BACKGROUND AND OBJECTIVES: Recent studies have examined the structure-function relationship of high-density lipoprotein (HDL). This study aimed to identify and rank HDL-associated proteins involved in several biological function of HDL.METHODS: HDLs isolated from 48 participants were analyzed. Cholesterol efflux capacity, effect of HDL on nitric oxide production, and vascular cell adhesion molecule-1 expression were assessed. The relative abundance of identified proteins in the highest vs. lowest quartile was expressed using the normalized spectral abundance factor ratio.RESULTS: After adjustment by multiple testing, six proteins, thyroxine-binding globulin, alpha-1B-glycoprotein, plasma serine protease inhibitor, vitronectin, angiotensinogen, and serum amyloid A-4, were more abundant (relative abundance ratio ≥2) in HDLs with the highest cholesterol efflux capacity. In contrast, three proteins, complement C4-A, alpha-2-macroglobulin, and immunoglobulin mu chain C region, were less abundant (relative abundance ratio <0.5). In terms of nitric oxide production and vascular cell adhesion molecule-1 expression, no proteins showed abundance ratios ≥2 or <0.5 after adjustment. Proteins correlated with the functional parameters of HDL belonged to diverse biological categories.CONCLUSIONS: In summary, this study ranked proteins showing higher or lower abundance in HDLs with high functional capacities and newly identified multiple proteins linked to cholesterol efflux capacity.
Amyloid ; Angiotensinogen ; Atherosclerosis ; Cardiovascular Diseases ; Cholesterol ; Complement System Proteins ; Immunoglobulin mu-Chains ; Lipoproteins ; Nitric Oxide ; Plasma ; Proteomics ; Serine Proteases ; Thyroxine-Binding Globulin ; Vascular Cell Adhesion Molecule-1 ; Vitronectin

PURPOSE: Lipid rafts are cholesterol enriched microdomains that colocalize signaling pathways involved in cell proliferation, metastasis, and angiogenesis. We examined the effect of methyl-β-cyclodextrin (MβCD)-mediated cholesterol extraction on the proliferation, adhesion, invasion, and angiogenesis of triple negative breast cancer (TNBC) cells. METHODS: We measured cholesterol and estimated cell toxicity. Detergent resistant membrane (DRM) and non-DRM fractions were separated using the OptiPrep gradient method. Cell cycles stages were analyzed by flow cytometry, apoptosis was assessed using the TdT-mediated dUTP nick end-labeling assay, and metastasis was determined using a Matrigel invasion assay. Neo-vessel pattern and levels of angiogenic modulators were determined using an in vitro angiogenesis assay and an angiogenesis array, respectively. RESULTS: The present study found that the cholesterol-depleting agent MβCD, efficiently depleted membrane cholesterol and caused concentration dependent (0.1–0.5 mM) cytotoxicity compared to nystatin and filipin III in TNBC cell lines, MDA-MB 231 and MDA-MB 468. A reduced proportion of caveolin-1 found in DRM fractions indicated a cholesterol extraction-induced disruption of lipid raft integrity. MβCD inhibited 52% of MDA-MB 231 cell adhesion on fibronectin and 56% of MDA-MB 468 cell adhesion on vitronectin, while invasiveness of these cells was decreased by 48% and 52% respectively, following MβCD treatment (48 hours). MβCD also caused cell cycle arrest at the G2M phase and apoptosis in MDA-MB 231 cells (25% and 58% cells, respectively) and in MDA-MB 468 cells (30% and 38% cells, respectively). We found that MβCD treated cells caused a 52% and 58% depletion of neovessel formation in both MDA-MB 231 and MDA-MB 468 cell lines, respectively. This study also demonstrated that MβCD treatment caused a respective 2.6- and 2.5-fold depletion of tyrosine protein kinase receptor (TEK) receptor tyrosine kinase levels in both TNBC cell lines. CONCLUSION: MβCD-induced cholesterol removal enhances alterations in lipid raft integrity, which reduces TNBC cell survival.
Apoptosis ; Caveolin 1 ; Cell Adhesion ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Line ; Cell Proliferation ; Cell Survival ; Cholesterol ; Detergents ; Fibronectins ; Filipin ; Flow Cytometry ; In Vitro Techniques ; Membrane Microdomains ; Membranes ; Methods ; Neoplasm Metastasis ; Nystatin ; Protein-Tyrosine Kinases ; Triple Negative Breast Neoplasms* ; Vitronectin

