Human Periodontal Ligament Stem Cell and Umbilical Vein Endothelial Cell Co-Culture to Prevascularize Scaffolds for Angiogenic and Osteogenic Tissue Engineering

(1) Background: Vascularization remains a critical challenge in bone tissue engineering. The objective of this study was to prevascularize calcium phosphate cement (CPC) scaffold by co-culturing human periodontal ligament stem cells (hPDLSCs) and human umbilical vein endothelial cells (hUVECs) for the first time; (2) Methods: hPDLSCs and/or hUVECs were seeded on CPC scaffolds. Three groups were tested: (i) hUVEC group (hUVECs on CPC); (ii) hPDLSC group (hPDLSCs on CPC); (iii) co-culture group (hPDLSCs + hUVECs on CPC). Osteogenic differentiation, bone mineral synthesis, and microcapillary-like structures were evaluated; (3) Results: Angiogenic gene expressions of co-culture group were 6–9 fold those of monoculture. vWF expression of co-culture group was 3 times lower than hUVEC-monoculture group. Osteogenic expressions of co-culture group were 2–3 folds those of the hPDLSC-monoculture group. ALP activity and bone mineral synthesis of co-culture were much higher than hPDLSC-monoculture group. Co-culture group formed capillary-like structures at 14–21 days. Vessel length and junction numbers increased with time; (4) Conclusions: The hUVECs + hPDLSCs co-culture on CPC scaffold achieved excellent osteogenic and angiogenic capability in vitro for the first time, generating prevascularized networks. The hPDLSCs + hUVECs co-culture had much better osteogenesis and angiogenesis than monoculture. CPC scaffolds prevacularized via hPDLSCs + hUVECs are promising for dental, craniofacial, and orthopedic applications.

Protein Micropatterning in 2.5D: An Approach to Investigate Cellular Responses in Multi-Cue Environments

The extracellular microenvironment is an important regulator of cell functions. Numerous structural cues present in the cellular microenvironment, such as ligand distribution and substrate topography, have been shown to influence cell behavior. However, the roles of these cues are often studied individually using simplified, single-cue platforms that lack the complexity of the three-dimensional, multi-cue environment cells encounter in vivo. Developing ways to bridge this gap, while still allowing mechanistic investigation into the cellular response, represents a critical step to advance the field. Here, we present a new approach to address this need by combining optics-based protein patterning and lithography-based substrate microfabrication, which enables high-throughput investigation of complex cellular environments. Using a contactless and maskless UV-projection system, we created patterns of extracellular proteins (resembling contact-guidance cues) on a two-and-a-half-dimensional (2.5D) cell culture chip containing a library of well-defined microstructures (resembling topographical cues). As a first step, we optimized experimental parameters of the patterning protocol for the patterning of protein matrixes on planar and non-planar (2.5D cell culture chip) substrates and tested the technique with adherent cells (human bone marrow stromal cells). Next, we fine-tuned protein incubation conditions for two different vascular-derived human cell types (myofibroblasts and umbilical vein endothelial cells) and quantified the orientation response of these cells on the 2.5D, physiologically relevant multi-cue environments. On concave, patterned structures (curvatures between κ = 1/2500 and κ = 1/125 μm^-1), both cell types predominantly oriented in the direction of the contact-guidance pattern. In contrast, for human myofibroblasts on micropatterned convex substrates with higher curvatures (κ ≥ 1/1000 μm^-1), the majority of cells aligned along the longitudinal direction of the 2.5D features, indicating that these cells followed the structural cues from the substrate curvature instead. These findings exemplify the potential of this approach for systematic investigation of cellular responses to multiple microenvironmental cues.

Rab1b-GBF1-ARFs mediated intracellular trafficking is required for classical swine fever virus replication in swine umbilical vein endothelial cells

Classical swine fever virus (CSFV), a plus-sense RNA virus, utilizes host intracellular membrane organelles for its replication. Our previous studies have shown that disruption of the intracellular membrane-trafficking events can inhibit CSFV replication. However, the underlying mechanism of this process in CSFV infection has not been elucidated. To determine the role of Golgi-associated anterograde and retrograde trafficking in CSFV replication, we revealed the effect of vesicular transport between Golgi and ER inhibitors Brefeldin A (BFA) and 2,2-methyl-N-(2,4,6,-trimethoxyphenyl) dodecanamide (CI-976), the GBF1 inhibitor golgicide A (GCA) on virus production. Our results showed that disruption of vesicular trafficking by BFA, CI-976, and GCA significantly inhibited CSFV infection. Subsequent experiments revealed that knockdown of Rab1b by lentiviruses and negative-mutant Rab1b-N121I transfection inhibited CSFV infection. Furthermore, we showed that the Rab1b downstream vesicular component effectors GBF1, and class I and class II ADP-ribosylation factors (ARFs) were also involved in virus replication. In addition, confocal microscopy assay showed that CSFV infection disrupted the Golgi apparatus resulting in extended Golgi distribution around the nucleus. We also showed that cell secretory pathway, measured using Gaussia luciferase flash assay, was blocked in CSFV infected cells. Taken together, these findings demonstrate that CSFV utilizes Rab1b-GBF1-ARFs mediated trafficking to promote its own replication. These findings also provide new insights into the intracellular trafficking pathways utilized for CSFV life cycle.

Toxicity of cooking oil fume derived particulate matter: Vitamin D3 protects tubule formation activation in human umbilical vein endothelial cells

Cooking oil fumes-derived PM_2.5 (COFs-derived PM_2.5) is the main source of indoor pollution. Exposure to COFs-derived PM_2.5 can cause oxidative stress and affect angiogenesis. Here we investigated the roles of vitamin D₃ (VD₃) in protecting tubule formation injury induced by COFs-derived PM_2.5, and the roles of ROS/NLRP3/VEGF signaling pathway in the effects. Human umbilical vein endothelial cells (HUVECs) were exposed to 0 (1‰ DMSO), 1000 nmol/l VD₃, 100 μg/ml PM_2.5, and 1000 nmol/l VD₃ + 100 μg/ml PM_2.5, respectively. Cell viability and tube formation, as well as protein and mRNA levels were measured. The results showed that exposure of COFs-derived PM_2.5 dose-and time-dependently reduced the viability of HUVECs, increased the levels of mitochondrial and intracellular ROS, and changed the mitochondrial membrane potential level. While co-incubation with VD₃ rescued these adverse effects. Both Western blot and real-time PCR (RT-PCR) showed that the expressions of NLRP3, caspase-1, Interleukin (IL)-1β, and IL-18 in COFs-derived PM_2.5 exposure group increased significantly, which could be effectively decreased by co-incubation with VD₃. COFs-derived PM_2.5 exposure could also reduce the expression of VEGF, while co-incubating HUVECs with VD₃ evidently up-regulated the protein level of VEGF in HUVECs. In addition, COFs-derived PM_2.5 could also inhibit the tube formation of HUVECs in vitro, which could be effectively rescued by the co-incubation of VD₃. Our study proved that COFs-derived PM_2.5 could damage the tubule formation of HUVECs in vitro, which could be effectively rescue by co-incubation with VD₃, in which processes the ROS/NLRP3/VEGF signaling pathway played a crucial role. It provides a new theoretical basis for further study on the toxicity of PM_2.5 to umbilical cord blood vessels.

β-aminoisobutyric acid protects against vascular inflammation through PGC-1β-induced antioxidative properties

BACKGROUD

Among various myocyte-derived bioactive molecules (myokines), β-aminoisobutyric acid (BAIBA) is a unique myokine that attenuates skeletal muscle insulin resistance and inflammation, increases browning of white adipose tissue, and enhances hepatic fatty acid oxidation, resulting in upregulated energy expenditure of the whole body. In the present study, we investigated the effects of BAIBA on the vascular endothelial cell function.

METHODS

The mRNA levels of proinflammatory molecules, antioxidants, and their related transcription regulators were examined by quantitative RT-PCR in BAIBA-treated human aortic or umbilical vein endothelial cells (HAEC or HUVEC, respectively), with or without tumor necrosis factor (TNF)-α stimulation. The protein expression and phosphorylation of AMP-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) were determined by Western blot analysis.

RESULTS

BAIBA pretreatment significantly suppressed the mRNA levels of the adhesion molecules in the TNF-α-stimulated HAEC and HUVEC. BAIBA treatment significantly increased the mRNA levels of antioxidant molecules, catalase, superoxide dismutases, thioredoxin, and gamma-glutamylcysteine ligases, together with mitochondrial biogenesis-related molecules, nuclear respiratory factor 1, and mitochondrial transcription factor A. In addition, BAIBA treatment significantly increased the transcription factors that regulated these genes [i.e., peroxisome proliferator-activated receptor (PPAR)-δ, PPAR-γ, estrogen-related receptor α (ERRα), and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1β]. Adenovirus-mediated PGC-1β overexpression significantly increased the mRNA levels of all antioxidant molecules. The phosphorylation levels of AMPK and eNOS were unaltered by BAIBA.

CONCLUSIONS

In vascular endothelial cells, BAIBA had antiatherogenic effects through the PGC-1β-ERRα/PPAR-δ and PPAR-γ pathway. This can explain the beneficial effects of exercise on vascular endothelial function.

