Norepinephrine induces brain tissue VEGF protein expression in severe burn rats

AIM:To investigate the effect of norepinep hrine (NE) on brain tissue VEGF protein expression in 24 h after severe burns.METHODS:(1) 40% total body surface area (TBSA) Ⅲ° burn model was made in Wistar males rats.Brain water (%) was examined at 24 h after burn.( 2) NE levels in the rat brain tissue were determined by high performence liquid chromatography.(3) VEGF protein levels in the rat brain tissue were determined by Western blotting at 24 h of postburn.RESULTS:(1) Brain edema exhibited at the burns and burn with no repinephrine groups.(2) A increase in NE levels in the rat brain tissue was obs erved at the burns.NE levels increased significantly in burn with norepinephrin e groups.(3) VEGF protein expression in the rat brain tissue was gradually incr eased with increasing in norepinephrine stimulating dose.VEGF protein expressio n in the burn rats brain tissue was significantly increased in burn with high d ose of norepinephrine stimulation.CONCLUSION:Norepinephrine induced VEGF protein expression in ra t brain tissue at 24 h after severe burn,suggesting that increases in norepinep hrine level postburn induce brain edema.     

Ligustilide inhibits angiogenesis and epithelial-mesenchymal transition in human hemangioendothelial cells by reducing VEGF levels

AIM To investigate the effect of ligustilide on human hemangioendothelial cells (HemECs) and to analyze its mechanism. METHODS The effect of ligustilide at different concentrations on the viability of HemECs was measured by CCK-8 assay. The HemECs were divided into control group and ligustilide （10, 25 and 50 μmol/L） treatment groups, and the proliferation of HemECs was detected by EdU staining. The effects of ligustilide on the angiogenesis of HemECs was tested by microtubule formation experiment. The protein expression of vascular endothelial growth factor (VEGF) and epithelial-mesenchymal transition (EMT)-related markers in HemECs cells was determined by Western blot. RESULTS There was no significant difference in the viability of the cells treated with ligustilide at the concentrations between 0.1~50 μmol/L compared with control cells. Compared with control group, ligustilide at 25 and 50 μmol/L significantly reduced the number of EdU-positive cells and microtubule-like structures (P<0.05), reduced the protein expression level of VEGF (P<0.05), increased the protein expression of E-cadherin, and decreased the protein expression of vimentin and β-catenin (P<0.05). Compared with control group, the expression of VEGF and vimentin was significantly up-regulated, and the protein expression of E-cadherin was significantly down-regulated in VEGF overexpression group (P<0.05). Compared with VEGF overexpression group, the expression of VEGF and vimentin in 50 μmol/L ligustilide-treated VEGF-overexpressing cells were significantly reduced (P<0.05), and the protein expression of E-cadherin was significantly increased (P<0.05). CONCLUSION Ligulide inhibits the proliferation of HemECs, and also inhibits the angiogenesis and EMT process of HemECs by reducing the level of VEGF.     

Effects of inhibition of Cripto gene siRNA on vascular endothelial growth factor of colon cancer cell line LS-174T

AIM:To study the effects of Cripto gene on vascular endothelial growth factor (VEGF) of colon carcinoma cells.METHODS:Cripto siRNA was designed and constructed. Colon cancer LS-174T cells were divided into 4 groups: control group and different dose (3.125, 6.25 and 12.5 nmol/L) of siRNA groups. After transfected for 24, 48 and 72 h, colon cancer cells were harvested to carry on the next tests. Expression of Cripto mRNA was determined with real-time PCR, and immunofluorescence isothiocyanate (FITC) labeling assay and Northern blotting were performed to examine the expression of protein and mRNA of VEGF, respectively. The cells in control group and cells transfected with 12.5 nmol/L siRNA were inoculated into nude mice respectively. 30 days after inoculated, the mice of two groups were executed, and immunohistochemical (ICH) assay was used to evaluate the VEGF protein of mice tumor. RESULTS:siRNA down-regulated the Cripto mRNA in a dose and time dependent manner. Protein and mRNA of VEGF in transfected cells reduced in a dose and time dependent manner. Compared to control, the expression of VEGF protein from ICH assay was lowered significantly (P<0.05).CONCLUSION:Cripto gene might contribute to the regulation of angiogenesis of colon carcinoma. The down-regulation of Cripto gene by siRNA can suppress angiogenesis of human colon cancer.     

