Vascular endothelial growth factor expression in superficial transitional cell bladder carcinoma

AIM:To study the expression of the VEGF in single and multiple superficial transitional cell bladder carcinoma and their clinical significance.METHODS:Immunohistochemical method was used to study the VEGF in 60 cases of superficial transitional cell bladder carcinoma and in 10 cases of normal bladder tissue as control. RESULTS:High expression of VEGF in bladder carcinoma cell was observed. The expression level of VEGF in multiple superficial transitional cell bladder carcinoma was higher than that in single superficial transitional cell bladder carcinoma. The recurrent rate in the patient with VEGF high expression was more than that in the patient with VEGF low expression. CONCLUSION:The expression level of VEGF was correlated to the biological behavior of superficial transitional cell bladder carcinoma.     

Microvessel density and expression of vascular endothelial growth factor in glomeruli of diabetic mice

AIM: To investigate the relationship between microvessel density (MVD) and expression of vascular endothelial growth factor (VEGF) in glomeruli of diabetic mice. METHODS: Streptozotocin-induced diabetic mice as well as the control mice were involved in this study for 6 weeks. The body weight and blood glucose level of the mice in each group were weekly measured at certain time point. The morphological changes of the kidney were observed under light microscope, and the diameter, perimeter and area of the glomeruli were detected by an image analysis system. The expression of CD34 and VEGF in glomeruli was examined by immunohistochemistry method, and MVD and VEGF index were also calculated. RESULTS: In comparison with the control mice, the blood glucose level was significantly increased,and the body weight was decreased in diabetic mice(P<0.01). The diameter, perimeter and area of glomeruli in diabetic mice were significant greater than those in control mice (P<0.05). Increased expression of CD34 and VEGF in the glomeruli of diabetic mice was observed. Glomerular MVD of diabetic mice was significantly higher than that of the controls (P<0.01), and was positively correlated with the VEGF index (r=0.9979, P<0.05). CONCLUSION: VEGF may promote the angiogenesis in glomeruli of diabetic mice. The increase in VEGF expression may play a role in the pathogenesis of diabetic nephropathy.     

Change of serum vascular endothelial growth factor level in patients with bladder transitional cell carcinoma

AIM:To investigate serum vascular endothelial growth factor (VEGF) level in patients with bladder transitional cell carcinoma(BTCC) and its clinical significance.METHODS:ELISA method was used to examine the serum VEGF level in 42 cases of bladder transitional cell carcinoma and in 10 cases of normal people as control. The change of VEGF in blood of the pre-operation and post-operation patients with BTCC was also compared.RESULTS:The VEGF level in blood of the patients was higher than that of the normal people, in spite of pre-operation, post-chemotherapy, and post-operation, but VEGF level decreased obviously after chemotherapy or operation. In addition, the plasma VEGF level was related to the grade and invasion of tumor.CONCLUSION:Detecting serum VEGF level can help us to assess the change of tumor and therapeutic effect.     

miR-126 regulates expression of vascular endothelial growth factor in EA.hy926 cells

AIM：To explore the effects of miR-126 on the expression of vascular endothelial growth factor (VEGF) in vascular endothelial cell line EA.hy926. METHODS：EA.hy926 cells were cultured in vitro and transfected with miR-126 mimics or miR-126 inhibitor by cation-mediated transfection method. The total RNA was extracted from the culture cells 36 h after transfection of miR-126 mimics or miR-126 inhibitor. The expression of VEGF at mRNA and protein levels was detected by real-time PCR and Western blotting. RESULTS：Thirty-six hours after transfection of miR-126 inhibitor at concentration of 50 nmol/L, the expression of VEGF at mRNA and protein levels increased significantly as compared with the negative control (P<001). However, transfection of miR-126 mimics at concentration of 50 nmol/L for 36 h significantly decreased the expression of VEGF at mRNA and protein levels as compared with the negative control. CONCLUSION：miR-126 inhibits the expression of VEGF. VEGF may be one of the target genes regulated by miR-126.     

