Effects of nicotine on the release of t-PA and PAI-1 in cultured human umbilical vein endothelial cells

AIM: To study the effect of nicotine on the release of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in human umbilical vein endothelial cells (HUVECs).METHODS: HUVECs were cultured in 24-well tissue-culture plates and randomly divided into control group and nicotine treatment groups. In nicotine treatment groups, HUVECs were either incubated with nicotine at the concentrations of 0.1, 1, 10 and 100 μmol/L for 12 h, or exposed to 100 μmol/L nicotine for 0 h, 4 h, 6 h, 8 h, 12 h and 24 h. The cells in control group were exposed to the same volume of PBS instead of nicotine at corresponding time points. The supernatants were collected for determining the concentrations of t-PA and PAI-1 by ELISA. RESULTS: (1) Compared with control group, the protein levels of PAI-1 in 100 μmol/L nicotine treatment group increased significantly (P<0.01). No significant difference of t-PA protein among the groups was observed (P>0.05). (2) After stimulated with 100 μmol/L nicotine for 4 h, 6 h, 8 h, 12 h and 24 h, the protein levels of PAI-1 in the cells increased over time and reached the peak at 12 h, which was significantly higher than those in the control cells (P<0.05). However, no significant difference of t-PA protein in these cells was found as compared to the controls (P>0.05).CONCLUSION: Nicotine inhibits the fibrinolytic activity in HUVECs in vitro, thereby damaging the vascular endothelial cells.     

Effects of simvastatin on cigarette smoke extract-induced sEPCR and EPCR expression in human umbilical vein endothelial cells

AIM: To investigate the effects of simvastatin on cigarette smoke extract (CSE)-induced expression levels of soluble endothelial cell protein C receptor (sEPCR) and membrane-associated endothelial cell protein C receptor (mEPCR ) in human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs at passage 4 to 6 were randomly divided into control group, 5% CSE group, simvastatin groups and simvastatin+CSE groups. In simvastatin groups, HUVECs were incubated with simvastatin at the concentrations of 50, 100 and 200 μmol/L for 24 h. In simvastatin+CSE groups, the cells were treated with simvastatin at the concentrations of 50, 100 and 200 μmol/L for 2 h, and then exposed to CSE for 24 h. The protein level of sEPCR in the culture supernatants was measured by ELISA. The cells were collected for determining the mRNA expression of mEPCR by real-time PCR. RESULTS: Compared with control group, the protein level of sEPCR was significantly increased, and the mRNA expression of mEPCR was significantly decreased in 5% CSE group (both P<0.05). The protein levels of sEPCR were significantly increased, and the mRNA expression of mEPCR was significantly decreased in 100 μmol/L and 200 μmol/L simvastatin groups. However, the protein levels of sEPCR were lower, and the mRNA expression of mEPCR was significantly higher in 100 μmol/L and 200 μmol/L simvastatin groups than those in 5% CSE group. Compared with 5% CSE group, the protein levels of sEPCR in simvastatin+CSE groups were significantly decreased, but higher than those in control group and simvastatin group with corresponding concentration. On the contrary, the mRNA expression of mEPCR in simvastatin+CSE groups was significantly increased, but lower than that in control group and simvastatin group with corresponding concentration (all P<0.05). CONCLUSION: Simvastatin obviously increases the mRNA expression of mEPCR, decreases the protein level of sEPCR, and attenuates the CSE-induced endothelial injury in vitro .     

Role of SIRT1/eNOS/NO signaling pathway in protective effect of ginsenoside Rb1 against replicative senescence of endothelial cells

AIM: To explore the effect of ginsenoside Rb1 on replicative senescence of endothelial cells and the role of SIRT1/eNOS/NO signaling pathway in this process. METHODS: The replicative senescence model of primary human umbilical vein endothelial cells (HUVECs) was established. The morphological change of the cells, the proportion of senescence-associated β-galactosidase (SA-β-Gal) positive cells and the plasminogen activator inhibitor 1 (PAI-1) expression were detected to assess the senescence model. The expression of eNOS and PAI-1 at mRNA and protein levels in the aging cells was determined by real-time PCR and Western blot before and after silencing of SIRT1 was performed. The NO concentration in the cell culture supernatant was measured by nitrate reductase assay. RESULTS: HUVECs with cumulative population-doubling level (CPDL) at 16 were chosen as the replicative senescence model in this research. Ginsenoside Rb1 at 80 μmol/L significantly reduced the expression of PAI-1 at mRNA and protein levels. Furthermore, ginsenoside Rb1 increased the expression of SIRT1 and eNOS at mRNA and protein levels, and increased the NO content. SIRT1 silencing inhibited the expression of eNOS at mRNA and protein levels and reduced NO generation, leading to an increase in the expression of PAI-1 at mRNA and protein levels. Upon intervention of ginsenoside Rb1, the eNOS and PAI-1 expression and the level of NO were not reversed. CONCLUSION: Ginsenoside Rb1 modulates SIRT1/eNOS/NO signaling pathway to prevent the replicative senescence of HUVECs.     