Effects of Scutellaria barbata flavonoids on abnormal expression of NOS,HSP70 and apoE induced by Aβ 25-35 in rat astrocytes

AIM:To study the effects of Scutellaria barbata flavonoids (SBF) on abnormal expression of nitric oxide synthase (NOS), heat-shock protein 70 (HSP70) and apolipoprotein E (apoE) induced by Aβ 25-35 in rat astrocytes. METHODS:The third generation of cultured rat astrocytes was divided into 5 groups. The cells in 3 drug treatment groups were given SBF at dose of 17.5 mg/L, 35 mg/L and 70 mg/L for 24 h, and then the cells in model group and 3 doses of SBF groups were exposed to Aβ 25-35 at concentration of 100 μmol/L for 24 h. The expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS) in the cultured cells was assayed by immunohistochemical method. The expression of HSP70 was estimated by Western blotting and the mRNA expression of apoE was assessed by RT-PCR. RESULTS:Compared with control group, the protein level of eNOS were significantly decreased and the protein level of iNOS increased (P<0.01) in model group. The protein expression of HSP70 and mRNA expression of apoE were notably increased (P<0.01) in model group. However, these disturbances were attenuated by SBF at dose of 17.5, 35 and 70 mg/L (P<0.01). CONCLUSION:SBF has an obvious protective effect on damaged astrocytes induced by Aβ 25-35, suggesting that SBF may be helpful for the treatment of Alzheimer disease.     

Effect of shRNA-mediated survivin gene silencing on sensitivity of lymphoma cells to adriamycin

AIM: This study was designed to use RNA interference technique to down-regulate the expression of survivin gene in human Burkitts lymphoma cell line Daudi and to explore the effect on sensitivity of Daudi cells to adriamycin. METHODS: The survivin-shRNA expression vector was constructed and transfected into Daudi cells. Expression of survivin mRNA and protein were assessed by RT-PCR and Western blotting analysis, respectively. Apoptosis index of transfected Daudi cells was quantified by flow cytometry. The sensitivity of Daudi cells to adriamycin (ADR) before and after transfection was detected by MTT test. RESULTS: The mRNA and protein levels of survivin were down-regulated by 62.32% and 61.88%, respectively, compared to those in control-shRNA treated group and PBS treated group (P<0.05). Meanwhile, the apoptosis index was significantly increased (19.10%±2.15%), compared to that in control group (4.48%±1.54%) and PBS group (4.35%±1.37%, P<0.05). The 50% inhibition concentration (IC50) of ADM to Daudi cells was significantly decreased (0.25±0.43) μmol/L, compared to that in control group (0.87±0.21) μmol/L and PBS group (0.91±0.36) μmol/L, P<0.05. CONCLUSION: Down-regulation of survivin expression in Daudi cells by shRNA effectively induces apoptosis and increases the sensitivity of Daudi cells to ADR.     

Regulation of estrogen on the expression of KLK6 mRNA and protein in human breast cancer cell line MCF-7

AIM:To investigate the effects of estrogen and tamoxifen on the expression of KLK6 mRNA and protein (hK6) in human breast cancer cell line MCF-7. METHODS:MCF-7 cells were incubated with 17-βE2 and tamoxifen at different concentrations for 72 hours, respectively. The expression levels of kallikrein 6 (KLK6) mRNA and protein were evaluated by fluorescence quantitative RT-PCR and flow cytometry, respectively. RESULTS:Compared with ethanol control, KLK6 mRNA expression levels were significantly decreased when 17-βE2 was added at concentrations of 10^-10 and 10^-8 mol/L (P<0.01). No statistical change was observed when 17-βE2 was at 10^-12 mol/L (P>0.05). Flow cytometry showed the same results. The average fluorescence intensity (AFI) that represents the level of hK6 was decreased after incubated with 17-βE2 (P<0.01). After incubation with tamoxifen, the levels of KLK6 mRNA and hK6 were increased (P<0.01). CONCLUSION:Estrogen down-regulates the expression levels of KLK6 mRNA and protein (hK6), while tamoxifen has an opposite effect.     

