Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

A MicroRNA Catalog of Swine Umbilical Vein Endothelial Cells Identified by Deep Sequencing

MicroRNAs （miRNAs） are endogenous -22 nt RNAs that play important regulatory roles in targeting mRNAs for cleavage or translational repression. Despite the discovery of increasing numbers of human and mouse miRNAs, little is known about miRNAs from pig. In this study, we sought to extend the repertoire of porcine small regulatory RNAs using Solexa sequencing. We sequenced a library of small RNAs prepared from immortalized swine umbilical vein endothelial cells （SUVECs）. We produced over 13.6 million short sequence reads, of which 8 547 658 perfectly mapped to the pig genome. A bioinformatics pipeline was used to identify authentic mature miRNA sequences. We identified 154 porcine miRNA genes, among which 146 were conserved across species, and 8 were pig-specific miRNA genes. The 146 miRNA genes encoded 116 conserved mature miRNAs and 66 miRNA^＊. The 8 pig-specific miRNA genes encoded 4 mature miRNAs. Four potential novel miRNAs were identified. The secondary structures of the 154 miRNA genes were predicted; 13 miRNAs have 2 structures, and miR-9 and miR-199 have 4 and 3 structures, respectively. 36 miRNAs were organized into 19 compact clusters, miR-206, miR-21 and miR-378 were the relatively highly expressed miRNAs. In conclusion, Solexa sequencing allowed the successful discovery of known and novel porcine miRNAs with high accuracy and efficiency. Furthermore, our results supply new data to the somewhat insufficient pig miRBase, and are useful for investigating features of the blood-brain barrier, vascular diseases and inflammation.

Kinase domain insert containing receptor promoter controlled suicide gene system selectively kills human umbilical vein endothelial cells

AIM： To study the selective killing of human umbilical vein endothelial cells （HUVECs） by a double suicide gene under the regulation of a kinase domain insert containing receptor （KDR） promoter and mediated by an adenoviral gene vector. METHODS： Human KDR promoter was cloned by polymerase chain reaction （PCR）, and two recombinant adenoviral plasmids pAdKDR-CdgIyTK, pAdCMV-CDglyTK were constructed according to a two-step transformation protocol. These two newly constructed plasmids were then transfected into 293 packaging cells to grow adenovirus, which were further multiplied and purified. HUVECs and LoVo cells were infected with either of the two resultant recombinant adenoviruses （AdKDR-CDglyTK and AdCMV-CDglyTK） respectively, and the infection rates were estimated by detection of green fluorescent protein （GFP） expression. Infected cells were cultured in culture media containing different concentrations of 5-fiuoroo/tosine （5-FC） and ganciclovir （GCV）, and the killing effects were measured. RESULTS： The two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were successfully constructed and transfected into 293 cells. The resultant recombinant adenoviruses infected cells caused similar infection rates; and the infected cells exhibited different sensitivity to the prodrugs： HUVECs infected with AdCMV-CDglyTK and LoVo cells infected with AdCMVo CDglyTK were highly sensitive to the prodrugs, and HUVECs infected with AdKDR-CDglyTK were similarly sensitive but significantly more sensitive than the LoVo cells infected with AdKDR-CdglyTK （P 〈 0.001）. CONCLUSION： Selective killing of HUVECs may be achieved by gene transfer of double suicide gene under the regulation of the KDR promoter. This finding may provide an optional way to target gene therapy of malignant tumors by abrogation of tumor blood vessels.

Martentoxin, a large-conductance Ca^(2+)-activated K^+ channel inhibitor, attenuated TNF-α-induced nitric oxide release by human umbilical vein endothelial cells

Martentoxin, a 4,046 Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch, has been demonstrated to block large-conductance Ca2＋-activated K＋ （BKca） channels; however, its biological roles are still largely unknown. In the present study, we investigated the pharmacological effects of martentoxin on regulating the production of nitric oxide induced by TNF-a in human umbilical vein endothelial cells （HU- VECs）. We found that, 1, 10 and 100 ~tmol/L martentoxin decreased nitric oxide production by HUVECs ex- posed to 10 ng/mL TNF for 6, 12 and 24 hours. We further demonstrated that martentoxin inhibited the activity of iNOS and retarded the down-regulation of eNOS mRNA induced by TNF-a. Therefore, martentoxin could be a potential therapeutic agent for vascular diseases.

