Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating im...Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.展开更多
Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator o...Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.展开更多
Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is prop...Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue.In our previous studies for delivering the therapeutic genes at the site of spinal cord injury,we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses(Ad5/35)carrying recombinant cDNA.In the present study,the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor(VEGF),glial cell line-derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury.Experimental animals were randomly divided into two groups of 4 pigs each:the therapeutic(infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35‐VEGF165,Ad5/35‐GDNF,and Ad5/35‐NCAM1)and control groups(infused with intact leucoconcentrate).The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed:(1)higher sparing of the grey matter and increased survivability of the spinal cord cells(lower number of Caspase-3-positive cells and decreased expression of Hsp27);(2)recovery of synaptophysin expression;(3)prevention of astrogliosis(lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells);(4)higher growth rates of regeneratingβIII-tubulin-positive axons accompanied by a higher number of oligodendrocyte transcription factor 2-positive oligodendroglial cells in the lateral corticospinal tract region.These results revealed the efficacy of intravenous infusion of the autologous genetically-enriched leucoconcentrate producing recombinant VEGF,GDNF,and NCAM in the acute phase of spinal cord injury on the positive changes in the post-traumatic remodeling nervous tissue at the site of direct injury.Our data provide a solid platform for a new ex vivo gene therapy for spinal cord injury and will facilitate further translation of regenerative therapies in clinical neurology.展开更多
To investigate whether peroxisome proliferators-activated receptor-γ （PPARγ） ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human sa...To investigate whether peroxisome proliferators-activated receptor-γ （PPARγ） ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in ei- ther heparinized blood （control group） or heparinized blood containing 20 μmol/L troglitazone （test group） for 1 h at room temperature. Tissue distribution and protein expression of VCAM-I, ICAM-I, and endothelial nitric oxide synthase （eNOS） were compared using immunohistochemistry and Western blot analysis. Myeloperoxidase （MPO） activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 （753±132 versus 7201±934; P〈0.01） , VCAM-1 （3731±294 versus 8292±793; P〈0.01）, and MPO activity （1.52±0.42 U/g, 5.04±1.26 U/g P〈0.01） were significantly lower in test group. In contract, eNOS expression （7983±834 versus 3989±1008; P〈0.01） was significantly higher in test group. PPARγ ligand troglitazone might reduce endothelial injury during the storage period of human saphenous vein grafts.展开更多
To evaluate the role of nitric oxide in the biological effects of vascular endothelial growth factor(VEGF)and the possible mechanism of VEGF,the in vitro cultured vascular endothelial cells of rabbit aorta were divide...To evaluate the role of nitric oxide in the biological effects of vascular endothelial growth factor(VEGF)and the possible mechanism of VEGF,the in vitro cultured vascular endothelial cells of rabbit aorta were divided into control group,VEGF-treated group and VEGF+N-nitro-L-arginine methyl ester(L-NAME)-treated group.The absorbance(A)value of vascular endothelial cells and the levels of prostaglandin(PGI2),endothelin-1(ET-1)and von Willebrand factor(vWF)in the supernatant were observed by water-soluble tetrazo-lium salt assay,radioimmunoassay and enzyme-linked immunosorbent assay.The A values and PGI2 in VEGF-treated group and VEGF+L-NAME-treated group were higher than those in control group(P<0.05 and P<0.01).The ET-1 and vWF were significantly decreased in VEGF-treated group and VEGF+L-NAME-treated group com-pared with the control(P<0.05 and P<0.01).These results indicate that VEGF could promote the proliferation and secretion of PGI2 and inhibit the secretion of ET-1 and vWF in vascular endothelial cells and that L-NAME could inhibit the effect of VEGF partially.Nitric oxide is an important mediator in the process of stimulating prolifera-tion and regulating secretion of vascular endothelial cells by VEGF.展开更多
Objective To explore the correlation between endothelia cells activation and cytokines (ET-1, NO) levels in patients with pulmonary hypertension (PH), and to discuss their roles in the development of PH. Methods Twent...Objective To explore the correlation between endothelia cells activation and cytokines (ET-1, NO) levels in patients with pulmonary hypertension (PH), and to discuss their roles in the development of PH. Methods Twenty patients with simple ventricular septal defect (VSD) were chosen as controls, and 30 patients with PH were studied. Plasma levels of ET-1 and NO were measured by radioimmunoassay or colorimetric method. Before cardiopulmonary bypass was established, the specimens from right lung were fixed with formaldehyde solution, embedded with paraffin and stained by SP immunohistochemistry. Intercellular adhesion molecule-1 (ICAM-1) expression was measured through the determination of the light density with computer imaging technology. Results Compared with that of the patients with simple VSD, the light density of ICAM-1 and plasma level of ET-1 increased in patients with PH; but plasma level of NO decreased (P<0.05). Positive correlation was observed between ICAM-1 and ET-1/NO (P<0.05). Conclusion Endothelia cells activation and imbalance of ET-1/NO might play an important role in the development of PH.展开更多
基金supported by NIH grant RO1 NS093985 (to DS, NZ, XW) and RO1 NS101955 (to DS)the VCU Microscopy Facility,supported,in part,by funding from NIH-NCI Cancer Center Support Grant P30 CA016059。
文摘Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.
