Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelial cell lines are commonly used in in vitro studies to avoid problems associated with the use of primary endothelial cells such as the presence of contaminating cells, the difficulty in obtaining larger numbers of cells, as well as the progressive loss of cell viability and expression of endothelial markers in the course of in vitro propagation. We have analyzed the characteristics defining distinctive endothelial phenotypes in the cell lines EA.hy926, ECV304, EVLC2, HAEND, HMEC-1, ISO-HAS-1 and a cell line recently generated in our laboratory, HPMEC-ST1.6R, and have compared these phenotypes with those found in primary human endothelial cells isolated from umbilical vein (HUVEC), lung (HPMEC), and skin (HDMEC). The analysis revealed significant differences in phenotype expression between primary cells and the cell lines. Constitutive expression of von Willebrand factor, CD31, and CD34 and induced expression of cell adhesion molecules, ICAM-1, VCAM-1, and E-selectin and cytokines, IL-6, IL-8, MCP-1, and GM-CSF on stimulation with proinflammatory stimuli, as well as the uptake of DiI-Ac-LDL and the formation of cord-like structures on Matrigel, were typically observed in the primary cells. However, most cell lines exhibited only a few of these endothelial characteristics. Only HPMEC-ST1.6R exhibited the major constitutive and inducible endothelial cell characteristics and showed an angiogenic response on Matrigel similar to that of primary HPMEC. Thus, HPMEC-ST1.6R will be a valuable in vitro model system in which to study pathomechanisms and angiogenesis of the mature microvascular endothelium in vitro.
 ...
PMID:In vitro expression of the endothelial phenotype: comparative study of primary isolated cells and cell lines, including the novel cell line HPMEC-ST1.6R. 1245 33

Migration of blood-borne lymphocytes into lymphoid tissues and sites of inflammation is initiated by vascular adhesion molecules and proinflammatory cytokines. Previous in vivo studies have shown that febrile temperatures dynamically stimulate adhesion in differentiated high endothelial venules (HEV), which are portals for lymphocyte extravasation. This report examines the direct effect of fever-range hyperthermia on the expression of adhesion molecules and cytokines by primary cultured endothelial cells. In both macrovascular (HUVEC) and microvascular (HMVEC) endothelial cells, fever-range hyperthermia (40 degrees C for 6-12 h) did not affect expression of adhesion molecules (ICAM-1, E-selectin, VCAM-1, P-selectin, PECAM-1, PNAd, MAdCAM-1), cytokine release (IL-1beta, TNF-alpha, IFN-gamma, IL-6, IL-11, IL-12, IL-13), or chemokine secretion (IL-8, RANTES, MCP-1, MIP-1beta, MIG). This is in contrast to the stimulatory effects of TNF-alpha or 43 degrees C heat shock. However, a novel role for fever-range hyperthermia was identified in augmenting actin polymerization in cultured endothelial cells and enhancing the ability of endothelial-derived factors to transactivate the alpha4beta7 integrin lymphocyte homing receptor. These findings provide insight into the tightly regulated effects of fever-range hyperthermia that exclude induction of adhesion in non-activated endothelium of normal blood vessels. Through these mechanisms, it is proposed that febrile temperatures associated with infection or clinical hyperthermia avoid the unproductive exodus of lymphocytes to non-involved extralymphoid tissues while simultaneously promoting lymphocyte delivery to sites of immune activation.
 ...
PMID:Cytokine and adhesion molecule expression in primary human endothelial cells stimulated with fever-range hyperthermia. 1253 53

