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Sample records for brain capillary endothelial

  1. Barrier Functionality of Porcine and Bovine Brain Capillary Endothelial Cells

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    Ailar Nakhlband

    2011-09-01

    Full Text Available Introduction: To date, isolated cell based blood-brain barrier (BBB models have been widely used for brain drug delivery and targeting, due to their relatively proper bioelectrical and permeability properties. However, primary cultures of brain capillary endothelial cells (BCECs isolated from different species vary in terms of bioelectrical and permeability properties. Methods: To pursue this, in the current investigation, primary porcine and bovine BCECs (PBCECs and BBCECs, respectively were isolated and used as an in vitro BBB model. The bioelectrical and permeability properties were assessed in BCECs co-cultured with C6 cells with/without hydrocortisone (550 nM. The bioelectrical properties were further validated by means of the permeability coefficients of transcellular and paracellular markers. Results: The primary PBCECs displayed significantly higher trans-endothelial electrical resistance (~900 W.cm2 than BBCECs (~700 W.cm2 - both co-cultured with C6 cells in presence of hydrocortisone. Permeability coefficients of propranolol/diazepam and mannitol/sucrose in PBCECs were ~21 and ~2 (×10-6 cm.sec-1, where these values for BBCECs were ~25 and ~5 (×10-6 cm.sec-1. Conclusion: Upon our bioelectrical and permeability findings, both models display discriminative barrier functionality but porcine BCECs seem to provide a better platform than bovine BCECs for drug screening and brain targeting.

  2. Internalization of targeted quantum dots by brain capillary endothelial cells in vivo.

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    Paris-Robidas, Sarah; Brouard, Danny; Emond, Vincent; Parent, Martin; Calon, Frédéric

    2016-04-01

    Receptors located on brain capillary endothelial cells forming the blood-brain barrier are the target of most brain drug delivery approaches. Yet, direct subcellular evidence of vectorized transport of nanoformulations into the brain is lacking. To resolve this question, quantum dots were conjugated to monoclonal antibodies (Ri7) targeting the murine transferrin receptor. Specific transferrin receptor-mediated endocytosis of Ri7-quantum dots was first confirmed in N2A and bEnd5 cells. After intravenous injection in mice, Ri7-quantum dots exhibited a fourfold higher volume of distribution in brain tissues, compared to controls. Immunofluorescence analysis showed that Ri7-quantum dots were sequestered throughout the cerebral vasculature 30 min, 1 h, and 4 h post injection, with a decline of signal intensity after 24 h. Transmission electron microscopic studies confirmed that Ri7-quantum dots were massively internalized by brain capillary endothelial cells, averaging 37 ± 4 Ri7-quantum dots/cell 1 h after injection. Most quantum dots within brain capillary endothelial cells were observed in small vesicles (58%), with a smaller proportion detected in tubular structures or in multivesicular bodies. Parenchymal penetration of Ri7-quantum dots was extremely low and comparable to control IgG. Our results show that systemically administered Ri7-quantum dots complexes undergo extensive endocytosis by brain capillary endothelial cells and open the door for novel therapeutic approaches based on brain endothelial cell drug delivery.

  3. Gene delivery of therapeutic polypeptides to brain capillary endothelial cells for protein secretion

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    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    of the proteins. Morphological examination of the protein expression was determined using immunofluorescence detecting FLAG. Additionally, the transfection efficiency were determined by Flow cytometry. Perspective: Our study opens for knowledge on how non-viral gene therapy to BCECs can lead to protein secretion......Background: The potential for treatment of chronic disorders affecting the CNS is complicated by the inability of several drugs to cross the blood-brain barrier (BBB). None-viral gene therapy applied to brain capillary endothelial cells (BCECs) denotes a novel approach to overcome the restraints....... Results: mRNA expression of proteins with neuroprotective potential in RBEC were enabled. Their expression patters were compared with those of RBE4 and HeLa cells using RT-qPCR analyzes. The evidence for protein synthesis and secretion was obtained by detection of FLAG-tagged to the C-terminal of any...

  4. Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.