Co-culture of Mesenchymal Stem Cells with Umbilical Vein Endothelial Cells under Hypoxic Condition

By co-culturing humm mesenchymal stem cells (hMSCs) and human umbilical rein endothelial cells (HUVECs) under hypoxia and creating a microenvironment similar to that of transplanted hMSCs for the treatment of avascular ni ANFH, the effect of hMSCs on survival, apoptosis, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) under the hypoxic condition were investigated in vitro. hMSCs and HUVECs were cultured and identified in vitro. Three kinds of conditioned media, CdM-CdMNOR, CdM-CdMHYP and HUVEC-CdMHYP were prepared. HUVECs were cultured with these conditioned media under hypoxia. The survival rate, apoptosis rate, migration and angiogenesis of HUVECs were respectively detected by CCK-8, flow cytometry, Transwell and tube formation assay. The content of SDF-1α, VEGF and IL-6 in CdM was determined by ELISA. Our results showed that hMSCs and HUVECs were cultured and identified successfully. Compared with MSC-CdMNOR and HUVEC-CdMHYP groups, the survival rate, migra-tion and angiogenesis of HUVECs in MSC-CdMHYP group were significantly increased while the apoptosis rate was declined (P<0.05). Moreover, the expression of SDF-1α, VEGF and IL-6 in MSC-CdMHYP group was up-regulated. Under hypoxia, the apoptosis of HUVECs was inhibited while survival, migration and angiogenesis were improved by co-culture of hMSCs and HUVECs. The underlying mechanism may be that hMSCs could secrete a number of cytokines and improve niche, which might be helpful in the treatment of femoral head necrosis.

Effect of IBD sera on expression of inducible and endothelial nitric oxide synthase in human umbilical vein endothelial cells

AIM： To study the expression of endothelial and inducible nitric oxide synthases （eNOS and iNOS） and their role in inflammatory bowel disease （IBD）. METHODS： We examined the effect of sera obtained from patients with active Crohn＇s disease （CD） and ulcerative colitis （UC） on the function and viability of human umbilical vein endothelial cells （HUVEC）. HUVECs were cultured for 0-48 h in the presence of a medium containing pooled serum of healthy controls, or serum from patients with active CD or UC. Expression of eNOS and iNOS was visualized by immunofluorescence, and quantified by the densitometry of Western blots. Proliferation activity was assessed by computerized image analyses of Ki-67 immunoreactive cells, and also tested in the presence of the NOS inhibitor, 10^-4 mol/L L-NAME. Apoptosis and necrosis was examined by the annexin-V-biotin method and by propidium iodide staining, respectively. RESULTS： In HUVEC immediately after exposure to UC, serum eNOS was markedly induced, reaching a peak at 12 h. In contrast, a decrease in eNOS was observed after incubation with CD sera and the eNOS level was minimal at 20 h compared to control （18%±16% vs 23%± 15% P〈0.01）. UC or CD serum caused a significant increase in iNOS compared to control （UC： 300%±21%; CD： 275% ± 27% vs 108% ± 14%, P〈0.01）. Apoptosis/necrosis characteristics did not differ significantly in either experiment. Increased proliferation activity was detected in the presence of CD serum or after treatment with L-NAME. Cultures showed tube-like formations after 24 h treatment with CD serum. CONCLUSION： IBD sera evoked changes in the ratio of eNOS/iNOS, whereas did not influence the viability of HUVEC. These involved down-regulation of eNOS and up-regulation of iNOS simultaneously, leading to increased proliferation activity and possibly a reduced antiinflammatory protection of endothelial cells.

Comparison of conventional and directional freezing for the cryopreservation of human umbilical vein endothelial cells

AIM:To compare conventional slow equilibrium cooling and directional freezing(DF) by gauze package for cryopreservation of human umbilical vein endothelial cells(HUVECs).METHODS:HUVECs were randomly assigned to conventional freezing(CF) and DF by gauze package group. The two groups of HUVECs were incubated with a freezing liquid consisting of 10% dimethylsulfoxide(DMSO), 60% fetal bovine serum(FBS) and 30%Dulbecco’s modified Eagle’s medium(DMEM) and then put into cryopreserved tubes. CF group, slow equilibrium cooling was performed with the following program:precool in 4℃ for 30 min,-20℃ for 1h, and then immersion in-80℃ refrigerator. DF group, the tubes were packaged with gauze and then directional freezing in-80℃ refrigerator straightly. One month later, the vitality of HUVECs were calculated between two groups.RESULTS:There was no significant difference in the survival rate and growth curve between CF and DF groups. The DF group was significantly better than CFgroup in adherent rates, morphological changes and proliferative ability.CONCLUSION:In the conventional cryopreserved method, cells are slow equilibrium cooling by steps(4℃,-20℃ and finally-80℃), which is a complicated and time-consuming process. But the improved DF by gauze package method is better than conventional method, for which is convenient and easy to operate.