AHV-PI attenuates endothelial cell injury induced by LPS

AIM:To investigate the effect of platelet inhibitor from Agkistrodon halys venom (AHV-PI) on lipopolysaccharide (LPS) induced human umbilical vein endothelial cells (HUVECs) injury in vitro, and to explore its mechanism. METHODS:Cultured HUVECs were induced inflammatory injury by LPS (1 mg/L). The experiment was divided into blank control group, LPS group, AHV-PI group and AHV-PI+LPS group. The viability of HUVECs was measured by MTT assay. The morphological changes of HUVECs were observed under inverted microscope. The optimum concentration of AHV-PI at 5 mg/L was selected. Flow cytometry was used to detect apoptosis of HUVECs. Immunohistochemical method was used to observe the expression of tissue type plasminogen activator (t-PA) and plasminogen activator indhibitor-1 (PAI-1) of HUVECs. ELISA was used to detect the concentrations of intercellular adhesion molecule-1 (ICAM-1) and tissue factor (TF) in the supernatant. The activation and translocation of NF-κB subunit p65 were observed by immunofluorescence staining. RESULTS:The HUVECs were spindle shaped, the ratio of length to width was increased, the cells were fibroblast-like, and granular substance appeared in the cytoplasm in LPS group. The viability and morphological changes of HUVECs were not significantly affected as treated with AHV-PI at concentration of 0~5 mg/L, but the viability of HUVECs induced by LPS was inhibited and the morphological changes were alleviated. Compared with the blank control group, the levels of TF and ICAM-1 in the supernatant increased, and the expression of t-PA and PAI-1 in the HUVECs was decreased in LPS group. Compared with the LPS group, the contents of TF and ICAM-1 in the supernatant were significantly decreased, the expression of t-PA and PAI-1 in the HUVECs was increased and the expression of nucleus NF-κB p65 was decreased in AHV-PI+LPS group (P<0.05). CONCLUSION:AHV-PI reduces HUVECs damage. The protective mechanism is related to the inhibition of cytokine secretion and NF-κB activation.     

Hydrogen sulfide attenuates human umbilical vein endothelial cell senescence via modulation of Sirt1/eNOS pathway

AIM: To explore the role of Sirt1/eNOS signalling pathway in the protective effect of hydrogen sulphide (H₂S) against endothelial cell senescence induced by high glucose.METHODS: High glucose (33 mmol/L) was applied to induce senescence in primary human umbilical vein endothelial cells (HUVECs). The cell viability, the proportion of senescence-associated β-galactosidase (SA-β-Gal) positive cells and the plasminogen activator inhibitor 1 (PAI-1) expression were detected to assess the senescence model. Mean while, Sirt1 siRNA was used to examine the effect of Sirt1 on eNOS expression and the senescence-related parameters.RESULTS: Treatment of HUVECs with high glucose decreased the cell viability slowly with a larger proportion of the cells stained with SA-β-Gal, and the protein expression of PAI-1 was dramatically increased. The increased cell viability, reduced SA-β-Gal positive cells and decreased protein expression of PAI-1 were detected after sodium hydrosulfide (NaHS, 100 μmol/L) treatment. Furthermore, NaHS treatment upregulated the protein expression of Sirt1 and eNOS, and eventually increased the production of nitric oxide (NO).CONCLUSION: Exogenous H₂S modulates Sirt1/eNOS/NO pathway to prevent HUVECs against high glucose-induced senescence.     

