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 investigate angiopoietin(Ang) and vascular endothelial growth factor(VEGF) expression in rats with ulcerative colitis(UC) and colorectal cancer(CRC).METHODS:Dysplasia and cancer were investigatedin rats that re...AIM:To investigate angiopoietin(Ang) and vascular endothelial growth factor(VEGF) expression in rats with ulcerative colitis(UC) and colorectal cancer(CRC).METHODS:Dysplasia and cancer were investigatedin rats that received three cycles of 3.5% dextran sulfate sodium(DSS) in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with 20 mg/kg 1,2-dimethylhydrazine(DMH)(CRC group).Colitis was investigated in rats that received three cycles of 3.5% DSS in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with saline(UC group).Rats without DSS or DMH treatment served as controls.Expression of the tyrosine kinase with immunoglobulinlike and EGF-like domains(Tie)-2 and its ligands,Ang-1 and Ang-2,as well as VEGF were evaluated in the colorectum by Western blotting.RESULTS:Compared with rats in the control group,rats in the CRC and UC groups developed the symptoms of acute colitis with diarrhea,rectal bleeding,wasting,and loss of body weight(P < 0.05).In addition,the mean length of colorectum of CRC and UC rats was significantly shorter than that of control rats(8.29 ± 0.21 and 8.31 ± 0.86,respectively,vs 12.34 ± 0.12 cm; P < 0.05).Furthermore,rats in the CRC group,but not in the UC or control groups,developed multiple tumors in the colorectal region.Western blot analysis revealed that rats in the CRC and UC groups had markedly increased protein levels of Ang-1,Ang-2,Tie-2,and VEGF in the colorectum compared to rats in the control group.CONCLUSION:Increased expression of Ang-1,Ang-2,Tie-2,and VEGF in ulcerative colitis-derived colorectal cancer might lead to chronic colitis and pathologic angiogenesis in rats.展开更多
Angiopoietin (Ang),as a cytokine found in recent years that can promote angiogenesis,belongs to a growth factor family including Ang 1,Ang 2,Ang 3 and Ang 4.Most research focus on Ang 1 and its receptor Tie 2.Differen...Angiopoietin (Ang),as a cytokine found in recent years that can promote angiogenesis,belongs to a growth factor family including Ang 1,Ang 2,Ang 3 and Ang 4.Most research focus on Ang 1 and its receptor Tie 2.Different from vascular endothelial growth factor,Ang 1/Tie 2 affect the end of angiogenesis,induce cell migration and maintain survive of endothelial cell and play an important role in angiogenesis and maintenance of the stability of the neoformative capillary network.Ang 1 is composed of 498 amino acids.The homology between human and mouse is 96.7%.Ang 1 is extensively distributed in tissues containing rich blood vessels such as muscle,prostate,ovary,uterus,but little is in tissues which have no or a few blood vessel.Adenovirus vector is able to transfect effectively Ang 1 gene to MSC.Previous studies have demonstrated that MSCAng 1 cell can highly express and secrete Ang 1 protein.MSCAng 1 could survive in the cardiac muscle tissue of acute myocardial infarction rat,and express exogenous Ang 1 protein for a period time.In acute myocardial infarction,MSCAng 1 cell have more potent effect on prompting angiogenesis than MSC cell.Moreover,MSCAng 1 cell could further reduce infarct size,increase thickness of cardiac ventricle wall,and improve cardiac muscle reconstitution.This study aim to find differential expressed protein related with Ang 1 using proteomic technologies.Protein spots showing significant difference by gel image analysis and statistics analysis were selected for identification using ESI MS/MS.We hope this work can provide new clues for the study on mechanism of action of Ang 1.展开更多
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
AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically ...AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically resected specimens of HCC and noncancerous liver （NCL） tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 （Ang-1）, angiopoietin-2 （Ang-2）, Tie2, and VEGF messenger RNA （mRNA） was examined by real-time quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes＇ expression level and its relationship with tumor＇s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density （MVD） and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC. RESULTS： Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue （P 〈 0.05）, whereas the Ang-1 and Tie2 mRNAs showed no statistical significance （P 〉 0.05）, though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/ Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/Ang-1 ratio, Ang-2 and VEGF were all associated with tumor＇s clinicopathological parameters （P 〈 0.05） except for histological grades （P 〉 0.05）. Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different （P 〉 0.05）. CONCLUSION： Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.展开更多
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.
