目的:观察与微血管系统重建过程密切相关的促血管生成素(Angiopoietin-1,Ang-1)及其受体含免疫球蛋白样环和上皮生长因子样域酪氨酸激酶-2(tyrosine kinase that contains immunoglobulin-like loops and epidermal growth factor-simil...目的:观察与微血管系统重建过程密切相关的促血管生成素(Angiopoietin-1,Ang-1)及其受体含免疫球蛋白样环和上皮生长因子样域酪氨酸激酶-2(tyrosine kinase that contains immunoglobulin-like loops and epidermal growth factor-similar domains-2,Tie-2)在大鼠基底核脑出血后表达的动态变化。方法:用Ⅶ型胶原酶诱导大鼠脑出血模型,采用HE染色观察大鼠脑组织形态学改变,免疫组化法检测第1、2、4、7、14、21和28d血管生成素Ang-1和其受体Tie-2的表达,计数阳性血管作为观察指标。结果:HE染色显示正常组及假手术组各时间点取材未见血肿及局部明显病理学改变,而模型组第4d血肿周围出现微血管段,而后阳性微血管段表达逐渐持续增多,至第21d大量伸入血肿区;免疫组化研究显示正常及假手术组不同时间点Ang-1和Tie-2表达均未见明显变化,模型组大鼠在脑出血后第2d起Ang-1和Tie-2阳性微血管表达明显多于其他两组,而后表达逐渐升高(P<0.01),至21d达到高峰,随后开始下降,28d时仍有表达。结论:在脑出血后,损伤区Ang-1及其受体Tie-2的表达上调,可能通过调节血管生成过程而促进脑出血损伤区微血管系统重建。展开更多
Buyang Huanwu decoction （BYHWD）, a traditional Chinese herbal prescription, has been widely used clinically to treat stroke in China for hundreds of years; however, the mechanisms of this drug for stroke treatment a...Buyang Huanwu decoction （BYHWD）, a traditional Chinese herbal prescription, has been widely used clinically to treat stroke in China for hundreds of years; however, the mechanisms of this drug for stroke treatment are still unclear. This study aims to observe the cerebral angiogenesis effects of BYHWD on chronic brain injury after focal cerebral ischemia in rats and to explore its possible mechanisms. The ischemia was induced by occlusion of the right middle cerebral artery for 90 min. BYHWD （12.5 and 25.0 g/（kg.d）, equivalent to the dry weight of the raw materials） was orally administered twice a day beginning 2 h after surgery. BYHWD significantly attenuated the neurological dysfunction, infarct volume, and brain atrophy after ischemia. There was a significant increase in the microvessel density, as assessed by immunofluorescence CD31, and a significant increase in angiopoietin-1 （Ang-1） in the pe- numbra areas of the rats was shown by immunohistochemical staining and Western blotting. The results indicate that the neurorestorative effects of BYHWD are associated with angiogenesis and the enhancement of the expressions of Ang-1 on chronic brain injury after focal cerebral ischemia.展开更多
Ephrin-B2 has been shown to participate in angiogenesis, but the underlying mechanisms involved remain unclear. In this study, a rat model of local cerebral ischemia was prepared by focal middle cerebral artery occlus...Ephrin-B2 has been shown to participate in angiogenesis, but the underlying mechanisms involved remain unclear. In this study, a rat model of local cerebral ischemia was prepared by focal middle cerebral artery occlusion, followed by 24-hour reperfusion. Then, ephrin-B2 protein was administered intracerebroventricularly for 3 consecutive days via a micro-osmotic pump. Western blot assay and quantitative real-time reverse transcription PCR demonstrated the expression levels of angiopoietin-1 （Ang-1） mRNA and protein in the penumbra cortex of the ephrin-B2 treated group were decreased at day 4 after reperfusion, and increased at day 28, while the expression levels of angiopoietin-2 （Ang-2） were highly up-regulated at all time points tested. Double immunofluorescent staining indicated that Ang-1 and Ang-2 were both expressed in vascular endothelial cells positive for CD31. These findings indicate that ephrin-B2 influences the expressions of Ang-1 and Ang-2 during angiogenesis following transient focal cerebral ischemia.展开更多
AIM： To evaluate the effects of angiopoietin-1 （Ang-1） on adhesion of gastric cancer cell line BGC-823 and expression of integrin β1, CD44V6, urokinase-type plasminogen activator （uPA） and matrix metalloproteina...AIM： To evaluate the effects of angiopoietin-1 （Ang-1） on adhesion of gastric cancer cell line BGC-823 and expression of integrin β1, CD44V6, urokinase-type plasminogen activator （uPA） and matrix metalloproteinase-2 （MMP-2）. METHODS： BGC-823 cells were transfected transiently with adenovirus-Ang-1 （Ad-Ang-1）. Cells transfected transiently with adenovirus-green fluorescent protein （Ad-GFP） and untransfected cells were used as a negative and blank control group, respectively. The cell adhesion rate between cell and extracellular matrix （ECM） was determined by cell adhesion assay. To investigate whether Ang-1 could reinforce gastric carcinoma metastasis, we performed migration and invasion assays in BGC-823 cells. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 were detected by reverse transcription polymerase chain reaction and Western blotting, respectively. The expression of integrin β1 and CD44V6 was measured by immunohistochemistry. RESULTS： BGC-823 cells were transfected successfully. The adhesion rate increased significantly in the Ad-Ang-1 group （P 〈 0.05）. The Ad-Ang-1-transfected group had a significant increase in migration and invasion compared with that of the mock-transfected and Ad-GFP groups. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 in the Ad- Ang-1 group was higher than that in the Ad-GFP and blank control groups （P 〈 0.05）. Compared with mocktransfected and Ad-GFP groups, integrin 131 and CD44V6 expression intensity greatly increased （P 〈 0.05）. CONCLUSION： Transfection of Ang-1 into human gastric cancer cell line BGC-823 can significantly increase expression of integrin β1 and CD44V6, by which cell adhesion and metastasis to the ECM are promoted.展开更多