LPS and cerulein induce isolated rat pancreatic tissue injury and inhibit expression of HSP60 protein

AIM: To investigate the effects of lipopolysaccharides (LPS) or cerulein on the expression of HSP60 in isolated rat pancreatic tissues. METHODS: The tissue of rat pancreas was isolated by surgical operation and prepared into tissue snips. The isolated pancreatic tissue was cultured, and stimulated with low- and high-concentrations of cerulein (Cer, 10-11 mol/L, 10-5 mol/L) or lipopolysaccharides (LPS, 10 mg/L, 20 mg/L). Normal saline (NS) was used as control reagent. Before stimulation and 1 h or 4 h after stimulation, the following parameters for evaluating injury were detected: the viability and the level of trypsinogen activation peptide (TAP) in the pancreatic tissues, and the level of interleukin 6 (IL-6) in the culture supernatants. Meanwhile, real-time PCR and Western blotting were used to determine the HSP60 expression at mRNA and protein levels respectively. RESULTS: Under the stimulation with LPS or cerulein, the viability of the pancreatic tissues decreased slightly at 1 h and became much lower with prolonged treatment for 4 h (P<0.05). The TAP level in the pancreatic tissues increased obviously at both 1 h and 4 h (P<0.05) after treatment, except LPS at lower dose. The IL-6 level in the culture supernatant showed no significant change at 1 h stimulation, then increased remarkably at 4 h after stimulation, especially under the conditions of stimulating with LPS or cerulein at higher doses (P<0.05). The expression of HSP60 at mRNA and protein levels decreased sharply with the increase in the concentration of LPS and the prolonged stimulation time; In cerulein stimulation group, the expression of HSP60 mRNA showed an obvious increase (P<0.01), whereas HSP60 protein was reduced remarkably, especially stimulated with cerulein at higher dose and with longer stimulation time (P<0.05). CONCLUSION: LPS or cerulein induce injuries in isolated pancreatic tissues in dose and time dependent manners. Meanwhile, the protein expression of HSP60 is reduced significantly, indicating that the decrease in the cellular protection of HSP60 may involve in the injury of pancreatic tissues.     

Effect of protein kinase C signal pathway on resistin expression in 3T3-L1 adipocytes

AIM：To investigate the effect of protein kinase C on resistin expression in 3T3-L1 adipocytes.METHODS：The differentiated 3T3-L1 adipocytes were incubated with 50 nmol/L phorbol 12-myristate 13-acetate (PMA) or 5 μmol/L Ro-31-8220 for 24 h.Expression of resistin mRNA was detected by RT-PCR and expression of resistin protein was detected by Western blotting.RESULTS：Compared with control,PMA increased the expression of resistin mRNA and protein in 3T3-L1 adipocytes significantly (P<0.01),while Ro-31-8220 decreased the expression of resistin mRNA and protein in 3T3-L1 adipocytes obviously (P<0.01).CONCLUSION：Protein kinase C signal pathway may regulate resistin expression in 3T3-L1 adipocytes.     

Relationship between zinc and zinc transporter expression in breast cancer MCF-7 cells

AIM: To study the changes of zinc transporter gene expression in MCF-7 cell line exposed to ZnCl₂ and TPEN. METHODS: Human breast cancer cell line MCF-7 was exposed to different concentrations of ZnCl₂ (0, 50, 100, 150, 200 μmol/L) and TPEN (0, 5, 10, 15 μmol/L), respectively. Twelve hours later, the cell viability was measured by MTT and levels of zinc transporter mRNA by RT-PCR. Zinquin was used to estimate the intracellular zinc concentrations. RESULTS: MCF-7 cells viability rate was significantly decreased when exposed to ZnCl₂ (with 150 μmol/L and 200 μmol/L) and TPEN. The intracellular zinc concentration was significantly increased when exposed to ZnCl₂ and decreased when exposed to TPEN. ZnT-1 mRNA level was increased along with the increasing concentration of ZnCl₂ but decreased when exposed to TPEN. The expressions of ZIP2 and ZIP10 were increased along with the increasing concentration of TPEN. CONCLUSION: ZnT-1 gene expression is induced by zinc supplement and repressed by zinc deficiency. ZIP2 and ZIP10 gene expressions are induced by zinc deficiency.     