Interleukin (IL) 33, a member of the IL-1 superfamily, is an "alarmin" protein and is secreted in its active form from damaged cells undergoing necrotic cell death. Mast cells are one of the main effector cell types in allergic disorders. They secrete a variety of mediators, including T helper 2 cytokines. As mast cells have high-affinity IgE receptors (FcepsilonRI) on their surface, they can capture circulating IgE. IgE-bound mast cells degranulate large amounts of histamine, heparin, and proteases when they encounter antigens. As IL-33 is an important mediator of innate immunity and mast cells play an important role in adaptive immune responses, interactions between the two could link innate and adaptive immunity. IL-33 promotes the adhesion of mast cells to laminin, fibronectin, and vitronectin. IL-33 increases the expression of adhesion molecules, such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1, in endothelial cells, thus enhancing mast cell adhesion to blood vessel walls. IL-33 stimulates mast cell proliferation by activating the ST2/Myd88 pathway; increases mast cell survival by the activation of survival proteins such as Bcl-XL; and promotes the growth, development, and maturation of mast cell progenitors. IL-33 is also involved in the activation of mature mast cells and production of different proinflammatory cytokines. The interaction of IL-33 and mast cells could have important clinical implications in the field of clinical urology. Epithelial dysfunction and mast cells could play an important role in the pathogenesis of interstitial cystitis. Urinary levels of IL-33 significantly increase in patients with interstitial cystitis. In addition, the number of mast cells significantly increase in the urinary bladders of patients with interstitial cystitis. Therefore, inhibition of mast cell activation and degranulation in response to increase in IL-33 is a potential therapeutic target in the treatment of interstitial cystitis.
Adaptive Immunity* ; Allergy and Immunology ; Blood Vessels ; Cell Death ; Cystitis, Interstitial ; Cytokines ; Endothelial Cells ; Fibronectins ; Heparin ; Histamine ; Humans ; Immunity, Innate ; Immunoglobulin E ; Interleukin-1 ; Interleukins ; Laminin ; Mast Cells* ; Peptide Hydrolases ; Receptors, IgE ; Urinary Bladder ; Urology ; Vascular Cell Adhesion Molecule-1 ; Vitronectin

Epstein-Barr virus (EBV) establishes a latent infection in greater than 90% of the world's adult population and associates with various tumors. EBV primarily infects epithelial cells and B cell in vivo. Mechanism of EBV infection in B cells is known to involve binding of EBV glycoprotein gp350 to CD21 on B cell surface. Epithelial cells are infected with EBV even though most of epithelial cells do not express CD21. Recently, integrin alphavbeta5, alphavbeta6 and alphavbeta8 on epithelial cells were reported to facilitate EBV infection by interacting with gHgL complex. We examined the expression profile of integrins known to be expressed on epithelial cells. Integrin alphavbeta5 and alphavbeta6, but not alphavbeta8 were detected in a gastric epithelial cell line, AGS. We then tested whether siRNAs specific to beta6 can inhibit EBV infection of epithelial cells. One among the four tested siRNAs significantly reduced beta6 expression and suppressed transfer infection of EBV to AGS cells. Our data suggest that siRNAs to integrins might be useful to control EBV infection to epithelial cells.
Adult ; B-Lymphocytes ; Epithelial Cells ; Epstein-Barr Virus Infections ; Glycoproteins ; Herpesvirus 4, Human ; Humans ; Integrin beta Chains ; Integrins ; Receptors, Vitronectin ; RNA, Small Interfering

BACKGROUND: We determined the changes of complement regulator gene expression in the amyloid-beta1-42(A beta1-42) and interferon-gamma(IFN-gamma)-stimulated human astrocytoma cell line. METHODS: The human astrocytoma cell line, U373MG, was stimulated with IFN-gamma(62.5-1,000U/ml) in the presence or absence of aggregated A beta1-42(1-20micrometer) for 24 hours. Messenger RNA expression of C1 inhibitor(C1-INH), complement factor I(CFI), clusterin, vitronectin, decay accelerating factor(DAF), membrane cofactor protein(MCP), and CD59 was measured by quantitative real-time reverse transcriptase-PCR. RESULTS: IFN-gamma(final concentration, 500U/ml) markedly increased the expression of mRNA for C1-INH in a time dependent fashion. A beta1-42(final concentration, 2micrometer) induced a slight increase in the expression of C1-INH. Messenger RNAs for CFI and clusterin were minimally increased, but other regulators were unchanged or decreased by either A beta1-42 or IFN-gamma. IFN-gamma overrode A beta1-42-induced mRNA expression of C1-INH when the cells were treated with these two reagents together. CONCLUSION: Among the complement regulator genes in the human astrocytoma cell line, U373MG, only C1-INH was significantly up-regulated by IFN-gamma with or without A beta1-42 administration.
Alzheimer Disease ; Aminopeptidases ; Amyloid beta-Peptides ; Astrocytoma ; Cell Line ; Clusterin ; Complement Factor I ; Complement System Proteins ; Genes, Regulator ; Humans ; Indicators and Reagents ; Interferon-gamma ; Interferons ; Membranes ; RNA, Messenger ; Vitronectin

OBJECTIVETo investigate the role of adhesion molecules alphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 in the tumor-endothelial cell adhesion in vitro.