AIM: To determine the inhibitory effect of the adenovirus- based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in h...AIM: To determine the inhibitory effect of the adenovirus- based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109. METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si (Eca109/Ang-1si), and Ad/si was used to infect Eca109 cells as control (Eca109/si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined. RESULTS: HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirus- transfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer.展开更多
Objectives This study investigated the efficacy of human skeletal myoblasts (SkM) mediated either human vascular endothelial growth factor-165 (hVEGF165) or angiopoietin-1 (Ang-1) on vascular development and myocardia...Objectives This study investigated the efficacy of human skeletal myoblasts (SkM) mediated either human vascular endothelial growth factor-165 (hVEGF165) or angiopoietin-1 (Ang-1) on vascular development and myocardial regional perfusion. Methods A porcine heart model of chronic infarction was created in 28 female swine by coronary artery ligation. The animals were randomized into: (1) group-1, DMEM injected (n=6), (2) group-2, Ad-null transduced SkM transplanted (n=6), (3) group-3, Ad-hVEGF165 transduced SkM transplanted (n=8), and (4) group-4, Ad-Ang-1 transduced SkM (n=8). Three weeks later, 5 ml DMEM containing 3×108 SkM carrying exogenous genes were intramyocardially injected into 20 sites in left ventricle in groups-2, -3 and -4. Animals in group-1 were injected 5 ml DMEM without cells. Animals were kept on 5 mg/kg cyclosporine per day for 6 weeks. Regional blood flow was measured using fluorescent microspheres. The heart was explanted at 2, 6 and 12 weeks after transplantation for histological studies. Results Histological examination showed survival of lac-z expressing myoblasts in host tissue. Capillary density based on Von Willebrand factor-VIII (vWF-VIII) at low power field (×100) was 57.13±11.85 in group-3 at 6 weeks and declined to 32.1±5.21 at 12 weeks, while it was 39.9±10.26 at 6 weeks and increased to 45.14±6.54 at 12 weeks in group-4. The mature blood vessel index was highest in group- 4 at 6 and 12 weeks after transplantation. The regional blood flow in the center and peri-infarct area was significantly increased in animals of groups-3 and -4. Conclusions SkM carrying either hVEGF165 or Ang-1 induced neovascularization with increased blood flow. Ang-1 overexpression resulted in mature and stable blood vessel formation and may be a more potent arteriogenic inducer for neovascularization.展开更多
AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent...AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent assays(ELISA) in samples from 179 cirrhotic and non-cirrhotic CHC patients, classified according to the METAVIR system.Groups were compared by non-parametric MannWhitney U test. Subsequently, the association of peripheral concentrations of angiopoietins with the stage of fibrosis was analyzed using Spearman correlation test. Finally, the accuracy, sensitivity and specificity of circulating angiopoietins for cirrhosis diagnosis were determined by the study of the respective area under the curve of receiver operator characteristics(AUC-ROC).RESULTS Peripheral blood concentrations of Ang1 and Ang2 in CHC patients were significantly related to fibrosis. While Ang1 was decreased in cirrhotic subjects compared to non-cirrhotic(P < 0.0001), Ang2 was significantly increased as CHC progressed to the end stage of liver disease(P < 0.0001). Consequently, Ang2/Ang1 ratio was notably amplified and significantly correlated with fibrosis(P < 0.0001). Interestingly, the individual performance of each angiopoietin for the diagnosis of cirrhosis reached notable AUC-ROC values(above 0.7, both), but the Ang2/Ang1 ratio was much better(AUC-ROC = 0.810) and displayed outstanding values of sensitivity(71%), specificity(84%) and accuracy(82.1%) at the optimal cut-off(10.33). Furthermore, Ang2/Ang1 ratio improved the performance of many other previously described biomarkers or scores of liver cirrhosis in CHC.CONCLUSION Ang2/Ang1 ratio might constitute a useful tool for monitoring the progression of chronic liver disease towards cirrhosis and play an important role as therapeutic target.展开更多