Effect of AG490 on expression of VEGF and HIF-1α in HEL cells

AIM: To investigate the effect of AG490 on the expression of VEGF and HIF-1α, and the capacity of invasion in human erythroleukemia (HEL) cells. METHODS: The HEL cells were treated with AG490 at different concentrations. The cell viability was detected by CCK-8 assay. The apoptosis was detected by Hoechst staining. The apoptosis and the cell cycle were analyzed by flow cytometry. The capacity of migration was evaluated by Transwell assay. The mRNA expression level of JAK2 was measured by RT-PCR. The protein levels of p-JAK2, VEGF and HIF-1α were determined by Western blot. RESULTS: The HEL cell viabilities were 88%, 75%, 48%, 10% and 0.12% after treated with AG490 at 20, 40, 60, 80 and 100 μmol/L for 48 h, respectively. The results of Hoechst staining showed that brilliant blue cells in 80 μmol/L AG490 group was significantly increased compared with control group for 48 h. The apoptosis rate of 80 μmol/L AG490 group was significantly increased compared with control group at 48 h after AG490 treatment. The number of membrane-permeating HEL cells in 20 μmol/L AG490 group at 24 h after AG490 treatment was significantly lower than that in control group (P<0.05). The mRNA level of JAK2 decreased in a concentration-dependent manner after the HEL cells were treated with different concentrations of AG490 for 48 h. The protein levels of p-JAK2, VEGF and HIF-1α were lower in AG490 treatment groups than those in control group (P<0.05). CONCLUSION: AG490 inhibits the expression of VEGF and HIF-1α in HEL cells by inhibiting JAK2 pathway.     

Effect of recombinant MIF on lung fibroblast proliferation and collagen synthesis in vitro

AIM: To investigate the influence and mechanism of recombinant macrophage migration inhibitory factor (rMIF) on fibroblasts. METHODS: MRC-5 fibroblasts were divided into two groups: the treated group was treated with rMIF (25-100 μg/L, 12 h, 24 h or 48 h) and the control was non-rMIF treatment. The activity of proliferation in both groups was investigated and compared by CCK-8 means. Synthesis of collagen in the culture supernatants was detected by the hydroxyproline. The expression of collagen type I mRNA was examined using RT-PCR analysis. The level of collagen type I protein induced by rMIF was quantified by Western blotting. RESULTS: The production of proliferation ratio of fibroblasts treated with 50 μg/L and 100 μg/L rMIF at 24 h or 48 h were increased obviously (P<0.05 or P<0.01). The collagen synthesis significantly increased after stimulation with 100 μg/L rMIF for 48 h (P<0.01). rMIF significantly increased the expression of collagen type I mRNA and protein in a dose dependent manner compared with control (P<0.05 or P<0.01). CONCLUSION: rMIF upregulates the proliferation of fibroblasts and has an effect on the production of collagen. These results suggest that MIF may play important roles in the pathogenesis of airway remodeling.     

Effect of monocyte-secreted VEGF induced by electrical burn serum on monocyte-endothelial cell adhesion

AIM: To observe the level of vascular endothelial growth factor (VEGF) secreted by monocytes cultured with electrical burn serum, and to explore the effect of VEGF on monocyte-endothelial cell adhesion.METHODS: The electrical burn serum of the rat was prepared. The normal serum from the rats without treating electric current was also collected for control. The contents of VEGF and its soluble receptor sFlt-1 in electrical burn group were determined by double-antibody sandwich ELISA. THP-1 cells were randomly divided into normal serum group and electrical burn serum group. The contents of VEGF and sFlt-1 in the culture supernatants were measured by double-antibody sandwich ELISA. THP-1 cells were also randomly divided into another 4 groups:normal serum group, electrical burn serum group, normal serum+inhibitor group and electrical burn serum+inhibitor group. THP-1 cells, which were incubated with the serum for 3 h and 6 h, were labeled with calcein-AM and then were added into the well with monolayer of endothelial cell line EA.hy926 to detect monocyte-endothelial cell adhesion.RESULTS: The levels of serum VEGF of the rats with electrical burns were significantly increased, the levels of serum sFlt-1 were significantly decreased as compared with the controls. The levels of VEGF secreted by THP-1 cells cultured with electrical burn serum were significantly increased, the levels of sFlt-1 were decreased correspondingly. Electrical burn serum enhanced monocyte-endothelial cell adhesion, sFlt-1 inhibited the adhesion between monocytes and endothelial cells.CONCLUSION: The monocytes exposed to the electrical burn serum secrete VEGF, which enhance the adhesion between monocytes and endothelial cells. Blockage of VEGF activity may effectively inhibit monocyte-endothelial cell adhesion.     

