OBJECTIVETo evaluate the functional regulation of endothelial Myosin light chain kinase (MLCK) in extravascular migration of fibrosarcoma HT1080 cells.

METHODSAn in vitro model of fibrosarcoma cell transmigration across a monolayer of HUVEC cultured on collagen gel was applied to observe extravascular migration of HT1080 cells,and were the electrical resistance of HUVEC monolayer and endothelial MLC phosphorylation in extravascular migration of HT1080 cells.

RESULTHT1080 cells migrated through endothelial cells into collagen gel, the electrical resistance of a HUVEC monolayer was reduced and endothelial MLC phosphorylation was enhanced in extravascular migration of fibrosarcoma cells. Endothelial MLCK inhibitor (ML-7) blocked extravascular migration of HT1080 cells and inhibited reduction of electrical resistance of a HUVEC monolayer and enhancement of endothelial MLC phosphorylation in extravascular migration of HT1080 cells in a dose-dependent manner.

CONCLUSIONEndothelial MLCK regulates fibrosarcoma cell transendothelial migration through MLC phosphorylation, leading to cytoskeletal reorganization and endothelial cell constriction, then fibrosarcoma cells migrate into extravascular tissue through the gaps between endothelial cells.

Cell Line, Tumor ; Cell Movement ; drug effects ; Endothelial Cells ; cytology ; enzymology ; Fibrosarcoma ; pathology ; physiopathology ; Humans ; Myosin-Light-Chain Kinase ; metabolism ; physiology ; Neoplasm Invasiveness ; Umbilical Veins ; cytology

OBJECTIVEThis study aimed at investigating whether notoginsenoside R1 (R1), a unique saponin found in Panax notoginseng could promote angiogenic activity on human umbilical vein endothelial cells (HUVECs) and elucidate their potential molecular mechanisms. In addition, vascular restorative activities of R1 was assessed in a chemically-induced blood vessel loss model in zebrafish.

METHODSThe in vitro angiogenic effect of R1 was compared with other previously reported angiogenic saponins Rg1 and Re. The HUVECs proliferation in the presence of R1 was determined by cell proliferation kit II (XTT) assay. R1, Rg1 and Re-induced HUVECs invasion across polycarbonate membrane was stained with Hoechst-33342 and quantified microscopically. Tube formation assay using matrigelcoated wells was performed to evaluate the pro-angiogenic actions of R1. In order to understand the mechanism underlying the pro-angiogenic effect, various pathway inhibitors such as SU5416, wortmannin (wort) or L-Nω-nitro- L-arginine methyl ester hydrochloride (L-NAME), SH-6 were used to probe the possible involvement of signaling pathway in the R1 mediated HUVECs proliferation. In in vivo assays, zebrafish embryos at 21 hpf were pre-treated with vascular endothelial growth factor (VEGF) receptor kinase inhibitor II (VRI) for 3 h only and subsequently post-treated with R1 for 48 h, respectively. The intersegmental vessels (ISVs) in zebrafish were assessed for the restorative effect of R1 on defective blood vessels.

RESULTSR1 could stimulate the proliferation of HUVECs. In the chemoinvasion assay, R1 significantly increased the number of cross-membrane HUVECs. In addition, R1 markedly enhanced the tube formation ability of HUVECs. The proliferative effects of these saponins on HUVECs were effectively blocked by the addition of SU5416 (a VEGF-KDR/Flk-1 inhibitor). Similarly, pre-treatment with wort [a phosphatidylinositol 3-kinase (PI3K)-kinase inhibitor], L-NAME [an endothelial nitric oxide synthase (eNOS) inhibitor] or SH-6 (an Akt pathway inhibitor) significantly abrogated the R1 induced proliferation of HUVECs. In chemicallyinduced blood vessel loss model in zebrafish, R1 significantly rescue the damaged ISVs.

CONCLUSIONR1, similar to Rg1 and Re, had been showed pro-angiogenic action, possibly via the activation of the VEGF-KDR/Flk-1 and PI3K-Akt-eNOS signaling pathways. Our findings also shed light on intriguing pro-angiogenic effect of R1 under deficient angiogenesis condition in a pharmacologic-induced blood vessels loss model in zebrafish. The present study in vivo and in vitro provided scientific evidence to explain the ethnomedical use of Panax notoginseng in the treatment of cardiovascular diseases, traumatic injuries and wound healing.

