We hypothesized that basal expression and colocalization of E-selectin, chemokine (e.g., CCL17), and ICAM-1 in dermal vessels could serve to recruit T cells to noninflamed human skin. Immunohistochemical staining for E-selectin and CD31 demonstrated E-selectin expression in a restricted subset of dermal vessels in noninflamed human skin from three different sites. Confocal multicolor immunofluorescence imaging revealed a nonuniform distribution of E-selectin in dermal vessels as well as colocalization of E-selectin with CCL17 and ICAM-1. Coexpression of these molecules on blood vessels in noninflamed skin provides the basis for a model of cutaneous immunosurveillance system active in the absence of pathologic inflammation.
TL;DR: Results indicate that E-selectin is required for the antiangiogenic activity of endostatin in vivo and ex vivo and confers endstatin sensitivity to nonresponsive human endothelial cells in vitro.
Abstract: Endostatin, a 20-kDa fragment of collagen XVIII, is a potent angiogenesis inhibitor. E-selectin, an inducible leukocyte adhesion molecule specifically expressed by endothelial cells, has also been implicated in angiogenesis. By using in vivo, ex vivo, and in vitro angiogenic assays, we investigated the functional relationship between endostatin and E-selectin. In corneal micropocket assays, recombinant endostatin administered i.p. by osmotic pump inhibited basic fibroblast growth factor-induced angiogenesis in WT, but not E-selectin-deficient, mice. Similarly, endostatin inhibited vascular endothelial growth factor-stimulated endothelial sprout formation from aortic rings dissected from WT but not from E-selectin-deficient mice. To further explore this apparent requirement for E-selectin in endostatin action, we manipulated E-selectin expression in cultured human endothelial cells. When E-selectin was induced by IL-1β, or lipopolysaccharide, human umbilical vein endothelial cells and human dermal microvascular endothelial cells each became markedly more sensitive to inhibition by endostatin in a vascular endothelial growth factor-induced cell migration assay. To dissociate E-selectin expression from other consequences of endothelial activation, human umbilical vein endothelial cells were transduced with an adenoviral human E-selectin expression construct; these cells also showed increased sensitivity to endostatin, and this effect required the E-selectin cytoplasmic domain. Taken together, these results indicate that E-selectin is required for the antiangiogenic activity of endostatin in vivo and ex vivo and confers endostatin sensitivity to nonresponsive human endothelial cells in vitro. E-selectin may be a useful predictor and modulator of endostatin efficacy in antiangiogenic therapy.
TL;DR: The role of selectins in metastasis and the potential of heparin to modulate malignancy are discussed.
Abstract: Selectins are cell adhesion molecules mediating attachment of leukocytes to activated endothelium as well as the adhesion reaction of tumors during malignancy. Heparin, which is known to attenuate metastasis, is a potent blocker of selectins. Here, the role of selectins in metastasis and the potential of heparin to modulate malignancy are discussed.
TL;DR: The results suggest that estrogen may protect against Tat-induced inflammatory reactions in human vascular endothelium via blocking the NF-kappaB-mediated molecular signaling pathways.
Abstract: Objective: It has been proposed that human immunodeficiency virus (HIV) infection-induced inflammatory environment may contribute to the pathogenesis of cardiovascular diseases. Recent studies have also demonstrated the potential role of estrogen as therapeutic agents in the prevention or treatment of cardiovascular diseases. In the present study, we assessed the hypothesis that estrogen may attenuate the HIV Tat protein-induced inflammatory pathways in human vascular endothelium. Methods: Expression of inflammatory mediators in human endothelial cells was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Electrophoretic mobility shift assay (EMSA) also was performed to investigate the DNA-binding activities of several transcription factors, which are known to regulate expression of these inflammatory genes. Results: Acute exposure of human endothelial cells to Tat markedly induced the mRNA and protein expression of IL-1β, MCP-1, VCAM-1, and E-selectin. Tat also stimulated the adherence of inflammatory cells to endothelial cell monolayers. Significant and dose-dependent increases in NF-κB DNA-binding activity were observed in human endothelial cells treated with Tat. However, Tat did not affect DNA-binding activities of AP-1, CREB, and STAT1. Pretreatment with 17β-estradiol dramatically blocked the activation of NF-κB in human endothelial cells exposed to Tat. In addition, 17β-estradiol selectively inhibited the Tat-induced expression of IL-1β. Conclusion: Our results suggest that estrogen may protect against Tat-induced inflammatory reactions in human vascular endothelium via blocking the NF-κB-mediated molecular signaling pathways. These data may contribute to understanding the pathogenesis of cardiovascular complications and development of therapeutic strategies for HIV-infected patients.