Effects of miR-21 antisense oligonucleotides on proliferation,migration and autophagy of human umbilical vein endothelial cells

Objective:To investigate the effects of microRNA-21 antisense nucleotide(AS-miR-21)on the proliferation,migration and autophagy of human umbilical vein endothelial cells(HUVECs).Methods:HUVECs were treated with1,000 nmol/L rapamycin for 6 h(rapamycin group)or ASmiR-21 transfection followed by 1,000 nmol/L rapamycin for6 h(AS-miR-21+rapamycin group).HUVECs without any treatment were defined as control group.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay,scratch wound healing assay and transwell test,respectively.The expressions of microtubule-associated protein light chain 3 Ⅱ/Ⅰ(LC3 Ⅱ/Ⅰ)and Becline-1 were determined by western blotting.Results:The rapamycin group showed decreased OD value and migration rate,an increased ratio of LC3 Ⅱ/Ⅰ and up-regulated expression of Beclin-1 compared with the control group(P<0.05).The AS-miR-21+rapamycin group demonstrated lower OD value,migration rate,the number of migrated cells,and significantly higher ratio of LC3 Ⅱ/Ⅰ and Beclin-1 protein expression level than the control group and the rapamycin group(P<0.05).Conclusion:AS-miR-21 suppressed the autophagy,proliferation and migration in the HUVECs model of autophagy induced by rapamycin.

The Effects and Mechanism of GSA on Expression of MCP-1 in Cultured Human Umbilical Vein Endothelial Cells

Objectives To investigate the effects and mechanism of glycated serum albumin(GSA) on expression of Monocyte chemoattratant protein-1(MCP-1) in Endothelial Cells. Methods Human Umbilical Vein Endothelial Cells (HUVEC)are cultured with GSA of different concentrations and interfered by glycosylation products inhibitor Aminoguanidine (AG) and anti-oxidant N-acetylcy-steine (NAC), The expression of MCP-1 are evaluated by Immunocytochemistry and Sandwich ELISA. MDA content and SOD activity are determined by the technique of TBA and XOD respectively. Results GSA can stimulate MCP-1 production and secretion. Immunocytochemistry showed that after HUVECs were cultured with 50 mg/L GSA, expression of MCP-1 in group 4hrs, 8hrs and 12hrs was 1.3, 1.9 and 2.8 fold as much as that in control group (P < 0.01), and there was significant difference among the experiment groups(P < 0.01). Sandwich ELISA showed that expression of MCP-1 in three different groups was 1.6, 2.4 and 3.0 fold as much as that in control group(P < 0.01), and there was significant difference among the experiment groups(P < 0.01); GSA can cause the decrease of SOD activity(P < 0.05) and increase of MDA content(P < 0.01); AG and NAC can restrain obviously the expression of MCP-1 of HUVECs stimulated by GSA(P < 0.01); NAC can restrain the effect of GSA on SOD activity and MDA content in HUVECs (P < 0.05). Conclusions GSA can stimulate the expression of MCP-1 of endothelial cells by inducing endothelial cells oxidative stress.

Knockdown of Ezrin Suppresses the Migration and Angiogenesis of Human Umbilical Vein Endothelial Cells In Vitro