Objective： Mesenchymal stem cell （MSC） transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purp...Objective： Mesenchymal stem cell （MSC） transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purpose of this study was to investigate the protective effect of angiopoietin-1 （Angl） preconditioning on MSC survival and sub- sequent heart function improvement after transplantation. Methods： MSCs were cultured with or without 50 ng/ml Angl in complete medium for 24 h prior to experiments on cell survival and transplantation. 3-（4,5- Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） and Hoechst staining were applied to evaluate MSC survival after serum deprivation in vitro, while cell survival in vivo was detected by terminal deoxynucleotidyl trans- ferase biotin-dUPT nick end labeling （TUNEL） assay 24 and 72 h after transplantation. Heart function and infarct size were measured four weeks later by small animal echocardiography and Masson＇s trichrome staining, respectively. Results： Angl preconditioning induced Akt phosphorylation and increased expression of Bcl-2 and the ratio of Bcl-2/Bax. In comparison with non-preconditioned MSCs, Angl-preconditioned cell survival was significantly in- creased while the apoptotic rate decreased in vitro. However, the PI3K/Akt pathway inhibitor, LY294002, abrogated the protective effect of Angl preconditioning. After transplantation, the Angl-preconditioned-MSC group showed a lower death rate, smaller infarct size, and better heart functional recovery compared to the non-preconditioned-MSC group. Conclusions： Angl preconditioning enhances MSC survival, contributing to further improvement of heart function.展开更多
Doxorubicin （Dox） is a major anticancer chemotherapeutic agent. However, it causes cardiomyopathy due to the side effect of cardiomyocyte apoptosis. We have previously reported that angiopoietin-1 significantly redu...Doxorubicin （Dox） is a major anticancer chemotherapeutic agent. However, it causes cardiomyopathy due to the side effect of cardiomyocyte apoptosis. We have previously reported that angiopoietin-1 significantly reduced myocardial infarction after ischemic injury and protected cardiomyocytes from oxidative stress-induced apoptosis. It is hypothesized that angiopoietin-1 may protect cardiomyocytes from Dox-induced apoptosis. Cardiomyocytes H9C2 were transfected with adenovirus expressing angiopoietin-1 （Ad5-Ang-1） 24 h before the cells were chal- lenged with Dox at a concentration of 2 ~tmol/L. Ad5-GFP served as the vector control. Cardiomyocyte apoptosis was evaluated using Annexin V-FITC staining and caspase-3 and caspase-8 activity was determined by Western blotting. The results showed that Dox treatment significantly induced cardiomyocyte apoptosis as evidenced by the greater number of Annexin V-FITC stained cells and increases in caspase-3 and caspase-8 activity. In contrast, overexpression of angiopoietin-1 significantly prevented Dox-induced cardiomyocyte apoptosis. To elucidate the mechanisms by which angiopoietin-1 protected cells from Dox-induced apoptosis, we analyzed both extrinsic and intrinsic apoptotic signaling pathways. We observed that angiopoietin-1 prevented Dox-induced activation of both extrinsic and intrinsic apoptotic signaling pathways. Specifically, angiopoietin-1 prevented DOX-induced in- creases in FasL and Bax levels and cleaved caspase-3 and caspase-8 levels in H9C2 cells. In addition, overexpres- sion of angiopoietin-1 also activated the pro-survival phosphoinositide-3 kinase （PI3K）/Akt signaling pathway and decreased Dox-induced nuclear factor-kappaB （NF-~：B） activation. Our data suggest that promoting the expression of angiopoietin-1 could be a potential approach for reducing Dox-induced cardiomyocyte cytoxicity.展开更多
Angiogenesis in ischemic tissue is a complex and multi-gene event. In the study, we constructed hypoxic re-sponse elements （HRE） and the Tet-On advanced double-controlled systems and investigated their effects on th...Angiogenesis in ischemic tissue is a complex and multi-gene event. In the study, we constructed hypoxic re-sponse elements （HRE） and the Tet-On advanced double-controlled systems and investigated their effects on the expression of hVEGF165 and angiopoietin-1 （Ang-1） genes in rat cardiomyocytes exposed to hypoxia and pharma-cologic induction. We infected neonatal rat cardiomyocytes with recombinant rAAV-rtTA-Rs-M2/rAAV-TRE-Tight-Ang-1 and rAAV-9HRE- hVEGF165. Our results indicated that the viral titer was 1×1012 vg /mL and the viral purity exceeded 98%. hVEGF165 expression was induced by hypoxia, but not by normoxia （P 0.001）. Ang-1 expression was evident under doxycycline induction, but undetectable without doxycycline induction （P 0.001）. Immunofluorescence staining showed that positively stained hVEGF165 and Ang-1 protein appeared only under both hypoxia and doxycycline induction. We demonstrate here that HRE and the recombinant Tet-On advanced double gene-controlled systems sensitively regulate the expression of hVEGF165 and Ang-1 genes in an altered oxygen environment and under pharmacological induction in vitro.展开更多