Curcumin inhibits HGF induced vascular endothelial cell migration and VEGF expression in vitro and in vivo

ATM: To explore the molecular mechanism that curcumin inhibits hepatocyte growth factor (HGF) induced angiogenesis. METHODS: The effects of curcumin, c-Met inhibitor SU11274, phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and mTOR inhibitor rapamycin on HGF-induced endothelial cell migration, tubule formation ability, vascular endothelial growth factor (VEGF) expression, related signaling pathways and the density of blood vessels in tumors were observed by the methods of capillary forming experiments, wound healing assay, Western blot and animal study. RESULTS: SU11274, LY294002, rapamycin and curcumin significantly inhibited HGF induced endothelial cell migration, tubule formation and VEGF expression, suppressed the phosphorylation of c-Met/AKT/mTOR/S6 pathway related molecules, reduced VEGF expression and microvascular density in the tumors. CONCLUSION: Curcumin inhibits HGF induced angiogenesis by inhibiting c-Met/AKT/mTOR/S6 pathway activation.     

Structure,function and signal transduction of vascular endothelial growth factor receptor-2

Angiogenesis, or the formation of new blood vessels out of pre-existing capillaries, is very important in many physiologic and pathologic processes, such as embryonic development, cancer, retinopathies, etc. Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a key role in angiogenesis. In this review, we discussed the structure, function and signal transduction of vascular endothelial growth factor receptor-2. Understanding these should provide important insights into how new strategies can be devised to interfere in the physiologic and pathologic processes involved in angiogensis.     

Mechanism of vascular endothelial growth factor in diabetic rat retinopathy

AIM: To study the molecular mechanism of vascular endothelial growth factor (VEGF) in pathogenesis of diabetes in rats. METHODS: The diabetic rat model was established by using streptozocin. The animals were divided into normal control (C group), diabetic for one month (M₁ group), for three months (M₃ group) and for five months (M₅ group). In situ hybridization and immunohistochemistry were conduced to observe the expression of VEGF on retinal digest preparation and paraffin section. RESULTS: 1. On paraffin section: the positive rate of VEGF expression in M₅ group was 67% by in situ hybridization and 89% by immunohistochemistry. There was only 34% positive expression of VEGF in M₃ group by immunohistochemistry. 2. On retinal digest preparation: the VEGF positive expression rate in M₅ group was 34% by in situ hybridization and 56% by immunohistochemistry. CONCLUSION: Both endothelial cells and Mural cells and Müller cells express VEGF. The source of VEGF may be from the paracrine pathway in early stage of diabetic retinopathy.     

Effects of inhibition of Cripto gene siRNA on vascular endothelial growth factor of colon cancer cell line LS-174T

AIM:To study the effects of Cripto gene on vascular endothelial growth factor (VEGF) of colon carcinoma cells.METHODS:Cripto siRNA was designed and constructed. Colon cancer LS-174T cells were divided into 4 groups: control group and different dose (3.125, 6.25 and 12.5 nmol/L) of siRNA groups. After transfected for 24, 48 and 72 h, colon cancer cells were harvested to carry on the next tests. Expression of Cripto mRNA was determined with real-time PCR, and immunofluorescence isothiocyanate (FITC) labeling assay and Northern blotting were performed to examine the expression of protein and mRNA of VEGF, respectively. The cells in control group and cells transfected with 12.5 nmol/L siRNA were inoculated into nude mice respectively. 30 days after inoculated, the mice of two groups were executed, and immunohistochemical (ICH) assay was used to evaluate the VEGF protein of mice tumor. RESULTS:siRNA down-regulated the Cripto mRNA in a dose and time dependent manner. Protein and mRNA of VEGF in transfected cells reduced in a dose and time dependent manner. Compared to control, the expression of VEGF protein from ICH assay was lowered significantly (P<0.05).CONCLUSION:Cripto gene might contribute to the regulation of angiogenesis of colon carcinoma. The down-regulation of Cripto gene by siRNA can suppress angiogenesis of human colon cancer.     