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    Sylvia Wagner

    Full Text Available BACKGROUND: The blood-brain barrier (BBB represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. CONCLUSIONS/SIGNIFICANCE: This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier.

  5. Transient oxygen-glucose deprivation sensitizes brain capillary endothelial cells to rtPA at 4h of reoxygenation.

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    Kuntz, Mélanie; Mysiorek, Caroline; Pétrault, Olivier; Boucau, Marie-Christine; Aijjou, Rachid; Uzbekov, Rustem; Bérézowski, Vincent

    2014-01-01

    Thrombolysis treatment of acute ischemic stroke is limited by the pro-edematous and hemorrhagic effects exerted by reperfusion, which disrupts the blood-brain barrier (BBB) capillary endothelium in the infarct core. Most studies of the ischemic BBB overlook the complexity of the penumbral area, where the affected brain cells are still viable following deprivation. Our present objective was to examine in vitro the kinetic impact of reoxygenation on the integrity of ischemic BBB cells after oxygen-glucose deprivation. Through the use of a co-culture of brain capillary endothelial cells and glial cells, we first showed that the transendothelial permeability increase induced by deprivation can occur with both preserved cell viability and interendothelial tight junction network. The subtle and heterogeneous alteration of the tight junctions was observable only through electron microscopy. A complete permeability recovery was then found after reoxygenation, when Vimentin and Actin networks were reordered. However, still sparse ultrastructural alterations of tight junctions suggested an acquired vulnerability. Endothelial cells were then exposed to recombinant tissue-type plasminogen activator (rtPA) to define a temporal profile for the toxic effect of this thrombolytic on transendothelial permeability. Interestingly, the reoxygenated BBB broke down with aggravated tight junction disruption when exposed to rtPA only at 4h after reoxygenation. Moreover, this breakdown was enhanced by 50% when ischemic glial cells were present during the first hours of reoxygenation. Our results suggest that post-stroke reoxygenation enables retrieval of the barrier function of brain capillary endothelium when in a non-necrotic environment, but may sensitize it to rtPA at the 4-hour time point, when both endothelial breakdown mechanisms and glial secretions could be identified and targeted in a therapeutical perspective.

  6. Gene delivery of therapeutic polypeptides into brain capillary endothelial cells for protein secretion

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    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben;

    has been to investigate the usage of BCEC as factories for recombinant protein production. A non-viral gene carrier was prepared from pullulan-spermine conjugated with plasmid DNA (Thomsen et al., 2011). In vitro transfection of Rat Brain Endothelial Cells (RBE4) and Human Brain Microvascular...... Endothelial cells (HBMECs) were conducted with three plasmids bearing cDNA encoding human BDNF, EPO or the FGL peptide. Results revealed a high expression of BDNF, EPO and FGL transcripts in transfected cells compared to the non-transfected cells, which strongly suggest that transfection were successful...

  7. Gene delivery into primary brain capillary endothelial cells for protein secretion

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    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Lichota, Jacek;

    model was established by co-culturing primary BCECs together with primary astrocytes, both of which were isolated from rats. This was done in order to study the possibility of using gene transfection in an environment closer to the in-vivo BBB situation. The in-vitro BBB barrier model showed trans...... for recombinant protein production. We have previously shown that it is possible to transfect human microvascular endothelial cells (HBMEC) and rat brain endothelial (RBE4) cells with genetic material encoding the human growth hormone (GH1) (Thomsen et al 2011). In the present study, however, an in-vitro BBB...

  8. A nanoengineered peptidic delivery system with specificity for human brain capillary endothelial cells

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    Wu, Linping; Moghimi, Seyed Moein

    2016-01-01

    The blood–brain-barrier (BBB) is a formidable obstacle for successful translocation of many drug molecules from the systemic circulation into the brain, and therefore a major challenge for neurotherapeutics. Nanoparticles may offer some opportunities for delivery of bioactive molecules into brain...

