BACKGROUNDIschemic disease is one of the leading causes of death in the world. In order to further study gene therapy for ischemic disease, we constructed a recombinant plasmid for co-expression of human angiopoietin-1 and vascular endothelial growth factor 165(VEGF165) gene in adeno-associated virus (AAV) gene delivery system.

METHODSHuman angiopoietin 1 and VEGF165 gene were obtained using PCR. The upstream of angiopoietin 1 contained restriction enzyme site HindIII, and the downstream of angiopoietin 1 contained restriction enzyme site BamHI. The upstream of VEGF165 contained restriction enzyme site BglII, and the downstream of VEGF165 contained restriction enzyme site BamHI. Using the multiple cloning sites (MCS) in plasmid pZero++ such as BamHI, BglII, HindIII, NotI, XhoI, XbaI, SalI, BspHI, KspI and the corresponding MCS in plasmid pAAV-MCS, angiopoietin 1 and VEGF165 gene were subcloned into pAAV-MCS.

RESULTSDNA sequencing revealed that the PCR- amplified angiopoietin 1 and VEGF165 were consistent with NCBI Gene Bank. The recombinant plasmid was identified using PCR and digestion, which proved to be consistent with our hypothesis. In recombinant plasmid, angiopoietin1 and VEGF possessed a CMV promoter and polyA terminator system respectively, thus assuring co-expression of the two genes.

CONCLUSIONSuccessful construction of AAV co-expression system for human angiopoietin 1 and VEGF165 gene will provide the foundation for gene therapy to cure severe ischemic disease.

Angiopoietin-1 ; genetics ; Dependovirus ; genetics ; Genetic Therapy ; Genetic Vectors ; genetics ; Humans ; Plasmids ; Vascular Endothelial Growth Factor A ; genetics

OBJECTIVETo explore the effects of angiopoietins (Ang-1 and Ang-2) and Tie-2 expression on microvessel density (MVD) in gastric cancers.

METHODSBy using semiquantitative RT-PCR, immunohistochemistry and image analysis system, the expression of Ang-1, Ang-2, Tie-2 mRNA and their proteins were detected in 68 primary gastric cancers and their adjacent normal tissues. Microvessel density (MVD) was figured out based on CD34 immunohistochemical staining.

RESULTSThe expression of all Ang-1, Ang -2, Tie-2 mRNA and their proteins was detected in gastric cancers and their paired adjacent gastric mucosa tissues. A negative correlation between Ang-1 protein, Tie-2 mRNA and MVD in gastric cancers was observed (r = -0.440, r = -0.267; P < 0.05), while the relation between Ang-2 mRNA and its protein, Ang-2/Ang-1 protein ratio with MVD were positive (r = 0.319, r = 0.729, r = 0.739; P < 0.05). It was found that MVD in groups with Ang-2 mRNA T/N ratio over 1.2 (the ratio of Ang-2 mRNA in gastric cancers and its adjacent normal mucosa) was higher than that in those with a ratio under 1.2, revealed by analysing the effects of Ang-1 and Ang-2 mRNA T/N ratio on MVD in gastric cancers.

CONCLUSIONAng-1 activates Tie-2 receptor, whereas Ang-2 antagonizes Ang-1 in the angiogenesis, and the Ang-2/Ang-1 ratio determines angiogenesis and tumor growth in gastric cancers. When the expression of Ang-2 is high and Ang-1 is low, the angiogenesis in gastric cancers is promoted, otherwise oppositely. The role of Ang-2 is dominant in the effect of Angs and their receptor on angiogenesis in gastric cancers.

Angiopoietin-1 ; biosynthesis ; genetics ; Angiopoietin-2 ; biosynthesis ; genetics ; Female ; Humans ; Male ; Microcirculation ; pathology ; Middle Aged ; Neoplasm Staging ; Neovascularization, Pathologic ; etiology ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, TIE-2 ; biosynthesis ; genetics ; Stomach Neoplasms ; blood supply ; metabolism ; pathology

OBJECTIVETo construct recombinant adeno-associated virus (rAAV) vector containing angiopoietin-1 (ANG-1) gene and to express the ANG-1 in targeting cells.