TL;DR: Investigation of the effect of non-fractionated water-soluble cigarette smoke extract (NFWS CSE) on DNA damage and cellular adhesion molecule expression in human umbilical vein endothelial cells (HUVECs) suggests that NF WS CSE exposure induces both DNA damageand the surface expression of adhesion molecules in HUV ECs.
TL;DR: The results indicate that the interaction of metastatic cancer cells with endothelial cells implies a specific sequence of signaling events that ultimately leads to an increase in their efficient transendothelial migration.
Abstract: HT-29 colon carcinoma cells attach to TNFα-activated human umbilical vein endothelial cells (HUVECs) by their specific binding to E-selectin. This interaction activates, in the cancer cells, the MAPK SAPK2/p38, which leads to their transendothelial migration (Laferriere et al., J Biol Chem 2001; 276: 33762). In this study, we investigated the role of E-selectin in activating integrins to modulate adhesion and regulate integrin-mediated events. Blocking the integrins from HT-29 cells (α2, α3, α6, αvβ5, β1 and β4) with specific antibodies revealed a role for β4 integrin in their adhesion to TNFα-treated HUVEC. The β4 integrin-dependent adhesion was maximal after 30 min, whereas the-E-selectin-dependent adhesion was maximal after 15 min. Integrin β4 became quickly phosphorylated upon addition of HT-29 cells to endothelial cells and the effect was independent of the expression of E-selectin. Moreover, a recombinant E-selectin/Fc chimera did not induce the phosphorylation of β4. The phosphorylation of β4 is not required for adhesion since adhesion was not affected in HT-29 cells that express a truncated form of β4 that is deleted from its cytoplasmic phosphorylatable domain. However, the expression of the non-phosphorylatable deletant of β4 was associated with decreased transendothelial cell migration underscoring the key role for the cytoplasmic domain of β4 in cell migration. We suggest: 1) that the adhesion of HT-29 cells to activated endothelial cells follows at least two essential sequential steps involving the binding of E-selectin to its receptor on carcinoma cells and then the binding of β4 to its own receptor on endothelial cells; 2) that the phosphorylation of integrin β4 contributes to enhance the motile potential of cancer cells and increase their trans-endothelial migration. Overall, our results indicate that the interaction of metastatic cancer cells with endothelial cells implies a specific sequence of signaling events that ultimately leads to an increase in their efficient transendothelial migration.
TL;DR: It is found that on FUT1 transduction, all cells exhibited a dramatic decrease in s Le(x) synthesis with a concomitant increase in Le(y) and Le(b) expression, without any detectable effect on the level of cell surface sLe(a) antigens, which may provide a basis for the development of anti-metastatic gene therapy.
Abstract: During inflammation, E- and P-selectins appear on activated endothelial cells to interact with leukocytes through sialyl-Lewis x and sialyl-Lewis a antigens (sLex/a). These selectins can also interact with tumor cells in a sialyl-Lewis-dependent manner and for this reason, they are thought to play a key role in metastasis. Diverting the biosynthesis of sialyl-Lewis antigens toward nonadhesive structures is an attractive gene therapy for preventing the hematogenous metastatic spread of cancers. We have previously shown that transfection of α(1,2)-fucosyltransferase-I (FUT1) in Chinese hamster ovary (CHO) cells had a slight effect on the overall sialylation while the synthesis of sLEx was dramatically prevented. We herein delivered the gene of FUT1 by a human immunodeficiency virus-derived lentiviral vector to three human cancer cell lines including pancreatic (BxPC3), hepatic (HepG2), and colonic (HT-29) cancer cells. We found that on FUT1 transduction, all cells exhibited a dramatic decrease in sLex synthesis with a concomitant increase in Ley and Leb expression, without any detectable effect on the level of cell surface sLea antigens. In parallel, FUT1-transduced HT-29 and HepG2 cells, but not BxPC3 cells, failed to interact with E-selectin as assessed by E-selectin-binding assay or dynamic adhesion to activated endothelial cells. We show also that transduced FUT1 efficiently fucosylates the P-selectin ligand PSGL-1 without altering P-selectin binding. These results have important implications for understanding cell-specific reactions underlying the synthesis of selectin ligands in cancer cells and may provide a basis for the development of anti-metastatic gene therapy.
TL;DR: It is suggested that nicotine could augment macrophages releasing TNF-α and IL-1β, furthermore TNF’s up-regulate the expression of adhesion molecule and increase adhesion of monocytes to HUVECs.
