Inhibition of viability of human retinal microvascular endothelial cells by vialinin A under high glucose condition

AIM:To investigate the effects of vialinin A on viability of human retinal endothelial cells(HRECs)under high glucose condition and its potential mechanism.METHODS:The HRECs were divided into four groups:normal glucose control group(NG,5 mmol/L D-glucose),high glucose group(HG,30 mmol/L D-glucose),HG+1μmol/L vialinin A group,and HG+5μmol/L vialinin A group.The cell viabilities were measured with cell counting kit-8(CCK-8)assay for proliferation,with scratch assay for migration,and tube formation,for evaluation of the impact of vialinin A on cellular behaviour.Real-time PCR and Western blotting were used to determine the expression level of vascular endothelial growth factor(VEGF).RESULTS:The proliferative capacity and migration of HRECs was reduced by 5μmol/L vialinin A in high glucose environment(both P<0.05).Vialinin A also inhibited highglucose-induced tube formation of HRECs.The expression level of VEGF and PI3K in HRECs was also significantly decreased by vialinin A(P<0.05).CONCLUSION:Vialinin A inhibits the cell viability of HRECs.It may serve as a potential target for anti-angiogenic therapy.

Human umbilical cord mesenchymal stem cells derivedexosomes on VEGF-A in hypoxic-induced mice retinal astrocytes and mice model of retinopathy of prematurity

AIM:To observe the effect of human umbilical cord mesenchymal stem cells(hUCMSCs)secretions on the relevant factors in mouse retinal astrocytes,and to investigate the effect of hUCMSCs on the expression of vascular endothelial growth factor-A(VEGF-A)and to observe the therapeutic effect on the mouse model of retinopathy of prematurity(ROP).METHODS:Cultured hUCMSCs and extracted exosomes from them and then retinal astrocytes were divided into control group and hypoxia group.MTT assay,flow cytometry,reverse transcription-polymerase chain reaction(RT-PCR)and Western blot were used to detect related indicators.Possible mechanisms by which hUCMSCs exosomes affect VEGF-A expression in hypoxia-induced mouse retinal astrocytes were explored.At last,the efficacy of exosomes of UCMSCs in a mouse ROP model was explored.Graphpad6 was used to comprehensively process data information.RESULTS:The secretion was successfully extracted from the culture supernatant of hUCMSCs by gradient ultracentrifugation.Reactive oxygen species(ROS)and hypoxia inducible factor-1α(HIF-1α)of mice retinal astrocytes under different hypoxia time and the expression level of VEGF-A protein and VEGF-A mRNA increased,and the ROP cell model was established after 6h of hypoxia.The secretions of medium and high concentrations of hUCMSCs can reduce ROS and HIF-1α,the expression levels of VEGF-A protein and VEGF-A mRNA are statistically significant and concentration dependent.Compared with the ROP cell model group,the expression of phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)signal pathway related factors in the hUCMSCs exocrine group is significantly decreased.The intravitreal injection of the secretions of medium and high concentrations of hUCMSCs can reduce VEGF-A and HIF-1αin ROP model tissues.HE staining shows that the number of retinal neovascularization in ROP mice decreases with the increase of the dose of hUCMSCs secretion.CONCLUSION:In a hypoxia induced mouse retinal astrocyte model,hUCMSCs exosomes are found to effectively reduce the expression of HIF-1αand VEGF-A,which are positively correlated with the concentration of hUCMSCs exosomes.HUCMSCs exosomes can effectively reduce the number of retinal neovascularization and the expression of HIF-1αand VEGF-A proteins in ROP mice,and are positively correlated with drug dosage.Besides,they can reduce the related factors on the PI3K/AKT/mTOR signaling pathway.