METHODSANG-1 cDNA was obtained from human spleen by RT-PCR and was inserted into AAV vectors to form rAAV ANG-1, the virus stocks in high titer were harvested. The rAAVANG-1 and rAAV GFP were transferred into pig mesenchymal stem cells and the expression of ANG-1 was detected by Western blot.

RESULTSThe cloned ANG-1 cDNA was 1515bp in length which was in accordance with that reported previously. Titration of rAAVANG-1 stock was 9 X 10(11)v.g/ml. The expression of ANG-1 gene was detected in transfected cells. Forty-eight hours after rAAV GFP was transfected into mesenchymal stem cells, 55% cells expressed GFP.

CONCLUSIONThe constructed rAAV ANG-1 vector has successfully transfered and expressed in pig mesenchymal stem cells.

Angiopoietin-1 ; biosynthesis ; genetics ; Animals ; DNA, Complementary ; genetics ; Dependovirus ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Mesenchymal Stromal Cells ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; Transfection

OBJECTIVETo investigate the expression of angiopoietin (Ang)-1 and Ang-2 in colorectal tumors and its relations to microvessel density (MVD) in tumor tissue.

METHODSAng-1, Ang-2 and factor VIII-related antigen were stained immunohistochemically in 91 cases of primary colorectal adenocarcinoma, 20 cases of colorectal adenoma and 24 cases of normal colorectal mucosal tissue, and MVD was also assayed in above tissue specimens.

RESULT(1) A significantly higher Ang-1 (7.07+/-2.00) was observed in normal tissue compared with 1.75 +/-1.98 in the adenoma and 1.40 +/- 1.22 in the adenocarcinoma (P<0.01). (2) Ang-2 protein positive rate in adenocarcinoma was significantly higher than that in normal tissue and adenoma (P<0.01). The expression of Ang-2 in adenocarcinoma was closely associated with poor differentiation and vessel invasion. (3) There were significant correlations between Ang-1 and Ang-2 (r=-0.338, P<0.01), Ang-1 and MVD (r=-0.388, P<0.01), Ang-2 and MVD (r=0.594, P<0.01) in the 135 cases.

CONCLUSIONThe overexpression of Ang-2 may play an important role in angiogenesis of colorectal adenocarcinoma. It can be regarded as an index for malignancy and prognosis in colorectal adenocarcinoma.

Adenocarcinoma ; blood supply ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Angiopoietin-1 ; biosynthesis ; genetics ; Angiopoietin-2 ; biosynthesis ; genetics ; Biomarkers, Tumor ; Capillaries ; pathology ; Colorectal Neoplasms ; blood supply ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; von Willebrand Factor ; biosynthesis ; genetics

Angiogenesis, formation of new microvessels providing oxygen and nutrient supply, is essential for tumor growth. It is dependent on the production of angiogenic growth factors by tumor cells. Angiopoietin 1 (Ang-1) and 2 (Ang-2) and their common receptor, Tie2, are thought to be critical regulators of tumor angiogenesis. We examined expression of Ang-1, Ang-2, and their common receptor Tie2 mRNAs and proteins in gastric cancers using in situ hybridization and immunohistochemistry. We also investigated the relationship between their expression and differentiation of cancer cells, lymph node metastasis, tumor size, depth of cancer cell invasion, TNM staging and microvessel density (MVD). The expression of Ang-1, Ang-2, and Tie2 mRNA in cancer cells significantly correlated with the MVD (p<0.001, <0.001 and =0.019, respectively). Ang-1 and Tie2 positivity correlated with advanced gastric cancers (p<0.05) and larger cancers had higher positive rates of Ang-1, Ang-2, and Tie2 mRNA expression (p<0.001, =0.010 and =0.039, respectively). Significant positive correlations were also found between mRNA expression of Tie2 and those of Ang-1 and Ang-2 (p<0.01 and <0.001, respectively). These findings indicate that the expression of Ang-1 and Ang-2 is important for tumor angiogenesis, and suggest a possible role of autocrine/paracrine function of angiopoietin/Tie2 system in gastric cancer progression.
Stomach Neoplasms/blood supply/*genetics/*metabolism/pathology ; Receptor, TIE-2/*genetics/*metabolism ; RNA, Neoplasm/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Neovascularization, Pathologic ; Middle Aged ; Male ; In Situ Hybridization ; Immunohistochemistry ; Humans ; Gene Expression ; Female ; Carcinoma, Signet Ring Cell/blood supply/genetics/metabolism/pathology ; Angiopoietin-2/*genetics/*metabolism ; Angiopoietin-1/*genetics/*metabolism ; Aged ; Adult ; Adenocarcinoma/blood supply/genetics/metabolism/pathology