TL;DR: The observation that the VCAM-1 gene is an important target of SOX18 provides the first molecular insights into the vascular abnormalities in the mouse mutant ragged and the human hypotrichosislymphedema-telangiectasia disorder.
TL;DR: Data indicate that ET-1 participates, via activation of ETA receptors, in altered leukocyte–endothelial cell interactions in DOCA–salt rats, possibly by modulating expression of CAMs, and that the inflammatory status is associated with cardiac damage in mineralocorticoid hypertension.
Abstract: Leukocyte adhesion to endothelial cells plays a key role in inflammatory processes associated with end-organ injury. Endothelin-1 (ET-1), which stimulates inflammatory processes, contributes to cardiovascular damage in deoxycorticosterone (DOCA)–salt hypertension. We investigated whether ETA receptor blockade modulates in vivo leukocyte–endothelial cell interactions and expression of cell adhesion molecules (CAM) involved in these processes. DOCA–salt and control uninephrectomized rats were treated with the ETA antagonist BMS182874 (40 mg/kg per day) or vehicle. Analysis of CAMs expression by reverse transcription-polymerase chain reaction and immunohistochemistry showed increased cardiac platelet selectin (P-selectin), detected mainly in endothelial cells, and vascular cell adhesion molecule-1 (VCAM-1), but not intercellular adhesion molecule-1 (ICAM-1), in DOCA–salt rats. Cardiac expression of endothelial selectin (E-selectin) was decreased, whereas immunoreactivity to ED-1 and myeloperoxidase (MPO) activity, markers of macrophage and leukocyte infiltration, respectively, were increased in DOCA-salt. Leukocyte–endothelial cell interaction, functionally assessed in venules of internal spermatic fascia by intravital microscopy, was significantly altered in DOCA–salt rats as evidenced by increased leukocyte adhesion and decreased rolling. BMS182874 treatment normalized leukocyte–endothelium interactions, decreased cardiac VCAM-1 expression in DOCA and control groups, and had no effects on ICAM-1 expression. BMS182874 also increased E-selectin and abolished P-selectin expression in DOCA-salt, but not in control rats. The ETA antagonist reduced cardiac ED-1 content and MPO activity and prevented cardiac damage in DOCA–salt rats. These data indicate that ET-1 participates, via activation of ETA receptors, in altered leukocyte–endothelial cell interactions in DOCA–salt rats, possibly by modulating expression of CAMs, and that the inflammatory status is associated with cardiac damage in mineralocorticoid hypertension.
TL;DR: S Sterically stabilised liposomes with the ligand at the terminal end of the polyethylene chain were the most effective inhibitors in all three assays and inhibited the adhesion of HT29 colon- and Lewis lung (LL) carcinoma cells by about 60-80%.
TL;DR: The severity and diversity of the histopathology of lupus nephritis are partially associated with the expression of vascular endothelial adhesion molecules in glomeruli.
TL;DR: Two P. gingivalis strains, ATCC 53799 and DSMZ 20709, infect endothelial cells and trigger signaling cascades leading to endothelial activation, which in turn may result in or promote severe local and systemic inflammation.
Abstract: Porphyromonas gingivalis is an important bacterium involved in periodontal diseases. Colonization by periodontopathogens has been associated with severe local inflammatory reactions in the connective tissue. In this study we characterized P. gingivalis-mediated infection and activation of human umbilical vein endothelial cells by using two strains of different virulence capacities, strains ATCC 53977 and DSMZ 20709. Both strains were able to adhere to and infect endothelial cells with an infection rate of 0.48% for ATCC 53977 and 0.007% for DSMZ 20709. The triggering of two signal transduction pathways in P. gingivalis-infected endothelial cells was demonstrated for both strains, with a rapid increase of p38 mitogen-activated protein kinase phosphorylation and a more delayed degradation of IκBα, followed by nuclear translocation of NF-κB. In addition, both strains induced enhanced expression of endothelial adhesion molecules E-selectin and intracellular adhesion molecule 1 (ICAM-1). Target cell activation was independent of bacterial fimbriae expression since the fimA knockout strain A7436 ΔfimA induced the same level of ICAM-1 as the corresponding wild type (A7436-WT). Thus, two P. gingivalis strains, ATCC 53799 and DSMZ 20709, infect endothelial cells and trigger signaling cascades leading to endothelial activation, which in turn may result in or promote severe local and systemic inflammation.
TL;DR: It is demonstrated that adhesion to E-selectin inhibits the proliferation of human CD34+ cells isolated either from human umbilical cord blood, adult mobilized blood, or steady-state bone marrow.