METHODSThe expression of alphavbeta3, alphavbeta5 and ICAM-1 in liver sinusoidal endothelial cells (LSEC) and liver cancer endothelial cells (T3A) cultured under normoxia or hypoxia were analyzed by RT-PCR and fluorescent activated cell sorter (FACS). The expression of Del-1 and L1 in six tumor cell lines under normoxia or hypoxia were analyzed by RT-PCR and Western blot, respectively. The adhesion of dye-labeled tumor cells and endothelial LSEC and T3A cells was measured by a fluorescence plate reader after their culture.

RESULTSThe expression of alphavbeta3 and alphavbeta5 were higher in T3A cells than that in LSEC cells, and were upregulated under hypoxia, while the expression of ICAM-1 was lower in T3A cells than that in LSEC cells, and was upregulated under hypoxia only in LSEC. The expression of Del-1 and L1 molecules were obviously different in various tumor cell lines and were differentially regulated under hypoxia. The adhesion of tumor cells with Del-1 or L1 expression was higher in T3A cells than that in LSEC cells, and was significantly increased under hypoxia condition. Furthermore, the adhesion of tumor cells to T3A could be inhibited by antibodies against alphavbeta3 and alphavbeta5, or SiRNAs for beta3 and beta5.

CONCLUSIONalphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 may play an important role in tumor cell migration.

Antibodies ; immunology ; Cell Adhesion ; Cell Hypoxia ; Cell Line, Tumor ; Endothelial Cells ; cytology ; metabolism ; Humans ; Integrin alphaVbeta3 ; genetics ; immunology ; metabolism ; Intercellular Adhesion Molecule-1 ; immunology ; metabolism ; Ligands ; Neoplasms ; metabolism ; pathology ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; pharmacology ; Receptors, Vitronectin ; genetics ; immunology ; metabolism

OBJECTIVETo analyze the phenotypic and functional characteristics of endothelial (T3A) cells derived from human hepatocellular cell carcinoma.

METHODSEndothelial cells were isolated from human hepatocellular carcinoma specimens. The identification of T3A cells was performed by checking von Willebrand Factor (vWF), CD31, CD34 and Dil-Ac-LDL uptake. The cell surface fenestrations, a specific morphological feature of tumor derived EC, were investigated by scanning and transmission electron microscopy. The phenotypic characteristics of T3A cells were analyzed by fluorescence-activated cell sorter (FACS) and were further conformed by real-time PCR at transcription level. Furthermore, tumor necrosis factor alpha (TNFalpha)-induced cytotoxicity was evaluated by 3-(4, 5-dimethythiazolyl) -2, -diphenyl-2H-tetrazolium-bromide (MTT) assay; Matrix metalloproteinase secretion was detected by zymography; Angiogenic ability in vitro was analyzed by culturing T3A cells in three-dimensional Matrigel plug. Coagulant and fibrinolytic activities were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe isolated T3A cells exhibited classic "spindle-shape" morphology and monolayer growth and contact inhibition properties. Immunofluorescent staining showed that T3A cells expressed vWF, CD31, CD34, and uptake of Dil-Ac-LDL at a high level. The cell surface fenestrations were observed on T3A cells by scanning and transmission electron microscopy. By FACS and real-time PCR, T3A cells were found to express alphav3, alphavbeta5 and TNF receptor p75 at high levels, and TNF receptor p55 and ICAM-1 at low levels, as compared with those in human liver sinusoidal endothelial cells (LSEC). In response to TNFalpha, LSEC exhibited a dose-dependent cytotoxicity, while T3A cells were resistant. Gelatin zymography showed that MMP-2 activity was higher in T3A cells than that in LSEC. In a three-dimensional plug of Matrigel, T3A cells exhibited stronger angiogenic ability as compared with LSEC. In addition, T3A cells released more tissue factor (TF), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) and urine plasminogen activator (u-PA) than LSEC in response to TNFalpha.

CONCLUSIONTumor-derived endothelial cells are phenotypically and functionally different from those derived from normal liver tissue.