Pulmonary fibrosis can be observed as an end state in a number of chronic inflammatory pulmonary diseases. Although the mechanisms by which lung fibrosis develops are not fully ascertained, recent findings suggest that oxidative stress may play an important role in the pathogenesis of tissue fibrosis affecting apoptosis of both structural and inflammatory cells and altering the cytokine microenvironment balance. Damage and alteration of alveolar epithelial cells is one of the hallmarks of interstitial lung fibrosis. Recently, it has been demonstrated that the presence of oxidative stress may lead to the damage, activation and/or apoptosis of alveolar epithelial cells either directly, through an imbalanced intracellular redox equilibrium, or indirectly, by activating redox-sensitive effector pathways, such as transcription factors and angiotensin converting enzyme, increasing the conversion of angiotensinogen into angiotensin II that can be considered a mediator of oxidative stress, capable of inducing apoptosis. Furthermore, it has been demonstrated that angiotensin II acts as a proinflammatory cytokine and is effective in activating fibroblasts through the release of transforming growth factor (TGF-beta). As well as activation, differentiation, proliferation and apoptosis of fibroblasts seem related to the oxidant/antioxidant balance, and the maintenance of a high intracellular level of reduced glutathione (GSH) is considered crucial in providing a reducing environment within the cell, able to protect against oxidative stress. In those conditions where oxidants, either inhaled or produced by inflammatory cell, increase, the ratio between GSH and oxidized glutathione (GSSH) may lower, influencing a variety of cellular redox-sensitive signaling processes such as the activation of nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) that lead to a transcriptional up-regulation of a number of genes involved in inflammation and/or fibrogenesis, including cytokines [interleukin (IL)-1,, tumor necrosis factor (TNF-alpha), IL-6] chemokines (IL-8), adhesion molecules (VCAM-1, ICAM-1) and growth factors (GM-CSF). In addition, several studies have shown that oxidative stress may also affect the immune response by inducing an up-regulation of HLA-DR as well as the expression of two costimulatory molecules such as CD40 and CD86, determining a persistent state of immune activation, and affecting the Th1/Th2 balance, modulating the T-cell effector response towards the Th2 phenotype. It is clear that a better understanding of the precise sequence of events that make the difference between normal tissue repair and fibrosis, including the role played by oxidative stress, will certainly improve our therapeutic approach to pulmonary fibrosis.
 ...
PMID:Role of oxidative stress in pulmonary fibrosis. 1261 77

Accumulating data show that fibroblasts are important regulators in the development and maintenance of allergic airway inflammation. However, most studies so far have used individual recombinant cytokines in high concentrations, unlikely to be found in vivo. We aimed to investigate how cytokines produced by peripheral blood mononuclear cells (PBMC) affect fibroblast functions. Primary airway fibroblasts where incubated with allergen-stimulated or non-stimulated PBMC supernatants from allergic patients. The levels of cytokines in PBMC supernatants were measured and the expression of CD54, CD40 and CD106 as well as the production of eotaxin, interleukin (IL)-6 and IL-8 were assessed in fibroblasts. Although the levels of single cytokines measured in PBMC supernatants were low, a significant up-regulation of the surface molecules as well as of IL-6 and IL-8 production was found in fibroblasts cultured with allergen-stimulated PBMC supernatants as compared to non-stimulated, while the increase in eotaxin production was not significant. The evaluation of correlations between cytokines produced by PBMC and effects seen on fibroblasts did not indicate a crucial role for any single cytokine. Furthermore, the addition of comparably low concentrations of recombinant interferon (rIFN)-gamma or recombinant tumour necrosis factor (rTNF)-alpha did not induce the same effects as PBMC supernatants, the only exception being TNF-alpha as a direct inducer of CD54 expression. Our results show that synergistic mechanisms has a more important role than single mediators, highlighting important differences between in vitro experiments, where effects of individual mediators are studied, versus the actual situation in vivo.
 ...
PMID:Low concentrations of cytokines produced by allergen-stimulated peripheral blood mononuclear cells have potent effects on nasal polyp-derived fibroblasts. 1269 13

Circulating B cells enter the CNS as part of normal immune surveillance and in pathologic states, including the common and disabling illness multiple sclerosis. However, little is known about the molecular mechanisms that mediate human B cell interaction with the specialized brain endothelial cells comprising the blood-brain barrier (BBB). We studied the molecular mechanisms that regulate the migration of normal human B cells purified ex vivo, across human adult brain-derived endothelial cells (HBECs). We found that B cells migrated across HBECs more efficiently than T cells from the same individuals. B cell migration was significantly inhibited by blocking Abs to the adhesion molecules ICAM-1 and VLA-4, but not VCAM-1, similar to the results previously reported for T cells. Blockade of the chemokines monocyte chemoattractant protein-1 and IL-8, but not RANTES or IFN-gamma-inducible protein-10, significantly inhibited B cell migration, and these results were correlated with the chemokine receptor expression of B cells measured by flow cytometry and by RNase protection assay. Tissue inhibitor of metalloproteinase-1, a natural inhibitor of matrix metalloproteinases, significantly decreased B cell migration across the HBECs. A comprehensive RT-PCR comparative analysis of all known matrix metalloproteinases and tissue inhibitors of metalloproteinases in human B and T cells revealed distinct profiles of expression of these molecules in the different cell subsets. Our results provide insights into the molecular mechanisms that underlie human B cell migration across the BBB. Furthermore, they identify potential common, and unique, therapeutic targets for limiting CNS B cell infiltration and predict how therapies currently developed to target T cell migration, such as anti-VLA-4 Abs, may impact on B cell trafficking.
 ...
PMID:Determinants of human B cell migration across brain endothelial cells. 1270 26