Animals ; Blood Vessels ; pathology ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Collagen ; pharmacology ; Disease Models, Animal ; Drug Combinations ; Ginsenosides ; chemistry ; pharmacology ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; enzymology ; physiology ; Humans ; Laminin ; pharmacology ; Neovascularization, Physiologic ; drug effects ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein Kinase Inhibitors ; pharmacology ; Proteoglycans ; pharmacology ; Proto-Oncogene Proteins c-akt ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism ; Zebrafish

Angiogenesis is critical and indispensable for tumor progression. Since VEGF is known to play a central role in angiogenesis, the disruption of VEGF-VEGF receptor system is a promising target for anti-cancer therapy. Previously, we reported that a hexapeptide (RRKRRR, RK6) blocked the growth and metastasis of tumor by inhibiting VEGF binding to its receptors. In addition, dRK6, the D-form derivative of RK6, retained its biological activity with improved serum stability. In the present study, we developed a serum-stable branched dimeric peptide (MAP2-dRK6) with enhanced anti-VEGF and anti-tumor activity. MAP2-dRK6 is more effective than dRK6 in many respects: inhibition of VEGF binding to its receptors, VEGF- and tumor conditioned medium-induced proliferation and ERK signaling of endothelial cells, and VEGF-induced migration and tube formation of endothelial cells. Moreover, MAP2-dRK6 blocks in vivo growth of VEGF-secreting colorectal cancer cells by the suppression of angiogenesis and the subsequent induction of tumor cell apoptosis. Our observations suggest that MAP2-dRK6 can be a prospective therapeutic molecule or lead compound for the development of drugs for various VEGF-related angiogenic diseases.
Amino Acid Sequence ; Angiogenesis Inhibitors/*pharmacology ; Animals ; Cell Movement/drug effects ; Cell Proliferation/drug effects ; Colorectal Neoplasms/*pathology/secretion ; Endothelial Cells/cytology/drug effects/enzymology ; Enzyme Activation/drug effects ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Humans ; Mice ; Mice, Nude ; Molecular Sequence Data ; Neovascularization, Pathologic/pathology/prevention & control ; Neovascularization, Physiologic/drug effects ; Peptides/chemistry/*pharmacology ; Protein Multimerization/*drug effects ; Protein Stability/drug effects ; Rats ; Serum ; Vascular Endothelial Growth Factor A/*antagonists & inhibitors/secretion

OBJECTIVETo investigate the effects and regulatory mechanism of ILK on angiogenesis in hypertrophic scar.

METHODSThe human scar microvascular endothelial cells (HSMECs) were isolated from 6 patients' hypertrophic scar in vitro. The HSMECs with good condition in 2nd to 4th generation were selected as experimental objectives. (1) HSMECs were divided into the blank control group (treated with routine culture), negative control group (treated with only Lipofectamine 2000), LY294002 group (incubated with 50 nmol/L LY294002), ILK siRNA group (incubated with 20 nmol/L ILK siRNA). RT-PCR and Western Blot were used to detect the expression of ILK mRNA and its protein after transfecion for 48 h. (2) The digested HSMECs of four groups were resuspended with DMEM without serum and then seeded onto the upper compartment of transwell insert which contained complete medium in its lower compartment. The cell migration experiment was stopped in 10 h and then the migrated cells were counted to analyze the effects of different interventions on the migration ability of HSMECs. (3) The thawed ECMatrix was put into each well of pre-colled 48-well tissue culture plate, and then the plate was put into the incubator at 37 degrees C to make it to become gel. The HSMECs of four groups were seeded onto the surface of the ECMatrix gel and were put into incubator. Eight random view-fields per well should be valued by the sheet of pattern recognition about angiogenesis after 8 hours to evaluate the ability of angiogenesis in vitro between four groups.

RESULTS(1) The expression of ILK mRNA (ILK mRNA = 0.829 +/- 0.109, t = 13.151, P = 0.006) and protein (ILK protein = 0.096 +/- 0.049, t = 36.656, P = 0.000) were both inhibited obviously in ILK siRNA group compared with the blank control group (ILK mRNA = 0.829 +/- 0.109, ILK protein = 1). And, the expression of ILK in LY294002 group was slightly lower than that of black control group, but there was no statistical difference. (2) The number of migrated cells in ILK siRNA group (88.111 +/- 3.079) and LY294002 group (138. 667 +/- 2.404) were respectively lower than that in blank control group (322.333 +/- 3.712, P < 0. 05) in 10th hour. (3) Compared to blank control group (4.333 +/- 0.191), the ability of angiogenesis in vitro decreased significantly ILK siRNA group (2.625 +/- 0.125) and LY294002 group (3.125 +/- 0.250), in which, the vascular network structures were not formed perfectly in 8th hour (P < 0.05).