Hydrogen sulfide ameliorates high glucose-induced endothelial cell senescence by suppressing oxidative stress

AIM：To explore the effect of hydrogen sulfide on the senescence of human umbilical vein endothelial cells (HUVECs) induced by high glucose. METHODS：Senescence model was established by treating HUVECs with 33 mmol/L glucose for 48 h. The parameters were detected to demonstrate the effect of hydrogen sulfide on senescence and the mechanism involved was also investigated. RESULTS：In the cells treated with high glucose, the proliferation was attenuated with a higher number of senescence-associated β-galactosidase (SA-β-Gal) positive cells, and plasminogen activator inhibitor 1 (PAI-1) protein expression, malondialdehyde (MDA) production and NF-κB p65 activity were increased significantly, but the expression of superoxide dismutase 1 (SOD1) was decreased. However, the cell number and SOD1 expression were increased, and the number of SA-β-Gal positive cells, PAI-1 protein expression, MDA production and the activity of NF-κB p65 were decreased after sodium hydrosulfide (100 and 200 μmol/L) treatment.CONCLUSION：Exo-genous hydrogen sulfide prevents HUVECs against high glucose-induced senescence by suppressing oxidative stress and NF-κB p65 activity.     

Effects of miR-30c on viability and migratory ability of HUVECs by targeting PAI-1

AIM: To investigate the effect of microRNA (miR)-30c on the viability and migratory ability of human umbilical vein endothelial cells (HUVECs) by targeting plasminogen activator inhibitor-1 (PAI-1).METHODS: The HUVECs were transfected with miR-30c mimic and inhibitor or negative control (NC), and then the expression levels of miR-30c, PAI-1 mRNA and protein were detected by RT-qPCR and Western blot. The viability and migratory ability of HUVECs were measured by CCK-8 assay and wound healing test. After bioinformatic analysis, the assessment of miR-30c binding to PAI-1 3'-UTR was carried out using a luciferase reporter gene assay. RESULTS: miR-30c directly down-regulated PAI-1 levels by binding to the 3' UTR seed sequence of PAI-1 mRNA. Furthermore, transfection of a miR-30c mimic down-regulated the expression of PAI-1 at mRNA and protein levels, leading to enhanced migratory ability and viability of the HUVECs. However, transfection of a miR-30c inhibitor up-regulated the expression of PAI-1 at mRNA and protein le-vels, leading to decreased migratory ability and viability. CONCLUSION: Regulation of miR-30c level changes the migratory ability and viability of HUVECs by affecting the PAI-1 expression, indicating the involvement of miR-30c in modulating endothelial function.     

Effects of folic acid and vitamin B12 on human umbilical vein endothelial cells against homocysteine-induced apoptosis

AIM: To investigate the effect of folic acid and vitamin B₁₂ on homocysteine (Hcy)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) through mammalian sterile 20-like kinase 1 (MST1). ME-THODS: HUVECs were cultured in the absence (control group), or presence of 100 μmol/L Hcy alone (Hcy group) or 100 μmol/L Hcy plus 30 μmol/L folic acid and vitamin B₁₂ (intervention group) for 72 h. The effect of Hcy on the apoptosis of HUVECs was analyzed by flow cytometry. The transfection efficiency of DNA methyltransferase 1 (DNMT1)-overexpressing adenovirus was observed under fluorescence inverted microscope. The mRNA and the protein levels of DNMT1 and MST1 were determined by RT-qPCR and Western blot. The DNA methylation level of MST1 promoter was detected by methylation-specific PCR. RESULTS: Compared with control group, the apoptotic rate (P<0.01) and the expression of MST1 at mRNA (P<0.01) and protein (P<0.05) levels in the HUVECs were significantly increased, while the mRNA levels of DNMT1 was decreased in Hcy group (P<0.01). In addition, folic acid and vitamin B₁₂ treatment significantly inhibited Hcy-mediated apoptosis of HUVECs (P<0.01), increase in MST1 mRNA level (P<0.01) and decrease in DNMT1 mRNA level (P<0.01). Meantime, the mRNA level of MST1 was positively correlated with the apoptotic rate of the HUVECs (r=0.943 9, P<0.001). The expression of DNMT1 at mRNA and protein levels was significantly increased after the transfection of DNMT1-overexpressing adenovirus into HUVECs (P<0.01), and a large amount of green fluorescent protein expression was observed. Meanwhile, the DNA methylation level of MST1 promoter was increased (P<0.01), while the protein level of MST1 was decreased (P<0.01).CONCLUSION: Up-regulation of MST1 promotes Hcy-induced apoptosis of HUVECs, while folic acid and vitamin B₁₂ exert an anti-apoptosis effect, which might be regulated by hypermethylation of MST1 promoter region.     