Vascular cell adhesion molecule (VCAM)-1 expression may be coupled to redox-sensitive regulatory pathways, and iron may play a role in generation of reactive oxygen species that participate in these signaling pathways. To investigate the role of iron in TNF alpha-induced VCAM-1 gene expression, human dermal microvascular endothelial cells (HDMEC) were stimulated with TNF alpha in the presence of iron chelators and examined for expression of VCAM-1. The iron chelators dipyridyl (DP) and desferoxamine (DFO) inhibited VCAM-1 protein and mRNA induction in a concentration- and time-dependent manner. The induction of VCAM-1 was not inhibited by nonmetal binding reactive oxygen species (ROS) scavengers, implying a direct effect of iron in the expression of these adhesion molecules. The effect of iron was mediated at the level of gene transcription since pretreatment with DP abrogated the TNF alpha-mediated up-regulation of VCAM-1 heterogeneous nuclear RNA. Pretreatment of HDMEC with DP prior to TNFalpha treatment had no effect on p65 nuclear localization, DNA binding, or serine phosphorylation. DP pretreatment inhibited TNF alpha- and IFN gamma-mediated interferon regulatory factor 1 (IRF-1) protein expression, although restoration of IRF-1 expression failed to reconstitute VCAM-1 expression. DP treatment also blocked VCAM-1 induction in human umbilical vein endothelium and blocked induction of a host of NF-kB activated genes in HDMEC including ICAM-1, IL-8, and tissue factor. I kappa B alpha, an NF-kappa B inducible and constitutively accessible gene not requiring chromatin remodeling for transcription, was not affected by DP treatment. These data suggest that iron plays a critical role in TNF alpha mediated VCAM-1 induction in HDMEC, and the target for iron effects may be IRF-1, NF-kappa B, and potentially chromatin remodeling.
 ...
PMID:Iron chelators inhibit VCAM-1 expression in human dermal microvascular endothelial cells. 1470 35

Bacterial lipopolysaccharide (LPS) stimulates Kupffer cells and participates in the pathogenesis of alcohol-induced liver injury. However, it is unknown whether LPS directly affects hepatic stellate cells (HSCs), the main fibrogenic cell type in the injured liver. This study characterizes LPS-induced signal transduction and proinflammatory gene expression in activated human HSCs. Culture-activated HSCs and HSCs isolated from patients with hepatitis C virus-induced cirrhosis express LPS-associated signaling molecules, including CD14, toll-like receptor (TLR) 4, and MD2. Stimulation of culture-activated HSCs with LPS results in a rapid and marked activation of NF-kappaB, as assessed by in vitro kinase assays for IkappaB kinase (IKK), IkappaBalpha steady-state levels, p65 nuclear translocation, NF-kappaB-dependent luciferase reporter gene assays, and electrophoretic mobility shift assays. Lipid A induces NF-kappaB activation in a similar manner. Both LPS- and lipid A-induced NF-kappaB activation is blocked by preincubation with either anti-TLR4 blocking antibody (HTA125) or Polymyxin B. Lipid A induces NF-kappaB activation in HSCs from TLR4-sufficient (C3H/OuJ) mice but not from TLR4-deficient (C3H/HeJ) mice. LPS also activates c-Jun N-terminal kinase (JNK), as assessed by in vitro kinase assays. LPS up-regulates IL-8 and MCP-1 gene expression and secretion. LPS-induced IL-8 secretion is completely inhibited by the IkappaB super repressor (Ad5IkappaB) and partially inhibited by a specific JNK inhibitor, SP600125. LPS also up-regulates cell surface expression of ICAM-1 and VCAM-1. In conclusion, human activated HSCs utilize components of TLR4 signal transduction cascade to stimulate NF-kappaB and JNK and up-regulate chemokines and adhesion molecules. Thus, HSCs are a potential mediator of LPS-induced liver injury.
 ...
PMID:Toll-like receptor 4 mediates inflammatory signaling by bacterial lipopolysaccharide in human hepatic stellate cells. 1271 78