Objective： To study the expression and the significance of Angiopoietin-1 （Ang-1） through observing the correlations among the expression of Ang-1 to clinicopathologic characteristics and microvessel density （MVD...Objective： To study the expression and the significance of Angiopoietin-1 （Ang-1） through observing the correlations among the expression of Ang-1 to clinicopathologic characteristics and microvessel density （MVD） in oral squamous cell carcinoma （OSCC）. Methods： Expressions of Angiopoietin-1 and CD34 in 41 human OSCC tissues, 30 adjacent noncancerous oral tissues and 10 normal oral mucosas were detected by immunohistochemical SABC method. MCD was also assessed. Results： Of the 41 OSCC tissues, 41.46% （17/41） was Ang-1 positive. The expression of Ang-1 was significantly lower in OSCC than that in adjacent noncancerous oral tissues （P〈0.05） and normal oral mucosa （P〈0.05）. The Ang-1 expression was significantly higher in high differentiated tumor than that in moderately differentiated tumor （P〈0.05）. The MVD was significantly higher in Ang-1-negative OSCC than in Ang-1-positive OSCC （P〈0.01）, and negatively correlated with the expression of Ang-1 （r=-0.32, P〈0.05）. Conclusion： Down-regulated expression of Ang-1 may play a crucial role in the development of OSCC. It negatively regulated the angiogenesis of tumor.展开更多
Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 （Tie-2） is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological funct...Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 （Tie-2） is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological functions such as swallowing. In the present study, a rat model of dysphagia following stroke was induced by middle cerebral artery occlusion to investigate the influence of low frequency electrical stimulus with bidirectional square waves and triangular waves on angiopoietin-1/-13e-2 mRNA expression. Reverse transcription-polymerase chain reaction results showed that low frequency electrical stimulus significantly improved the neurological scores of the model rats, and increased angiopoietin-1/＇13e-2 mRNA expression. This demonstrates that low frequency electrical stimulation can ameliorate neurological function in rats with focal brain ischemia, potentially through regulation of angiopoietin-1/-13e-2 expression in the angiogenesis pathway.展开更多
The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN mod...The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN model was established in adult male SD rats, and the sham-operated group and 5/6 STN group were set up. The renal function and histopathological changes were examined at the 1st, 2nd, 4th, 8th and 12th week after operation. The expression orAng-1, TSP-1 and CD31 in renal tissues was detected by using immunohistochemistry. From 2nd to 8th week after operation, Ang-1 was significantly expressed in glomeruli of rats with STN. Ang-1 staining in glomeruli of STN group was increased significantly as compared with that in sham-operated group at 4th and 8th week after operation, and subsequently decreased after the 12th week. The expression of TSP-1 was increased significantly in STN group. As compared with sham-operated group, the CD31 expression was significantly down-regulated from the 2nd week. The expression of Ang-1 mRNA was detected by using RT-PCR at the same time points. The expression of Ang-1 mRNA in renal tissue of rats with STN was significantly up-regulated at the 2nd, 4th and 8th week after operation as compared with that in STN group at other time points or in sham-operated group at the same time points, while decreased evidently at the 12th week as compared with that in sham-operated group. It is concluded that there are changes in the mRNA expression of Ang-1, and the significant up-regulation of the expression of TSP-1 in renal tissue of rats with STN, which may be involved in the remnant renal microvasculature injury.展开更多
This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybr...This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybridization respectively. Computerized image analysis system was used to measure the average optical intensity of Ang-1/-2 in endometria at different time points after gestation. Mice were randomly divided into 5 groups： control group, D2 group （2 days after pregnancy）, D4 group （4 days after pregnancy）, D6 group （6 days after pregnancy） and D8 group （8 days after pregnancy）, each containing 15 mice. The results showed that the expression of Ang-1 and Ang-2 was very different among 4 groups （P〈0.01）. Immunohistochemical staining revealed that Ang-1 was localized in the cytoplasma of stromal cells 2 days after pregnancy （day 2）, and in luminal epithelial cells on day 4. The protein of Ang-2 was mainly expressed in the cytoplasma of glandular epithelia and stromal cells. With gestation time, the positive reactions of Ang-1/-2 were stronger in the endometria of the pregnant mice （P〈0.01）. In situ hybridization showed Ang-I mRNA in stromal cells on day 2. Hybridization signal was localized in both stromal cells and vessel epithelial cells on day 4; Ang-2 mRNA was expressed in stromal cells and glandular epithelia on day 2; high mRNA levels appeared in stromal cells, glandular epithelia and vascular endothelia on day 4; an increasing in mRNA expression of Ang-1/-2 was observed on day 6 and day 8 （P〈0.01）. It is suggested that Ang-1/-2 may play an important role in the cross-talk between blastocyst and maternal endometrium during the process of embryo implantation.展开更多