Hydrogen sulfide attenuates endothelial cell senescence via inhibiting over-phosphorylation of protein kinase B

AIM To explore the effect of hydrogen sulfide on the senescence of human umbilical vein endothelial cells (HUVECs) induced by hydrogen peroxide (H₂O₂) and the possibly involved mechanism. METHODS Senescence model was established by treating HUVECs with H₂O₂ at 60 μmol/L for 1 h and then cultured for 24 h. The several parameters were detected to demonstrate the effect of hydrogen sulfide on senescence by Western blot. RESULTS In the cells treated with H₂O₂, a larger proportion of cells were stained with β-galactosidase (SA-β-Gal), and the protein expression of plasminogen activator inhibitor 1 (PAI-1) was dramatically increased (P<0.05). The less SA-β-Gal positive cells and decreased protein of PAI-1 were detected when the cells were pretreated with 100 μmol/L sodium hydrosulfide (NaHS). Furthermore, NaHS treatment inhibited the phosphorylation of protein kinase B (PKB/Akt). Meanwhile, LY294002, the specific inhibitor of Akt, was also able to reverse the cellular senescence induced by H₂O₂ in HUVECs. CONCLUSION Exogenous hydrogen sulfide prevents HUVECs against H₂O₂-induced senescence partially via the inhibition of Akt over-phosphorylation.     

Effects of tetrahydroxystilbene-2-O-β-D-glucoside on apoptosis and expression of bcl-2/bax/caspase-3 in HUVECs treated with homocysteine

AIM：To explore the effects of tetrahydroxystilbene-2-O-β-D-glucoside (TSG) from Polygonum multiflorum on the apoptosis and the mRNA expression of bcl-2, bax and caspase-3 in human umbilical vein endothelial cells (HUVECs) treated with homocysteine (Hcy). METHODS：Cultured HUVECs were treated with Hcy (3 mmol/L) to establish a Hcy-damaged model. HUVECs in TSG treated groups were pre-incubated with TSG at concentrations of 1 μmol/L and 10 μmol/L for 2 h before treated with Hcy. Cell nuclear damage was detected by Hoechst 33342 staining. Cell apoptosis was determined by flow cytometry. The mRNA expression of bcl-2, bax and caspase-3 was measured by real-time fluorescence quantitative RT-PCR. RESULTS： After treatment with Hcy at concentration of 3 mmol/L, the nuclear damage and apoptotic rate of HUVECs were higher than that in normal group. The expression of bcl-2 was lower, and the expression of Bax and caspase-3 was higher than that in normal group. On the other hand, pre-incubation with TSG at concentrations of 1 μmol/L and 10 μmol/L decreased the nuclear damage and cell apoptosis, increased the expression of bcl-2, and decreased the expression of bax and caspase-3 as compared with the cells only treated with Hcy. CONCLUSION：TSG reduces the apoptosis of HUVECs induced by Hcy, and the mechanism might be associated with regulating the expression of bcl-2, bax and caspase-3.     

Role of TGF-β1-activated p38 MAPK in up-regulation of PAI-1 expression by TGF-β1 in human ovarian cancer cells

AIM: To investigate the relationship between up-regulation of plasminogen activator inhibitor-1(PAI-1) expression and activation of p38 mitogen-activated protein kinase(p38 MAPK) and extracellular signal-regulated kinase(ERK) pathways by TGF-β1 in human ovarian cancer cells. METHODS: PAI-1 expression in human ovarian cancer cells treated with TGF-β1(10 μg/L)was assayed by real-time PCR and Western blotting. The activation of p38 MAPK and ERK was determined by Western blotting using phosphorylated p38 MAPK and phosphorylated ERK antibodies. Specific p38 MAPK inhibitor(SB203580) or ERK inhibitor(PD98059) was used to inhibit their activation. RESULTS: TGF-β1 up-regulated the expression of PAI-1, and activated p38 MAPK and ERK pathways in the ovarian cancer cells. Inhibition of p38 MAPK activation by SB203580 resulted in significant inhibition of the mRNA expression of PAI-1 induced by TGF-β1. However, inhibition of ERK activation did not significantly alter TGF-β1-induced increase in PAI-1 mRNA level. CONCLUSION: TGF-β1-activated p38 MAPK pathway contributes to the up-regulation of PAI-1 expression by TGF-β1 in ovarian cancer cells.     

