Cell migration plays an important role in repair of injury, angiogenesis, cancer metastasis and so on. In this paper the effects of basic fibroblast growth factor (bFGF) of different concentrations on ECV-304 cell migration, and the dynamic changes in focal adhesion kinase (FAK) were observed. The relationship between FAK and cell migration induced by bFGF was studied. A ECV-304 cell scratch wound model was established and the images of cell migration were quantitatively measured using a computer-assisted videomicroscopic system. The dynamic changes in FAK content (Western blot), FAK activity (immunoprecipitation plus Western blot) and FAK mRNA (RT-PCR) were measured in vitro. The expression of integrin alpha3 was investigated using immunocytochemical staining (ABC method). The results showed that bFGF produced a dual-phase regulatory effect on ECV-304 migration when the cell confluent areas reached 90%-95% in culture. It was found that compared with the control group (0 ng/ml bFGF), the cell migration was stimulated (P<0.05), inhibited (P<0.05) and unchanged when the cultured cells were treated with bFGF at the concentrations of 5, 10 and 15 ng/ml, respectively. The content and activity of FAK protein were markedly up-regulated in 5 ng/ml bFGF group and down-regulated in 15 ng/ml bFGF group, respectively. FAK mRNA expression came to the peak in 5 ng/ml bFGF group after 6 h culture and there was a significant difference compared with the control group. In various experimental groups there were no significant differences in the expression of integrin alpha3 compared with the control group according to the immunocytochemical staining. The results mentioned above suggest that different concentrations of bFGF have a dual-phase effect on the migration of cultured ECV-304 cells, which correlates positively with FAK content, activity and mRNA in cultured ECV-304 cell scratch wound model. The FAK plays an important role in the signal transduction pathway of cell migration induced by bFGF, while bFGF can regulate the content of FAK in ECV-304 cells at gene transcription level.
Cell Movement ; physiology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; Fibroblast Growth Factor 2 ; physiology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrin alpha3 ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; RNA, Messenger ; metabolism ; Umbilical Veins ; cytology

OBJECTIVETo investigate the role of cytoplasmic domain of integrin alpha IIb in platelet signal transduction.

METHODSBinding capacity of integrin alpha IIb(R995A) to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting.

RESULTSWithout activation, wild-type alpha IIb beta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha IIb(R995A)beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alpha IIb beta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions.

CONCLUSIONThe mutation in integrin alpha IIb(R995A) alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.

Animals ; Blood Platelets ; metabolism ; CHO Cells ; Cell Adhesion ; Cricetinae ; Cricetulus ; Cytoplasm ; metabolism ; Dual Specificity Phosphatase 2 ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Phosphorylation ; Platelet Glycoprotein GPIIb-IIIa Complex ; genetics ; metabolism ; physiology ; Point Mutation ; Protein Phosphatase 2 ; Protein Tyrosine Phosphatases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Signal Transduction ; Transfection

BACKGROUNDPulmonary artery smooth muscle cell (PASMC) proliferation plays an important role in pulmonary vessel structural remodelling. At present, the mechanisms related to proliferation of PASMCs are not clear. Focal adhesion kinase (FAK) is a widely expressed nonreceptor protein tyrosine kinase. Recent research indicates that FAK is implicated in signalling pathways which regulate cytoskeletal organization, adhesion, migration, survival and proliferation of cells. Furthermore, there are no reports about the role of FAK in human pulmonary artery smooth muscle cells (HPASMCs). We investigated whether FAK takes part in the intracellular signalling pathway involved in HPASMCs proliferation and apoptosis, by using antisense oligodeoxynucleotides (ODNs) to selectively suppress the expression of FAK protein.

METHODSCultured HPASMCs stimulated by fibronectin (40 microg/ml) were passively transfected with ODNs, sense FAK, mismatch sense and antisense-FAK respectively. Expression of FAK, Jun NH2-terminal kinase (JNK), cyclin-dependent kinase 2 (CDK 2) and caspase-3 proteins were detected by immunoprecipitation and Western blots. Cell cycle and cell apoptosis were analysed by flow cytometry. In addition, cytoplasmic FAK expression was detected by immunocytochemical staining.

RESULTSWhen compared with mismatch sense group, the protein expressions of FAK, JNK and CDK 2 in HPASMCs decreased in antisense-FAK ODNs group and increased in sense-FAK ODNs group significantly. Caspase-3 expression upregulated in HPASMCs when treated with antisense ODNs and downregulated when treated with sense ODNs. When compared with mismatch sense ODNs group, the proportion of cells at G1 phase decreased significantly in sense ODNs group, while the proportion of cells at S phase increased significantly. In contrast, compared with mismatch sense ODNs group, the proportion of cells at G1 phase was increased significantly in antisense-FAK ODNs group. The level of cell apoptosis in antisense-FAK group was higher than in the mismatch sense group and the latter was higher than sense-FAK group. In addition, the sense-FAK ODNs group was strongly stained by immunocytochemistry, whereas the antisense-FAK ODNs group was weakly stained.