Progressive tumor growth is dependent on angiogenesis. The mechanisms by which endothelial cells（ECs） are incorporated to develop new blood vessels are not well understood. Recent studies reveal that the ezrin radixin moesin（ERM） family members are key regulators of cellular activities such as adhesion, morphogenetic change, and migration. We hypothesized that ezrin, one of the ERM family members, may play important roles in ECs organization during angiogenesis, and new vessels formation in preexisting tissues. To test this hypothesis, in this study, we investigated the effects of ezrin gene silencing on the migration and angiogenesis of human umbilical vein endothelial cells（HUVECs） in vitro. HUVECs were transfected with plasmids with ezrin-targeting short hairpin RNA by using the lipofectamine-2000 system. Wound assay in vitro and three-dimensional culture were used to detect the migration and angiogenesis capacity of HUVECs. The morphological changes of transfected cells were observed by confocal and phase contrast microscopy. Our results demonstrated that the decreased expression of ezrin in HUVECs significantly induced the morphogenetic changes and cytoskeletal reorganization of the transfected cells, and also reduced cell migration and angiogenesis capacity in vitro, suggesting that ezrin play an important role in the process of HUVECs migration and angiogenesis.

Up-regulation interleukin-6 and interleukin-8 by activated protein C in lipopolysaccharide-treated human umbilical vein endothelial cells

Objective: To investigate the effect of activated protein C (APC) on inflammatory responses in human umbilical vein endothelial cells (HUVEC) stimulated with lipopolysaccharide (LPS). Methods: The second passage of collagenase digested HUVEC was divided into the following groups: serum free medium control group (SFM control), phosphate buffer solution control group (PBS control), LPS group with final concentration of 1 μg/ml (LPS group), APC group with final concentration of 7 μg/ml, Pre-APC group (APC pretreatment for 30 min prior to LPS challenge), and Post-APC group (APC administration 30 min after LPS challenge). Supernatant was harvested at 0, 4, 8, 12 and 24 h after LPS challenge. Interleukin-6 (IL-6) and Interleukin-8 (IL-8) levels were analyzed with ELISA. Cells were harvested at 24 h after LPS challenge, and total RNA was extracted. Mes-senger RNA levels for IL-6 and IL-8 were semi-quantitatively determined by RT-PCR. Results: Compared with control group, IL-6 and IL-8 levels steadily increased 4 to 24 h after LPS stimulation. APC treatment could increase LPS-induced IL-6 and IL-8 production. The mRNA levels of IL-6 and IL-8 exhibited a similar change. Conclusion: APC can further increase the level of IL-6 and IL-8 induced by LPS. The effect of these elevated cytokines is still under investigation.

Changes in Human Umbilical Vein Endothelial Cells Induced by Endothelial Nitric Oxide Synthase Traffic Inducer

This study investigated the changes in human umbilical vein endothelial cells （HUVECs） induced by overexpression of endothelial nitric oxide synthase traffic inducer （NOSTRIN） and its role in cellular injury. Recombinant NOSTRIN-expressing and empty vectors were transfected into cultured HUVECs, and factor Ⅷ-related antigen was examined by using immunohistochemical analysis. Growth curves were generated for both transfected and untransfected cells and these indicated that the prolifera- tive ability of cells overexpressing NOSTRIN was significantly decreased. The expression of NOSTRIN and eNOS proteins was detected by using Western blot analysis, endothelial NOS （eNOS） activity was assayed by using spectrophotometry, and NO2-/NO3- levels were measured usin~ nitrate reductase. Immunohistochemical analysis demonstrated that all groups expressed NOSTRIN in the plasma mem- brane and cytoplasm, and Western blot analysis confirmed that NOSTR1N levels were significantly higher in cells transfected with the NOSTR1N plasmid （P〈0.01）. The activity of eNOS and the levels of NO2-/NO3 were significantly decreased in NOSTRIN overexpressing cells as compared with empty vector and untransfected cells （P〈0.01 and P〈0.01, respectively）. Morphological and ultrastructural changes were observed under light and electron microscopy, and it was found that NOS- TRIN-overexpressing cells were elongated with deformities of the karyotheca, injury to the plasma membrane, increased lipids in the cytoplasm, and shortened microvilli. This study showed that overex- pression of NOSTRIN had a significant effect on eNOS activity in HUVECs and resulted in significant cellular damage.