β-Estradiol 17-acetate enhances the in vitro vitality of endothelial cells isolated from the brain of patients subjected to neurosurgery

In the current landscape of endothelial cell isolation for building in vitro models of the blood-brain barrier,our work moves towards reproducing the features of the neurovascular unit to achieve glial compliance through an innovative biomimetic coating technology for brain chronic implants.We hypothesized that the autologous origin of human brain mic rovascular endothelial cells(hBMECs)is the first requirement for the suitable coating to prevent the glial inflammato ry response trigge red by foreign neuroprosthetics.Therefo re,this study established a new procedure to preserve the in vitro viability of hBMECs isolated from gray and white matter specimens taken from neurosurge ry patients.Culturing adult hBMECs is generally considered a challenging task due to the difficult survival ex vivo and progressive reduction in proliferation of these cells.The addition of 10 nMβ-estradiol 17-acetate to the hBMEC culture medium was found to be an essential and discriminating factor promoting adhesion and proliferation both after isolation and thawing,suppo rting the well-known protective role played by estrogens on microvessels.In particular,β-estradiol 17-acetate was critical for both freshly isolated and thawed female-derived hBMECs,while it was not necessary for freshly isolated male-derived hBMECs;however,it did countera ct the decay in the viability of the latter after thawing.The tumo r-free hBMECs were thus cultured for up to 2 months and their growth efficiency was assessed befo re and after two periods of cryopreservation.Des pite the thermal stress,the hBMECs remained viable and suitable for re-freezing and storage for several months.This approach increasing in vitro viability of hBMECs opens new perspectives for the use of cryopreserved autologous hBMECs as biomimetic therapeutic tools,offering the potential to avoid additional surgical sampling for each patient.

Down-regulation of histone deacetylase 7 reduces biological activities of retinal microvascular endothelial cells under high glucose condition and related mechanism

AIM:To investigate the expression and effect of histone deacetylase 7(HDAC7)in human retinal microvascular endothelial cells(HRMECs)under high glucose condition and related mechanism,and the expression of HDAC7 in the retinal tissue in diabetic rats.METHODS:The expression of HDAC7 in HRMECs under high glucose and the retinal tissue from normal or diabetic rats were detected with immunohistochemistry and Western blot.LV-shHDAC7 HRMECs were used to study the effect of HDAC7 on cell activities.Cell count kit-8(CCK-8),5-ethynyl2’-deoxyuridine(EdU),flow cytometry,scratch test,Transwell test and tube formation assay were used to examine the ability of cell proliferation,migration,and angiogenesis.Finally,a preliminary exploration of its mechanism was performed by Western blot.RESULTS:The expression of HDAC7 was both upregulated in retinal tissues of diabetic rats and high glucosetreated HRMECs.Down-regulation of HDAC7 expression significantly reduced the ability of proliferation,migration,and tube formation,and reversed the high glucose-induced high expression of CDK1/Cyclin B1 and vascular endothelial growth factor in high glucose-treated HRMECs.CONCLUSION:High glucose can up-regulate the expression of HDAC7 in HRMECs.Down-regulation of HDAC7 can inhibit HRMECs activities.HDAC7 is proposed to be involved in pathogenesis of diabetic retinopathy and a therapeutic target.

Transforming growth factor-β2 induces morphological alteration of human corneal endothelial cells in vitro

AIM:To investigate the morphological altering effect of transforming growth factor-β2(TGF-β2) on untransfected human corneal endothelial cells(HCECs)in vitro.METHODS:After untransfected HCECs were treated with TGF-β2 at different concentrations, the morphology,cytoskeleton distribution, and type IV collagen expression of the cells were examined with inverted contrast light microscopy, fluorescence microscopy,immunofluorescence or Western Blot.RESULTS:TGF-β2 at the concentration of 3-15 μg/L had obviously alterative effects on HCECs morphology in dose and time-dependent manner, and 9 μg/L was the peak concentration. TGF-β2(9 μg/L) altered HCE cell morphology after treatment for 36 h, increased the mean optical density(P 【0.01) and the length of F-actin,reduced the mean optical density(P 【0.01) of the collagen type IV in extracellular matrix(ECM) and induced the rearrangement of F-actin, microtubule in cytoplasm and collagen type IV in ECM after treatment for 72 h.·CONCLUTION: TGF-β2 has obviously alterative effect on the morphology of HCECs from polygonal phenotype to enlarged spindle-shaped phenotype, in dose and time-dependence manner by inducing more, elongation and alignment of F-actin, rearrangement of microtubule and larger spread area of collagen type IV.