Pathological alterations in the brain can cause microglial activation(MA).Thus,inhibiting MA could provide a new approach for treating neurodegenerative disorders.To investigate the effect of C16 peptide and angiopoie...Pathological alterations in the brain can cause microglial activation(MA).Thus,inhibiting MA could provide a new approach for treating neurodegenerative disorders.To investigate the effect of C16 peptide and angiopoietin-1(Ang1)on inflammation following MA,we stimulated microglial BV-2 cells with lipopolysaccharide(LPS)and used dexmedetomidine(DEX)as a positive control.Specific inhibitors of Tie2,avβ3 and a5β1 integrins,and PI3K/Akt were applied to investigate the neuron-protective and anti-inflammatory effects and signaling pathway of C16+Angl treatment in the LPS-induced BV-2 cells.Our results showed that C16+Ang1 treatment reduced the microglia M1 phenotype but promoted the microglia M2 phenotype.展开更多
基金Projcct sup portcd bythc Plan of Zhejiang Scientific Rcscarch in Traditional Chincsc Medicinc （No. 2010ZZ007）, China
文摘Buyang Huanwu decoction （BYHWD）, a traditional Chinese herbal prescription, has been widely used clinically to treat stroke in China for hundreds of years; however, the mechanisms of this drug for stroke treatment are still unclear. This study aims to observe the cerebral angiogenesis effects of BYHWD on chronic brain injury after focal cerebral ischemia in rats and to explore its possible mechanisms. The ischemia was induced by occlusion of the right middle cerebral artery for 90 min. BYHWD （12.5 and 25.0 g/（kg.d）, equivalent to the dry weight of the raw materials） was orally administered twice a day beginning 2 h after surgery. BYHWD significantly attenuated the neurological dysfunction, infarct volume, and brain atrophy after ischemia. There was a significant increase in the microvessel density, as assessed by immunofluorescence CD31, and a significant increase in angiopoietin-1 （Ang-1） in the pe- numbra areas of the rats was shown by immunohistochemical staining and Western blotting. The results indicate that the neurorestorative effects of BYHWD are associated with angiogenesis and the enhancement of the expressions of Ang-1 on chronic brain injury after focal cerebral ischemia.
文摘Ephrin-B2 has been shown to participate in angiogenesis, but the underlying mechanisms involved remain unclear. In this study, a rat model of local cerebral ischemia was prepared by focal middle cerebral artery occlusion, followed by 24-hour reperfusion. Then, ephrin-B2 protein was administered intracerebroventricularly for 3 consecutive days via a micro-osmotic pump. Western blot assay and quantitative real-time reverse transcription PCR demonstrated the expression levels of angiopoietin-1 （Ang-1） mRNA and protein in the penumbra cortex of the ephrin-B2 treated group were decreased at day 4 after reperfusion, and increased at day 28, while the expression levels of angiopoietin-2 （Ang-2） were highly up-regulated at all time points tested. Double immunofluorescent staining indicated that Ang-1 and Ang-2 were both expressed in vascular endothelial cells positive for CD31. These findings indicate that ephrin-B2 influences the expressions of Ang-1 and Ang-2 during angiogenesis following transient focal cerebral ischemia.
文摘AIM： To evaluate the effects of angiopoietin-1 （Ang-1） on adhesion of gastric cancer cell line BGC-823 and expression of integrin β1, CD44V6, urokinase-type plasminogen activator （uPA） and matrix metalloproteinase-2 （MMP-2）. METHODS： BGC-823 cells were transfected transiently with adenovirus-Ang-1 （Ad-Ang-1）. Cells transfected transiently with adenovirus-green fluorescent protein （Ad-GFP） and untransfected cells were used as a negative and blank control group, respectively. The cell adhesion rate between cell and extracellular matrix （ECM） was determined by cell adhesion assay. To investigate whether Ang-1 could reinforce gastric carcinoma metastasis, we performed migration and invasion assays in BGC-823 cells. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 were detected by reverse transcription polymerase chain reaction and Western blotting, respectively. The expression of integrin β1 and CD44V6 was measured by immunohistochemistry. RESULTS： BGC-823 cells were transfected successfully. The adhesion rate increased significantly in the Ad-Ang-1 group （P 〈 0.05）. The Ad-Ang-1-transfected group had a significant increase in migration and invasion compared with that of the mock-transfected and Ad-GFP groups. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 in the Ad- Ang-1 group was higher than that in the Ad-GFP and blank control groups （P 〈 0.05）. Compared with mocktransfected and Ad-GFP groups, integrin 131 and CD44V6 expression intensity greatly increased （P 〈 0.05）. CONCLUSION： Transfection of Ang-1 into human gastric cancer cell line BGC-823 can significantly increase expression of integrin β1 and CD44V6, by which cell adhesion and metastasis to the ECM are promoted.