BIOINFORMATIC ANALYSIS OF DOSE- AND TIME-DEPENDENT miRNome RESPONSES

The advent of new 'omics' techniques determined a massive boost in the measurement of the whole spectra of molecules within cells, favoring promising new radiobiological studies at low doses. The main aim of this work was to assess the radiation-induced perturbations of miRNA profiles and their temporal dynamics. Human Umbilical Vein Endothelial Cells were irradiated with low doses of γ-rays. At different time points post-irradiation, cells were harvested and miRNAs isolated. A full mapping of the miRNA sequences via Next-Generation-Sequencing analysis was performed followed by bioinformatic analyses. Pathway enrichment analyses on the differentially expressed miRNAs focused both on the averaged effects of different doses over the 24-h experiment and on the altered temporal dynamics of the miRNA profiles. These complementary analyses provided a picture of the dose- and time-dependent miRNAs responses, allowing to better explore the candidate biomarkers linked to radiation exposures and their corresponding pathways and functions.

Effect of gestational age on migration ability of the human umbilical cord vein mesenchymal stem cells

PURPOSE

Migration ability of mesenchymal stem cells (MSCs) towards chemotactic mediators is a determinant factor in cell therapy. MSCs derived from different sources show different properties. Here we compared the migration ability of the term and the pre-term human umbilical cord vein MSCs (hUCV-MSCs).

MATERIALS/METHODS

MSCs were isolated from term and pre-term umbilical cord vein, and cultured to passage 3-4. Migration rate of both groups was assessed in the presence of 10% FBS using chemotaxis assay. Surface expression of CXCR4 was measured by flow cytometery. The relative gene expression of CXCR4, IGF1-R, PDGFRα, MMP-2, MMP-9, MT1-MMP and TIMP-2 were evaluated using real time PCR.

RESULTS

The isolation rate of the pre-term hUCV-MSCs was higher than the term hUCV-MSCs. Phenotype characteristics and differentiation ability of the term and pre-term hUCV-MSCs were not different. The migration rate of the pre-term hUCV-MSCs was more than the term hUCV-MSCs. Gene and surface expressions of the CXCR4 were both significantly higher in the pre-term hUCV-MSCs (P≤0.05). The mRNA levels of PDGFRα, MMP-2, MMP-9, MT1-MMP and TIMP-2 showed no significant difference between the two groups.

CONCLUSION

Our results showed that the gestational age can affect the migration ability of the hUCV-MSCs.

Comparison of Specific Adsorbents for Tumor Necrosis Factor-α and Therapeutic Anti-Tumor Necrosis Factor-α Antibodies: An in Vitro Sepsis Model

Background

Tumor necrosis factor alpha (TNF-α), as a key mediator, represents a major point of attack in sepsis. Since it has been shown that systemic anti-TNF-α antibodies do not improve the situation of septic patients, the use of specific adsorption technology in the treatment of sepsis could have beneficial effects.

Methods

Magnetic beads coated with polyclonal or with monoclonal anti-TNF-α antibodies were investigated in vitro in order to analyze their ability to prevent TNF-α induced adhesion of peripheral blood mononuclear cells (PBMCs) at human umbilical vein endothelial cells (HUVECs). Additionally, therapeutical monoclonal anti-TNF-α antibodies were proofed for inhibitory effects of TNF-α mediated activation of HUVECs.

Results

We have shown, in vitro, that beads coated with polyclonal or monoclonal anti-TNF-α antibodies were able to significantly reduce monocyte adhesion. It was possible to decrease monocyte adhesion from nearly 9% to 3% within 2 hours and from 18% to 2% within 6 hours of TNF-α treatment by the simultaneous use of beads coated with polyclonal anti-TNF-α antibodies. Beads coated with monoclonal anti-TNF-α antibodies could even prevent monocyte adhesion within the first 2 hours, and reduced monocyte adhesion to 2% during 6 hours of incubation with TNF-α. On the other hand, application of therapeutic anti-TNF-α antibodies showed no significant difference compared to the measured monocyte adhesion values of activated endothelial cells.

Conclusion

Adsorption techniques using specific adsorbents, possibly used in MDS (Microspheres-Based Detoxification System), are efficient in specific reduction of TNF-α and pathophysiological consequences, since monocyte adhesion at activated HUVECs was shown to be reduced. (Int J Artif Organs 2006; 29: 1140–7)

Human Umbilical Vessels: Choosing the Optimal Decellularization Method

There is an increasing demand of small-diameter vascular grafts for treatment of circulatory pathologies. Decellularization offers the possibility of using human blood vessels as scaffolds to create vascular grafts. Umbilical vessels have great potential because of their availability and morphological characteristics. Various decellularization techniques have been used in umbilical vessels, but consensus on which is the most appropriate has not yet been reached. The objective of this review is to analyze the morphological and biomechanical characteristics of decellularized human umbilical arteries and veins with different techniques. Evidence indicates that the umbilical vessels are a viable option to develop small-diameter vascular grafts. Detergents are the agents most often used and with most evidence. However, further studies are needed to accurately analyze the components of the extracellular matrix and biomechanical characteristics, as well as the capacity for recellularization and in vivo functionality.

Calli Essential Oils Synergize with Lawsone against Multidrug Resistant Pathogens

The fast development of multi-drug resistant (MDR) organisms increasingly threatens global health and well-being. Plant natural products have been known for centuries as alternative medicines that can possess pharmacological characteristics, including antimicrobial activities. The antimicrobial activities of essential oil (Calli oil) extracted from the Calligonum comosum plant by hydro-steam distillation was tested either alone or when combined with lawsone, a henna plant naphthoquinone, against MDR microbes. Lawsone showed significant antimicrobial activities against MDR pathogens in the range of 200-300 µg/mL. Furthermore, Calli oil showed significant antimicrobial activities against MDR bacteria in the range of 180-200 µg/mL, Candida at 220-240 µg/mL and spore-forming Rhizopus fungus at 250 µg/mL. Calli oil's inhibition effect on Rhizopus, the major cause of the lethal infection mucormycosis, stands for 72 h, followed by an extended irreversible white sporulation effect. The combination of Calli oil with lawsone enhanced the antimicrobial activities of each individual alone by at least three-fold, while incorporation of both natural products in a liposome reduced their toxicity by four- to eight-fold, while maintaining the augmented efficacy of the combination treatment. We map the antimicrobial activity of Calli oil to its major component, a benzaldehyde derivative. The findings from this study demonstrate that formulations containing essential oils have the potential in the future to overcome antimicrobial resistance.

Fibrinogen regulates the expression of inflammatory chemokines through NF-κB activation of endothelial cells

The objective of this study was to characterize the role of fibrinogen in stimulating expression of inflammatory chemokines in endothelial cells through NF-κB activation. Human umbilical vein endothelial cells (HUVEC) were exposed to fibrinogen up to 3,000 µg/ml, and NF-κB activation was assessed using electrophoretic mobility shift assay (EMSA). Fibrinogen exposure resulted in a concentration dependent increase in NF-κB activation that reached a maximum at 1,000 µg/ml after 4 hours and was sustained up to 24 hours. The effect was inhibited by antibodies to αvβ3 and α5β1 and by the GRGDS peptide, indicating integrin involvement. Preincubation with Mn2+ lowered the fibrinogen concentration-dependence, consistent with integrin activation. Supershift assays demonstrated involvement of the p50, p65 and c-Rel components of NF-κB. Fibrinogen exposure also resulted in up-regulation of expression of monocyte chemoattractant protein-1 (MCP-1) and of interleukin-8 as shown by RNase protection assays and by real-time RT-PCR. Increased secretion of MCP-1 was confirmed by ELISA. Parthenolide, an IκB kinase inhibitor, prevented up-regulation of MCP-1 by fibrinogen, linking this response to NF-κB activation. From our findings, we conclude that fibrinogen regulates NF-κB activation and expression of inflammatory chemokines in endothelial cells and may be involved in mediating inflammatory processes.

On the mode of action of thrombin-induced angiogenesis: thrombin peptide, TP508, mediates effects in endothelial cells via αvβ3 integrin

In a previous report we have presented evidence that thrombin interacts with αvβ3 integrin in endothelial cells at the molecular and cellular level. This interaction was shown to be of functional significance in vitro and in vivo and contributed to activation of angiogenesis by thrombin. In the present study, we have used a synthetic thrombin peptide, TP508, which represents residues 183 to 200 of human thrombin. This peptide lacks the catalytic site of thrombin but contains the thrombin RGD sequence. Immobilized (surface-coated) TP508 peptide, like thrombin, supported αvβ3 integrin-dependent endothelial cell attachment and haptotactic migration. These effects were specific (a scrambled TP508 peptide was without effect), and dosedependent. The RGD sequence was essential since a modified TP508 peptide, which contained RAD sequence instead of RGD, was inactive. Immobilized TP508 peptide stimulated phosphorylation of mitogen-activated protein kinases and focal adhesion kinase, the signal transduction pathways characteristic for integrin activation. On the other hand, TP508 peptide, when in solution, did not mimic other thrombin-promoted angiogenic effects, such as that of activation gelatinase A, upregulation of expression of vascular endothelial growth factor receptor mRNA or prostacyclin PGI2 release in endothelial cells. On the contrary, soluble TP508 acted as an antagonist for the aforementioned effects of thrombin. TP508 peptide inhibited these thrombin-induced effects through a RGD and α. vβ3-related mechanism. The antagonism with thrombin or thrombin receptor activating peptide was specific and involved at least in part mitogen-activated protein kinases activation. These results point to the importance of RGD sequence of thrombin in mediating effects on endothelial cells and angiogenesis.

