Objective： A new rat model of cerebral infarction was developed to elucidate the contribution of vascular endothelial cell during focal cerebral infarction formation. Methods： Forty-eight Sprague-Dawley （SD） rats ...Objective： A new rat model of cerebral infarction was developed to elucidate the contribution of vascular endothelial cell during focal cerebral infarction formation. Methods： Forty-eight Sprague-Dawley （SD） rats were randomly divided into the model group, sham operation group, and control group for indexes observation of triphenyltetrazolium chloride （TTC） dyeing, neurological deficit, plasma tissue-type plasminogen activator （tPA） activity, plasminogen activator inhibitor （PAl） activity, thromboxane B2（TXB2） content, and 6-keto-prostaglandin （6-keto-PGF1α） content. Results： （1） The highest neurological score appeared at 6 h after operation, descending significantly at sequential time. （2） Using TTC dyeing and optical microscope technique, pathological changes in brains were observed. （3） Compared with control group and sham operation groups, there was a decrease in tPA activity of model rats at the initial 12 h after injection of sodium laurate （P〈0.05）, PAl activity decreased markedly in the model group at 24 h after injection of sodium laurate. （4） In plasma TXB2 concentration reached the highest level compared at 6 h after injection of sodium laurate, but there were not obvious differences in plasma 6-keto-PGF1α concentration among all groups （P〉 0.05）. Conclusion. Focal cerebral infarction in rats could be induced by some sodium laurate, showing ischemic cerebrum necrosis, function disorder of vascular endothelium-platelet, fibrinolysis abnormality. This model could play an important role in researching the contribution of vascular endothelial cell during cerebral infarction development, preventing and curing by traditional Chinese medicine.展开更多
Neural stem/progenitor cell （NSC） transplantation has been shown to effectively improve neurological function in rats with hypoxic-isch- emic brain damage. Vascular endothelial growth factor （VEGF） is a signaling ...Neural stem/progenitor cell （NSC） transplantation has been shown to effectively improve neurological function in rats with hypoxic-isch- emic brain damage. Vascular endothelial growth factor （VEGF） is a signaling protein that stimulates angiogenesis and improves neural regeneration. We hypothesized that transplantation of VEGF-transfected NSCs would alleviate hypoxic-ischemic brain damage in neo- natal rats. We produced and transfected a recombinant lentiviral vector containing the VEGF165gene into cultured NSCs. The transfected NSCs were transplanted into the left sensorimotor cortex of rats 3 days after hypoxic-ischemic brain damage. Compared with the NSCs group, VEGF mRNA and protein expression levels were increased in the transgene NSCs group, and learning and memory abilities were significantly improved at 30 days. Furthermore, histopathological changes were alleviated in these animals. Our findings indicate that transplantation of VEGF-transfected NSCs may facilitate the recovery of neurological function, and that its therapeutic effectiveness is better than that of unmodified NSCs.展开更多
Neural stem cells are characterized by the ability to differentiate and stably express exogenous ge- nes. Vascular endothelial growth factor plays a role in protecting local blood vessels and neurons of newborn rats w...Neural stem cells are characterized by the ability to differentiate and stably express exogenous ge- nes. Vascular endothelial growth factor plays a role in protecting local blood vessels and neurons of newborn rats with hypoxic-ischemic encephalopathy. Transplantation of vascular endothelial growth factor-transfected neural stem cells may be neuroprotective in rats with cerebral palsy. In this study, 7-day-old Sprague-Dawley rats were divided into