OBJECTIVETo study the effects of prolonged 85% oxygen exposure on lung vascular development and the expression of angiopoietin-1 (Ang-1) in the neonatal rat lungs.

METHODSNinety-six Sprague-Dawley rat pups were randomly exposed to air (control group) and 85% oxygen (experimental group) 6 hrs after birth. The rats were sacrificed 3, 7 and 14 days after exposure and their lungs were sampled. The lung sections were stained with hematoxylin and eosin for histological evaluation and analysis of vessel volume density. Expressions of angiopoietin-1 (Ang-1) in lung tissue were measured by immunohistochemistry. Expression of Ang-1 protein and mRNA was detected by Western Blot and Real time-PCR.

RESULTSAfter being exposed to 85% oxygen for 14 days, lung tissues had pathological changes as "new" bronchopulmonary dysplasia (BPD). The RAC on day 7 and day 14 in experimental group decreased significantly as compared with the control group [(10.55 ± 0.13) vs. (11.74 ± 0.19), (12.47 ± 0.05) vs. (15.03 ± 0.16), P < 0.05]. The X-ray showed that the diameter of lung vessel was much smaller and the vessels had less branches in experimental group compared with the control group on day 14. The vessel volume density on day 14 in experimental group decreased significantly as compared with the control group [(3.55 ± 0.09) vs. (6.03 ± 0.16), P < 0.05]. Immunohistochemistry and Western blotting showed that the expressions of Ang-1 protein on day 7 and day 14 in the experimental group decreased significantly as compared with the control group [(4.27 ± 0.34) vs. (3.10 ± 0.29), P < 0.05, (5.65 ± 0.49) vs. (3.21 ± 0.28), P < 0.01], [(0.88 ± 0.31) vs. (0.41 ± 0.12), P < 0.05, (0.90 ± 0.29) vs. (0.21 ± 0.06), P < 0.01]. The expressions of Ang-1 mRNA on day 7 and day 14 in the experimental group also decreased significantly as compared with the control group [(0.85 ± 0.14) vs. (0.44 ± 0.21), P < 0.05, (0.87 ± 0.24) vs. (0.24 ± 0.05), P < 0.01].

CONCLUSIONSProlonged exposure of high concentration of oxygen may cause impairment of lung vascular development by inhibiting expression of Ang-1 in neonatal rats, which is likely to contribute to pathogenesis of BPD.

Angiopoietin-1 ; metabolism ; Animals ; Animals, Newborn ; Hyperoxia ; Lung ; blood supply ; metabolism ; Pulmonary Artery ; growth & development ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo observe the effect of Taohong Siwu decoction (THSWD) on micro-vascular density (MVD) in rat uterus, the content of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) in serum, and the expression of tyrosine kinasa receptor (Tie-2) in uterus.

METHODEarly pregnancy rats were intragastrically administrated with misoprostol (100 microg x kg(-1)) and mifepristong (8.3 mg x kg(-1)) to established the incomplete-abortion model. The incomplete-abortion rats were randomly divided into the model group (the same volume of distilled water), the positive control group (at the daily dose of 4.3 g x kg(-1) Motherwort Particles), and THSWD-treated groups (at the daily dose of 18.0, 9.0 and 4.5 g x kg(-1)). Pregnant rats were taken as the control group (the same volume of distilled water). After the successive oral administration for 7 days, blood was collected from aorta abdominalis, and rat uterine tissues were collected. The content of serum Ang-1 and Ang-2 were detected by ELISA; And the levels of Tie-2 and MVD in uterine tissues were detected by SP immunohistochemistry.