基金The Natural Science Foundation of China, No.30471718
文摘AIM: To determine the inhibitory effect of the adenovirus- based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109. METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si (Eca109/Ang-1si), and Ad/si was used to infect Eca109 cells as control (Eca109/si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined. RESULTS: HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirus- transfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer.
文摘Objectives This study investigated the efficacy of human skeletal myoblasts (SkM) mediated either human vascular endothelial growth factor-165 (hVEGF165) or angiopoietin-1 (Ang-1) on vascular development and myocardial regional perfusion. Methods A porcine heart model of chronic infarction was created in 28 female swine by coronary artery ligation. The animals were randomized into: (1) group-1, DMEM injected (n=6), (2) group-2, Ad-null transduced SkM transplanted (n=6), (3) group-3, Ad-hVEGF165 transduced SkM transplanted (n=8), and (4) group-4, Ad-Ang-1 transduced SkM (n=8). Three weeks later, 5 ml DMEM containing 3×108 SkM carrying exogenous genes were intramyocardially injected into 20 sites in left ventricle in groups-2, -3 and -4. Animals in group-1 were injected 5 ml DMEM without cells. Animals were kept on 5 mg/kg cyclosporine per day for 6 weeks. Regional blood flow was measured using fluorescent microspheres. The heart was explanted at 2, 6 and 12 weeks after transplantation for histological studies. Results Histological examination showed survival of lac-z expressing myoblasts in host tissue. Capillary density based on Von Willebrand factor-VIII (vWF-VIII) at low power field (×100) was 57.13±11.85 in group-3 at 6 weeks and declined to 32.1±5.21 at 12 weeks, while it was 39.9±10.26 at 6 weeks and increased to 45.14±6.54 at 12 weeks in group-4. The mature blood vessel index was highest in group- 4 at 6 and 12 weeks after transplantation. The regional blood flow in the center and peri-infarct area was significantly increased in animals of groups-3 and -4. Conclusions SkM carrying either hVEGF165 or Ang-1 induced neovascularization with increased blood flow. Ang-1 overexpression resulted in mature and stable blood vessel formation and may be a more potent arteriogenic inducer for neovascularization.
基金Supported by the Ministerio de Ciencia e Innovación(SAF:2010/21805,partially)CIBERehd(Instituto de Salud CarlosⅢ,Madrid)+1 种基金Fundación Mutua Madrile■a(to Moreno-Otero R)a grant from Asociación Espa■ola Contra el Cáncer(AIO 2010,AECC,to Sanz-Cameno P)
文摘AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent assays(ELISA) in samples from 179 cirrhotic and non-cirrhotic CHC patients, classified according to the METAVIR system.Groups were compared by non-parametric MannWhitney U test. Subsequently, the association of peripheral concentrations of angiopoietins with the stage of fibrosis was analyzed using Spearman correlation test. Finally, the accuracy, sensitivity and specificity of circulating angiopoietins for cirrhosis diagnosis were determined by the study of the respective area under the curve of receiver operator characteristics(AUC-ROC).RESULTS Peripheral blood concentrations of Ang1 and Ang2 in CHC patients were significantly related to fibrosis. While Ang1 was decreased in cirrhotic subjects compared to non-cirrhotic(P < 0.0001), Ang2 was significantly increased as CHC progressed to the end stage of liver disease(P < 0.0001). Consequently, Ang2/Ang1 ratio was notably amplified and significantly correlated with fibrosis(P < 0.0001). Interestingly, the individual performance of each angiopoietin for the diagnosis of cirrhosis reached notable AUC-ROC values(above 0.7, both), but the Ang2/Ang1 ratio was much better(AUC-ROC = 0.810) and displayed outstanding values of sensitivity(71%), specificity(84%) and accuracy(82.1%) at the optimal cut-off(10.33). Furthermore, Ang2/Ang1 ratio improved the performance of many other previously described biomarkers or scores of liver cirrhosis in CHC.CONCLUSION Ang2/Ang1 ratio might constitute a useful tool for monitoring the progression of chronic liver disease towards cirrhosis and play an important role as therapeutic target.