five groups： （1） sham operation （control）, （2） cerebral palsy model alone or with （3） phosphate-buffered saline, （4） vascular en- dothelial growth factor 165 ＋ neural stem cells, or （5） neural stem cells alone. The cerebral palsy model was established by ligating the left common carotid artery followed by exposure to hypox- ia. Phosphate-buffered saline, vascular endothelial growth factor ＋ neural stem cells, and neural stem cells alone were administered into the sensorimotor cortex using the stereotaxic instrument and microsyringe. After transplantation, the radial-arm water maze test and holding test were performed. Immunohistochemistry for vascular endothelial growth factor and histology using hematoxylin-eosin were performed on cerebral cortex. Results revealed that the number of vas- cular endothelial growth factor-positive cells in cerebral palsy rats transplanted with vascular endothelial growth factor-transfected neural stem cells was increased, the time for finding water and the finding repetitions were reduced, the holding time was prolonged, and the degree of cell degeneration or necrosis was reduced. These findings indicate that the transplantation of vascu- lar endothelial growth factor-transfected neural stem cells alleviates brain damage and cognitive deficits, and is neuroprotective in neonatal rats with hypoxia ischemic-mediated cerebral palsy.展开更多
Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by ...Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].展开更多
目的:观察急性心肌梗死(Acute Myocardial Infarction,AMI)患者循环内皮细胞(CEC)核DNA改变的特点,检测血浆中血管性血友病因子(Von Willebr and factor,vWF)、内皮细胞蛋白C受体(vascular endothelial cell protein C receptor,EPCR)...目的:观察急性心肌梗死(Acute Myocardial Infarction,AMI)患者循环内皮细胞(CEC)核DNA改变的特点,检测血浆中血管性血友病因子(Von Willebr and factor,vWF)、内皮细胞蛋白C受体(vascular endothelial cell protein C receptor,EPCR)的含量变化,探讨其临床意义。方法:应用单细胞凝胶电泳技术(SCGE)检测102例AMI组患者和75例健康对照组CEC核DNA的损伤;以酶联免疫吸附试验(ELISA)进一步检测两组vWF、EPCR的含量。结果:SCGE显示,AMI组患者93.72%±6.75%CEC核DNA电泳呈明显的"彗星"状,其彗尾DNA%含量为42.22%±1.56%;对照组10.24%±4.33% CEC核DNA表现为"彗星"状,其彗尾DNA%含量为6.31%±2.41%。AMI组与对照组彗星率、彗尾DNA%含量相比均有显著性差异(P<0.001)。AMI组vWF、EPCR的含量显著高于对照组(P<0.01)。结论:AMI组患者血管内皮细胞明显损伤;血浆中vWF、EPCR的含量明显升高,早期检测血浆vWF、EPCR的含量可能有利于AMI的治疗,甚至预防。展开更多
文摘Objective： A new rat model of cerebral infarction was developed to elucidate the contribution of vascular endothelial cell during focal cerebral infarction formation. Methods： Forty-eight Sprague-Dawley （SD） rats were randomly divided into the model group, sham operation group, and control group for indexes observation of triphenyltetrazolium chloride （TTC） dyeing, neurological deficit, plasma tissue-type plasminogen activator （tPA） activity, plasminogen activator inhibitor （PAl） activity, thromboxane B2（TXB2） content, and 6-keto-prostaglandin （6-keto-PGF1α） content. Results： （1） The highest neurological score appeared at 6 h after operation, descending significantly at sequential time. （2） Using TTC dyeing and optical microscope technique, pathological changes in brains were observed. （3） Compared with control group and sham operation groups, there was a decrease in tPA activity of model rats at the initial 12 h after injection of sodium laurate （P〈0.05）, PAl activity decreased markedly in the model group at 24 h after injection of sodium laurate. （4） In plasma TXB2 concentration reached the highest level compared at 6 h after injection of sodium laurate, but there were not obvious differences in plasma 6-keto-PGF1α concentration among all groups （P〉 0.05）. Conclusion. Focal cerebral infarction in rats could be induced by some sodium laurate, showing ischemic cerebrum necrosis, function disorder of vascular endothelium-platelet, fibrinolysis abnormality. This model could play an important role in researching the contribution of vascular endothelial cell during cerebral infarction development, preventing and curing by traditional Chinese medicine.