The effects of microRNA-34a regulating Notch-1/NF-κB signaling pathway on lipopolysaccharide-induced human umbilical vein endothelial cells

BACKGROUND: Notch-1/NF-κB signaling plays a key role in the cecal ligation and puncture(CLP)-induced sepsis. This study aims to investigate the intervention effects of microRNA-34a(miR-34a) lentivirus regulating Notch-1/NF-κB signaling pathway on lipopolysaccharide(LPS)-induced human umbilical vein endothelial cells(HUVEC).METHODS: HUVEC were divided into four groups as the following: they were infected with negative control lentivirus(NC group) or miR-34a lentivirus(OE group); LPS(1 g/mL) was added on the third day on the basis of NC group and OE group for 24 hours(NC+LPS group or OE+LPS group). The levels of TNF-α, IL-1β, IL-6, and IL-10 in the cell supernatants, and the mRNA and protein expression of Notch-1 and NF-κB in the HUVEC were evaluated.RESULTS: After 24 hours, the levels of TNF-α, IL-1β, IL-6 in the cell supernatants and the protein expression of NF-κB from NC+LPS group were significantly higher than those of NC group, but IL-10 level and the protein expression of Notch-1 in NC+LPS group were the opposite. After intervention of miR-34a lentivirus, the cell supernatants TNF-α and the protein expression of NF-κB in OE+LPS group after 24 hours markedly decreased compared to NC+LPS group. While the cell supernatants IL-1β and IL-6 and the mRNA expression of NF-κB slightly decreased in OE+LPS group, IL-10 and the mRNA and protein expression of Notch-1 were the opposite.CONCLUSION: miR-34a regulating Notch-1/NF-κB signaling pathway can reduce the HUVEC damage caused by LPS stimulation.

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.

Damaging Effect of Cigarette Smoke Extract on PrimaryCultured Human Umbilical Vein Endothelial Cells and Its Mechanism

Objective To investigate the cellular effects of cigarette smoke extract (CSE) on primarily cultured human umbilical vein endothelial cells (HUVEC). Methods The effects of CSE (5%-20%) and nicotine (10-4 mol/L) on HUVEC viability, proliferation, angiogenesis and apoptosis were observed. Results CSE decreased HUVEC survival rate and angiogenesis after 24 h as well as its proliferation after 48 h in a dose-dependent manner. Moreover, CSE induced apoptosis of HUVEC as indicated in condensation of nuclear chromatin and the presence of hypodiploid DNA. HUVEC incubated with CSE for 24 h gave a significant decrease in the expression of Bcl-2 as well as the decline in the Bcl-2/Bax ratio accompanied with the loss of mitochondrial membrane potential and excess cytosolic calcium. Our study also observed that p53 protein level decreased, rather than increased in cells treated with CSE. Nicotine had no discernible inhibitory effects on the above indices of HUVEC. Conclusion Exposure to CSE other than nicotine causes inhibition of viability, proliferation and differentiation of HUVEC. CSE-induced HUVEC injury is mediated in part through accelerated apoptosis but independent of p53 pathway. It appears that mitochondria have played a key role in the apoptosis of HUVEC induced by CSE.

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.