基金supported by the Natural Science Foundation of Zhejiang Province (No. Y2100362)the Qianjiang Talents Project of Science and Technology Department of Zhejiang Province (No. 2011R10022), China
文摘Objective： Mesenchymal stem cell （MSC） transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purpose of this study was to investigate the protective effect of angiopoietin-1 （Angl） preconditioning on MSC survival and sub- sequent heart function improvement after transplantation. Methods： MSCs were cultured with or without 50 ng/ml Angl in complete medium for 24 h prior to experiments on cell survival and transplantation. 3-（4,5- Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） and Hoechst staining were applied to evaluate MSC survival after serum deprivation in vitro, while cell survival in vivo was detected by terminal deoxynucleotidyl trans- ferase biotin-dUPT nick end labeling （TUNEL） assay 24 and 72 h after transplantation. Heart function and infarct size were measured four weeks later by small animal echocardiography and Masson＇s trichrome staining, respectively. Results： Angl preconditioning induced Akt phosphorylation and increased expression of Bcl-2 and the ratio of Bcl-2/Bax. In comparison with non-preconditioned MSCs, Angl-preconditioned cell survival was significantly in- creased while the apoptotic rate decreased in vitro. However, the PI3K/Akt pathway inhibitor, LY294002, abrogated the protective effect of Angl preconditioning. After transplantation, the Angl-preconditioned-MSC group showed a lower death rate, smaller infarct size, and better heart functional recovery compared to the non-preconditioned-MSC group. Conclusions： Angl preconditioning enhances MSC survival, contributing to further improvement of heart function.
基金supported by the National Natural Science Foundation of China (No. 30971258)the National 973 project of China(NO.2012CB517503)+1 种基金the Key Project of Natural Science Foundation of Jiangsu Province (No. 11KJA310004)Jiangsu "Six Personnel Peak" Talent-Funded Projects
文摘Doxorubicin （Dox） is a major anticancer chemotherapeutic agent. However, it causes cardiomyopathy due to the side effect of cardiomyocyte apoptosis. We have previously reported that angiopoietin-1 significantly reduced myocardial infarction after ischemic injury and protected cardiomyocytes from oxidative stress-induced apoptosis. It is hypothesized that angiopoietin-1 may protect cardiomyocytes from Dox-induced apoptosis. Cardiomyocytes H9C2 were transfected with adenovirus expressing angiopoietin-1 （Ad5-Ang-1） 24 h before the cells were chal- lenged with Dox at a concentration of 2 ~tmol/L. Ad5-GFP served as the vector control. Cardiomyocyte apoptosis was evaluated using Annexin V-FITC staining and caspase-3 and caspase-8 activity was determined by Western blotting. The results showed that Dox treatment significantly induced cardiomyocyte apoptosis as evidenced by the greater number of Annexin V-FITC stained cells and increases in caspase-3 and caspase-8 activity. In contrast, overexpression of angiopoietin-1 significantly prevented Dox-induced cardiomyocyte apoptosis. To elucidate the mechanisms by which angiopoietin-1 protected cells from Dox-induced apoptosis, we analyzed both extrinsic and intrinsic apoptotic signaling pathways. We observed that angiopoietin-1 prevented Dox-induced activation of both extrinsic and intrinsic apoptotic signaling pathways. Specifically, angiopoietin-1 prevented DOX-induced in- creases in FasL and Bax levels and cleaved caspase-3 and caspase-8 levels in H9C2 cells. In addition, overexpres- sion of angiopoietin-1 also activated the pro-survival phosphoinositide-3 kinase （PI3K）/Akt signaling pathway and decreased Dox-induced nuclear factor-kappaB （NF-~：B） activation. Our data suggest that promoting the expression of angiopoietin-1 could be a potential approach for reducing Dox-induced cardiomyocyte cytoxicity.
基金supported by a grant from the National Natural Science Foundation of China (No.30672081)
文摘Angiogenesis in ischemic tissue is a complex and multi-gene event. In the study, we constructed hypoxic re-sponse elements （HRE） and the Tet-On advanced double-controlled systems and investigated their effects on the expression of hVEGF165 and angiopoietin-1 （Ang-1） genes in rat cardiomyocytes exposed to hypoxia and pharma-cologic induction. We infected neonatal rat cardiomyocytes with recombinant rAAV-rtTA-Rs-M2/rAAV-TRE-Tight-Ang-1 and rAAV-9HRE- hVEGF165. Our results indicated that the viral titer was 1×1012 vg /mL and the viral purity exceeded 98%. hVEGF165 expression was induced by hypoxia, but not by normoxia （P 0.001）. Ang-1 expression was evident under doxycycline induction, but undetectable without doxycycline induction （P 0.001）. Immunofluorescence staining showed that positively stained hVEGF165 and Ang-1 protein appeared only under both hypoxia and doxycycline induction. We demonstrate here that HRE and the recombinant Tet-On advanced double gene-controlled systems sensitively regulate the expression of hVEGF165 and Ang-1 genes in an altered oxygen environment and under pharmacological induction in vitro.
基金This work was supported by the Medical Science Grant of Sichuan Province Key Sci & Tech Subjects (No. 20020807) and Guizhou Province Government Century Grant (No.9813).