Relationship between 936C/T polymorphism in 3’-untranslated region of vascular endothelial growth factor gene and diabetic retinopathy in China

AIM: To study the distribution of 936C/T polymorphism in 3’- untranslated region of vascular endothelial growth factor (VEGF) gene in Chinese Han population and to analyze the relationship between the polymorphism and diabetic retinopathy (DR). METHODS: Two hundred and fifty-four patients with type 2 diabetes mellitus recruited in this study were divided into NPDR group (non-proliferative diabetic retinopathy), PDR group (proliferative diabetic retinopathy) and DM (diabetes without retinopathy) group. The normal control group consisted of 120 subjects. Genotypes were identified by PCR-RFLP among all the subjects, while other clinical parameters were measured. Serum levels of VEGF were tested by the method of ELISA. RESULTS: The frequencies of both genotype CC and allele C were significantly higher in NPDR group and PDR group than those in NC group (²=9.934, ²=4.899, P<0.05 and ²=10.895, ²=5.714, P<0.05) and DM group (²=7.490, ²=4.448, P<0.05 and ²=8.333, ²=5.227, P<0.05). However, the frequencies of genotype (TT+CT) and allele T were significantly lower in NPDR group and PDR group than those in NC group (²=9.934, ²=10.895, P<0.01 and ²=4.899, ²=5.714, P<0.05) and DM group (²=7.490, ²=8.333, P<0.01 and ²=4.448, ²=5.227, P<0.05). Multivariate logistic regression analysis showed that the levels of glycohemoglobin(HbA1c), total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C) and plasma VEGF presented a positive correlation with DR, respectively, and the 936C/T mutation of VEGF exhibited a negative correlation with DR (β=-1.027, OR=0.343, P<0.01, CI: 0.157-0.723). CONCLUSION: Allele 936C of VEGF may be a genetic marker susceptible to DR, while allele 936T may be a protective genetic marker of DR. The 936C/T mutation of VEGF may be a protective factor against DR.     

Effects of cellular repressor of E1A-stimulated genes on VEGF release and monolayer permeability of human vascular endothelial cells

AIM: To study the effects and mechanism of cellular repressor of E1A-stimulated genes (CREG) on VEGF release and monolayer permeability of human vascular endothelial cells (ECs). METHODS: The monolayer permeability of ECs was measured by transwell chamber model. The expression and localization of F-actin and VE-cadherin were examined by immunofluroscence using Olympus IX-70 fluorescent microscope. Enzyme-linked immunosorbent assay (ELISA) were performed to determine the concentration of vascular endothelial growth factors(VEGF) in the culture medium. VEGF neutrilization antibody was used to block the expression of VEGF in the cells. RESULTS: The monolayer permeability of CREG over-expressing ECs (EO group) was significantly higher than that of the normal control ECs (EN group, P<0.05). The monolayer permeability of CREG suppressing ECs (ES group) was lower than that in EN group (P<0.05). F-actin cytoskeleton in EO group showed disorganized, polymerized and bundled obviously to form large quantity of stress fibers in the central portion of the cells, whereas F-actin in EO group was mainly observed in the peripheral portion of the cells and only small amounts in the central portion of the cells. A widespread gap formation and a loss of VE-cadherin staining at the periphery were found in the cells of EO group. Inversely, the cells in ES group showed the localization of VE-cadherin at the cell-cell contacts tightly and the formation of zipper-like structures. Compared with EN group, the secretion of VEGF in the cell culture supernatants increased in EO group, but decreased in ES group (P<0.05). Furthermore, the changes of ECs permeability, cytoskeleton reorganization and loss of VE-cadherin induced by CREG were abolished by the addition of anti-VEGF neutralizing antibody. CONCLUSION: CREG over-expression increases the monolayer permeability of ECs, induces the cytoskeleton reorganization and reduces VE-cadherin expression by enhancing the secretion of VEGF in vitro.     