Effect of luteolin on apoptosis and vascular endothelial growth factor in human choroidal melanoma cells

AIM:To investigate the effects of luteolin on apoptosis,the cell cycle,and the expression and secretion of vascular endothelial growth factor(VEGF)in human choroidal melanoma cells(C918 and OCM-1).METHODS:C918 and OCM-1 cells cultured in vitro were treated with various concentrations of luteolin(0,5,10,15μmol/L).Cell growth was observed with an inverted microscope,and cell cycle arrest was detected by propidium iodide(PI)staining using flow cytometry.Apoptosis was detected by Hoechst33342 staining,and apoptosis rate was determined by Annexin V-FITC/PI experiments using flow cytometry.The expression of apoptosis-related proteins Bcl-2,Bax and VEGF was analyzed using Western blots.The levels of VEGF secreted by the cells into the supernatant was analyzed using ELISA.RESULTS:After treating with 5 to 15μmol/L luteolin for 48 h,the fusion degree of C918 and OCM-1 cells decreased,and more floating apoptotic cells appeared.Luteolin treatment increased the G0-G1 phase ratio of the C918 and OCM-1 cells,blocked cell cycle progression,and increased the apoptosis rate of the C918 and OCM-1 cells.Western blot showed that luteolin decreased the expression of Bcl-2 and VEGF in the C918 and OCM-1 cells and increased the expression of Bax protein.The ELISA results showed that 10 to 15μmol/L luteolin decreased the cell secretion of VEGF.CONCLUSION:Luteolin may induce apoptosis by regulating the levels of apoptosis-related proteins in C918 and OCM-1 cells.Luteolin can induce cell cycle arrest,decrease the expression of VEGF.

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.

Epigallocatechin-3-gallate attenuates lipopolysaccharideinduced inflammation in human retinal endothelial cells

AIM:To investigate the mechanism underlying the anti-inflammatory effects of epigallocatechin-3-gallate(EGCG)in lipopolysaccharide(LPS)-stimulated human retinal endothelial cells(HRECs).METHODS:HRECspre-treatedwithEGCG(0-100μmol/L)were stimulated with LPS(250 ng/mL).Levels of tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),monocyte chemotactic protein-1(MCP-1)and nitric oxide(NO)in the supernatants were determined by enzyme-linked immunosorbent assay(ELISA)and Griess assay.The protein expression of phosphorylated extracellular signal-regulated kinase(ERK)1/2 and p38 mitogen-activated protein kinases(p38)were determined by Western blot analysis.RESULTS:EGCG pre-treatment significantly inhibited the secretion of TNF-α,VEGF,MCP-1 and NO in LPSstimulated HRECs.Moreover,EGCG effectively attenuated LPS-induced activation and phosphorylation of ERK1/2 and p38 in HRECs in a dose-dependent manner.CONCLUSION:EGCG exhibited inhibitory effects on LPS-induced pro-inflammatory cytokines production by modulating ERK1/2 and p38 pathways in HRECs,suggesting EGCG as a potential candidate for antiinflammatory intervention.

New categorization of human vascular endothelial cells by pro-vs anti-proliferative phenotypes