Syndecan-4-dependent signaling in the inhibition of endotoxin-induced endothelial adherence of neutrophils by antithrombin

Circulating endotoxin is elevated in sepsis and plays a role in endothelial dysfunction whereas antithrombin is decreased by virtue of its consumption during complex formation with clotting factors and by proteolytic degradation by granulocyte elastase. Dysfunction of endothelium results in enhanced leukocyte rolling and diapedesis into tissues leading to edema formation and injury. Antithrombin exerts beneficial effects on endothelial function in sepsis. A direct anti-inflammatory action of anti-thrombin in inflammatory cells is exerted via heparan sulfate proteoglycans. In this study, we investigated whether antithrom-bin affects endotoxin-induced adhesion of neutrophils to human endothelial cells in vitro and whether glycosaminoglycans are involved in its signaling. Adhesion of human neutrophils to monolayers of umbilical vein endothelial cells was tested under static conditions. Endothelial cells were pretreated with endotoxin, interleukin-1, heparinase-I, chondroitinase-ABC or anti-syndecan-4-antibody. Endotoxin and interleukin-1 increased neutrophil adherence to human umbilical vein endothelial cells which was inhibited by antithrombin. Concomitant incubation with pentasaccharide abolished this effect of antithrombin. Treatment of endothelial cells with heparinase or chondroitinase led to higher adhesion and prevented effects of antithrom-bin. With antibodies to syndecan-4, enhanced adhesion of neutrophils was observed. As studied by Western blotting, endo-toxin-induced signaling was diminished by antithrombin and the effect was reversible by chondroitinase or heparinase. From our results, we can conclude that endotoxin-induced adhesion of leukocytes to endothelium can be reversed by ligation of syndecan-4 with antithrombin´s heparin-binding site and interferences with stress response signaling events in endothelium.

Antiinflammatory activity of astragaloside IV is mediated by inhibition of NF-κB activation and adhesion molecule expression

The regulated expression of adhesion molecules on the surface of endothelial cells is a key process in the pathogenesis of inflammation. The saponin astragaloside IV (AS-IV), a 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol purified from the Chinese medical herb Astragalus membranaceus(Fisch) Bge.has been shown to have anti-inflammatory effects in vivo.In this study we have investigated the effect of AS-IV on cytokine-and LPS-stimulated expression of adhesion molecules in and leukocyte adhesion to endothelial cells. We have demonstrated that AS-IV significantly reduced the adhesion promoting activity of LPS-stimulated HUVECs for polymorph-nuclear leukocytes (PMNs) and the monocytic cell line THP-1. Furthermore, by using specific cell ELISAs we could show that AS-IV decreased the LPS-induced expression of E-selectin and VCAM-1 on the surface of HUVECs in a dose and time dependent manner, whereas the expression of ICAM-1 was not affected by AS-IV. AS-IV also inhibits TNFβ-induced VCAM-1 expression. The saponin octyl-D-glucopyranoside had no effect on the LPS-induced expression of E-selectin and VCAM-1 excluding an unspecific detergent-like effect of AS-IV. Moreover, AS-IV significantly inhibited LPS- and TNFβ-induced specific mRNA levels for E-selectin and VCAM-1. Finally, we could show that AS-IV completely abolished LPS- and TNFα-induced nuclear translocation of NF-κB and NF-κB DNA binding activity in endothelial cells. We conclude that the ability of AS-IV to inhibit the NF-κB pathway might be one underlying mechanism contributing to its anti-inflammatory potential in vivo.

Enhancement of neovascularization with cord blood CD133+ cell-derived endothelial progenitor cell transplantation

The endothelial progenitor cells (EPCs) are responsible for postnatal vasculogenesis in physiological and pathological neovascularization and have been used for attenuating ischemic diseases. However, EPCs from umbilical cord blood (CB) were not well understood and the homing mechanisms of EPCs remain unclear. To determine the potential application of CB-derived EPCs, we established a culture system to induce the differentiation of CB cells into EPCs. Purified CB CD133+ cells proliferated and, after further vascular endothelial growth factor receptor 2 (VEGFR-2) antibody purification, differentiated into EPCs expressing endothelial markers, such as VE-cadherin, VEGFR-2, CD31, von Willebrand factor (vWF) and WeibelPalade bodies. These cells could also take up acetylated lower density lipoprotein (Ac-LDL) and bind Ulex europaeus agglutinin-1 (UEA-1).When expanded EPCs were transplanted via tail vein into nude mice, they incorporated into capillary networks in ischemic hindlimb, augmented neovascularization, and improved ischemic limb salvage. In addition, in ischemic tissue, there were elevated expressions of VEGF and stromal derived factor 1α???????????(SDF-1α), both of which had chemotactic effect on EPCs. Moreover, P-/E-selectins was found on mouse ischemic endothelium and P-selectin glycoprotein ligand-1 (PSGL-1) on CB-derived EPCs. Neutralizing antibody against PSGL-1 blocked the homing of EPCs to ischemic area by 61%. These results demonstrate that CB CD133+ cell-derived EPCs can be applied for therapeutic neovascularization in ischemic diseases, and reveal important roles of chemoattractants and adhesive molecules in the homing of EPCs.

Activated protein C generation is greatly decreased in plasma from newborns compared to adults in the presence or absence of endothelium

Activated protein C (APC) generation strongly affects sepsis and thrombosis by inhibition of thrombin generation. However, it is unclear if there are age-related differences in effectiveness of protein C (PC). We studied age effects on plasma APC generation ± endothelium. Defibrinated (Ancrod) plasma (from adults or newborns (umbilical cord)) was recalcified with buffer containing tissue factor ± thrombomodulin (TM) on either plastic or endothelium (HUVEC) at 37oC. Timed subsamples of reaction mixture were taken into either heparin-EDTA or FFRCMK-EDTA solutions and analyzed for APC-PC inhibitor (APC-PCI) or APC-α1antitrypsin (APC-α1AT) by ELISAs. Since heparin converts free APC to APC-PCI, the difference in APCPCI measured in heparin-EDTA and FFRCMK-EDTA samples was equal to free active APC. APC-α2macroglobulin (APC-α2M) was measured as remaining chromogenic activity in heparin-EDTA. Free APC, APC-PCI and APC-α1AT were decreased in newborn compared to adult plasma on plastic. However, APC-α2M made up a larger fraction of inhibitor complexes in newborn plasma. On endothelium, significantly more APC, APC-PCI and APC-α1AT were generated in either plasma compared to that on plastic with excess added TM. APC, APC-PCI and APC-α1AT were also reduced and total APC-α2M increased in newborn plasma on HUVEC. Addition of PC to newborn plasma gave APC generation similar to adult plasma. Thus, free APC, APC-PCI and APC-α1AT generation is reduced in newborn compared to adult plasma with or without endothelium, likely due to reduced plasma PC levels. Endothelium enhances APC generation, regardless of plasma type, possibly because of cell surface factors such as TM, phospholipid and endothelial PC receptor.

AGEs, macrophage colony stimulating factor and vascular adhesion molecule blood levels are increased in patients with diabetic microangiopathy

In vitro experiments and animal models indicate that advanced glycation end products (AGEs) may play a crucial role in the vascular dysfunctions observed in patients with diabetes mellitus. These results prompted us to study subrogate markers of inflammation or vascular dysfunction in type II diabetic patients. Monocyte count and activation are dependent upon macrophage colony stimulating factors (M-CSF). Soluble vascular cell adhesion molecule (sVCAM-1) blood levels have been proposed as a marker for endothelium activation. To explore a possible relationship between these factors in diabetic patients, we measured a chemically defined AGE, N(carboxymethyl)lysineprotein (CML-protein) in a group of normal subjects (n = 55) and of diabetic patients (n = 40) using ELISA. Simultaneously, we determined M-CSF and sVCAM-1 blood levels. We found that CML-protein blood levels were significantly higher in patients with diabetes compared to non-diabetic subjects (40.2 ± 4.7 and 7.9 ± 0.7 pmol/mg protein respectively, p < 0.0001). M-CSF was increased while sVCAM-1 blood levels were normal in the group of diabetics. M-CSF blood level was correlated to CML-protein blood level (p < 0.05). In addition CML-protein, M-CSF and sVCAM-1 were increased in patients with microangiopathy. These results suggest that AGE may contribute to vascular dysfunction including microangiopathy.