CONCLUSIONSThe ability of HSMECs' migration and angiogenesis in vitro are inhibited significantly when the expression of ILK is down-regulated. It reveals that ILK may play an role in the regulation of scar angiogenesis.

Cell Movement ; Cell Proliferation ; Chromones ; pharmacology ; Cicatrix, Hypertrophic ; enzymology ; pathology ; Endothelial Cells ; cytology ; drug effects ; Humans ; Lipids ; pharmacology ; Morpholines ; pharmacology ; Neovascularization, Pathologic ; etiology ; pathology ; Protein-Serine-Threonine Kinases ; genetics ; physiology ; RNA, Messenger ; analysis ; RNA, Small Interfering ; metabolism

OBJECTIVETo investigate the killing effect of herpes simplex virus thymidine kinase gene expression actuated by the promoter of the vascular endothelial growth factor gene on human hepatocellular tumor cells under hypoxic condition.

METHODSRecombinant adenoviral vectors, AdVEGF-tk and AdVEGF-GFP, were constructed with HSV-tk or GFP under the control of VEGF promoter through AdEasy system. Then GFP expression in hepatoma cell line HepG2 and normal liver cell line L02 transfected with AdVEGF-GFP were observed under fluorescence microscope, and the sensitivity to GCV of the AdVEGF-tk-transfected cells under normoxia or hypoxia condition were monitored by MTT method.

RESULTSGFP expression actuated by VEGF promoter was detected in sporadic L02 cells, but in almost all HepG2 cells after transfected with AdVEGF-GFP. With GCV at 10 micro g/ml and MOI at 100, L02 cells were insensitive to GCV under oxic condition, but more than 70% L02 cells were killed under hypoxic condition. Moreover, HepG2 cells infected with AdVEGF-tk showed the increased GCV sensitivity under hypoxia (over 80% killed) as compared with normoxia (over 60% killed) conditions.

CONCLUSIONHypoxia enhances the GCV sensitivity of human hepatocellular tumor cells infected with recombinant AdVEGF-tk under the control of VEGF promoter.

Adenoviridae ; genetics ; Carcinoma, Hepatocellular ; pathology ; Endothelial Growth Factors ; genetics ; Gene Expression ; drug effects ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; Humans ; Hypoxia ; Intercellular Signaling Peptides and Proteins ; genetics ; Liver Neoplasms ; pathology ; Lymphokines ; genetics ; Oxygen ; pharmacology ; Promoter Regions, Genetic ; physiology ; Simplexvirus ; enzymology ; Thymidine Kinase ; genetics ; metabolism ; Tumor Cells, Cultured ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

Axl encodes the tyrosine-protein kinase receptor, participating in the proliferation and migration of many cells. This study examined the role of Axl in functions of endothelial progenitor cells (EPCs). Axl was detected by RT-PCR and Western blotting in both placentas and EPCs from normal pregnancy and preeclampsia patients. The Axl inhibitor, BMS777-607, was used to inhibit the Axl signalling pathway in EPCs. Cell proliferation, differentiation, migration and adhesion were measured by CCK-8 assay, cell differentiation assay, Transwell assay, and cell adhesion assay, respectively. Results showed the expression levels of Axl mRNA and protein were significantly higher in both placentas and EPCs from preeclampsia patients than from normal pregnancy (P<0.05). After treatment with BMS777-607, proliferation, differentiation, migration and adhesion capability of EPCs were all significantly decreased. Our study suggests Axl may play a role in the function of EPCs, thereby involving in the pathogenesis of preeclampsia.
Adult ; Aminopyridines ; pharmacology ; Blood Pressure ; Case-Control Studies ; Cell Adhesion ; drug effects ; Cell Differentiation ; drug effects ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Female ; Fetal Blood ; cytology ; enzymology ; Gene Expression Regulation ; Gestational Age ; Human Umbilical Vein Endothelial Cells ; drug effects ; enzymology ; pathology ; Humans ; Placenta ; metabolism ; physiopathology ; Pre-Eclampsia ; blood ; genetics ; physiopathology ; Pregnancy ; Primary Cell Culture ; Protein Kinase Inhibitors ; pharmacology ; Proto-Oncogene Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Pyridones ; pharmacology ; RNA, Messenger ; antagonists & inhibitors ; genetics ; metabolism ; Receptor Protein-Tyrosine Kinases ; antagonists & inhibitors ; genetics ; metabolism ; Stem Cells ; drug effects ; enzymology ; pathology

OBJECTIVETo test whether tanshinone II A (Tan II A), a highly valued herb derivative to treat vascular diseases in Chinese medicine, could protect endothelial cells from bacterial endotoxin (lipopolysaccharides, LPS)-induced endothelial injury.