  9. Regulation of store-operated Ca{sup 2+} entry activity by cell cycle dependent up-regulation of Orai2 in brain capillary endothelial cells

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    Kito, Hiroaki [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto (Japan); Yamamura, Hisao; Suzuki, Yoshiaki; Yamamura, Hideto [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Ohya, Susumu [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

    2015-04-10

    Store-operated Ca{sup 2+} entry (SOCE) via Orai1 and STIM1 complex is supposed to have obligatory roles in the regulation of cellular functions of vascular endothelial cells, while little is known about the contribution of Orai2. Quantitative PCR and Western blot analyses indicated the expression of Orai2 and STIM2, in addition to Orai1 and STIM1 in bovine brain capillary endothelial cell line, t-BBEC117. During the exponential growth of t-BBEC117, the knockdown of Orai1 and STIM1 significantly reduced the SOCE activity, whereas Orai2 and STIM2 siRNAs had no effect. To examine whether endogenous SOCE activity contributes to the regulation of cell cycle progression, t-BBEC117 were synchronized using double thymidine blockage. At the G2/M phase, Ca{sup 2+} influx via SOCE was decreased and Orai2 expression was increased compared to the G0/G1 phase. When Orai2 was knocked down at the G2/M phase, the decrease in SOCE was removed, and cell proliferation was partly attenuated. Taken together, Orai1 significantly contributes to cell proliferation via the functional expression, which is presumably independent of the cell cycle phases. In construct, Orai2 is specifically up-regulated during the G2/M phase, negatively modulates the SOCE activity, and may contribute to the regulation of cell cycle progression in brain capillary endothelial cells. - Highlights: • Orai1 is essential for SOCE activity in brain capillary endothelial cells (BCECs). • Cell cycle independent expression of Orai1 regulated SOCE and cell proliferation. • Orai2 was up-regulated only at G2/M phase and this consequently reduced SOCE. • Orai2 as well as Orai1 is a key player controlling SOCE and proliferation in BCECs.

  10. Sodium-dependent vitamin C transporter 2 (SVCT2 expression and activity in brain capillary endothelial cells after transient ischemia in mice.

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    Burkhard Gess

    Full Text Available Expression and transport activity of Sodium-dependent Vitamin C Transporter 2 (SVCT2 was shown in various tissues and organs. Vitamin C was shown to be cerebroprotective in several animal models of stroke. Data on expression, localization and transport activity of SVCT2 after cerebral ischemia, however, has been scarce so far. Thus, we studied the expression of SVCT2 after middle cerebral artery occlusion (MCAO in mice by immunohistochemistry. We found an upregulation of SVCT2 after stroke. Co-stainings with Occludin, Von-Willebrand Factor and CD34 demonstrated localization of SVCT2 in brain capillary endothelial cells in the ischemic area after stroke. Time-course analyses of SVCT2 expression by immunohistochemistry and western blots showed upregulation in the subacute phase of 2-5 days. Radioactive uptake assays using (14C-labelled ascorbic acid showed a significant increase of ascorbic acid uptake into the brain after stroke. Taken together, these results provide evidence for the expression and transport activity of SVCT2 in brain capillary endothelial cells after transient ischemia in mice. These results may lead to the development of novel neuroprotective strategies in stroke therapy.

  11. Involvement of insulin-degrading enzyme in insulin- and atrial natriuretic peptide-sensitive internalization of amyloid-β peptide in mouse brain capillary endothelial cells.

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    Ito, Shingo; Ohtsuki, Sumio; Murata, Sho; Katsukura, Yuki; Suzuki, Hiroya; Funaki, Miho; Tachikawa, Masanori; Terasaki, Tetsuya