Influence of low frequency electric fields on anti- and pro-coagulability of the vascular endothelium: new insights into high-voltage electrical injury

After high-voltage electric injury, patients often show tissue necrosis and thrombosis of blood vessels even remote from entry and exit site of electrical current. In this study, plasma levels of TAT, F1+2, PAI-1, and t-PA were determined in vivo in three patients with high-voltage injury for 96 hours after trauma. In order to analyse a possible effect on haemostasis related to endothelial cell damage, protein S, TF, ET-1, PGI2, NO, t-PA, and PAI-1 were determined for 72 hours in vitro in cell culture supernatant of HUVECs that had been exposed to 1, 10, 30, and 50 electric field periods of 50 Hz with field strength of 60 V/cm and duration of 20 ms. Furthermore, expression of thrombomodulin was immunohistochemically analysed. Clotting activation could be observed in our patients by increased levels of F1+2 and TAT between 12 and 72 hours after injury, whereas fibrinolysis was disturbed due to high PAI-1. One patient presented thrombosis of vessels by day 3. In vitro, PAI-1 increased significantly (p<0.05) in medium of cells with an application of 30 and 50 periods between 2 and 48 hours. Between 4 and 72 hours, the concentration of t-PA was significantly lower (p<0.05) in the medium of HUVECs exposed to 10, 30, and 50 periods, whereas there was a significant increase (p<0.05) in the concentration of TF in the cell groups with an application of 30 and 50 periods. 24, 48, and 72 hours after injury, there was just weak or no staining for thrombomodulin in HUVECs with an application of 30 and 50 periods. The disturbed balance between clotting system and fibrinolysis seen in vitro after electric injury might explain the clinical observation of a progressive thrombosis of blood vessels after electric injury leading to tissue loss.

Attenuating Effect of Long-term Culture of Umbilical Cord Vein Mesenchymal Stromal Cells on Pulmonary Fibrosis in C57BL/6 Mice

In recent studies, mesenchymal stromal cells (MSCs) have been increasingly employed to treat various diseases like pulmonary fibrosis (PF). There are very few MSCs in tissues so in order to obtain their sufficient numbers for therapeutic applications, their in vitro expansion is necessary. The aim of this study was to investigate the effects of long-term culture of the human umbilical cord vein MSCs (hUCV-MSCs) on pulmonary fibrosis in mice. MSCs were first isolated from human umbilical cord vein and cultured up to 18 passages. In C57BL/6 mice, 15 min after belomycin instillation, UCV-MSCs at passages (P) 0, 4, 8, 12, and 18 (long-term culture) were transplanted intratracheally. Mice were weighted every 5 days and were euthanized on day 21. For histopathological examination, the lung sections were stained with hematoxylin-eosin (HE) and Masson's trichrome. The mRNA expression of TGF-β1, alpha-smooth muscle actin (α-SMA), and collagen type I alpha 1 (COL1A1) in lung tissues were assessed using RT-PCR. For cell tracking, human cytochrome B DNA was detected in mice lung tissues by PCR. The weight of mice receiving long-term culture of UCV-MSCs increased compared to other mice (p=0.056). Also, transplantation of UCV-MSCs at P18 led to increased alveolar space and decreased connective tissue and collagen deposition of the lung tissues. The mRNA expression of TGF-β1, α-SMA, and COL1A1 also decreased in this group. The results showed that intratracheally transplanted long-term culture of the UCV-MSCs attenuated lung fibrosis in mice.

Endothelial cells express a matrix protein which binds activated factor XII in a zinc-independent manner

Recent studies have shown that peptides identified as surface binding regions of high molecular mass kininogen (HK) and factor XII (FXII) inhibit the Zn2+-dependent binding of FXII to confluent layers of human umbilical vein endothelial cells (HUVEC). This indicates that negatively charged FXII binding surfaces, such as sulfatides and dextran sulfate, may interfere with the binding of FXII to confluent layer of HUVEC. Upon investigating this hypothesis it was unexpectedly found that sulfatides enhanced a specific binding of FXII to a matrix protein expressed during growth of the endothelial cells and that this binding was independent of the presence of Zn2+. The function of sulfatides was partly to minimize nonspecific electrostatic binding and partly to induce and enhance autoactivation of FXII generating αFXIIa. Western blot analysis of the extracts of the matrix incubated with FXII and sulfatides showed that the binding was specific for αFXIIa. The dissociation constant for binding αFXIIa was 12. 8 ± 0. 4 nM (n=4). The binding of αFXIIa to ECM was mapped to the heavy chain as no binding was observed of the light chain containing the catalytic domain. HK, which previously has been shown to completely abolish the Zn2+-dependent binding of FXII to confluent layers of HUVEC, did not inhibit the binding of αFXIIa to the matrix but sulfatides enhanced binding of FXII to ECM. This suggests that HK interferes with the binding of FXII to sulfatides and thereby the autoactivation of FXII. Trypsin treatment of the matrix protein completely abolished the binding, and fibronectin but not laminin was found to bea suitable target. The binding of activated FXII to the ECM suggests that FXIIa may bea modulator of cellular adhesion, migration and vascularization.

Mxi1-0 regulates the growth of human umbilical vein endothelial cells through extracellular signal-regulated kinase 1/2 (ERK1/2) and interleukin-8 (IL-8)-dependent pathways

Mxi1 plays an important role in the regulation of cell proliferation. Mxi1-0, a Mxi1 isoform, has a different N-terminal amino acid sequence, intracellular location and expression profile from Mxi1. However, the precise role of Mxi1-0 in cell proliferation and the molecular mechanism underlying its function remain poorly understood. Here, we showed that Mxi1-0 suppression decreased the proliferation of human umbilical vein endothelial cells (HUVECs) along with cell accumulation in the G2/M phase. Mxi1-0 suppression also significantly decreased the expression and secretion of interleukin (IL-8). Neutralizing IL-8 in conditioned medium (CM) from Mxi1-0-overexpressed HUVECs significantly eliminated CM-induced proliferation of HUVECs. In addition, Mxi1-0 suppression significantly decreased the activity of MAP kinase ERK1/2. Treatment of HUVECs with U0126, an ERK1/2 signaling inhibitor, attenuated autocrine production of IL-8 induced by Mxi1-0 overexpression. On the other hand, Mxi1-0 overexpression-induced IL-8 increased the level of phosphorylated ERK1/2 in HUVECs, and such increasing was diminished in cells incubated with CM, which neutralized with anti-IL-8 antibody. Taken together, our results suggest that Mxi1-0 regulates the growth of HUVECs via the IL-8 and ERK1/2 pathways, which apparently reciprocally activate each other.

Sargassum fusiforme polysaccharides inhibit VEGF-A-related angiogenesis and proliferation of lung cancer in vitro and in vivo

Sargassum fusiforme (Harv.) is a brown alga belonging to the Sargasaceae family. The Sargassum fusiforme polysaccharides (SFPS) have demonstrated good anti-tumor and immunomodulatory activity. However, the underlying mechanisms of its anti-tumorigenesis, especially the anti-angiogenic activity is yet to be established. In the present study, we attempted to determine the effects of SFPS on the human lung adenocarcinoma SPC-A-1 cells and its xenograft model. The results showed that SFPS provides a concentration-dependent inhibition of SPC-A-1 cell proliferation in in vitro and the tumor growth in in vivo studies. Immunohistochemistry studies revealed that the administration of SFPS significantly decreased CD31, VEGF-A expression and the tumor microvessel density (MVD). SFPS also provided a dose-dependent impairment of cell vitality, induction of cell cycle arrest and apoptosis of human umbilical vein endothelial cells (HUVECs). SFPS inhibited the expression of VEGF-A in tumor cells and its receptor VEGFR2 in HUVECs. The HUVEC tube formation assay showed that SFPS could abrogate the tube formation with relatively decreased tubes length of tube-like capillary similar to anti-VEGF antibody, Avastin®. These findings suggested that SFPS could be used as an alternative anticancer drug as they inhibited the angiogenesis and the microvessel formation through disruption of VEGF signals apart from direct tumor cytotoxicity.

Three-Dimensional Coculture Model to Analyze the Cross Talk Between Endothelial and Smooth Muscle Cells

The response of blood vessels to physiological and pathological stimuli partly depends on the cross talk between endothelial cells (EC) lining the luminal side and smooth muscle cells (SMC) building the inner part of the vascular wall. Thus, the in vitro analysis of the pathophysiology of blood vessels requires coculture systems of EC and SMC. We have developed and validated a modified three-dimensional sandwich coculture (3D SW-CC) of EC and SMC using open μ-Slides with a thin glass bottom allowing direct imaging. The culture dish comprises an intermediate plate to minimize the meniscus resulting in homogenous cell distribution. Human umbilical artery SMC were sandwiched between coatings of rat tail collagen I. Following SMC quiescence, human umbilical vein EC were seeded on top of SMC and cultivated until confluence. By day 7, EC had formed a confluent monolayer and continuous vascular endothelial (VE)-cadherin-positive cell/cell contacts. Below, spindle-shaped SMC had formed parallel bundles and showed increased calponin expression compared to day 1. EC and SMC were interspaced by a matrix consisting of laminin, collagen IV, and perlecan. Basal messenger RNA (mRNA) expression levels of E-selectin, angiopoietin-1, calponin, and intercellular adhesion molecule 1 (ICAM-1) of the 3D SW-CC was comparable to that of a freshly isolated mouse inferior vena cava. Addition of tumor necrosis factor alpha (TNF α) to the 3D SW-CC induced E-selectin and ICAM-1 mRNA and protein induction, comparable to the EC and SMC monolayers. In contrast, the addition of activated platelets induced a significantly delayed but more pronounced activation in the 3D SW-CC compared to EC and SMC monolayers. Thus, this 3D SW-CC permits analyzing the cross talk between EC and SMC that mediate cellular quiescence as well as the response to complex activation signals.