基金Supported by Science and Technology Project of Liaoning Province,No.2013225303the Science and Technology Project of Shenyang City,No.F13-316-1-40
文摘AIM:To investigate angiopoietin(Ang) and vascular endothelial growth factor(VEGF) expression in rats with ulcerative colitis(UC) and colorectal cancer(CRC).METHODS:Dysplasia and cancer were investigatedin rats that received three cycles of 3.5% dextran sulfate sodium(DSS) in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with 20 mg/kg 1,2-dimethylhydrazine(DMH)(CRC group).Colitis was investigated in rats that received three cycles of 3.5% DSS in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with saline(UC group).Rats without DSS or DMH treatment served as controls.Expression of the tyrosine kinase with immunoglobulinlike and EGF-like domains(Tie)-2 and its ligands,Ang-1 and Ang-2,as well as VEGF were evaluated in the colorectum by Western blotting.RESULTS:Compared with rats in the control group,rats in the CRC and UC groups developed the symptoms of acute colitis with diarrhea,rectal bleeding,wasting,and loss of body weight(P < 0.05).In addition,the mean length of colorectum of CRC and UC rats was significantly shorter than that of control rats(8.29 ± 0.21 and 8.31 ± 0.86,respectively,vs 12.34 ± 0.12 cm; P < 0.05).Furthermore,rats in the CRC group,but not in the UC or control groups,developed multiple tumors in the colorectal region.Western blot analysis revealed that rats in the CRC and UC groups had markedly increased protein levels of Ang-1,Ang-2,Tie-2,and VEGF in the colorectum compared to rats in the control group.CONCLUSION:Increased expression of Ang-1,Ang-2,Tie-2,and VEGF in ulcerative colitis-derived colorectal cancer might lead to chronic colitis and pathologic angiogenesis in rats.
文摘Angiopoietin (Ang),as a cytokine found in recent years that can promote angiogenesis,belongs to a growth factor family including Ang 1,Ang 2,Ang 3 and Ang 4.Most research focus on Ang 1 and its receptor Tie 2.Different from vascular endothelial growth factor,Ang 1/Tie 2 affect the end of angiogenesis,induce cell migration and maintain survive of endothelial cell and play an important role in angiogenesis and maintenance of the stability of the neoformative capillary network.Ang 1 is composed of 498 amino acids.The homology between human and mouse is 96.7%.Ang 1 is extensively distributed in tissues containing rich blood vessels such as muscle,prostate,ovary,uterus,but little is in tissues which have no or a few blood vessel.Adenovirus vector is able to transfect effectively Ang 1 gene to MSC.Previous studies have demonstrated that MSCAng 1 cell can highly express and secrete Ang 1 protein.MSCAng 1 could survive in the cardiac muscle tissue of acute myocardial infarction rat,and express exogenous Ang 1 protein for a period time.In acute myocardial infarction,MSCAng 1 cell have more potent effect on prompting angiogenesis than MSC cell.Moreover,MSCAng 1 cell could further reduce infarct size,increase thickness of cardiac ventricle wall,and improve cardiac muscle reconstitution.This study aim to find differential expressed protein related with Ang 1 using proteomic technologies.Protein spots showing significant difference by gel image analysis and statistics analysis were selected for identification using ESI MS/MS.We hope this work can provide new clues for the study on mechanism of action of Ang 1.
文摘AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically resected specimens of HCC and noncancerous liver （NCL） tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 （Ang-1）, angiopoietin-2 （Ang-2）, Tie2, and VEGF messenger RNA （mRNA） was examined by real-time quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes＇ expression level and its relationship with tumor＇s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density （MVD） and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC. RESULTS： Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue （P 〈 0.05）, whereas the Ang-1 and Tie2 mRNAs showed no statistical significance （P 〉 0.05）, though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/ Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/Ang-1 ratio, Ang-2 and VEGF were all associated with tumor＇s clinicopathological parameters （P 〈 0.05） except for histological grades （P 〉 0.05）. Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different （P 〉 0.05）. CONCLUSION： Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.