Expression and significance of stanniocalcin 2 in diabetic retinopathy

AIM To investigate the expression level of stanniocalcin 2 (STC2) in vitreous tissues of rats with diabetic retinopathy (DR), and to explore the relationship between STC2 and vascular endothelial growth factor (VEGF). METHODS Wistar rats were randomly divided into control group and DR group. The DR model was constructed by injection of streptozotocin. RT-qPCR, Western blot and ELISA were used to detect the expression levels of STC2 and VEGF in rat vitreous tissues. Rat retinal ganglion cells were treated with VEGFA, and the expression of STC2 was detected by RT-qPCR, Western blot and ELISA. The retinal ganglion cells were also treated with STC2 protein, and then the expression of VEGF was detected by RT-qPCR, Western blot and ELISA. Co-immunoprecipitation was used to detect the interaction between VEGF and STC2. RESULTS Compared with control group, the mRNA and protein levels of STC2 were significantly increased in vitreous tissues of the rats with DR, and the expression level of VEGF was also significantly increased in DR group (P<0.01). The expression level of STC2 was positively correlated with VEGF expression. VEGF induced the expression of STC2 in rat retinal ganglion cells and promoted its secretion. STC2 protein induced the expression and secretion of VEGF in rat retinal ganglion cells, and VEGF had certain interaction with STC2. CONCLUSION STC2 expression is significantly increased in vitreous tissues of the rats with DR, and is closely related to VEGF.     

Effects of conditioned medium of ADSCs transfected with VEGF on dermal fibroblasts and umbilical vein endothelial cells in vitro

AIM: To investigate the influence of conditioned medium (CM) of human adipose-derived stem cells (HADSCs) transfected with vascular endothelial growth factor (VEGF) gene on human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs) in vitro.METHODS: The HADSCs, HDFs and HUVECs were prepared and identified. The HADSCs were transfected with lentivirus carrying VEGF165 gene and the CM was collected regularly. ELISA method was used to detect the growth factor secretion in the CM. The VEGF-CM mixed with complete medium were divided into 5 groups for culturing with HDFs or HUVECs. The cell viability was measured by CCK-8 assay. The optimal ratio of VEGF-CM, normal CM (Nor-CM) and complete medium were applied to HDFs or HUVECs. The migration ability was detected by wound-healing assay. RESULTS: The results of ELISA showed that the expression levels of VEGF and basic fibroblast growth factor (bFGF) in VEGF-CM group were higher those in Nor-CM group (P<0.05). Compared with other groups, the cell viability and migration abilities of HDFs and HUVECs were obviously enhanced in VEGF-CM group (P<0.05). CONCLUSION: The HADSCs transfected with VEGF165 gene greatly enhances the expression of VEGF and bFGF. The CM of HADSCs promotes the viability and migration abilities of HDFs and HUVECs in vitro.     

Expression of VEGF and bFGF in rat model of pressure ulcer

AIM:To study the effects of vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(bFGF) on the molecular pathogenesis of pressure ulcer.METHODS:SD rats were randomly divided into control group and experiment group. The pressure ulcer model was established by magnetic disk circulating compression method. HE staining was used to observe the pathological changes of the skin in the rats. The expression of VEGF and bFGF in the tissues was detected by immunohistochemical method. RESULTS:The expression of VEGF and bFGF in the tissues of rat Ⅲ-degree pressure ulcer was lower than that in the surrounding tissues and normal skin(P<0.01). The changes of VEGF and bFGF were consistent(κ=0.58). CONCLUSION:The expression levels of VEGF and bFGF are decreased in the tissues of rat pressure ulcer, suggesting that they may be the potential key factors in the difficult healing of pressure ulcer.     

Role of focal adhsion kinase in vascular endothelial cell migration

Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase (PTK) that can localize indirectly to sites of clustering integrin family of heterodimeric receptors. As an important structure and signaling molecule in the adhesive complexes, which are large and stable referred as 'focal adhesions’ or relatively small and transient within filopodia and lamellipodia named 'focal complexes’, FAK is closely related with cell death, proliferation and migration. In this review, we discuss the function of FAK in the regulation of endothelial cell migration based on current data.     