Effect of Apple Extracts on NF-κB Activation in Human Umbilical Vein Endothelial Cells

The mechanisms by which foods, such as fruit, are able to reduce the risk of chronic disease are still unclear. Several fruit products, including apples and apple juice, that are flavonoid-rich are reported to increase antioxidant levels in human subjects. This is supported by the finding from our previous studies that the chronic consumption of apple juice by human subjects reduced ex vivo low-density lipoprotein (LDL) oxidation; we hypothesized that this was due to the flavonoid in the apple juice, which, as we reported earlier, reduced in vitro LDL oxidation. To further explore whether the mixture of flavonoids and other phytochemicals in apples are biologically relevant antioxidants, we tested the effects of this flavonoid-rich apple extract (AE) on oxidant-related pathways in a model of the endothelium: human umbilical vascular endothelial cells (HUVECs). The effects of AE on oxidant-responsive (i.e., tumor necrosis factor [TNF]-α-induced) nuclear factor (NF)-κB signaling in cell culture were assessed in transfected HUVECs by using a construct that expressed luciferase under the control of NF-κB. Incubation of HUVEC for 24 hrs with up to 10 mM (as gallic acid equivalents) of AE demonstrated no cytotoxicity, as determined by lactate dehydrogenase release, caspase 3 activation, and apoptosis marker–based FACS analysis. AE after a 24-hr incubation period at either 200 or 2000 nM showed a complex pattern of decreased basal and TNF-α-stimulated NF-κB signaling (63% maximal decrease) as assessed by luciferase activity in the transfected HUVECs, as well as by reduced levels of IκBα protein phosphorylation detected by Western blot analysis. We suggest that AE downregulates NF-κB signaling and that this is indicative of an antioxidant effect of the flavonoids present in AE.

Estradiol-17β increases 12- and 15-lipoxygenase (type2) expression and activity and reactive oxygen species in human umbilical vascular smooth muscle cells

The net vascular effect of estrogens on the vasculature is still under debate. Here we tested the effects of estradiol- 17β (E2) as well as estrogen-receptor subtype specific and non-specific agonists and antagonists on the expression and eicosanoid production of lipoxygenase (LO) enzymes expressed in culture human umbilical vascular smooth muscle cells (VSMC), the platelet type 12LO and 15LO type 2. E2 increased 12 and 15LO mRNA expression by 2-3 folds and elicited an acute 50% increase 12 and 15 hydroxyeicosatetraenoic acid (HETE) production. Neither estrogen receptor ERα nor ERβ-specific agonists were able to reproduce the induction of LO expression, but E2-induced expression was effectively blocked by ER non-specific and receptor subtype specific antagonists. Because 12 and 15HETE can increase reactive oxygen species in other cell types, we tested the possibility that E2 could raise ROS through LO. Indeed, E2 as well as the LO products 12 and 15HETE increased reactive oxygen species (ROS) in VSMC. E2-dependent and HETE-induced ROS could be blocked by NAD (P) H-oxidase inhibitors and by the ER general antagonist ICI. E2-induced ROS was partially (∼50%) blocked by the LO inhibitor baicalein, but the LO blocker had no effect on 12 or 15HETE- induced ROS formation, thus suggesting that part of E2-dependent ROS generation resulted from E2-induced 12 and 15HETE. Collectively these findings unveil an unrecognized effect of E2 in human VSMC, to induce 12 and 15LO type 2 expression and activity and suggest that E2-dependent ROS formation in VSMC may be partially mediated by the induction of 12 and 15HETE.

Maternal Plasma From Pregnant Women With Umbilical Placental Vascular Disease Does Not Affect Endothelial Cell mRNA Expression of Nitric Oxide Synthase

OBJECTIVE

In placental vascular disease identified by umbilical artery Doppler study we have shown the existence of a factor in fetal plasma that causes activation of endothelial cells in culture with expression of cell adhesion molecules and nitric oxide synthase, apoptosis, and proinflammatory cytokine production. The present work was carried out to investigate a maternal origin for this factor active in the fetal circulation.

METHODS

We collected maternal plasma from pregnant women with Doppler-defined umbilical placental vascular disease and examined its effect on endothelial cells in culture. Aliquots from a common culture of human umbilical vein endothelial cells (HUVEC) were incubated with maternal plasma from women with normal pregnancy (n = 23), umbilical placental vascular disease defined by abnormal umbilical artery Doppler (n = 30, with or without preeclampsia), and preeclampsia with normal umbilical artery Doppler (n = 14). The expression of mRNA for inducible and endothelial constitutive nitric oxide synthase (iNOS and ecNOS, respectively) was assessed by reverse transcriptase polymerase chain reaction.

RESULTS

There was no significant increase in either the iNOS or the ecNOS mRNA expression by HUVEC cultured with maternal plasma from pregnancies with umbilical placental vascular disease compared with normal pregnancy (iNOS 1.49 +/- 0.35 versus 1.38 +/- 0.25; ecNOS 1.51 +/- 0.35 versus 1.25 +/- 0.27; P >.05). In the placental vascular disease group the results were similar for the presence or absence of maternal preeclampsia. In the samples from women with preeclampsia with normal umbilical Doppler, both iNOS and ecNOS mRNA expression (iNOS 1.42 +/- 0.53; ecNOS 1.46 +/- 0.39; P >.05) did not differ from normal.

CONCLUSION

Maternal plasma from pregnancies with umbilical placental vascular disease did not affect endothelial cell expression of nitric oxide synthase. This finding does not support a maternal origin for the factor demonstrated in fetal plasma. These results suggest separate pathogenic pathways for the endothelial cell activation seen in preeclampsia and fetal growth restriction associated with abnormal umbilical artery Doppler flow velocity waveforms. These findings are also consistent with the concept that the vascular pathology in the fetal placenta may be primary and that the uteroplacental circulation is reduced in response rather than acts as a constraint.

β-Carotene Inhibits Tumor-Specific Angiogenesis by Altering the Cytokine Profile and Inhibits the Nuclear Translocation of Transcription Factors in B16F-10 Melanoma Cells

Angiogenesis is the formation of new blood vessels out of the preexisting vascular network and involves a sequence of events that are of key importance in a broad array of physiological and pathological processes. The growth of tumor and metastasis are dependent on the formation of new blood vessels. The present study therefore aims at evaluating the antiangiogenic effect of β-carotene using in vivo and in vitro models. Male C57BL/6 mice as well as B16F-10 cells were used for the experimental study. The in vivo study includes the inhibitory effect of β-carotene on the formation of tumor-directed capillaries. Rat aortic ring assay, human umbilical vein endothelial cell proliferation, migration, and tube formation are used for assessing the in vitro antiangiogenic effect of β-carotene. The differential regulation of proinflammatory cytokines as well as the inhibitory effect of β-carotene on the activation and nuclear translocation of transcription factors are also assessed. β-Carotene treatment significantly reduces the number of tumor-directed capillaries accompanied by altered serum cytokine levels. β-Carotene is able to inhibit proliferation, migration, and tube formation of endothelial cells. β-Carotene treatment downregulates the expression of matrix metalloproteinase (MMP)—2, MMP-9, prolyl hydroxylase, and lysyl oxidase gene expression and upregulates the expression of tissue inhibitor of metalloproteinase (TIMP)—1 and TIMP-2. The study reveals that β-carotene treatment could alter proinflammatory cytokine production and could inhibit the activation and nuclear translocation of p65, p50, c-Rel subunits of nuclear factor-κ B, and other transcription factors such as c-fos, activated transcription factor-2, and cyclic adenosine monophosphate response element—binding protein in B16F-10 melanoma cells. These observations show that β -carotene exerts its antiangiogenic effect by altering the cytokine profile and could inhibit the activation and nuclear translocation of transcription factors.

A simple and biosafe method for isolation of human umbilical vein endothelial cells

Human umbilical vein endothelial cells (HUVECS) are used as an irreplaceable tool for the study of vascular diseases. However, the technicians who isolate HUVECs are largely exposed to potential infectious threats. Here we report the development of a specialized instrument to protect researchers from known or unknown infectious agents when they operate on human umbilical cords. This instrument can be assembled by common laboratory supplies and adapted to accommodate umbilical cords of different lengths. When the cord is enclosed within the instrument, the risk of sample contamination and operator infection is greatly reduced. Using our instrument, endothelial cells were successfully isolated from human umbilical veins without contamination. The cells were verified by their cobblestone-like morphology and by immunofluorescence staining (Factor VIII and CD31 positivity and α-SMA negativity). Our instrument simplifies and optimizes the cell extraction process, and most importantly elevates the biosafety to a higher level during the isolation of human umbilical vein endothelial cells.

