为了探讨局灶性脑缺血再灌注大鼠采用Ephrin-B2干预促进大鼠神经功能的恢复及作用机制,本研究选取了72只成年雄性SD大鼠,采用随机数字表法分为:空白组(等量生理盐水)、假手术组(等量生理盐水)、模型组(等量生理盐水)和干预组(Ephrin-B2...为了探讨局灶性脑缺血再灌注大鼠采用Ephrin-B2干预促进大鼠神经功能的恢复及作用机制,本研究选取了72只成年雄性SD大鼠,采用随机数字表法分为:空白组(等量生理盐水)、假手术组(等量生理盐水)、模型组(等量生理盐水)和干预组(Ephrin-B2连续干预3 d),每组各18只。通过对比各组大鼠神经功能评分,检测对比各组大鼠缺血侧大脑海马组织中血管细胞间黏附分子-1(VCAM-1)、核转录因子(NF-κB)蛋白、微血管密度的水平,检测并比较各组大鼠缺血侧海马组织中血管内皮生长因子(VEGF)m RNA及蛋白的表达水平,我们发现造模后第4、8、12、14天,干预组大鼠的神经功能评分显著的低于模型组(p<0.05);造模后第4、8、12、14天,干预组、模型组大鼠的缺血侧大脑海马组织中VCAM-1、NF-κB蛋白显著的高于空白组和假手术组(p<0.05);干预组大鼠的缺血侧大脑海马组织中VCAM-1、NF-κB蛋白显著的低于模型组(p<0.05);造模后第4、8、12、14天,干预组大鼠的缺血脑组织中微血管密度显著的高于模型组(p<0.05);造模后第4、8、12、14天,干预组、模型组大鼠的血侧脑组织VEGF m RNA及蛋白显著的高于空白组和假手术组(p<0.05);干预组大鼠的血侧脑组织VEGF m RNA及蛋白显著的高于模型组(p<0.05)。本研究表明,局灶性脑缺血再灌注大鼠采用Ephrin-B2干预能促进大鼠神经功能的恢复,可能与促进新生血管形成有关。展开更多
AIM:Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meanin...AIM:Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meaning of this system in the adult human gut is unknown. We investigated the Eph/ephrin mRNA expression in the intestinal epithelium of healthy controls and patients with inflammatory bowel disease (IBD). METHODS: mRNA expression profiles of all Eph/ephrin family members in normal small intestine and colon were established by real-time RT-PCR. In addition, differential expression in IBD was investigated by cDNA array technology, and validated by both real-time RT-PCR and immunohistochemistry. Potential effects of enhanced EphB/ephrin-B signaling were analyzed in an in vitro IEC-6 cell scratch wound model. RESULTS: Human adult intestinal mucosa exhibits a complex pattern of Eph receptors and ephrins. Beside the known prominent co-expression of EphA2 and ephrinAl, we found abundantly co-expressed EphB2 and ephrin-B1/2. Interestingly, cDNA array data, validated by real-time PCR and immunohistochemistry, showed upregulation of ephrin-B2 in both perilesional and lesional intestinal epithelial cells of IBD patients, suggesting a role in epithelial homeostasis. Stimulation of ephrin-B signaling in ephrin- B1/2 expressing rat IEC-6-cells with recombinant EphB1-Fc resulted in a significant dose-dependent acceleration of wound closure. Furthermore, fluorescence microscopy showed that EphB1-Fc induced coordinated migration of wound edge cells is associated with enhanced formation of lamellipodial protrusions into the wound, increased actin stress fiber assembly and production of laminin at the wound edge. CONCLUSION: EphB/ephrin-B signaling might represent a novel protective mechanism that promotes intestinal epithelial wound healing, with potential impact on epithelial restitution in IBD.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
文摘为了探讨局灶性脑缺血再灌注大鼠采用Ephrin-B2干预促进大鼠神经功能的恢复及作用机制,本研究选取了72只成年雄性SD大鼠,采用随机数字表法分为:空白组(等量生理盐水)、假手术组(等量生理盐水)、模型组(等量生理盐水)和干预组(Ephrin-B2连续干预3 d),每组各18只。通过对比各组大鼠神经功能评分,检测对比各组大鼠缺血侧大脑海马组织中血管细胞间黏附分子-1(VCAM-1)、核转录因子(NF-κB)蛋白、微血管密度的水平,检测并比较各组大鼠缺血侧海马组织中血管内皮生长因子(VEGF)m RNA及蛋白的表达水平,我们发现造模后第4、8、12、14天,干预组大鼠的神经功能评分显著的低于模型组(p<0.05);造模后第4、8、12、14天,干预组、模型组大鼠的缺血侧大脑海马组织中VCAM-1、NF-κB蛋白显著的高于空白组和假手术组(p<0.05);干预组大鼠的缺血侧大脑海马组织中VCAM-1、NF-κB蛋白显著的低于模型组(p<0.05);造模后第4、8、12、14天,干预组大鼠的缺血脑组织中微血管密度显著的高于模型组(p<0.05);造模后第4、8、12、14天,干预组、模型组大鼠的血侧脑组织VEGF m RNA及蛋白显著的高于空白组和假手术组(p<0.05);干预组大鼠的血侧脑组织VEGF m RNA及蛋白显著的高于模型组(p<0.05)。本研究表明,局灶性脑缺血再灌注大鼠采用Ephrin-B2干预能促进大鼠神经功能的恢复,可能与促进新生血管形成有关。
基金Supported by the Gennan Research Society (DFG-SFB 585/A8) and the Dr. Heinz Maurer Grant KFB 1.7
文摘AIM:Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meaning of this system in the adult human gut is unknown. We investigated the Eph/ephrin mRNA expression in the intestinal epithelium of healthy controls and patients with inflammatory bowel disease (IBD). METHODS: mRNA expression profiles of all Eph/ephrin family members in normal small intestine and colon were established by real-time RT-PCR. In addition, differential expression in IBD was investigated by cDNA array technology, and validated by both real-time RT-PCR and immunohistochemistry. Potential effects of enhanced EphB/ephrin-B signaling were analyzed in an in vitro IEC-6 cell scratch wound model. RESULTS: Human adult intestinal mucosa exhibits a complex pattern of Eph receptors and ephrins. Beside the known prominent co-expression of EphA2 and ephrinAl, we found abundantly co-expressed EphB2 and ephrin-B1/2. Interestingly, cDNA array data, validated by real-time PCR and immunohistochemistry, showed upregulation of ephrin-B2 in both perilesional and lesional intestinal epithelial cells of IBD patients, suggesting a role in epithelial homeostasis. Stimulation of ephrin-B signaling in ephrin- B1/2 expressing rat IEC-6-cells with recombinant EphB1-Fc resulted in a significant dose-dependent acceleration of wound closure. Furthermore, fluorescence microscopy showed that EphB1-Fc induced coordinated migration of wound edge cells is associated with enhanced formation of lamellipodial protrusions into the wound, increased actin stress fiber assembly and production of laminin at the wound edge. CONCLUSION: EphB/ephrin-B signaling might represent a novel protective mechanism that promotes intestinal epithelial wound healing, with potential impact on epithelial restitution in IBD.
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.