Farrerol inhibits nicotine-induced proliferation of pulmonary vascular smooth muscle cells by enhancing Kv1.5 and Kv2.1 expression

AIM:To study the effect of farrerol (Far) on nicotine-induced proliferation of rat pulmonary smooth muscle cells (PASMCs), and further to explore its relationship with voltage-dependent potassium channels (Kv) 1.5 and Kv2.1. METHODS:Firstly, the effect of nicotine on the proliferation of PASMCs was detected by cell counting method, and the optimal concentration of nicotine was selected. Primary cultured PASMCs were randomly divided into 5 groups:normal control group, nicotine (1 μmol/L)group, nicotine (1 μmol/L) + Far (10^-6 mol/L, 10^-5 mol/L and 10^-4 mol/L) Far group. The activity of caspase-3 was measured by apoptosis kit, the cell viability was measured by CCK-8 assay, the apoptotic rate was analyzed by flow cytometry. The expression of Kv1.5 and Kv2.1, and apoptosis-related factors Bcl-2 and Bax at mRNA and protein levels was determined by RT-qPCR and Western blot respectively. RESULTS:Nicotine at 1 μmol/L increased the number of PASMCs to the maximum extent (P<0.01). Nicotine at 1 μmol/L significantly reduced the caspase-3 activity and enhanced the cell viability of the PASMCs (P<0.01). Farrerol at 10^-6~10^-4 mol/L eliminated the effect of PASMCs induced by nicotine in a concentration dependent manner. Compared with control group, nicotine at 1 μmol/L significantly increased the proliferation and inhibited the apoptotic rate of rat PASMCs (P<0.01). The apoptotic rate of PASMCs in farrerol intervention group was significantly higher than that in nicotine group (P<0.01). Nicotine at 1 μmol/L significantly inhibited the expression of Kv1.5, Kv2.1 and Bax but increased the expression of Bcl-2 in PASMCs (P<0.01). Farrerol at 10^-5 mol/L obviously inhibited the effect of PASMCs induced by nicotine. CONCLUSION:Farrerol eliminates nicotine-induced inhibition of caspase-3 and Bax, and enhancement of Bcl-2 in PASMCs by enhancing Kv1.5 and Kv2.1 expression.     

Nodosin induces apoptosis of HepG2 cells by increasing Apaf-1 expression and activating caspase-3

AIM:To investigate the effects of nodosin on apoptosis of human hepatocellular carcinoma HepG2 cells. METHODS:HepG2 cells were treated with nodosin at different concentrations (1.25 μmol/L, 2.5 μmol/L, 5 μmol/L, 10 μmol/L and 20 μmol/L) for 24 h. The morphological changes of the HepG2 cells were observed by Hoechst 33258 staining and electron microscopy. The apoptotic rates were analyzed by flow cytometry. The mRNA expression of apoptotic protease-activating factor-1 (Apaf-1) was detected by RT-qPCR. The protein levels of pro-caspase-3, caspase-3 and cleaved caspase-3 were determined by Western blot. RESULTS:HepG2 cells showed obvious cell shrinkage and nucleus drift when treated with nodosin as the concentration was increased. Many apoptotic bodies were observed in 5 μmol/L, 10 μmol/L and 20 μmol/L nodosin groups. The mRNA expression of Apaf-1 was increased in 5 μmol/L, 10 μmol/L and 20 μmol/L nodosin groups as compared with control group (P<0.05). The protein levels of pro-caspase-3, caspase-3 and cleaved caspase-3 were increased with the increasing dose of nodosin (P<0.05). CONCLUSION:Nodosin induces the apoptosis of HepG2 cells. This effect was related to increasing Apaf-1 mRNA expression and subsequently promoting the activation of caspase-3.     