AIM: To integrally understand the effects of human vascular endothelial cells(VECs) on the proliferation of vascular smooth muscle cells(VSMCs).METHODS: Various kinds of human VECs of different origins were co-cultured with human aortic smooth muscle cells, a representative of human VSMCs. To exclude the irrelevant effects due to growth competition between VECs and VSMCs, the proliferation of VECs had previously been arrested via a low-dose gamma rayirradiation. To discriminately analyze the proliferation of VSMCs from that of VECs, the former cells were labeled with red fluorescent dye while the latter cells were labeled with green fluorescent dye before performing coculture experiments. After 4 d, total cells were harvested and subjected to flow cytometric analyses. Decrements in red fluorescence intensities due to proliferationmediated dilutions were measured and mathematically processed using a specific software to quantitatively evaluate the proliferation of VSMCs. The findings obtained from the flow cytometry-based analyses were further validated by microscopic observations. RESULTS: Commercially available primary cultured human VECs exclusively promoted VSMC proliferation regardless of their tissue origins and we termed these pro-proliferative VECs as "typeⅠ". By contrast, VECs freshly generated from human bone marrow-derived endothelial progenitors cells or human pluripotent stem cells including embryonic stem cells and induced pluripotent stem cells suppressed VSMC proliferation and we termed these anti-proliferative VECs as "typeⅡ". Repetitive subcultures as well as oxidative stress induced "type Ⅱ VECs to typeⅠ" conversion along with an induction of Regulator of G-protein signaling 5(RGS5)Compatibly, anti-oxidant treatments suppressed both the subculture-dependent "typeⅡ to typeⅠ" conversion and an induction of RGS5 gene. Immunostaining studies of clinical specimens indicated that RGS5 protein expressions in endothelial layers were low in norma arteries but they were up-regulated in pathologica arteries including hypertension, atherosclerosis and autoimmune vasculitis in a dose-dependent manner Overexpression and knockdown of RGS5 caused that"typeⅡ to typeⅠ" and "typeⅠ to type Ⅱ" phenotype conversions of VECs, respectively. CONCLUSION: Human VECs are categorized into two types: pro-proliferative RGS5^(high) VECs(typeⅠ) and antiproliferative RGS5 ^(low) VECs(typeⅡ).

Inhibitory effects of safranal on laser-induced choroidal neovascularization and human choroidal microvascular endothelial cells and related pathways analyzed with transcriptome sequencing

AIM:To determine the effects of safranal on choroidal neovascularization(CNV)and oxidative stress damage of human choroidal microvascular endothelial cells(HCVECs)and its possible mechanisms.METHODS:Forty-five rats were used as a laser-induced CNV model for testing the efficacy and safety of safranal(0.5 mg/kg·d,intraperitoneally)on CNV.CNV leakage on fluorescein angiography(FA)and CNV thickness on histology was compared.HCVECs were used for a H_(2)O_(2)-induced oxidative stress model to test the effect of safranal in vitro.MTT essay was carried to test the inhibition rate of safranal on cell viability at different concentrations.Tube formation was used to test protective effect of safranal on angiogenesis at different concentrations.mRNA transcriptome sequencing was performed to find the possible signal pathway.The expressions of different molecules and their phosphorylation level were validated by Western blotting.RESULTS:On FA,the average CNV leakage area was 0.73±0.49 and 0.31±0.11 mm^(2)(P=0.012)in the control and safranal-treated group respectively.The average CNV thickness was 127.4±18.75 and 100.6±17.34μm(P=0.001)in control and safranal-treated group.Under the condition of oxidative stress,cell proliferation was inhibited by safranal and inhibition rates were 7.4%-35.4%at the different concentrations.For tube formation study,the number of new branches was 364 in control group and 35,42,and 17 in 20,40,and 80μg/mL safranal groups respectively(P<0.01).From the KEGG pathway bubble graph,the PI3K-AKT signaling pathway showed a high gene ratio.The protein expression was elevated of insulin receptor substrate(IRS)and the phosphorylation level of PI3K,phosphoinositide-dependent protein kinase 1/2(PDK1/2),AKT and Bcl-2 associated death promoter(BAD)was also elevated under oxidative stress condition but inhibited by safranal.CONCLUSION:Safranal can inhibit CNV both in vivo and in vitro,and the IRS-PI3K-PDK1/2-AKT-BAD signaling pathway is involved in the pathogenesis of CNV.

Pro-vs anti-stenotic capacities of type-Ⅰ vs type-Ⅱ human induced pluripotent-derived endothelial cells