Protective effect of capsaicin on lipopolysaccharide-induced activation of vascular endothelial cells

AIM:To investigate the effect of capsaicin on lipopolysaccharide (LPS)-induced activation of cultured endothelial cells of mouse aorta in vitro. METHODS:The endothelial cells were isolated from mouse aorta and cultured in vitro, and the specific cell markers of the cells were identified by immunofluorescence staining. The cells were stimulated with LPS (100 μg/L) combined with or without capsaicin, and the cells and supernatant were collected at 12 h, 24 h and 48 h. The levels of soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1) and soluble P-selectin (sP-selectin) in the supernatant were measured by ELISA. The levels of nuclear NF-κB p65 and cytopasmic p-IκBα and IκBα were detected by Western blotting. RESULTS:Compared with control group, the levels of sP-selectin, sICAM-1 and sVCAM-1 in LPS group were significantly increased (P<0.05), and LPS promoted the expression of sICAM-1 and sVCAM-1 in a time-dependent manner. Compared with LPS group at the same time point, capsaicin inhibited the expression of sP-selectin, sICAM-1 and sVCAM-1 in a dose-dependent manner. Compared with control group, the protein levels of NF-κB p65 and p-IκBα in LPS group at 24 h were significantly increased (P<0.05), while the protein level of IκBα in LPS group at 24 h were significantly decreased (P<0.05). Compared with LPS group, capsaicin decreased the protein levels of NF-κB p65 and p-IκBα and increased the protein level of IκBα in a dose-dependent manner. CONCLUSION: Capsaicin has a protective effect on LPS-induced vascular endothelial cell activation, which potentially contributes to the suppression of IκBα degradation and NF-κB p65 nuclear translocation.     

Transforming growth factor α promotes the proliferation,migration and adhesion of human endothelial progenitor cells

AIM: To explore the effects of transforming growth factor-α (TGF-α) in the monoclonal formation, proliferation, migration and adhesiveness of human endothelial progenitor cells (EPCs). METHODS: The isolated and cultured EPCs were treated with various concentrations of TGF-α (final concentrations of 1, 5, 10 μg/L, respectively). At the same time, the PBS control and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) group (10 μg/L TGF-α plus 1: 1 000 EGFR-TKI) were set. The effects of TGF-α on monoclonal formation, proliferation, migration and adhesiveness of EPCs were determined by clone formation experiment, thiazolyl blue tetrazolium bromide (MTT), EdU, Transwell and adhesion assays, respectively. The expression of epithelial growth receptor (EGFR) and vascular endothelial growth factor (VEGF) were measured by Western blotting. RESULTS: Different concentrations of TGF-α all significantly induced the monoclonal formation, proliferation, migration and adhesiveness of EPCs (P<0.01), which were inhibited by EGFR-TKI. The results of Western blotting showed that TGF-α also induced the expression of EGFR and VEGF with a certain concentration effect (P<0.01). CONCLUSION: By combining with EGFR induced the expression of VEGF, TGF-α significantly promotes the related cell function of monoclonal formation, proliferation, migration, adhesiveness in EPCs.     

Plasma circulating miR-126 in patients with coronary artery heart disease and its effect on vascular endothelial cells

AIM: To investigate the role of plasma circulating miR-126 and miR-16 in the patients with coronary artery heart disease and to explore the influence of miR-126 on vascular endothelial cells. METHODS: Plasma total RNA was isolated from 52 patients with stable coronary artery disease and 52 healthy volunteers. The circulating miR-126 and miR-16 in those people were detected using specific primers. Endothelial cell line EA.hy926 was transfected with a miR -126 inhibitor, and total RNA of the cells was isolated 30 h after transfection to detect the expression level of vascular endothelial growth factor (VEGF). RESULTS: The expression of plasma circulating miR-126 was significantly decreased in the patients with coronary artery heart disease compared with healthy controls (P<0.05). No significant difference of circulating miR-16 between the patients with coronary artery heart disease and healthy controls was observed (P>0.05). The expression of VEGF in the endothelial cell line EA.hy926 transfected with miR-126 inhibitor was 2.08 times higher than that in negative control cells 30 h after transfection (P<0.05). CONCLUSION: Plasma circulating miR-126 is significantly decreased in the patients with coronary artery heart disease. Plasma circulating miR-16 in the patients with coronary artery heart disease and in the healthy controls is stable. miR-126 negatively regulates the expression of VEGF in vascular endothelial cells.