TL;DR: It is demonstrated that GITR plays an important role in the ischemia and reperfusion injury and the hypothesis that modulation of GITr expression may represent a novel and possible strategy is put forward.
Abstract: In the present study, we used glucocorticoid-induced tumor necrosis factor (TNF) receptor family gene knockout (GITR-KO) mice to evaluate a possible role of GITR on the pathogenesis of splanchnic artery occlusion (SAO) shock, which was induced in mice by clamping the superior mesenteric artery and the celiac artery for 30 min, followed thereafter by release of the clamp (reperfusion). At 60 min after reperfusion, animals were killed for histological examination and biochemical studies. There was a marked increase in the lipid peroxidation in the ileum of the SAO-shocked, GITR wild-type (WT) mice after reperfusion. The absence of GITR significantly reduced the lipid peroxidation in the intestine. SAO-shocked WT mice developed a significant increase of ileum tissue, TNF-alpha, and myeloperoxidase activity and marked histological injury. SAO shock was also associated with a significant mortality (5% survival at 24 h after reperfusion). Reperfused ileum tissue sections from SAO-shocked WT mice showed positive staining for P-selectin, intercellular adhesion molecule 1 (ICAM-1), and E-selectin. The intensity and degree of P-selectin, E-selectin, and ICAM-1 were markedly reduced in tissue section from SAO-shocked, GITR-KO mice. SAO-shocked, GITR-KO mice also showed a significant reduction of the TNF-alpha production and neutrophil infiltration into the reperfused intestine, an improved histological status of the reperfused tissues, and an improved survival. Taken together, our results clearly demonstrate that GITR plays an important role in the ischemia and reperfusion injury and put forward the hypothesis that modulation of GITR expression may represent a novel and possible strategy.
TL;DR: Results indicate that the endothelium of the tissue-engineered blood vessel produced by the self-assembly approach displays advantageous qualities with regard to the vessel's future implantation as a small-diameter vascular prosthesis.
TL;DR: It is suggested that IVIG inhibits NF-κB activation induced by TNF-α in CAEC, thereby possibly modulating IL-6 production and E-selectin expression.
Abstract: Objective:Kawasaki disease (KD) is an acute febrile vasculitis of unknown etiology that may lead to cardiovascular disorders. High-dose intravenous immunoglobulin (IVIG) therapy is well established as a standard therapy for KD. Tumor necrosis factor-α (TNF-α) is responsible for the pathogenesis of acute KD. We examined whether or not IVIG inhibits TNF-α-induced activation of transcription factor NF-κB, a factor that is essential for the expression of proinflammatory cytokines, in human coronary artery endothelial cells (CAEC). Methods:The inhibitory effect of IVIG on NF-κB activation induced by TNF-α was evaluated by Western blot analysis and ELISA. Moreover, the inhibitory effects of IVIG on IκBα degradation, interleukin-6 (IL-6) production, and E-selectin expression induced by TNF-α were evaluated by Western blot analysis, ELISA, and flow cytometry, respectively. Results:Western blot analysis and ELISA demonstrated that IVIG inhibits NF-κB activation induced by TNF-α in CAEC. Moreover, IVIG inhibited IκBα degradation, IL-6 production, and E-selectin expression induced by TNF-α in CAEC. Conclusions:The data suggest that IVIG inhibits NF-κB activation induced by TNF-α in CAEC, thereby possibly modulating IL-6 production and E-selectin expression.
Journal Article•
TL;DR: Transfection studies using promoter reporter gene constructs of ICAM-1, VCAM- 1, and E-selectin demonstrated that these shear stress modulations of gene expression occur at the transcriptional levels.
Abstract: Objective— Vascular endothelial cells (ECs) are subjected to shear stress and cytokine stimulation. We studied the interplay between shear stress and cytokine in modulating the expression of adhesion molecule genes in ECs. Methods and Results— Shear stress (20 dynes/cm2) was applied to ECs prior to and/or following the addition of tumor necrosis factor (TNF)-α. Shear stress increased the TNF-α–induced expression of intercellular adhesion molecule-1 (ICAM-1) at both mRNA and surface protein levels, but decreased the TNF-α–induced expression of vascular adhesion molecule-1 (VCAM-1) and E-selectin. Transfection studies using promoter reporter gene constructs of ICAM-1, VCAM-1, and E-selectin demonstrated that these shear stress modulations of gene expression occur at the transcriptional levels. After 24-hour preshearing followed by 1 hour of static incubation, the effect of preshearing on TNF-α–induced ICAM-1 mRNA expression vanished. The recovery of the TNF-α–induced VCAM-1 and E-selectin mRNA expressions f...