Effect of Xiaoyaosan on proliferation and differentiation of hippocampus nerve precursor cells under high corticosterone condition

AIM:To investigate the effect of Xiaoyaosan (XYS) drug-containing serum on proliferation and differentiation of hippocampus nerve precursor cells (HNPC) under high corticosterone (CORT) concentration condition. METHODS:Serum-free culture in vitro was adopted to culture HNPC. CORT at concentration of 120 μmol/L was used to establish the high CORT concentration condition. XYS is composed of Bupleurum Chinese DC, Chinese angelica root, Paeonia lactiflora Pal1, India bread, Largehead atractylodes rhizome, peppermint herb, fresh ginger and Licorice root. XYS drug-containing serum of different dose were prepared.10% drug-containing serum and 10% serum were adopted. RU38486, an antagonist of CORT, was used as positive control. MTT method was used to detect proliferation rate of HNPC, the methods of immunofluorescence ambi-tagged by BrdU with TUNEL, β-tubulin-Ⅲ and glial fibrillary acidic protein (GFAP) with TUNEL respectively were adopted to detect the proliferation and differentiation of HNPC. RESULTS:CORT at concentration of 120 μmol/L degraded the proliferation rate of HNPC significantly (P<0.01), which was reversed by RU38486 (P<0.05). 10% XYS drug-containing serum of each dose enhanced the proliferation rate (P<0.05 or P<0.01). After 120 μmol/L CORT processed, the staining fluorescence intensity ratio of BrdU/TUNEL of HNPC degraded significantly (P<0.01), while increased after treatment with RU38486 and 10% XYS drug-containing serum of each dose (P<0.01). Under high CORT concentration condition, the apoptotic rates of glial cells and neurons differentiated from HNPC increased significantly (P<0.01). RU38486 and 10% XYS drug-containing serum of each dose inhibited the apoptotic rates of glial cells and neurons (P<0.05 or P<0.01). CONCLUSION:Under high CORT concentration condition, XYS promotes the proliferation of HNPC, and inhibits the apoptotic rates of glial cells and neurons differentiated from HNPC, which act as the effect of anti-damage of CORT to hippocampus in stress state.     

Role of p38 MAPK in cyclic mechanical stretch induced HMGB1 expression in alveolar macrophages

AIM: To investigate the role of p38 mitogen-activated protein kinase (MAPK) in cyclic mechanical stretch induced the expression of high mobility group box 1 protein (HMGB1) in alveolar macrophages (AMs). METHODS: AMs were cultured and seeded at 1×108 cells/L in 6-well Bioflex cell culture plates. Subsequently, the cells were exposed to cyclic mechanical stretch at 20% (group B) elongation using Flexercell 4000T cell stretching unit. In group C, cells were pre-treated with SB203580 (40 μmol/L) for 2 h before mechanical stretch. Group A served as control. The expression of HMGB1 mRNA in alveolar macrophages was detected by RT-PCR. p38 MAPK activity and the expression of HMGB1 protein were measured by Western blotting analysis. RESULTS: The expression of HMGB1 mRNA and protein, and the activity of p38 MAPK in AMs were significantly increased in group B than those in group A (P<0.05). SB203580, an inhibitor of p38 MAPK, significantly inhibited the inducing effect of mechanical stretch (P<0.05). CONCLUSION: Mechanical stretch regulates the expression of HMGB1 mRNA and protein in alveolar macrophages by activating p38 MAPK signal pathway.     

Effect of all trans retinoic acid on VEGF expression in colorectal carcinoma cell strain with different proliferation potential

AIM:To investigate the Effects of ATRA on vascular endothelial growth factor (VEGF) expression in colorectal carcinoma cell strain with different proliferative potential, and to study the role of VEGF in colorectal carcinoma with invasion and metastasis. METHODS:The state of proliferation in CW-2 and LS174T cell strain were investigated by using cell culture, ATRA intervention, MTT and FACS. Quantitative expression of VEGF mRNA in colorectal carcinoma was detected by Northern blotting. The protein expression of VEGF was observed by immunohistochemistry. RESULTS:Growth curve of MTT showed that proliferation of LS174T cell strain was faster than those of CW-2, FACS showed that the cells in S phase of LS174T cell strain were more than those of CW-2. Detection by Northern blotting and immunohistochemistry showed that the expression of VEGF mRNA in LS174T cell strain was obviously higher than those in CW-2. Furthermore, ATRT at a dose of 10-5 mol/L significantly inhibited cell proliferation and VEGF expression in LS1747 cell strain.CONCLUSION:VEGF promotes angiogenesis and increases blood supply in colorectal carcinoma, which is closely correlated with tumor growh. all-trans retinoic acid (ATRA) may restrain cell proliferation of colorectal carcinoma through down regulation of VEGF expression.     