Progesterone suppressed vasoconstriction in human umbilical vein via reducing calcium entry

The aim of this study was to evaluate the actions of progesterone on human umbilical vein (HUV) from normal pregnancies and the possible underlying mechanisms involved. HUV rings were suspended in organ baths and exposed to progesterone followed by phenylephrine (PE) or serotonin (5-HT). Progesterone suppressed PE- or 5-HT-induced vasoconstriction in HUV rings. The inhibitory effect induced by progesterone was not influenced by nitric oxide syntheses inhibitor, prostaglandins syntheses blocker, the integrity of endothelium, selective progesterone receptor or potassium channel antagonists. Further testing showed that progesterone and nifedipine (a blocker for L-type calcium channels) produced similar inhibitory effects on PE-, 5-HT-, Bay-k8644-, KCl-induced vasoconstriction in Krebs solution as well as CaCl2-induced vasoconstriction in Ca(2+)-free Krebs solution. But the inhibitory effect of mibefradil (mibe, a blocker for L-type (CaV1.2) and T-type calcium channels (CaV3.2)) on PE-, 5-HT-induced vasoconstriction was significantly greater than progesterone or nifedipine in Krebs solution. Furthermore, progesterone did not affect the vasoconstriction caused by PE, 5-HT, or caffeine in Ca(2+)-free Krebs solution. In addition, incubation HUV with progesterone did not change CaV1.2 and progesterone receptor (PR) expressions. The results gained demonstrated that progesterone could suppress multiple agonist-induced vasoconstrictions in HUV, mainly due to a reduction of calcium entry through L-type calcium channels, not endothelium-dependent vascular relaxation pathways, potassium channels, or Ca(2+) release from intracellular stores, providing new information important to further understanding the contribution of progesterone in the regulation of the placental-fetal circulation.

Resveratrol Protects against TNF-α-Induced Injury in Human Umbilical Endothelial Cells through Promoting Sirtuin-1-Induced Repression of NF-KB and p38 MAPK

Inflammation and reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerosis. Resveratrol has been shown to possess anti-inflammatory and antioxidative stress activities, but the underlying mechanisms are not fully understood. In the present study, we investigated the molecular basis associated with the protective effects of resveratrol on tumor necrosis factor-alpha (TNF-α)-induced injury in human umbilical endothelial cells (HUVECs) using a variety of approaches including a cell viability assay, reverse transcription and quantitative polymerase chain reaction, western blot, and immunofluorescence staining. We showed that TNF-α induced CD40 expression and ROS production in cultured HUVECs, which were attenuated by resveratrol treatment. Also, resveratrol increased the expression of sirtuin 1 (SIRT1); and repression of SIRT1 by small-interfering RNA (siRNA) and the SIRT1 inhibitor Ex527 reduced the inhibitory effects of resveratrol on CD40 expression and ROS generation. In addition, resveratrol downregulated the levels of p65 and phospho-p38 MAPK, but this inhibitory effect was attenuated by the suppression of SIRT1 activity. Moreover, the p38 MAPK inhibitor SD203580 and the nuclear factor (NF)-κB inhibitor pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as resveratrol on TNF-α-induced ROS generation and CD40 expression. Thus, our study provides a mechanistic link between resveratrol and the activation of SIRT1, the latter of which is involved in resveratrol-mediated repression of the p38 MAPK/NF-κB pathway and ROS production in TNF-α-treated HUVECs.

Proteomic Analysis of Mesenchymal Stem Cells

Mesenchymal stem or stromal cells (MSCs) are of great interest in biomedical sciences and disease treatment because of their multipotency and wide range of applications for tissue repair and suppression of the immune system. Proteomic analysis of these unique cells has contributed to the identification of important pathways utilized by MSCs to differentiate into distinct tissues as well as important proteins responsible for their special function in vivo and in vitro. However, comparison of proteomic studies in MSCs still suffers from the heterogeneity of MSC preparations. In addition, as proteomics technology advances, several studies can be revisited in order to increase the depth of analysis and, therefore, elucidate more refined mechanisms involved in MSC functionalities. Here, we present detailed protocols to obtain MSCs, as well as protocols to perform in-depth profiling and quantification of alterations in MSC proteomes.

Theranostic Gold Nanomicelles made from Biocompatible Comb-like Polymers for Thermochemotherapy and Multifunctional Imaging with Rapid Clearance

A new generation of photothermal theranostic agents based on assembling 6 nm gold nanoparticles (AuNPs) is developed by using a novel comb-like amphipathic polymer as the template. The small AuNPs are assembled into DOX@gold nanomicelles, which show strong absorbance in the near-infrared region, for multimodal bioimaging and highly effective in vivo chemotherapy and photothermal therapy.

[The effect of Connexin43 downregulation on biological functions of HUVEC]

Connexin43 has been shown to play a pivotal role in wound healing process. Wound repair is enhanced by acute downregulation of connexin43, by increasing proliferation and migration of keratinocyte and fibroblast. Angiogenesis is also a central feature of wound repair, but little is known about the effects of connexin43 modulation on functions of endothelial cells. We used connexin43 specific small interference RNA (siRNA) to reduce the expression of connexin43 in human umbilical vein endothelial cell (HUVEC), and investigated the effects of connexin43 downregulation on intercellular communication, viability, proliferation, migration and angiogenic activity of HUVEC. Treatment of siRNA markedly reduced the expression of connexin43 by -80% in HUVEC (P < 0.05), and decreased the intercellular communication by -65% (P < 0.05). The viability, proliferation, migration and angiogenic activity of HUVEC decreased significantly (P < 0.05), compared with that of the normal cells. The results suggest that temporally downregulation of connexin43 expression at early stage of wound to inhibit the abnormal angiogenesis characterized with leaky and inflamed blood vessels, maybe a prerequisite for coordinated normal healing process.

The behavior of lipid debris left on cell surfaces from microbubble based ultrasound molecular imaging

Lipid monolayer coated microbubbles are currently being developed to identify vascular regions that express certain surface proteins as part of the new technique of ultrasound molecular imaging. The microbubbles are functionalized with targeting ligands which bind to the desired cells holding the microbubbles in place as the remaining unbound microbubbles are eliminated from circulation. Subsequent scanning with ultrasound can detect the highly reflectant microbubbles that are left behind. The ultrasound scanning and detection process results in the destruction of the microbubble, creating lipid fragments from the monolayer. Here we demonstrate that microbubbles targeted to 4T1 murine breast cancer cells and human umbilical cord endothelial cells leave behind adhered fragments of the lipid monolayer after exposure to ultrasound with peak negative pressures of 0.18 and 0.8MPa. Most of the observed fragments were large enough to be resistant to receptor mediated endocytosis. The fragments were not observed to incorporate into the lipid membrane of the cell over a period of 96min. They were not observed to break into smaller pieces or significantly change shape but they were observed to undergo translation and rotation across the cell surface as the cells migrated over the substrate. These large fragments will apparently remain on the surface of the targeted cells for significant periods of time and need to be considered for their potential effects on blood flow through the microcapillaries and potential for immune system recognition.

A novel modular bioreactor to in vitro study the hepatic sinusoid

We describe a unique, versatile bioreactor consisting of two plates and a modified commercial porous membrane suitable for in vitro analysis of the liver sinusoid. The modular bioreactor allows i) excellent control of the cell seeding process; ii) cell culture under controlled shear stress stimulus, and; iii) individual analysis of each cell type upon completion of the experiment. The advantages of the bioreactor detailed here are derived from the modification of a commercial porous membrane with an elastomeric wall specifically moulded in order to define the cell culture area, to act as a gasket that will fit into the bioreactor, and to provide improved mechanical robustness. The device presented herein has been designed to simulate the in vivo organization of a liver sinusoid and tested by co-culturing endothelial cells (EC) and hepatic stellate cells (HSC). The results show both an optimal morphology of the endothelial cells as well as an improvement in the phenotype of stellate cells, most probably due to paracrine factors released from endothelial cells. This device is proposed as a versatile, easy-to-use co-culture system that can be applied to biomedical research of vascular systems, including the liver.

[Ephrin B2 is involved in Porphyromonas gingivalis infection-enhanced adhesion of THP-1 to human umbilical vein endothelial cells]

OBJECTIVE

To investigate the mechanisms of Porphyromonas gingivalis (Pg) infection-mediated enhancement of adhesion between monocytes THP-1 and human umbilical vein endothelial cells (HUVEC) by detecting the effect of erythropoietin producing hepatomocellular receptor interacting protein B2 (Ephrin B2) and its receptors on the adhesion.

METHODS

PgATCC33277 was cultured in an anaerobic jar, and THP-1 cells were infected with various concentrations of Pg at multiplicity of infection (MOI) of 1:100 for 8 and 24 h, respectively. The expression of Ephrin B2 receptor of THP-1 cells was detected. After removal of the free Pg, THP-1 cells were cocultured with HUVEC (overexpress of EphrinB2 or not) for 24 h to detect the expression of Ephrin B2 of HUVEC cells after additional cultivation for 23 h.

RESULTS

The adhesion of THP-1 cells post infection by Pg to HUVEC was enhanced. The mRNA levels of Ephrin B2 receptors, including EphB3 (5.169±0.152, P = 0.005), EphB4 (11.040±1.195, P = 0.001), and EphA4 (4.976± 0.122, P = 0.001) expressed by THP-1, and Ephrin B2 (8.938±0.962, P = 0.008) expressed by HUVEC were significantly elevated 24 h post infection of Pg. Over expression of Ephrin B2 in HUVEC promoted the adhesion of THP-1 to HUVEC.