Antigens, CD34 ; metabolism ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Cell Shape ; Cells, Cultured ; Endothelial Cells ; metabolism ; pathology ; ultrastructure ; Gene Expression ; Humans ; Integrin alphaVbeta3 ; metabolism ; Integrins ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Lipoproteins, LDL ; metabolism ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Lung ; blood supply ; metabolism ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Microscopy, Electron, Scanning ; Neovascularization, Pathologic ; metabolism ; pathology ; Phenotype ; Plasminogen Activator Inhibitor 1 ; metabolism ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Receptors, Tumor Necrosis Factor, Type I ; metabolism ; Receptors, Vitronectin ; metabolism ; Tissue Plasminogen Activator ; metabolism ; Tumor Cells, Cultured ; Tumor Necrosis Factor Decoy Receptors ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology ; von Willebrand Factor ; metabolism

Collagen Type I ; biosynthesis ; Hepatocyte Growth Factor ; biosynthesis ; Hepatocytes ; cytology ; metabolism ; physiology ; Liver Cirrhosis ; metabolism ; pathology ; physiopathology ; Liver Regeneration ; Receptors, Vitronectin ; biosynthesis

Adhesion and migration of vascular smooth muscle cells (VSMCs) play an important role in the pathogenesis of atherosclerosis. These processes involve the interaction of VSMCs with extracellular matrix proteins. Here, we investigated integrin isoforms and signaling pathways mediating the adhesion and migration of VSMCs on betaig-h3, a transforming growth factor (TGF)-beta-inducible extracellular matrix protein that is elevated in atherosclerotic plaques. Adhesion assays showed that the alphavbeta5 integrin is a functional receptor for the adhesion of aortic VSMCs to betaig-h3. An YH18 motif containing amino acids between 563 and 580 of betaig-h3 was an essential motif for the adhesion and growth of VSMCs. Interaction between the YH18 motif and the alphavbeta5 integrin was responsible for the migration of VSMCs on betaig-h3. Inhibitors of phosphatidylinositide 3-kinase, extracellular signal-regulated kinase (ERK), and Src kinase reduced the adhesion and migration of VSMCs on betaig-h3. betaig-h3 triggered phosphorylation and activation of AKT, ERK, focal adhesion kinase, and paxillin mediating the adhesion and migration of VSMCs. Taken together, these results suggest that betaig-h3 and alphavbeta5 integrin play a role in the adhesion and migration of VSMCs during the pathogenesis of atherosclerosis.
src-Family Kinases/antagonists & inhibitors ; Transforming Growth Factor beta/genetics/*physiology ; Signal Transduction/*physiology ; Receptors, Vitronectin/genetics/*physiology ; Protein-Tyrosine Kinases/antagonists & inhibitors ; Paxillin/metabolism ; Myocytes, Smooth Muscle/drug effects/metabolism ; Muscle, Smooth, Vascular/cytology/drug effects/*metabolism ; Morpholines/pharmacology ; Molecular Sequence Data ; Integrins/genetics/*physiology ; Humans ; Flavonoids/pharmacology ; Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors ; Extracellular Matrix Proteins/genetics/*physiology ; Enzyme Inhibitors/pharmacology ; Chromones/pharmacology ; Cells, Cultured ; Cell Movement/*physiology ; Cell Adhesion/physiology ; Animals ; Amino Acid Sequence ; Amino Acid Motifs/genetics ; 1-Phosphatidylinositol 3-Kinase/antagonists & inhibitors

BACKGROUND: Microglia is a primary cellular component of neuritic plaques in Alzheimer's disease. Beta amyloid deposits attract microglia and activate them to produce inflammatory mediators. The objectives of this study were to characterize activation of the microglia; production of reactive oxygen species (ROS), constitutive and upregulated expression of complement regulators, and intracellular localization of amyloid by phagocytosis. METHODS: BV-2 cells, mouse microglia cell line, were incubated for 3~18 hours with a single dose of 20 micro M of aggregated A beta1-42. ROS measurement was done with FACScan. Messenger RNA expressions of C1-INH, vitronectin, CD59, clusterin, factor H, and superoxide dismutase (SOD) were detected by RT-PCR. The intensity of bands from 6% polyacrylamide electrophoretic gel was analyzed by a bioimage analyzer. The intracellular localization of A beta in the phagocytosed microglia was observed by transmission electron microscope. RESULTS: A beta1-42 activates microglia with an increase of ROS production. Expression of mRNA for SOD was also increased. Messenger RNA for C1-INH and vitronectin were upregulated. A beta fibrils were located in the phagosome of microglia. CONCLUSIONS: A beta activated microglia are playing dual roles as effector and scavenger cell, which as a result, may contribute to the chronic neuroinflammation of Alzheimer's disease.
Alzheimer Disease ; Amyloid ; Amyloid beta-Peptides ; Animals ; Cell Line ; Clusterin ; Complement Factor H ; Complement System Proteins* ; Genes, Regulator* ; Mice ; Microglia ; Phagocytosis* ; Phagosomes ; Plaque, Amyloid ; Reactive Oxygen Species* ; RNA, Messenger ; Superoxide Dismutase ; Vitronectin