文摘Objective： To study the expression and the significance of Angiopoietin-1 （Ang-1） through observing the correlations among the expression of Ang-1 to clinicopathologic characteristics and microvessel density （MVD） in oral squamous cell carcinoma （OSCC）. Methods： Expressions of Angiopoietin-1 and CD34 in 41 human OSCC tissues, 30 adjacent noncancerous oral tissues and 10 normal oral mucosas were detected by immunohistochemical SABC method. MCD was also assessed. Results： Of the 41 OSCC tissues, 41.46% （17/41） was Ang-1 positive. The expression of Ang-1 was significantly lower in OSCC than that in adjacent noncancerous oral tissues （P〈0.05） and normal oral mucosa （P〈0.05）. The Ang-1 expression was significantly higher in high differentiated tumor than that in moderately differentiated tumor （P〈0.05）. The MVD was significantly higher in Ang-1-negative OSCC than in Ang-1-positive OSCC （P〈0.01）, and negatively correlated with the expression of Ang-1 （r=-0.32, P〈0.05）. Conclusion： Down-regulated expression of Ang-1 may play a crucial role in the development of OSCC. It negatively regulated the angiogenesis of tumor.
基金the National High-Tech R&D Program of China (863 Program), No.2007AA022Z482
文摘Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 （Tie-2） is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological functions such as swallowing. In the present study, a rat model of dysphagia following stroke was induced by middle cerebral artery occlusion to investigate the influence of low frequency electrical stimulus with bidirectional square waves and triangular waves on angiopoietin-1/-13e-2 mRNA expression. Reverse transcription-polymerase chain reaction results showed that low frequency electrical stimulus significantly improved the neurological scores of the model rats, and increased angiopoietin-1/＇13e-2 mRNA expression. This demonstrates that low frequency electrical stimulation can ameliorate neurological function in rats with focal brain ischemia, potentially through regulation of angiopoietin-1/-13e-2 expression in the angiogenesis pathway.
文摘The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN model was established in adult male SD rats, and the sham-operated group and 5/6 STN group were set up. The renal function and histopathological changes were examined at the 1st, 2nd, 4th, 8th and 12th week after operation. The expression orAng-1, TSP-1 and CD31 in renal tissues was detected by using immunohistochemistry. From 2nd to 8th week after operation, Ang-1 was significantly expressed in glomeruli of rats with STN. Ang-1 staining in glomeruli of STN group was increased significantly as compared with that in sham-operated group at 4th and 8th week after operation, and subsequently decreased after the 12th week. The expression of TSP-1 was increased significantly in STN group. As compared with sham-operated group, the CD31 expression was significantly down-regulated from the 2nd week. The expression of Ang-1 mRNA was detected by using RT-PCR at the same time points. The expression of Ang-1 mRNA in renal tissue of rats with STN was significantly up-regulated at the 2nd, 4th and 8th week after operation as compared with that in STN group at other time points or in sham-operated group at the same time points, while decreased evidently at the 12th week as compared with that in sham-operated group. It is concluded that there are changes in the mRNA expression of Ang-1, and the significant up-regulation of the expression of TSP-1 in renal tissue of rats with STN, which may be involved in the remnant renal microvasculature injury.
文摘This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybridization respectively. Computerized image analysis system was used to measure the average optical intensity of Ang-1/-2 in endometria at different time points after gestation. Mice were randomly divided into 5 groups： control group, D2 group （2 days after pregnancy）, D4 group （4 days after pregnancy）, D6 group （6 days after pregnancy） and D8 group （8 days after pregnancy）, each containing 15 mice. The results showed that the expression of Ang-1 and Ang-2 was very different among 4 groups （P〈0.01）. Immunohistochemical staining revealed that Ang-1 was localized in the cytoplasma of stromal cells 2 days after pregnancy （day 2）, and in luminal epithelial cells on day 4. The protein of Ang-2 was mainly expressed in the cytoplasma of glandular epithelia and stromal cells. With gestation time, the positive reactions of Ang-1/-2 were stronger in the endometria of the pregnant mice （P〈0.01）. In situ hybridization showed Ang-I mRNA in stromal cells on day 2. Hybridization signal was localized in both stromal cells and vessel epithelial cells on day 4; Ang-2 mRNA was expressed in stromal cells and glandular epithelia on day 2; high mRNA levels appeared in stromal cells, glandular epithelia and vascular endothelia on day 4; an increasing in mRNA expression of Ang-1/-2 was observed on day 6 and day 8 （P〈0.01）. It is suggested that Ang-1/-2 may play an important role in the cross-talk between blastocyst and maternal endometrium during the process of embryo implantation.
文摘Pathological alterations in the brain can cause microglial activation(MA).Thus,inhibiting MA could provide a new approach for treating neurodegenerative disorders.To investigate the effect of C16 peptide and angiopoietin-1(Ang1)on inflammation following MA,we stimulated microglial BV-2 cells with lipopolysaccharide(LPS)and used dexmedetomidine(DEX)as a positive control.Specific inhibitors of Tie2,avβ3 and a5β1 integrins,and PI3K/Akt were applied to investigate the neuron-protective and anti-inflammatory effects and signaling pathway of C16+Angl treatment in the LPS-induced BV-2 cells.Our results showed that C16+Ang1 treatment reduced the microglia M1 phenotype but promoted the microglia M2 phenotype.