Sinomenine inhibits TNF-α-induced VCAM-1 expression on human umbilical vein endothelial cells

AIM: To investigate whether sinomenine(SN) can decrease TNF-α-induced VCAM-1 expression in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were isolated from freshly collected umbilical cords.Positive control samples were stimulated with TNF-α, omitting SN. Negative control samples were treated in the same way, omitting TNF-α and SN. Experiment samples were co-cultured with TNF-α and SN at different concentration (0.25, 0.5, and 1.0 mol/L),or TNF-α and dexamethasone(Dex) at concentration of 1.0×10^-6mol/L.Cells were harvested after cultivation with the drugs for 12 hours. VCAM-1 mRNA expression was detected by real-time quantitative PCR, and VCAM-1 expression was detected by flow cytometry (FCM).RESULTS: VCAM-1 mRNA and VCAM-1 were induced by TNF-α. Compared with the positives, the relative VCAM-1 mRNA expression decreased to varying degrees in the experiment groups (P<0.05), and SN at concentration of 0.5 mol/L and 1.0 mol/L inhibited expression of VCAM-1 (P<0.05). SN at concentration of 1.0 mol/L decreased VCAM-1 expression by 28.8%(P<0.05), and SN at concentration of 0.5 mol/L reduced VCAM-1 expression by 21.68%(P<0.05). But SN at concentration of 0.25 mol/L and Dex at concentration of 1.0×10^-6mol/L didnt depress expression of VCAM-1. CONCLUSION: SN may inhibit TNF-α-induced VCAM-1 expression in HUVECs in vitro.     

Apoptosis induced by simvastatin in rat vascular smooth muscle cells through calpain and caspase-3-dependent pathways

AIM:Hydroxymethylglutaryl CoA (HMG-CoA) reductase inhibitors, such as simvastatin, have been shown to reduce atherosclerotic cardiovascular morbidity and mortality by mechanisms unrelated to its lipid-lowering effect. Several studies have shown that simvastatin induces apoptosis in a varieties of cell lines including vascular smooth muscle cells (VSMC). The aim of this study was to investigate the signal pathways involved in apoptosis induced by simvastatin.METHODS:Cultured VSMC were treated with simvastatin. Calpain activity was determined by measuring Ca²⁺ ionophore-specific calpain substrate (suc-LLVY-AMC), caspase-3 activation was detected by Western blot, and apoptotic changes were distinguished by annexin Ⅴ binding and DNA laddering.RESULTS:After incubated with 30 μmol/L simvastatin for 8 h, calpain activity had a marked increase (P<0.05, n=4) and reached to more than 3-fold of control at 12 h (P＜0.01). Caspase-3 also activated by simvastatin after 12 h. PD150606, a cell-permeable selective calpain inhibitor, decreased simvastatin-induced apoptosis rate from 24.2%±1.7% to 9.5%±1.9% (P＜0.01) and also prevented simvastatin-induced DNA laddering. Furthermore, 100 μmol/L PD150606 efficiently inhibited simvastatin-induced caspase-3 activation.CONCLUSION:Simvastatin induces apoptosis by activating caspase-3 via calcium-dependent protease calpain.     

Tumor necrosis factor-related apoptosis-inducing ligand participates in injury of vascular endothelial cells induced by rapamycin in vitro

AIM: To investigate the effects of rapamycin on apoptosis, proliferation, migration ability and tumor related apoptosis inducing ligand(TRAIL) in cultured human umbilical vein endothelial cells(HUVECs). METHODS: Cultured HUVECs were treated with rapamycin at the concentrations of 0, 1, 10 and 100 μg/L for 24 h. The cell proliferation was measured by CCK-8 method. The cell migration ability was detected by Transwell chambers and wound healing test. The apoptotic index of HUVECs was quantitatively determined by measuring the activation of caspase-3. The morphological changes of the apoptotic cells were observed by DAPI staining. The expression of TRAIL was detected by Western blotting. RESULTS: A 24 h-incubation with rapamycin(1-100 μg/L) caused significant cell loss associated with the increase in apoptosis, as quantified by the determination of caspase-3 activity(P<0.01) in HUVECs. Obvious apoptotic morphology was observed by DAPI staining in HUVECs incubated with rapamycin. Rapamycin at the concentrations of 1-100 μg/L also impaired the migration ability of HUVECs(P<0.01). In addition, rapamycin(10-100 μg/L) inhibited the proliferation of HUVECs, whereas rapamycin at 1 μg/L had no such effect(P<0.01). Rapamycin(10-100 μg/L) also induced TRAIL expression in a dose-dependent manner(P<0.01). CONCLUSION: Rapamycin induces apoptosis, and inhibits the proliferation and migration of HUVECs. The up-regulation of TRAIL might be related to the injury of vascular endothelial cells caused by rapamycin.