基金This study was supported in part by grants from the National Natural Science Foundation of China （No. 30571994, No. 30570713 and No. 30630032）.
文摘Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.
基金supported by a grant from the Russian Science Foundation,No. 16-15-00010 (to RRI)funded by government assignment for FRC Kazan Scientific Center of RAS
文摘Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue.In our previous studies for delivering the therapeutic genes at the site of spinal cord injury,we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses(Ad5/35)carrying recombinant cDNA.In the present study,the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor(VEGF),glial cell line-derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury.Experimental animals were randomly divided into two groups of 4 pigs each:the therapeutic(infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35‐VEGF165,Ad5/35‐GDNF,and Ad5/35‐NCAM1)and control groups(infused with intact leucoconcentrate).The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed:(1)higher sparing of the grey matter and increased survivability of the spinal cord cells(lower number of Caspase-3-positive cells and decreased expression of Hsp27);(2)recovery of synaptophysin expression;(3)prevention of astrogliosis(lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells);(4)higher growth rates of regeneratingβIII-tubulin-positive axons accompanied by a higher number of oligodendrocyte transcription factor 2-positive oligodendroglial cells in the lateral corticospinal tract region.These results revealed the efficacy of intravenous infusion of the autologous genetically-enriched leucoconcentrate producing recombinant VEGF,GDNF,and NCAM in the acute phase of spinal cord injury on the positive changes in the post-traumatic remodeling nervous tissue at the site of direct injury.Our data provide a solid platform for a new ex vivo gene therapy for spinal cord injury and will facilitate further translation of regenerative therapies in clinical neurology.
基金the Health Min-istry of Hubei Province (JX2B16).
文摘To investigate whether peroxisome proliferators-activated receptor-γ （PPARγ） ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in ei- ther heparinized blood （control group） or heparinized blood containing 20 μmol/L troglitazone （test group） for 1 h at room temperature. Tissue distribution and protein expression of VCAM-I, ICAM-I, and endothelial nitric oxide synthase （eNOS） were compared using immunohistochemistry and Western blot analysis. Myeloperoxidase （MPO） activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 （753±132 versus 7201±934; P〈0.01） , VCAM-1 （3731±294 versus 8292±793; P〈0.01）, and MPO activity （1.52±0.42 U/g, 5.04±1.26 U/g P〈0.01） were significantly lower in test group. In contract, eNOS expression （7983±834 versus 3989±1008; P〈0.01） was significantly higher in test group. PPARγ ligand troglitazone might reduce endothelial injury during the storage period of human saphenous vein grafts.
基金supported by a grant from the Natural Science Foundation of Hubei Province(No.2003ABA135).
文摘To evaluate the role of nitric oxide in the biological effects of vascular endothelial growth factor(VEGF)and the possible mechanism of VEGF,the in vitro cultured vascular endothelial cells of rabbit aorta were divided into control group,VEGF-treated group and VEGF+N-nitro-L-arginine methyl ester(L-NAME)-treated group.The absorbance(A)value of vascular endothelial cells and the levels of prostaglandin(PGI2),endothelin-1(ET-1)and von Willebrand factor(vWF)in the supernatant were observed by water-soluble tetrazo-lium salt assay,radioimmunoassay and enzyme-linked immunosorbent assay.The A values and PGI2 in VEGF-treated group and VEGF+L-NAME-treated group were higher than those in control group(P<0.05 and P<0.01).The ET-1 and vWF were significantly decreased in VEGF-treated group and VEGF+L-NAME-treated group com-pared with the control(P<0.05 and P<0.01).These results indicate that VEGF could promote the proliferation and secretion of PGI2 and inhibit the secretion of ET-1 and vWF in vascular endothelial cells and that L-NAME could inhibit the effect of VEGF partially.Nitric oxide is an important mediator in the process of stimulating prolifera-tion and regulating secretion of vascular endothelial cells by VEGF.
基金this work was supported by Xi'an Science and technology Research Fund (GG04134)
文摘Objective To explore the correlation between endothelia cells activation and cytokines (ET-1, NO) levels in patients with pulmonary hypertension (PH), and to discuss their roles in the development of PH. Methods Twenty patients with simple ventricular septal defect (VSD) were chosen as controls, and 30 patients with PH were studied. Plasma levels of ET-1 and NO were measured by radioimmunoassay or colorimetric method. Before cardiopulmonary bypass was established, the specimens from right lung were fixed with formaldehyde solution, embedded with paraffin and stained by SP immunohistochemistry. Intercellular adhesion molecule-1 (ICAM-1) expression was measured through the determination of the light density with computer imaging technology. Results Compared with that of the patients with simple VSD, the light density of ICAM-1 and plasma level of ET-1 increased in patients with PH; but plasma level of NO decreased (P<0.05). Positive correlation was observed between ICAM-1 and ET-1/NO (P<0.05). Conclusion Endothelia cells activation and imbalance of ET-1/NO might play an important role in the development of PH.