METHODSEndothelial cell injury was induced by treating human umbilical vein endothelial cells (HUVECs) with 0.2 μg/mL LPS for 24 h. Y27632 and valsartan were used as positive controls. The effects of tanshinone II A on the LPS-induced cell viability and apoptosis rate of HUVECs were tested by flow cytometry, cell migration by transwell, adhesion by a 96-well plate pre-coated with vitronectin and cytoskeleton reorganization by immunofluorescence assay. Rho/Rho kinase (ROCK) pathway-associated gene and protein expression were examined by microarray assay; quantitative real-time polymerase chain reaction and Western blotting were used to confirm the changes observed by microarray.

RESULTSTan II A improved cell viability, suppressed apoptosis and protected cells from LPS-induced reductions in cell migration and adhesion at a comparable magnitude to that of Y27632 and valsartan. Tan II A, Y27632 and valsartan also normalized LPS-induced actomyosin contraction and vinculin protein aggregation. A microarray assay revealed increased levels of fibronectin, integrin A5 (ITG A5), Ras homolog gene family member A (RhoA), myosin light chain phosphatase, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K, or PIP2 in Western blotting), focal adhesion kinase, vascular endothelial growth factor and vascular endothelial growth factor receptor 2 in the damaged HUVECs, which were attenuated to different degrees by Tan II A, Y27632 and valsartan.

CONCLUSIONTan II A exerted a strong protective effect on HUVECs, and the mechanism was caused, at least in part, by a blockade in the Rho/ROCK pathway, presumably through the down-regulation of ITG A5.

Apoptosis ; drug effects ; Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Cytoprotection ; drug effects ; Cytoskeleton ; drug effects ; metabolism ; Diterpenes, Abietane ; chemistry ; pharmacology ; Down-Regulation ; drug effects ; genetics ; Human Umbilical Vein Endothelial Cells ; drug effects ; enzymology ; pathology ; Humans ; Integrin alphaV ; metabolism ; Lipopolysaccharides ; Myosin Light Chains ; metabolism ; Oligonucleotide Array Sequence Analysis ; Phosphatidylinositol 4,5-Diphosphate ; metabolism ; Protective Agents ; pharmacology ; Signal Transduction ; drug effects ; Up-Regulation ; drug effects ; genetics ; Vinculin ; metabolism ; rho GTP-Binding Proteins ; metabolism ; rho-Associated Kinases ; metabolism

BACKGROUND/AIMS: We examined the effects of cilostazol on mitogen-activated protein kinase (MAPK) activity and its relationship with cilostazol-mediated protection against apoptosis in lipopolysaccharide (LPS)-treated endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were exposed to LPS and cilostazol with and without specific inhibitors of MAPKs; changes in MAPK activity in association with cell viability and apoptotic signaling were investigated. RESULTS: Cilostazol protected HUVECs against LPS-induced apoptosis by suppressing the mitochondrial permeability transition, cytosolic release of cytochrome c, and subsequent activation of caspases, stimulating extracellullar signal-regulated kinase (ERK1/2) and p38 MAPK signaling, and increasing phosphorylated cAMPresponsive element-binding protein (CREB) and Bcl-2 expression, while suppressing Bax expression. These cilostazol-mediated cellular events were effectively blocked by MAPK/ERK kinase (MEK1/2) and p38 MAPK inhibitors. CONCLUSIONS: Cilostazol protects HUVECs against LPS-induced apoptosis by suppressing mitochondriadependent apoptotic signaling. Activation of ERK1/2 and p38 MAPKs, and subsequent stimulation of CREB phosphorylation and Bcl-2 expression, may be responsible for the cellular signaling mechanism of cilostazolmediated protection.
Apoptosis/*drug effects ; Caspases/metabolism ; Cell Line ; Cell Survival/drug effects ; Cyclic AMP Response Element-Binding Protein/metabolism ; Cytochromes c/metabolism ; Dose-Response Relationship, Drug ; Endothelial Cells/*drug effects/enzymology/pathology ; Humans ; Lipopolysaccharides/*toxicity ; Mitochondrial Membrane Transport Proteins/drug effects/metabolism ; Mitogen-Activated Protein Kinase 1/antagonists & inhibitors/*metabolism ; Mitogen-Activated Protein Kinase 3/antagonists & inhibitors/*metabolism ; Phosphodiesterase Inhibitors/*pharmacology ; Phosphorylation ; Protein Kinase Inhibitors/pharmacology ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Signal Transduction/*drug effects ; Tetrazoles/*pharmacology ; Time Factors ; bcl-2-Associated X Protein/metabolism ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/*metabolism