Gadolinium-promoted angiogenesis involves the activation of PKCα/β_2 and MAPKs in human umbilical vein endothelial cells

Gadolinium has been widely used as a contrast agent for magnetic resonance imaging in clinical practice. Recently, it was reported that gadolinium is involved in nephrogenic systemic fibrosis, although the exact mechanism by which gadolinium triggers nephrogenic systemic fibrosis remains unclear. In this study, we show that gadolinium chloride （GdC13） induced human umbilical vein endothelial cells （HUVECs） to migrate in Matrigel and tubulogenesis during wound healing. Chick chorioallantoic membrane assay confirmed that GdC13 stimulates angiogenesis. Under the optimal angiogenic concentration of GdC13 （1 0 ~tM）, intracellular calcium concentration and reactive oxygen species generation were elevated. Moreover, western blotting results indicate that in cells treated with GdC13, Ca2＋-dependent PKCa/132 was phosphorylated, and MAPKs pathways were also activated. Taken together, GdC13 has a potential effect on angiogenesis in HUVECs, and the possible mechanisms may involve oxidative stress and calcium-related signalin~ pathways.

Culture supernatants of breast cancer cell line MDA-MB-231 treated with parthenolide inhibit the proliferation, migration, and lumen formation capacity of human umbilical vein endothelial cells

Background Parthenolide has been tested for anti-tumor activities, such as anti-proliferation and pro-apoptosis in recent studies. However, little is known about its role in the process of tumor angiogenesis. This study aims to investigate the effects and potential mechanisms of parthenolide on the proliferation, migration and lumen formation capacity of human umbilical vein endothelial cells. Methods Different concentrations of parthenolide were applied to the human breast cancer cell line MDA-MB-231 cells. After 24-hour incubation, the culture supernatants were harvested and used to treat human umbilical vein endothelial cells for 24 hours. Then an inverted fluorescence phase contrast microscope was used to evaluate the human umbilical vein endothelial cells. The secretion of vascular endothelial growth factor （VEGF）, interleukin （IL）-8 and matrix metalloproteinases （MMP）-9 in the culture supernatant of the MDA-MB-231 cells was then measured with enzyme-linked immunosorbent assay （ELISA） assays. Results Suppression of proliferation, migration, and the lumen formation capacity of human umbilical vein endothelial cells was observed in the presence of the culture supernatants from the breast cancer cell line treated with different concentrations of parthenolide. Parthenolide decreased the levels of the angiogenic factors MMP-9, VEGF, and IL-8 secreted by the MDA-MB-231 cells. Conclusions Parthenolide may suppress angiogenesis through decreasing angiogenic factors secreted by breast cancer cells to interfere with the proliferation, migration and lumen-like structure formation of endothelial cells, thereby inhibiting tumor growth. It is a promising potential anti-angiogenic drug.

Effects of Danhong Injection(丹红注射液) and Its Main Components on Anticoagulation and Fibrinolysis in Cultured Vein Endothelial Cells

Objective： To observe the effects of Danhong Injection （丹红注射液） and its main components, including daiclzein and hydroxysafflor yellow A （HSYA）, on the anticoagulation, fibrinolysis, anti-apoptosis in hypoxia model of vein endothelial cells （VECs）. Methods： VECs were prepared and were put in a hypoxia environment, which consisted of mixed gas of 95% N2 and 5% CO2 mixed gas, when reached confluent culture. Five groups used different treatments, including normal control group, hypoxia group, daiclzein group, HSYA group and Danhong Injection group. The VECs were identified by fluorescence double labeling methods. The morphology was observed by a phase contrast microscopy. The effects of Danhong Injection, daiclzein and HSYA on 6 keto prostaglandin F1α （6-keto-PGF1 α） level was measured by the method of radioimmunoassay （RIA）. Superoxide dismutase （SOD） activity was tested by water soluble tetrazolium salt. The content of malondialdehyde （MDA） was measured by thiobarbituric acid. The activities of tissue-type plasminogen activator （t-PA） and plasminogen activator inhibitor （PAl） were measured by the method of chromogenic substrate. The contents of endothelin （ET） and nitric oxide （NO） were detected by non-equilibrium RIA and enzyme- linked immunosorbent assay. Cells apoptosis rate was determined by flow cytometry. Results： Compared with the normal control group, the floating cells number, PAl activity, ET and MDA contents, and cells apoptosis rate in the culture solution of hypoxia group were all significantly increased, whereas the 6-keto-PGF1 α and NO contents, and t-PA and SOD activities were decreased significantly （P〈0.01）. Compared with the hypoxia group, Danhong Injection markedly increased the 6-keto-PGF1 α content and SOD activity, regulated PAl and t-PA activities, ET and NO contents, and decreased MDA content and cells apoptosis rate （P〈0.05 or P〈0.01）. Conclusions： Danhong Injection and its main components played an important role in protecting primary VECs from hypoxic damage by regulating the secretion and vasomotor function of VECs. The function of Danhong Injection was most remarkable.

Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide

Endothelial cell death due to increased reactive oxygen species(ROS) may contribute to the initial endothelial injury,which promotes atherosclerotic lesion formation.Piper sarmentosum(PS),a natural product,has been shown to have an antioxidant property,which is hypothesized to inhibit production of ROS and prevent cell injury.Thus,the present study was designed to determine the effects of PS on the hydrogen peroxide(H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells(HUVECs).In this experiment,HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation(LSGS).HUVECs were treated with various concentrations of H2O2(0-1000 μmol/L) and it was observed that 180 μmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Using the above concentration as the positive control,the H2O2-induced HUVECs were concomitantly treated with various concentrations(100,150,250 and 300 μg/ml) of three different extracts(aqueous,methanol and hexane) of PS.Malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX) levels showed a significant increase(P<0.05) in HUVECs compared to the negative control.However,PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA,SOD,CAT and GPX levels(P<0.05).Furthermore,PS had exhibited ferric reducing antioxidant power with its high phenolic content.Hence,it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs.

A comparison study of the targeting properties of NGR-liposomes and RGD-liposomes towards human umbilical vein endothelial cells

Endothelial cells in the angiogenic vessels of solid tumors over-express several proteins, which could be recognized by some peptide ligands. In this study, the targeting properties of two peptides, RGD （arginine-glycine-aspartic acid） and NGR （asparagine-glycine-arginine）, towards human umbilical vein endothelial cells （HUVEC） were compared in vitro using doxorubicin entrapped liposomes as vehicles. The doxorubicin-loaded sterically stabilized liposomes （SSL-DOX） and RGD or NGR modified liposomes （RGD-SSL-DOX or NGR-SSL-DOX） were prepared and characterized. The studied properties included particle size, zeta potential, encapsulation efficiency and in vitro release rate. Flow cytometry, confocal microscopy and SRB assay were used on HUVEC to assess the targeting effect of the two peptides towards endothelial cells of tumor vasculature. All of the liposomes prepared in this study were obtained with encapsulation efficiencies of above 98%, particle sizes of about 65-75 nm and slight negative surface charges. The in vitro release results demonstrated that the modification of RGD or NGR did not alter the release behaviors of liposomes. It was observed in flow cytometry that the uptake of doxorubicin by HUVEC from SSL-DOX, NGR-SSL-DOX, RGD-SSL-DOX and doxorubicin solution followed the order of doxorubicin solution〉RGD-SSL-DOX 〉NGR-SSL-DOX〉SSL-DOX, and the intemalized doxorubicin distributed in both nuclei and cytoplasm for ligand modified SSL and only in nuclei for non-targeted SSL. The order of cytotoxicity in SRB assay was the same as that of the uptake study. The characterization study indicated that modifications did not significantly change the properties of the sterically stabilized liposomes. HUVEC treated with both modified liposomes showed higher uptake of doxorubicin as compared to those with SSL-DOX as a result of the receptor-mediated endocytosis. Moreover, RGD-SSL-DOX exhibited better targeting effect than NGR-SSL-DOX.

Ginsenoside Rb1 Protects Human Umbilical Vein Endothelial Cells against High Glucose-Induced Mitochondria-Related Apoptosis through Activating SIRT3 Signalling Pathway