CONCLUSIONSThe results suggest that FAK relates to the proliferation of HPASMCs. Antisense-FAK ODNs inhibit HPASMCs proliferation and facilitate their apoptosis. It is possible that FAK via JNK, CDK 2 signalling pathways enhances HPASMCs proliferation and via caspase-3 inhibits HPASMCs apoptosis.

Apoptosis ; CDC2-CDC28 Kinases ; analysis ; Caspase 3 ; Caspases ; analysis ; Cell Cycle ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cyclin-Dependent Kinase 2 ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Immunohistochemistry ; JNK Mitogen-Activated Protein Kinases ; analysis ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; physiology ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; Protein-Tyrosine Kinases ; analysis ; physiology ; Pulmonary Artery ; cytology

Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; Neoplasms ; Phosphorylation

Animals ; Colonic Neoplasms ; metabolism ; pathology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrins ; metabolism ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Protein-Tyrosine Kinases ; metabolism ; Rectal Neoplasms ; metabolism ; pathology ; Signal Transduction

OBJECTIVESTo investigate the effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on integrin signaling and apoptosis in fibronectin (FN) -stimulated hepatic stellate cells (HSCs).

METHODS3H-thymidine incorporation, annexin-V/propidium iodide double-labeled flow cytometry (FCM) and transmission electron microscopy were employed to estimate the influence of RGDS on the proliferation and apoptosis of HSCs. And the adhesion rates were observed by toluidine blue colorimetric assay. The expression of focal adhesion kinase (FAK) mRNA and protein in HSCs was detected using RT-PCR and western blotting analysis, respectively.

RESULTSRGDS tetrapeptide at the concentrations of 25 microg/ml, 50 microg/ml and 100 microg/ml inhibited the proliferation of HSCs and induced HSCs apoptosis in dose-dependent and time-dependent manners, with the apoptotic rates of 9.49%, 27.67%, 31.59%, and the necrotic rates of 3.47%, 5.38%, 9.10%, respectively. Both the rates were higher than those in FN group (apoptotic rate: 3.44%; necrotic rate: 2.39%), F=8.02, P<0.05. After adding RGDS tetrapeptide to HSCs for 2 hours, the adhesive inhibition rates were 8.82%, 29.41% and 45.59%, respectively, which were higher than that in FN group (F=20.58, P<0.01). After exposure of HSCs to RGDS tetrapeptide for 24 hours, FAK protein decreased, and FAK mRNA was down-regulated earlier, about 2 hours after exposure to RGDS tetrapeptide.

CONCLUSIONThese results suggest that RGDS tetrapeptide may induce apoptosis of HSC in both dose-dependent and time-dependent manners in vitro, which may be related to the disruption of cell matrix adhesion and down-regulation of FAK expression.

Apoptosis ; drug effects ; Fibronectins ; pharmacology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Hepatocytes ; cytology ; physiology ; Humans ; Integrins ; metabolism ; physiology ; Liver ; cytology ; physiology ; Oligopeptides ; pharmacology ; Platelet Aggregation Inhibitors ; pharmacology ; Protein-Tyrosine Kinases ; biosynthesis ; genetics ; metabolism ; Signal Transduction

Synaptic plasticity has been thought to be a mechanism of synaptic maturation, learning and memory. In this study, the possible involvement of Rac, RhoA, proline-rich tyrosine kinase 2 (PYK2) and focal adhesion kinase (FAK) in the synaptic plasticity was investigated using PC12 cells and rat brains. The followings are the results. 1. Depolarization induced extracellular signal-regulated kinase (ERK) activation but did not activate Rac and RhoA in PC12 cells. 2. ERK activation and c-fos expression were observed after electroconvulsive shock (ECS) but the activity of Rac and RhoA was not changed following ECS. 3. PYK2 not FAK activation was observed after ECS. 4. The activity of PYK2 was increased with postnatal development but that of FAK was decreased with ages. 5. The expression of Rac and PYK2 was clearly observed in the postsynaptic density but that of RhoA and FAK was not. These findings indicate that PYK2 seems to play an important role in activity-dependent synaptic plasticity in vivo brain.
Animals ; Brain ; Electroshock ; Focal Adhesion Kinase 2 ; Focal Adhesion Protein-Tyrosine Kinases ; GTP Phosphohydrolases* ; Learning ; Memory ; Nervous System* ; PC12 Cells ; Phosphotransferases ; Plastics ; Post-Synaptic Density ; Rats ; Signal Transduction*

OBJECTIVETo study the inhibitory effects of antisense focal adhesion kinase (FAK) oligodeoxynucleotides (ODN) on the invasion of Bel 7402 cells, and investigate the mechanisms.

METHODSLipofecTAMINE-mediated antisense FAK ODN was transfected into Bel 7402 cells. Cell number and viability were evaluated every 24 hours by trypan blue dye exclusion. Cell attachment assay was carried out at intended time points in a microculture well pre-coated with fibronectin (FN). The invasive activity of tumor cells was assayed in a transwell cell culture chamber. Cell cycle and cell apoptosis analysis were performed with flow cytometry (FCM).