Inhibitors of CaMKⅡ suppress the expression of TNF-α, TGF-β1 and collagen I,III in cardiac fibroblasts treated with angiotensin II or electrical field stimulation

AIM: To observe the role of calcium/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) in the proliferation, released cytokines and expression of collagen Ⅰ and Ⅲ in rat cardiac fibroblasts induced by angiotensin Ⅱ (AngⅡ) or electrical field stimulation (EFS).METHODS: The cultured cardiac fibroblasts were isolated from the neonatal rats of 1-3 days and used in the 3rd passage. The cells were divided into 10 groups: control group, 0.1 μmol/L AngⅡ group, 0.1 μmol/L AngⅡ+0.5 μmol/L KN92 group, 0.1 μmol/L AngⅡ+0.5 μmol/L KN93 group, 0.1 μmol/L AngⅡ+0.5 μmol/L AIP group; 10V 1.0 Hz EFS group, 10 V 1.0 Hz EFS+0.5 μmol/L KN92 group, 10 V 1.0 Hz EFS+0.5 μmol/L KN93 group, 10 V 1.0 Hz EFS+0.5 μmol/L AIP group, 10 V 1.0 Hz EFS+0.1 μmol/L AngⅡ group.MTT was used to detect the proliferation of cardiac fibroblasts. The release of cytokines was measured by ELISA. The mRNA expression of TNF-α, TGF-β₁ and collagen Ⅰ, Ⅲ was determined by RT-PCR.RESULTS: CaMKⅡ inhibitors (0.5 μmol/L KN93 or 0.5 μmol/L AIP) prevented the proliferation and the increase in the expression of TGF-β₁ and TNF-α in cardiac fibroblasts induced by AngⅡ (0.1 μmol/L) or EFS (10 V 1.0 Hz). CaMKⅡ inhibitors (0.5 μmol/L AIP or 1.0 μmol/L AIP) also prevented the increase in mRNA expression of collagen Ⅰ and Ⅲ induced by 0.1 μmol/L AngⅡ. CONCLUSION: Inhibition of CaMKⅡ prevents the proliferation of cardiac fibroblasts induced by AngⅡ or EFS. The possible mechanism of CaMKⅡ inhibitors may be involved in preventing the mRNA expression and release of cytokines (TGF-β₁ and TNF-α), and regulating collagen I and III expression.     

NBP promotes angiogenesis of HUVECs by activating VEGF/VEGFR2-Notch1/Dll4 signal pathway

AIM: To investigate the effects of DL-3-n-butylphthalidle (NBP) on angiogenesis of human umbilical vein endothelial cells (HUVECs) and the role of vascular endothelial growth factor (VEGF)/VEGF receptor 2(VEGFR2)-Notch1/Delta-like ligand 4 (Dll4) signaling pathway in this process. METHODS: The serum-free medium and anoxic tank were used to simulate the conditions of hypoxia and ischemia (H/I). HUVECs were divided into control group, H/I group, H/I+NBP_high group and H/I+NBP_low group. The HUVECs in control group were conventionally cultured, and those in H/I group were cultured under H/I intervention. The HUVECs in H/I+NBP_high group were treated with NBP at 20 μmol/L under H/I intervention. The HUVECs in H/I+NBP_low group were treated with NBP at 5 μmol/L under H/I intervention. The cell viability of each group was measured by CCK-8 assay. The migration ability of the HUVECs in each group was detected by cell scratch test. The vessel formation ability of the HUVECs was examined by in vitro angiogenesis assay. The expression of VEGFR2, Notch1 and Dll4 at mRNA and protein levels was determined by qPCR and Western blot, and the expression of VEGF was determined by qPCR and ELISA. RESULTS: NBP increased the viability of HUVECs, and promoted the migration ability and the formation of blood vessels in vitro under H/I intervention. These effects of NBP at high dose were more significant than those at low dose. NBP increased the expression of VEGF, VEGFR2, Notch1 and Dll4 at mRNA and protein levels (P<0.05). CONCLUSION: NBP promotes HUVECs to form blood vessels under H/I intervention. The mechanism may be related to the activation of VEGF/VEGFR2-Notch1/Dll4 signaling pathway.