CONCLUSIONS

Ephrin B2 and its receptors are involved in Pg infection mediated enhancement of the adhesion of THP-1 to HUVEC cells, suggesting that Ephrin B2 participates in the development of atherosclerosis.

Characterization of the dynamic activities of a population of microbubbles driven by pulsed ultrasound exposure in sonoporation

Ultrasound-driven microbubble activities have been exploited to transiently disrupt the cell membrane (sonoporation) for non-viral intracellular drug delivery and gene transfection both in vivo and in vitro. In this study, we investigated the dynamic behaviors of a population of microbubbles exposed to pulsed ultrasound and their impact on adherent cells in terms of intracellular delivery and cell viability. By systematically analyzing the bubble activities at time scales relevant to pulsed ultrasound exposure, we identified two quantification parameters that categorize the diverse bubble activities subjected to various ultrasound conditions into three characteristic behaviors: stable cavitation/aggregation (type I), growth/coalescence and translation (type II) and localized inertial cavitation/collapse (type III). Correlation of the bubble activities with sonoporation outcome suggested that type III behavior resulted in intracellular delivery, whereas type II behavior caused the death of a large number of cells. These results provide useful insights for rational selection of ultrasound parameters to optimize outcomes of sonoporation and other applications that exploit the use of ultrasound-driven bubble activities.

Inhibition of P38 MAPK Reduces Tumor Conditioned Medium-Induced Angiogenesis in Co-Cultured Human Umbilical Vein Endothelial Cells and Fibroblasts

Tumor conditioned medium (CM) has been widely used to stimulate endothelial cells to form capillary-like structures in in vitro angiogenesis models. We report herein the effect of HT1080 and A549 CM after they were mixed with microvascular endothelial cells medium-2 (EGM-2) on angiogenesis in human umbilical vein endothelial cells (HUVECs). Both HT1080 and A549 CM decreased HUVEC proliferation, to different extents. While A549 CM significantly increased capillary-like structure formation in a co-culture system, no effect of HT1080 was apparent. Inhibition of p38 mitogen-activated protein kinase (MAPK) blocked both basal and A549 CM induced capillary-like structure formation, but inhibition of extracellular signal-regulated kinases (ERK) and that of c-Jun N-terminal protein kinases (JNK) MAPK had no such effect. Activation of ERK MAPK was inhibited by both CMs, whereas p38 MAPK was inactivated by HT1080 and activated by A549 CM and a control. Neither CM had an effect on JNK MAPK. The results suggest that p38 MAPK played a critical role in capillary-like structure formation in the co-culture, partly via promotion of apoptosis in HUVECs.

Isolation of Antioxidative Phenolic Glucosides from Lemon Juice and Their Suppressive Effect on the Expression of Blood Adhesion Molecules

Phenolic glucosides having radical scavenging activity were examined from the fraction eluted with 20% methanol on Amberlite XAD-2 resin applied to lemon (Citrus limon) juice by using reversed phase chromatography. Four phenolic glucosides were identified as 1-feruloyl-beta-D-glucopyranoside, 1-sinapoyl-beta-D-glucopyranoside, 6,8-di-C-glucosylapigenin and 6,8-di-C-glucosyldiosmetin by (1)H-NMR, (13)C-NMR, and MS analyses. They exhibited radical scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide, although the activity was low in comparison with eriocitrin, a potent antioxidant in lemon fruit, and the eriodictyol of its aglycone. The phenolic compounds in lemon juice were examined for their suppressive effect on the expression of blood adhesion molecules by measuring the expression of intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells (HUVECs) induced by necrosis factor-alpha (TNF-alpha). 6,8-Di-C-glucosylapigenin, apigenin, and diosmentin of the flavones were found to significantly suppress the expression of ICAM-1 at 10 muM (P<0.05). The phenolic glucosides isolated in this study were contained in comparative abundance in daidai (Citrus aurantium) and niihime (Citrus unshiu x Citrus tachibana) among the sour citrus juices.

Sesquiterpenes from Neurolaena lobata and their antiproliferative and anti-inflammatory activities

Five new sesquiterpenes, neurolobatin A (1), neurolobatin B (2), 5β-hydroxy-8β-isovaleroyloxy-9α-hydroxycalyculatolide (3), 3-epi-desacetylisovaleroylheliangine (4), and 3β-acetoxy-8β-isovaleroyloxyreynosin (5), were isolated from the aerial parts of Neurolaena lobata. The structures were established by means of a combined spectroscopic data analysis, including ESIMS, APCI-MS, and 1D- and 2D-NMR techniques. Neurolobatin A (1) and B (2) are unusual isomeric seco-germacranolide sesquiterpenes with a bicyclic acetal moiety, compounds 3 and 4 are unsaturated epoxy-germacranolide esters, and compound 5 is the first eudesmanolide isolated from the genus Neurolaena. The isolated compounds (1-5) were shown to have noteworthy antiproliferative activities against human tumor cell lines (A2780, A431, HeLa, and MCF7). The anti-inflammatory effects of 1-5, evaluated in vitro using LPS- and TNF-α-induced IL-8 expression inhibitory assays, revealed that all these compounds strongly down-regulated the LPS-induced production of IL-8 protein, with neurolobatin B (2) and 3-epi-desacetylisovaleroylheliangine (4) being the most effective.

Sauchinone from Saururus chinensis protects vascular inflammation by heme oxygenase-1 induction in human umbilical vein endothelial cells

Sauchinone, a diastereomeric lignan isolated from the roots of Saururus chinensis (LOUR.) BAILL. (Saururaceae), is reported to exert a variety of biological activities such as hepatoprotective, anti-inflammatory actions and inhibitory effects on bone resorption. In this study, we investigated the effect of sauchinone in suppressing cell adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) expression in high glucose stimulated human umbilical vein endothelial cells (HUVEC). Sauchinone inhibited the phosphorylation and degradation of IκB-α, as well as the nuclear translocation of nuclear factor kappa B (NF-κB) p65 caused by the stimulation of high glucose. In addition, sauchinone induced heme oxygenase (HO)-1 expression through nuclear translocation of nuclear factor E2-related factor 2 in HUVEC. The effects of sauchinone on the high glucose-induced expression of VCAM-1 and ICAM-1 and nuclear translocation of NF-κB p65 were partially reversed by transfection of the cells with HO-1 siRNA. These findings suggest that sauchinone-induced HO-1 expression plays a key role in the vascular protective effects of sauchinone in HUVEC.

[Protective effect of different solvent extracts from platycladi cacumen carbonisatum on LPS-induced human umbilical vein endothelial cells damage]

OBJECTIVE

To study the protective effect of different solvent extracts from Platycladi Cacumen Carbonisatum (PCC) on LPS-induced human umbilical vein endothelial cell damage, and discuss the effective extracts from PCC for protecting vascular endothelial cells and their possible active substances.

METHOD

HUVECs were cultured in vitro; And LPS was adopted to establish the human umbilical vein endothelial cell damage model. MTT colorimetric method was used to determine cell activity; Xanthine oxidase method was adopted to detect the activity of superoxide dismutases (SOD) in the cell culture fluid; The TBA method was adopted to determine the content of malondialdehyde (MDA); The nitrate reductase method was used to detect the content of nitric oxide (NO); And UPLC/Q-TOF-MS was used to analyze the difference in flavonoids components among different solvent extracts from PCC.

RESULT

Compared with the model group, N-butanol extract (100 mg x L(-1)) and ethylacetate extract (100, 50 mg x L(-1)) could significantly enhance the cell activity (P < 0.05), significantly reduce MDA and NO content, and increase SOD activity (P < 0.05). Among the four solvent extracts, the content of total flavonids were the highest in ethyl acetate extract, the lowest in water extract and equivalent in N-butanol and petroleum benzene extract. In terms of the contents of quercitrin and myricitrin, N-butanol extract were second only to ethyl acetate extract.

CONCLUSION

Ethylacetate extract from PCC has a notable antagonistic effect in the damage induced by LPS to HUVECs, and thus is the most effective extract from PCC in protecting vascular endothelial cells. Quercitrin, myricitrin or multiple flavonoids that it contains may be their active substances for protecting vascular endothelial cells. Its mechanism may be related to the decrease in the production of NO and the inhibition of lipid peroxidation in cells.