RESULTTHSWD remarkably increased the levels of MVD in uterus of medicine-induced abortion rats, the content of Ang-1 and Ang-2 in serum, and the expression of Tie-2 in uterine tissues.

CONCLUSIONTHSWD has the effect in markedly promoting angiogenesis in incomplete-abortion rats. Its mechanism may be related to the regulation of concentrations of Ang-1 and Ang-2 in serum and Tie-2 in uterine tissues.

Abortion, Incomplete ; blood ; drug therapy ; genetics ; Angiopoietin-1 ; blood ; genetics ; Angiopoietin-2 ; blood ; genetics ; Animals ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Gene Expression ; drug effects ; Humans ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Receptor, TIE-2 ; genetics ; metabolism ; Uterus ; blood supply ; drug effects ; metabolism

AIM: Microvasculature and microenvironment play important roles in proliferation, invasion, metastasis and prognosis in non-small cell lung cancer (NSCLC), which might be altered by many anti-angiogenic drugs. Epigallocatechin-3-gallate (EGCG), a natural anti-angiogenesis agent refined from green tea, was defined to have multiple effects on angiogenesis factors, such as endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and angiopoietins (ANGs). Hypothesizing that EGCG might regulate microvasculature and microenvironment in NSCLC, the effects of EGCG on microvessel density (MVD), expression of Ang-1 and Ang-2, interstitial fluid pressure (IFP), tumor hypoxia, and chemotherapy sensitivity were examined. METHODS AND RESULTS: EGCG treatment of A549 cells in mice bearing xenografts in vivo led to a significant decrease of MVD detected by CD31, and of Ang-2 expression detected by quantum dots double-label immunofluorescence assessment, while Ang-1 decreased with no significance. Decreased IFP was measured by the Wink-in-needle method, while hypoxia was assessed by polarographic electrode and pimonidazole (PIMO) immunohistochemistry. Assuming that these changes would increase response to chemotherapy, tumor growth studies were p[erformed in nude mice with xenografts, which were then treated with EGCG and the chemotherapeutic agent cisplatin. EGCG therapy combined with cisplatin led to synergistic inhibition of tumor growth, compared with administration of each treatment separately (P < 0.001). According to linear regression analysis, IFP was positively correlated with PIMO staining (R(2) = 0.618, P = 0.002), Ang-2 was correlated with MVD (R(2) = 0.423, P = 0.022), IFP (R(2) = 0.663, P = 0.01) and PIMO staining (R(2) = 0.694, P = 0.01). CONCLUSION IFP and delivery of oxygen might be improved by rebalance of Ang-1/Ang-2 under the treatment of EGCG in NSCLC, which also acts as a sensitizer of chemotherapy. These studies established a new mechanism for using EGCG as an adjuvant chemotherapy agent through modifying microvasculature and microenvironment.
Angiogenesis Inhibitors ; administration & dosage ; Angiopoietin-1 ; genetics ; metabolism ; Angiopoietin-2 ; genetics ; metabolism ; Animals ; Antineoplastic Agents ; therapeutic use ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; metabolism ; Catechin ; administration & dosage ; analogs & derivatives ; Chemotherapy, Adjuvant ; Cisplatin ; therapeutic use ; Drug Therapy, Combination ; Extracellular Fluid ; drug effects ; metabolism ; Female ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Oxygen ; metabolism

OBJECTIVETo examine the temporal and spatial expression of vascular endothelial growth factor (VEGF) and angiopoietins (Ang) in rat brain after cerebral ischemia, and to elucidate the roles they played in angiogenesis and vascular permeability.

METHODSRats were subjected to either middle cerebral artery occlusion (MCAO) or sham operation. Reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry were used to detect the expression of VEGF, Ang-1 and Ang-2 at different time points after ischemia. CD31 was used to label endothelial cells after MCAO. Vascular permeability was determined by Evans blue.