To deliver selectively anti-inflammatory agents into activated endothelial cells, drug-targeting conjugates were developed. Dexamethasone (Dexa) was covalently linked to a monoclonal antibody specifically recognizing E-selectin, which is strongly upregulated in endothelial cells at inflammatory sites. In the present study, the pharmacological effects of this Dexa-mouse antihuman E-selectin antibody (H18/7) (Ab(hEsel)) conjugate were investigated and compared to the effects obtained by free Dexa in human umbilical vein endothelial cells. Flow cytometry and ELISA were performed to analyze the levels of cell adhesion molecules (ICAM-1 and VCAM-1) and secreted cytokines (IL-6 and IL-8). The studies were extended by analysis of a complex gene expression pattern, using a cDNA expression array containing 268 genes encoding human cytokines/cytokine-receptors. Fifty genes and 28 genes were upregulated (ratio> or =2) upon incubation of human umbilical vein endothelial cells with TNFalpha for 6 and 24hr, respectively. This gene expression profile was markedly altered when cells were activated with TNFalpha in the presence of Dexa (100 nM) or Dexa-Ab(hEsel) conjugate (10 micro g/mL conjugate corresponding to 100 nM Dexa). Relative and competitive RT-PCR analysis verified downregulation of TNFalpha-mediated expression of CD40L and IL-8 by Dexa and Dexa-Ab(hEsel), respectively. These results indicated a successful internalization and processing of Dexa-Ab(hEsel) in activated endothelial cells, allowing the intracellularly delivered Dexa to exert its pleiotropic anti-inflammatory activity.
 ...
PMID:Delivery of pharmacologically active dexamethasone into activated endothelial cells by dexamethasone-anti-E-selectin immunoconjugate. 1275 9

Conjunctival epithelial cells do not act only as mechanical barriers, preventing the entry of particles, bacteria, viruses, and noxious substances into the eye but they are also active participants in the regulation of allergic inflammation via expressing adhesion/effector molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, human leukocyte antigen-DR, CD40/CD40L, Fas/Fas ligand) on their surfaces and releasing numerous proinflammatory cytokines, such as eotaxin, regulated on activation normal T-cell expressed and released (RANTES), macrophage inflammatory protein-1, interleukin (IL)-8, IL-6, and tumor necrosis factor-a, which are necessary for the proliferation, differentiation, activation, and chemotaxis of various inflammatory cells into the conjunctiva. Histamine, released from the conjunctival mast cells, might stimulate the synthesis of proinflammatory molecules such as IL-6 and IL-8 by the epithelial cells through the receptors that couple to inositol phosphate generation and, therefore, amplify the allergic response. The relationship between the epithelium and allergy should be considered in detail in future studies aiming at an effective control and treatment of all forms of allergic conjunctivitis.
 ...
PMID:Epithelial cells in ocular allergy. 1279 Dec 15

Lipopolysaccharide (endotoxin) tolerance is well described in monocytes and macrophages, but is less well characterized in endothelial cells. Because intestinal microvascular endothelial cells exhibit a strong immune response to LPS challenge and play a critical regulatory role in gut inflammation, we sought to characterize the activation response of these cells to repeated LPS exposure. Primary cultures of human intestinal microvascular endothelial cells (HIMEC) were stimulated with LPS over 6-60 h and activation was assessed using U937 leukocyte adhesion, expression of E-selectin, ICAM-1, VCAM-1, IL-6, IL-8, manganese superoxide dismutase, HLA-DR, and CD86. Effect of repeat LPS stimulation on HIMEC NF-kappaB and mitogen-activated protein kinase (MAPK) activation, generation of superoxide anion, and Toll-like receptor 4 expression was characterized. LPS pretreatment of HIMEC for 24-48 h significantly decreased leukocyte adhesion after subsequent LPS stimulation. LPS pretreatment inhibited expression of E-selectin, VCAM-1, IL-6, and CD86, while ICAM-1, IL-8, and HLA-DR were not altered. Manganese superoxide dismutase expression increased with repeated LPS stimulation, with a reduction in intracellular superoxide. NF-kappaB activation was transiently inhibited by LPS pretreatment for 6 h, but not at later time points. In contrast, p44/42 MAPK, p38 MAPK, and c-Jun N-terminal kinase activation demonstrated inhibition by LPS pretreatment 24 or 48 h prior. Toll-like receptor 4 expression on HIMEC was not altered by LPS. HIMEC exhibit endotoxin tolerance after repeat LPS exposure in vitro, characterized by diminished activation and intracellular superoxide anion concentration, and reduced leukocyte adhesion. HIMEC possess specific mechanisms of immunoregulatory hyporesponsiveness to repeated LPS exposure.
 ...
PMID:Mechanisms of endotoxin tolerance in human intestinal microvascular endothelial cells. 1279 22


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>