Objective:To investigate whether ginsenoside Rb1(Rb1)can protect human umbilical vein endothelial cells(HUVECs)against high glucose-induced apoptosis and examine the underlying mechanism.Methods:HUVECs were divided into 5 groups:control group(5.5 mmol/L glucose),high glucose(HG,40 mmol/L)treatment group,Rb1(50μmol/L)treatment group,Rb1 plus HG treatment group,and Rb1 and 3-(1 H-1,2,3-triazol-4-yl)pyridine(3-TYP,16μmol/L)plus HG treatment group.Cell viability was evaluated by cell counting kit-8 assay.Mitochondrial and intracellular reactive oxygen species were detected by Mito Sox Red mitochondrial superoxide indicator and dichloro-dihydro-fluorescein diacetate assay,respectively.Annexin V/propidium iodide staining and fluorescent dye staining were used to measure the apoptosis and the mitochondrial membrane potential of HUVECs,respectively.The protein expressions of apoptosis-related proteins[Bcl-2,Bax,cleaved caspase-3 and cytochrome c(Cyt-c)],mitochondrial biogenesis-related proteins[proliferator-activated receptor gamma coactivator 1-alpha,nuclear respiratory factor-1 and mitochondrial transcription factor A],acetylation levels of forkhead box O3 a and SOD2,and sirtuin-3(SIRT3)signalling pathway were measured by immunoblotting and immunoprecipitation.Results:Rb1 ameliorated survival in cells in which apoptosis was induced by high glucose(P<0.05 or P<0.01).Upon the addition of Rb1,mitochondrial and intracellular reactive oxygen species generation and malondialdehyde levels were decreased(P<0.01),while the activities of antioxidant enzymes were increased(P<0.05 or P<0.01).Rb1 preserved the mitochondrial membrane potential and reduced the release of Cyt-c from the mitochondria into the cytosol(P<0.01).In addition,Rb1 upregulated mitochondrial biogenesis-associated proteins(P<0.01).Notably,the cytoprotective effects of Rb1 were correlated with SIRT3 signalling pathway activation(P<0.01).The effect of Rb1 against high glucose-induced mitochondria-related apoptosis was restrained by 3-TYP(P<0.05 or P<0.01).Conclusion:Rb1 could protect HUVECs from high glucose-induced apoptosis by promoting mitochondrial function and suppressing oxidative stress through the SIRT3 signalling pathway.

Expression of platelet-endothelial cell adhesion molecule-1 in human umbilical vein endothelial cells by exposure to advanced glycosylation end products and inflammatory mediators

Objective To determine whether advanced glycosylation end products modified bovine serum albumin (AGEs-BSA) affects endothelial cell lateral junction protein, platelet-endothelial cell adhesion molecule-1 (PECAM-1) in the presence or absence of inflammatory mediators.Methods Cultured human umbilical vein endothelial cells (HUVECs) were exposed to AGEs-BSA for 6, 12, 24, and 36 hours, and exposed to AGEs-BSA glycosylated with different concentrations of glucose, tumor necrosis factord-α (TNF-α), interferon (IFN-γ), TNF-α + IFN-y and AGEs-BSA + TNF-α for 24 hours, respectively. Expression of PECAM-1 mRNA was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) with β-actin as an internal standard, and sequencing of RT-PCR products was performed to confirm the specificity of amplification for PECAM-1 gene. The endothelial cell surface expression of PECAM-1 was determined by flow cytometry (FCM).Results There were no significant changes in the expression of PECAM-1 mRNA and protein when the cells were exposed to AGEs-BSA with different concentrations or periods ( P>0. 05). However, PECAM-1 expression was reduced in the cells treated with TNF-α, IFN-y, TNF-α + IFN-γ and AGEs-BSA + TNF-α. The level of PECAM-1 treated with AGEs-BSA + TNF-α was lower than that of TNF-α treated alone (P<0. 01).Conclusions AGEs-BSA had no effect on the expression of PECAM-1 mRNA and protein in cultured HUVEC. With the presence of inflammatory mediator TNF-α, AGEs-BSA decreased the level of PECAM-1, which might reduce the adhesion interaction between adjacent endothelial cells, enhance the permeability of endothelial cells, and might be implicated in the endothelial dysfunction and pathogenesis of atherosclerosis in patients with diabetes mellitus. The significance of this phenomenon in intracellular signal transduction remains to be determined.

Effects of leptin-modified human placenta-derived mesenchymal stem cells on angiogenic potential and peripheral inflammation of human umbilical vein endothelial cells(HUVECs) after X-ray radiation

Combined radiation-wound injury(CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells(HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells(HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8(CCK-8) assay. The secretion of pro-inflammatory cytokines(human granulocyte macrophage-colony stimulating factor(GM-CSF), interleukin(IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay(ELISA). The expression of pro-angiogenic factors(vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(b FGF)) mRNA was detected by real-time quantitative polymerase chain reaction(RT-qPCR) assay. Relevant molecules of the nuclear factor-κB(NF-κB) and Janus kinase(JAK)/signal transducer and activator of transcription(STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs(HPMSCs/leptin) exhibited better cell proliferation, migration, and angiogenic potential(expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines(human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.