RESULTSVEGF was markedly increased at 2 h, had an initial peak at 12 h (0.7249 ± 0.1933, P < 0.01), and a second peak at 7 days (0.5264 ± 0.1519, P < 0.01). Ang-2 mRNA and protein significantly increased after MCAO, both of them peaked at 12 h (0.6747 ± 0.2416, P < 0.01; 1.1197 ± 0.1780, P < 0.01). In contrast, Ang-1 mRNA and protein gradually decreased after MCAO, respectively reaching a minimum at 3 d (0.3220 ± 0.1427, P < 0.01) and 1 d (0.1298 ± 0.0293, P < 0.01). Changes in the expression of these factors correlated with the progress of angiogenesis and vascular permeability. Evans blue test revealed that the vascular permeability gradually increased, and peaked at day 1 after ischemia [(6.219 ± 0.887) µg/g, P < 0.01].

CONCLUSIONDynamic temporal changes in VEGF, Ang-1 and Ang-2 expression stimulate the cerebral angiogenesis after focal cerebral ischemia.

Angiopoietin-1 ; genetics ; metabolism ; Angiopoietin-2 ; genetics ; metabolism ; Animals ; Blotting, Western ; Capillary Permeability ; Immunohistochemistry ; Infarction, Middle Cerebral Artery ; metabolism ; pathology ; physiopathology ; Male ; Neovascularization, Physiologic ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVETo study the effects of combination of angiopoietin-1 (ANG-1) and vascular endothelial growth factor₁₆₅ (VEGF₁₆₅) gene transfer mediated by recombinant adeno-associated viral vector on the neovascularization in chronic ischemic porcine myocardium.

METHODSAn ameroid constrictor was implanted around the left circumflex coronary artery (LCX) via endoscopy. Six weeks later, coronary angiography revealed that the myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX). Sixteen swine with the total occlusion or partial stenosis (> 85 %) of the LCX were divided into 4 groups (4 in each group): group I, group II and group IV (control) received direct myocardium injection of rAAV₂ VEGF₁₆₅, rAAV₂ ANG-1 or PBS alone, respectively; group III received rAAV₂ VEGF₁₆₅ and rAAV₂ ANG-1. Selective coronary angiography and ultrasonography were performed perioperatively to evaluate the cardiac function and the formation of collateral circulation. The expression of VEGF₁₆₅ and ANG-1 proteins were assessed using ELISA or Western blot. The degree of angiogenesis was assessed by use of immunohistochemical analysis.

RESULTAngiography showed that the occlusion of all LCX was completed or exceeded 95% 6 weeks after ameroid constrictor implantation, indicating the successful establishment of animal model. The expression levels of VEGF₁₆₅ in group I and III and ANG-1 in groups II and III began to increase at d7 after transfection and reached the peak at d14; then decreased gradually to the normal level after 3 months. The expression levels of VEGF₁₆₅ in group II and group IV or that of ANG-1 protein in group I and group IV had no markedly changes at different time after transfection. There were significant increase in capillary density and arteriole density and more side branch vessels formed in group III compared with other groups. Echocardiographic measurements showed that the left ventricular systolic function of animals in groups I, II and III increased significantly after gene transfection, especially in group III; but there was no changes in group IV.

CONCLUSIONMyocardial perfusion and the left ventricular systolic function are improved after rAAV₂ VEGF₁₆₅ or rAAV₂ ANG-1 transfection, which is associated with the angiogenesis in porcine model of chronic myocardial ischemia.

Adenoviridae ; genetics ; Angiopoietin-1 ; genetics ; Animals ; Collateral Circulation ; Coronary Vessels ; physiopathology ; Disease Models, Animal ; Genetic Therapy ; Genetic Vectors ; Male ; Myocardial Ischemia ; physiopathology ; therapy ; Neovascularization, Physiologic ; Swine ; Swine, Miniature ; Transfection ; Vascular Endothelial Growth Factor A ; genetics