RESULTSThe expression of p125FAK in the group treated with antisense FAK ODN (6.49%+/-0.10%) significantly decreased, compared with those in the group treated with sense FAK ODN (14.33%+/-1.88%) and control group (16.68%+/-1.62%), F=7.66, P<0.01. Antisense FAK ODN significantly inhibited the growth of Bel 7402 cells by 30%-60%, the attachment by 25%-55%, and the invasion, 15%-25%. The decreased expression of FAK in Bel 7402 cells caused a G2/M cell cycle arrest, and the cells at S phase decreased significantly. The occurrence of apoptosis detected by FCM increased significantly in the group treated with antisense FAK ODN.

CONCLUSIONSInhibition of FAK expression significantly decreases the attachment between ECM and Bel 7402 cells, and the ability of Bel 7402 cells to invade the reconstituted basement membrane. In addition, FAK suppression significantly inhibits the proliferation of Bel 7402 cells in vitro, and increases their apoptosis.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Adhesion ; Cell Division ; genetics ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Gene Expression Regulation, Enzymologic ; Gene Expression Regulation, Neoplastic ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Neoplasm Invasiveness ; Oligonucleotides, Antisense ; pharmacology ; Protein-Tyrosine Kinases ; pharmacology ; Transfection

OBJECTIVETo study the effects of focal adhesion kinase (FAK) phosphorylation on smooth muscle cells (SMCs) adhesion and migration stimulated by fibronectin.

METHODSAdhesion and migration of cultured SMCs were stimulated by different concentrations of fibronectin (FN), FAK and its phosphorylation were detected by immunoprecipitation and Western blot. FAK antisense oligodeoxynucleotides (ODNs) were transfected into SMCs by cationic lipid to investigate its modulatory effects on tyrosine phosphorylation. SMCs adhesion and migration were also measured by morphological enumeration and modified Boyden Chambers, respectively.

RESULTSFAK were expressed when SMCs adhesion and migration were successfully simulated by different concentrations of FN. FAK phosphorylation were detected only at 20 microg/ml FN or more. FAK antisense ODNs were transfected efficiently by cationic lipid and FAK phosphorylation was inhibited substantially. The SMCs migration rate in the 5 - 60 microg/ml FN groups was reduced by 17.89% - 27.67%. Cell migration stimulated by FN at 10, 20, 40 and 60 microg/ml were reduced by 23.26%, 21.63%, 19.31% and 17.88%, respectively (P < 0.05).

CONCLUSIONSFAK phosphorylation and FAK-mediated signal transduction play important roles in SMCs adhesion and migration stimulated by ECM. The process can be inhibited effectively by FAK antisense ODNs.

Animals ; Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Cells, Cultured ; DNA, Antisense ; genetics ; physiology ; Dose-Response Relationship, Drug ; Enzyme Activation ; drug effects ; Fibronectins ; pharmacology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Muscle, Smooth, Vascular ; cytology ; drug effects ; Phosphorylation ; drug effects ; Protein-Tyrosine Kinases ; genetics ; metabolism ; Rats ; Transfection

AIMTo study the effects of FAK-ERK1/2 signaling pathway and FAK antisense oligodeoxynucleotides (ODNs) on vascular smooth muscle cell (SMC) migration and adhesion stimulated by fibronectin (FN).

METHODSMigration and adhesion of cultured SMCs were stimulated by different concentrations of FN, FAK, ERK1/2. And their phosphorylation were detected by immunoprecipitation and Western blot. FAK antisense ODNs were transfected into SMCs by cationic lipid to investigate its modulatory effects on tyrosine phosphorylation, SMCs migration and adhesion were also measured by modifing Boyden Chamber and morphological enumeration, respectively.

RESULTSFAK were expressed when SMCs adhesion and migration were successfully simulated by FN (5, 10, 20, 40, 60 micrograms.mL-1), high contents of FAK and ERK1/2 phosphorylation were detected by 20 micrograms.mL-1 FN or more. FAK antisense ODNs were transfected efficiently by cationic lipid. FAK and ERK1/2 phosphorylation were inhibited magnificently after FAK antisense ODNs transfection. Cell migration stimulated by FN 10, 20, 40 and 60 micrograms.mL-1 were reduced by 23.26%, 21.63%, 19.31% and 17.88% respectively (P < 0.05). SMCs adhesive spreading in 5-60 micrograms.mL-1 FN groups were reduced by 17.89%-27.67% (P < 0.05).

CONCLUSIONFAK-ERK1/2 mediated signal transduction play important roles in SMCs migration and adhesion stimulated by extracellular matrix. The process can be inhibited by FAK antisense ODNs effectively.

Animals ; Aorta ; cytology ; Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Cells, Cultured ; Fibronectins ; pharmacology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Mitogen-Activated Protein Kinase 1 ; biosynthesis ; metabolism ; Mitogen-Activated Protein Kinase 3 ; Mitogen-Activated Protein Kinases ; biosynthesis ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; genetics ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Transfection