基金supported by the National Natural Science Foundation of China,No.81070523 and 81270728
文摘Neural stem/progenitor cell （NSC） transplantation has been shown to effectively improve neurological function in rats with hypoxic-isch- emic brain damage. Vascular endothelial growth factor （VEGF） is a signaling protein that stimulates angiogenesis and improves neural regeneration. We hypothesized that transplantation of VEGF-transfected NSCs would alleviate hypoxic-ischemic brain damage in neo- natal rats. We produced and transfected a recombinant lentiviral vector containing the VEGF165gene into cultured NSCs. The transfected NSCs were transplanted into the left sensorimotor cortex of rats 3 days after hypoxic-ischemic brain damage. Compared with the NSCs group, VEGF mRNA and protein expression levels were increased in the transgene NSCs group, and learning and memory abilities were significantly improved at 30 days. Furthermore, histopathological changes were alleviated in these animals. Our findings indicate that transplantation of VEGF-transfected NSCs may facilitate the recovery of neurological function, and that its therapeutic effectiveness is better than that of unmodified NSCs.
基金supported by grants from the National Natural Science Foundation of China,No.81070523,81270728
文摘Neural stem cells are characterized by the ability to differentiate and stably express exogenous ge- nes. Vascular endothelial growth factor plays a role in protecting local blood vessels and neurons of newborn rats with hypoxic-ischemic encephalopathy. Transplantation of vascular endothelial growth factor-transfected neural stem cells may be neuroprotective in rats with cerebral palsy. In this study, 7-day-old Sprague-Dawley rats were divided into five groups： （1） sham operation （control）, （2） cerebral palsy model alone or with （3） phosphate-buffered saline, （4） vascular en- dothelial growth factor 165 ＋ neural stem cells, or （5） neural stem cells alone. The cerebral palsy model was established by ligating the left common carotid artery followed by exposure to hypox- ia. Phosphate-buffered saline, vascular endothelial growth factor ＋ neural stem cells, and neural stem cells alone were administered into the sensorimotor cortex using the stereotaxic instrument and microsyringe. After transplantation, the radial-arm water maze test and holding test were performed. Immunohistochemistry for vascular endothelial growth factor and histology using hematoxylin-eosin were performed on cerebral cortex. Results revealed that the number of vas- cular endothelial growth factor-positive cells in cerebral palsy rats transplanted with vascular endothelial growth factor-transfected neural stem cells was increased, the time for finding water and the finding repetitions were reduced, the holding time was prolonged, and the degree of cell degeneration or necrosis was reduced. These findings indicate that the transplantation of vascu- lar endothelial growth factor-transfected neural stem cells alleviates brain damage and cognitive deficits, and is neuroprotective in neonatal rats with hypoxia ischemic-mediated cerebral palsy.
基金supported by Health and Medical Research Fund,the Food and Health Bureau,The Government of the Hong Kong Special Administrative Region(03142256)General Research Fund,Hong Kong Research Grants Council(GRF#HKU773613M)+1 种基金Seed Funding Programme for Basic Research(201811159123,201910159191)The University of Hong Kong(all to ACYL)。
文摘Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].
文摘目的:观察急性心肌梗死(Acute Myocardial Infarction,AMI)患者循环内皮细胞(CEC)核DNA改变的特点,检测血浆中血管性血友病因子(Von Willebr and factor,vWF)、内皮细胞蛋白C受体(vascular endothelial cell protein C receptor,EPCR)的含量变化,探讨其临床意义。方法:应用单细胞凝胶电泳技术(SCGE)检测102例AMI组患者和75例健康对照组CEC核DNA的损伤;以酶联免疫吸附试验(ELISA)进一步检测两组vWF、EPCR的含量。结果:SCGE显示,AMI组患者93.72%±6.75%CEC核DNA电泳呈明显的"彗星"状,其彗尾DNA%含量为42.22%±1.56%;对照组10.24%±4.33% CEC核DNA表现为"彗星"状,其彗尾DNA%含量为6.31%±2.41%。AMI组与对照组彗星率、彗尾DNA%含量相比均有显著性差异(P<0.001)。AMI组vWF、EPCR的含量显著高于对照组(P<0.01)。结论:AMI组患者血管内皮细胞明显损伤;血浆中vWF、EPCR的含量明显升高,早期检测血浆vWF、EPCR的含量可能有利于AMI的治疗,甚至预防。