Death-domain associated protein-6 (DAXX) mediated apoptosis in hantavirus infection is counter-balanced by activation of interferon-stimulated nuclear transcription factors

Hantaviruses are negative strand RNA species that replicate predominantly in the cytoplasm. They also activate numerous cellular responses, but their involvement in nuclear processes is yet to be established. Using human umbilical vein endothelial cells (HUVECs), this study investigates the molecular finger-print of nuclear transcription factors during hantavirus infection. The viral-replication-dependent activation of pro-myelocytic leukemia protein (PML) was followed by subsequent localization in nuclear bodies (NBs). PML was also found in close proximity to activated Sp100 nuclear antigen and interferon-stimulated gene 20 kDa protein (ISG-20), but co-localization with death-domain associated protein-6 (DAXX) was not observed. These data demonstrate that hantavirus triggers PML activation and localization in NBs in the absence of DAXX-PLM-NB co-localization. The results suggest that viral infection interferes with DAXX-mediated apoptosis, and expression of interferon-activated Sp100 and ISG-20 proteins may indicate intracellular intrinsic antiviral attempts.

trans-Resveratrol in Gnetum gnemon protects against oxidative-stress-induced endothelial senescence

Gnetum gnemon is an arboreal dioecious plant that is cultivated in Indonesia. The seeds of this species mainly contain dimeric stilbenoid compounds [gnetin C (1), gnemonoside A (2), and gnemonoside D (3)] along with trans-resveratrol (4). trans-Resveratrol has been reported to have antiaging, anticancer, and antidiabetic effects, as well as being a calorie restriction mimetic. SIRT1 exerts a protective effect against vascular senescence. In this study, the effects of these four main stilbenoid derivatives of a G. gnemon seed endosperm ethanolic extract on endothelial senescence were investigated. In streptozotocin-induced diabetic mice, administration of the G. gnemon ethanolic extract increased SIRT1 and decreased endothelial senescence. The concentration of 1 in blood plasma was 6-fold higher than 4 in these mice. Next, the in vitro effects of the four main stilbenoid derivatives of G. gnemon seeds were investigated. Senescent human umbilical vein endothelial cells were induced by hydrogen peroxide. Endothelial senescence was inhibited by 4, which increased the expression of endothelial nitric oxide synthase and SIRT1, whereas 1-3 had no effect. These results indicated that the ethanolic extract of G. gnemon seeds inhibits endothelial senescence, suggesting that 4 plays a critical role in the prevention of endothelial senescence.

Interaction of Leptospira interrogans with human proteolytic systems enhances dissemination through endothelial cells and protease levels

We have recently reported the ability of Leptospira to capture plasminogen (PLG) and generate plasmin (PLA) bound on the microbial surface in the presence of exogenous activators. In this work, we examined the effects of leptospiral PLG binding for active penetration through the endothelial cell barrier and activation. The results indicate that leptospires with PLG association or PLA activation have enhanced migration activity through human umbilical vein endothelial cell (HUVEC) monolayers compared with untreated bacteria. Leptospira cells coated with PLG were capable of stimulating the expression of PLG activators by HUVECs. Moreover, leptospires endowed with PLG or PLA promoted transcriptional upregulation matrix metalloprotease 9 (MMP-9). Serum samples from patients with confirmed leptospirosis showed higher levels of PLG activators and total MMP-9 than serum samples from normal (healthy) subjects. The highest level of PLG activators and total MMP-9 was detected with microscopic agglutination test (MAT)-negative serum samples, suggesting that this proteolytic activity stimulation occurs at the early stage of the disease. Furthermore, a gelatin zymography profile obtained for MMPs with serum samples from patients with leptospirosis appears to be specific to leptospiral infection because serum samples from patients with unrelated infectious diseases produced no similar degradation bands. Altogether, the data suggest that the Leptospira-associated PLG or PLA might represent a mechanism that contributes to bacterial penetration of endothelial cells through an activation cascade of events that enhances the proteolytic capability of the organism. To our knowledge, this is the first proteolytic activity associated with leptospiral pathogenesis described to date.

N-Epsilon-(carboxymethyl)lysine is unable to induce endothelial dysfunction but is able to attenuate Ages-induced endothelium damage in human umbilical vein endothelial cells

N-Epsilon-carboxymethyllysine (CML), one of the main compounds in advanced glycation end products (AGEs), has been thought to be a high bioaffinity ligand of the receptor for AGEs (RAGE), and is involved in the pathogenesis in endothelial dysfunction in diabetic vascular complications. However, some researchers believed that CML was unable to bind to RAGE and could not induce endothelium damage. In our present experiment, the role of CML in inducing endothelial dysfunction, preventing AGEs-induced damage and binding to RAGE was explored in human umbilical vein endothelial cells (HUVECs). The treatment with CML could not induce the endothelial dysfunction by itself, including upregulation on transforming growth factor-betai (TGF-beta1), intercellular adhesion molecule-1 (ICAM-1) and RAGE proteins expressions, apoptosis and cell viability in HUVECs. However, pretreatment with CML could attenuate AGEs-induced endothelial dysfunction. Fluorescence polarization assay showed that CML had a bioaffinity to RAGE. The IC50 of CML binding to RAGE (10 ng and 100 ng) were 7.133 x 10-8M and 1.563 x 10-6M, respectively. Our findings indicate that CML has no cytotoxic injury to endothelium but has a bioaffinity for the binding to RAGE.

[Isolation, culture, and identification of canine umbilical vein vascular endothelial cells]

OBJECTIVE

To establish a simple and efficient method to isolate and culture the umbilical vein vascular endothelial cells in canine.

METHODS

Twelve umbilical cords [(13.0 +/- 1.5) cm in length] were taken from 12 newborn pups of Beagles. And then the vascular endothelial cells were isolated from these umbilical cords digested by 1% collagenase type I for 5, 7, and 10 minutes respectively (4 umbilical cords in each group). After cultured, the vascular endothelial cells were identified by morphology, immunofluorescence, and flow cytometry. And the growth curvature of umbilical vein vascular endothelial cells was detected by MTT assay.

RESULTS

Few vascular endothelial cells were collected at 5 and 10 minutes after digestion; many vascular endothelial cells were seen at 7 minutes, and became cobblestone with culture time, with a large nucleus; after passage, cell morphology had no obvious change. Fluorescence microscope results showed that positive von Willebrand factor (vWF) and CD31 cells were observed in most of cells. The flow cytometry test displayed that the positive cell rates of vWF and CD31 were 99.0% +/- 0.7% and 98.0% +/- 1.2%, respectively. The above results indicated that cultured cells were vascular endothelial cells. MTT assay showed that vascular endothelial cells proliferation increased significantly with culture time.

CONCLUSION

Enzyme digestion is a convenient method to isolate vascular endothelial cells from canine umbilical vein, and a large number of cells and high purity of cells can be obtained by the method.

[Effects of danshen on NO and ET-1 secreted by endothelial cells induced by the serum of pre-eclampsia patients]

OBJECTIVE

To explore the protective effects of danshen (Salvia Miltiorrhiza) on vascular endothelial cells in hypertension patients in the gestation period.

METHODS

The umbilical vein endothelial cells pre-incubated with Danshen solution at different concentrations (0, 100, 200, and 300 mg/L) were randomly divided into 3 groups, i.e., the blank control group (8 cases), the normal control group (14 cases, cultured in the serum from 14 normal pregnant women), and the observation group (14 cases, cultured in the serum from 14 pregnant women with severe pre-eclampsia). The levels of nitric oxide (NO) and endothelin-1 (ET-1) in each culture supernatant were detected respectively.

RESULTS

The ET-1 level was higher in 300 mg/L Danshen solution group than in 0 mg/L and 100 mg/L Danshen solution groups (P <0.05). The NO level was lower in the observation group than in the blank control group and the normal control group (P <0. 05). The NO level was higher in 200 mg/L Danshen solution group than in 0 mg/L Danshen solution group (P <0.05). The NO level was higher in 300 mg/L Danshen solution group than in 0 mg/L, 100 mg/L, and 200 mg/L Danshen solution groups (P <0.05).

CONCLUSION

Danshen could increase the secretion of NO from in vitro umbilical vein endothelial cells cultured in the serum from patients with pre-eclampsia, and reduce the secretion of ET-1.

Osteogenic and angiogenic potentials of monocultured and co-cultured human-bone-marrow-derived mesenchymal stem cells and human-umbilical-vein endothelial cells on three-dimensional porous beta-tricalcium phosphate scaffold

The use of biodegradable beta-tricalcium phosphate (β-TCP) scaffolds holds great promise for bone tissue engineering. However, the effects of β-TCP on bone and endothelial cells are not fully understood. This study aimed to investigate cell proliferation and differentiation of mono- or co-cultured human-bone-marrow-derived mesenchymal stem cells (hBMSCs) and human-umbilical-vein endothelial cells (HUVECs) on a three-dimensional porous, biodegradable β-TCP scaffold. In co-culture studies, the ratios of hBMSCs:HUVECs were 5:1, 1:1 and 1:5. Cellular morphologies of HUVECs, hBMSCs and co-cultured HUVECs/hBMSCs on the β-TCP scaffolds were monitored using confocal and scanning electron microscopy. Cell proliferation was monitored by measuring the amount of double-stranded DNA (dsDNA) whereas hBMSC and HUVEC differentiation was assessed using the osteogenic and angiogenic markers, alkaline phosphatase (ALP) and PECAM-1 (CD31), respectively. Results show that HUVECs, hBMSCs and hBMSCs/HUVECs adhered to and proliferated well on the β-TCP scaffolds. In monoculture, hBMSCs grew faster than HUVECs on the β-TCP scaffolds after 7 days, but HUVECs reached similar levels of proliferation after 14 days. In monoculture, β-TCP scaffolds promoted ALP activities of both hBMSCs and HUVECs when compared to those grown on tissue culture well plates. ALP activity of cells in co-culture was higher than that of hBMSCs in monoculture. Real-time polymerase chain reaction results indicate that runx2 and alp gene expression in monocultured hBMSCs remained unchanged at days 7 and 14, but alp gene expression was significantly increased in hBMSC co-cultures when the contribution of individual cell types was not distinguished.