AIM:To verify in vivo relevance of the categorization of human vascular endothelial cells(VECs)into type-I(proproliferative)and type-II(anti-proliferative).METHODS:Endothelial layers of murine femoral arteries were removed by wire injury(WI)operation,a common technique to induce arteriostenosis.Type-I and type-II VECs produced from human induced pluripotent stem cells(iPSCs),whose characters were previously determined by their effects on the proliferation of vascular smooth muscle cells in in vitro co-culture experiments,were mixed with Matrigel?Matrix.The mixtures were injected into subcutaneous spaces around WI-operated femoral arteries for the transplanted human iPSC-derived VECs(iPSdECs)to take a route to the luminal surface via vasa vasorum,a nutrient microvessel for larger arteries.Histologies of the femoral arteries were examined over time.The presence of human iPSdECs was checked by immunostaining studies using an antibody that specifically recognizes human VECs.Degrees of stenosis of the femoral arteries were calculated after three weeks.To determine the optimal experimental condition,xenotransplantation experiments were performed under various conditions using immunocompromised mice as well as immunocompetent mice with or without administration of immunosuppressants.RESULTS:Because immunocompromised mice showed unexpected resistance to WI-induced arteriostenosis,we performed xenotransplantation experiments using immunocompetent mice along with immunosuppressant administrations.After one week,luminal surfaces of the WI-operated arteries were completely covered by human iPSdECs,showing the efficacy of our novel transplantation technique.After three weeks,type-IiPSdECs-transplanted arteries underwent total stenosis,while type-II-iPSdECs-transplanted arteries remained intact.However,untransplanted arteries of immunosuppressant-treated mice also remained intact by unknown reasons.We found that transplanted human VECs had already been replaced by murine endothelial cells by this time,indicating that a transient existence of human type-II-iPSdECs on arterial luminal surfaces can sufficiently prevent the development of stenosis.Thus,we re-performed xenotransplantation experiments using immunocompetent mice without administrating immunosuppressants and found that arteriostenosis was accelerated or prevented by transplantation of type-I or type-II iPSdECs,respectively.Similar results were obtained from the experiments using human embryonic stem cell-derived VECs at early passages(i.e.,type-II)and late passages(i.e.,type-I).CONCLUSION:Pro-and anti-stenosis capacities of type-I and type-II human iPSdECs were verified,respectively,promising a therapeutic application of allogenic iPSdECs.

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.

Interaction between Colon Cancer Cells and Human Liver Sinusoidal Endothelial Cells Promotes Liver Metastasis of Tumor Cells

OBJECTIVE To investigate the effect of co-culture between colon cancer cells （SW1116） and human liver sinusoidal endothelial cells （HLSECs） on cancer cell metastasis, and to provide a novel model for studying the mechanism of colon cancer liver metastasis. METHODS HLSECs and SW1116 were co-cultured for 21 rounds in vitro. Transwell migration, gelatin-zymography, CCK-8 proliferation and colony formation assays were used to examine the invasion, proliferation, and colony forming ability of cancer cells. Assays were carried out to examine tumor growth ability and liver metastasis. The associated molecular change was examined by western blotting. RESULTS After 21 selection rounds, colon cancer cells SWl 1161）21 displayed a clear boundary. Compared with the 5W1116 cells, SW1116P21 cells had a greater invasive ability, cell proliferation and colony formation in soft agar. A gelatin-zymography assay showed that the ability of SW1116P21 cells to secrete matrix metalloproteinase-2/9 was significantly greater than that of SWl116 cells. Additionally, the capacity for subcutaneous tumor formation of SW1116P21 was significantly increased. It was found that mice injected with SW1116P21 cells developed significantly more visually observable liver nodules than mice injected with SW1116 cells. Western blotting showed increased vimentin expression and decreased E-cadherin expression in the SW1116P21 cells, compared with the SWl 116 cells. CONCLUSION The interaction between SW1116 and HLSECs may promote tumor cell invasion, proliferation and colony formation in vitro, and tumor formation and liver metastasis in vivo. An epithelial-mesenchymal transition occurs in SWl 116P21 cells, which contributes to the change in the characteristics of tumor cells.

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.

Effects of Fumonisin B1 on Biomechanics and Cytoskeleton of Human Umbilical Vein Endothelial Cells

Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.

Rhizoma Chuanxiong regulates vascular endothelial growth factor production in hypoxic human umbilical vein endothelial cells in vitro and in peri-infarct rat brain tissue

BACKGROUND： Vascular endothelial growth factor （VEGF） acts as ＂molecular bridge＂ following ischemic stroke to improve and restore blood supply and reduce infarction volume. Clinical studies have demonstrated the efficacy of Rhizoma Chuanxiong （Chuanxiong） in the treatment of ischemic cerebrovascular diseases. However, whether it promotes endogenous VEGF expression in ischemic stroke remains unknown. OBJECTIVE： To investigate the influence of Rhizoma Chuanxiong on VEGF production in vitro cultured human umbilical vein endothelial cells and on VEGF expression in ischemic cerebral tissues to explore its role in angiogenesis. DESIGN, TIME AND SETTING： In vitro basic comparison of traditional Chinese drug-containing serum pharmacology; in vivo randomized, controlled, animal experiment. This study was performed at the Medical Laboratory of West China Hospital, Sichuan University between December 2002 and April 2004. MATERIALS： Two Chinese rabbits were selected. One was intragastrically perfused with 5.8 g/kg Rhizoma Chuanxiong extract twice per day for three consecutive days to prepare Rhizoma Chuanxiong extract-containing serum. The remaining rabbit was intragastrically perfused with the same volume of normal saline twice per day for three consecutive days. Rhizoma Chuanxiong extract was provided by Beijing Traditional Chinese Medicine Research Institute, predominantly composed of ligustrazine, ligustilide, and ferulic acid. ChemiKineTM human VEGF Kit was purchased from Chemicon, USA; mouse anti-VEGF monoclonal antibody and biotin-goat anti-mouse IgG were purchased from Santa Cruz Biotechnology. Inc., USA. METHODS： （1） In vitro experiment： in vitro cultured human umbilical vein endothelial cells were separately incubated in rabbit serum with 10% Rhizoma Chuanxiong extract, normal medium without rabbit serum, and rabbit serum without Rhizoma Chuanxiong extract （blank control）. In addition, cells from the three groups were incubated under normoxia （5% CO2, 95% air） and hypoxia （1% 02, 5% CO2, 94% N2）, respectively, for 24 hours. （2） In vivo experiment： a total of 4/44 Sprague Dawley rats were selected for the sham-operated group （no occlusion）, and the remaining rats were used to establish a cerebral ischemiaJreperfusion model by suture occlusion. 32 animals with ischemia/reperfusion injury were randomly divided into treatment and model groups, with 16 rats in each group. Both groups were intraperitoneally infused with 0.58 g/kg Rhizoma Chuanxiong extract and normal saline two hours following reperfusion. The sham-operated group was administrated normal saline. Animals were treated with saline or Chuanxiong extracts （0.58 g/kg） twice per day for three consecutive days. MAIN OUTCOME MEASURES： In vitro experiment： VEGF concentration was detected in each group by enzyme-linked immunosorbent assay. In vivo experiment： behavioral alterations of rats were evaluated by neurological function scale; infarct volume was assessed by hematoxylin-eosin staining; VEGF protein expression in the infarct regions was determined by immunohistochemistry. RESULTS： （1） VEGF levels were similar between the three groups under normexic condition （P 〉 0.05）; while hypoxia induced VEGF production （P 〈 0.01 ）. VEGF levels in the drug-containing serum group were particularly higher compared with the other groups （P 〈 0.01）. （2） Compared with normal saline treatment, Rhizoma Chuanxiong extract significantly improved the neurological scale and reduced cerebral infarct volumes （P〈 0.05）. The percent of VEGF-positive cells was significantly greater than the model group （P 〈 0.05）. The sham-operated group exhibited normal neurological function, with no infarct focus. CONCLUSION： Rhizoma Chuanxiong extract-containing rabbit serum effectively promoted cultured VEGF production under hypoxia. Rhizoma Chuanxiong extract upregulated VEGF expression in the infarct region, improved neurological function, and reduced infarct size.