    2014-01-01

    Cerebral clearance of amyloid-β peptide (Aβ), which is implicated in Alzheimer's disease, involves elimination across the blood-brain barrier (BBB), and we previously showed that an insulin-sensitive process is involved in the case of Aβ1-40. The purpose of this study was to clarify the molecular mechanism of the insulin-sensitive Aβ1-40 elimination across mouse BBB. An in vivo cerebral microinjection study demonstrated that [125I]hAβ1-40 elimination from mouse brain was inhibited by human natriuretic peptide (hANP), and [125I]hANP elimination was inhibited by hAβ1-40, suggesting that hAβ1-40 and hANP share a common elimination process. Internalization of [125I]hAβ1-40 into cultured mouse brain capillary endothelial cells (TM-BBB4) was significantly inhibited by either insulin, hANP, other natriuretic peptides or insulin-degrading enzyme (IDE) inhibitors, but was not inhibited by phosphoramidon or thiorphan. Although we have reported the involvement of natriuretic peptide receptor C (Npr-C) in hANP internalization, cells stably expressing Npr-C internalized [125I]hANP but not [125I]hAβ1-40, suggesting that there is no direct interaction between Npr-C and hAβ1-40. IDE was detected in plasma membrane of TM-BBB4 cells, and internalization of [125I]hAβ1-40 by TM-BBB4 cells was reduced by IDE-targeted siRNAs. We conclude that elimination of hAβ1-40 from mouse brain across the BBB involves an insulin- and ANP-sensitive process, mediated by IDE expressed in brain capillary endothelial cells.

  12. Up-regulation of K{sub ir}2.1 by ER stress facilitates cell death of brain capillary endothelial cells

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    Kito, Hiroaki [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Yamazaki, Daiju [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Biological Chemistry, Kyoto University, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Ohya, Susumu; Yamamura, Hisao [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

    2011-07-29

    Highlights: {yields} We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. {yields} The ER stress facilitated the expression of inward rectifier K{sup +} channel (K{sub ir}2.1) and induced sustained membrane hyperpolarization. {yields} The membrane hyperpolarization induced sustained Ca{sup 2+} entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. {yields} The K{sub ir}2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K{sup +} channel (K{sub ir}2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K{sub ir} channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca{sup 2+} concentration due to Ca{sup 2+} influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K{sub ir}2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  13. Transport of monocarboxylic acids at the blood-brain barrier: Studies with monolayers of primary cultured bovine brain capillary endothelial cells

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    Terasaki, T.; Takakuwa, S.; Moritani, S.; Tsuji, A. (Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Kanazawa University (Japan))

    1991-09-01

    The kinetics and mechanism of the transport of monocarboxylic acids (MCAs) were studied by using primary cultured bovine brain capillary endothelial cells. Concentration-dependent uptake of acetic acid was observed, and the kinetic parameters were estimated as follows: the Michaelis constant, Kt, was 3.41 {plus minus} 1.87 mM, the maximum uptake rate, Jmax, was 144.7 {plus minus} 55.7 nmol/mg of protein/min and the nonsaturable first-order rate constant, Kd, was 6.66 {plus minus} 1.98 microliters/mg of protein/min. At medium pH below 7.0, the uptake rate of (3H)acetic acid increased markedly with decreasing medium pH, whereas pH-independent uptake was observed in the presence of 10 mM acetic acid. An energy requirement for (3H)acetic acid uptake was also demonstrated, because metabolic inhibitors (2,4-dinitrophenol and rotenone) reduced significantly the uptake rate (P less than .05). Carbonylcyanide-p-trifluoro-methoxyphenylhydrazone, a protonophore, inhibited significantly the uptake of (3H)acetic acid at medium pH of 5.0 and 6.0, whereas 4,4{prime}-diisothiocyanostilben-2,2{prime}-disulfonic acid did not. Several MCAs inhibited significantly the uptake rate of (3H)acetic acid, whereas di- and tricarboxylic acids did not. The uptake of (3H)acetic acid was competitively inhibited by salicylic acid, with an inhibition constant, Ki, of 3.60 mM, suggesting a common transport system between acetic acid and salicylic acid. Moreover, at the medium pH of 7.4, salicylic acid and valproic acid inhibited significantly the uptake of (3H)acetic acid, demonstrating that the transport of MCA drugs could also be ascribed to the MCA transport system at the physiologic pH.

  14. Targeting Cells With MR Imaging Probes: Cellular Interaction And Intracellular Magnetic Iron Oxide Nanoparticles Uptake In Brain Capillary Endothelial and Choroidal Plexus Epithelial Cells

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    Cambianica, I.; Bossi, M.; Gasco, P.; Gonzalez, W.; Idee, J. M.; Miserocchi, G.; Rigolio, R.; Chanana, M.; Morjan, I.; Wang, D.; Sancini, G.

    2010-10-01

    Magnetic iron oxide nanoparticles (NPs) are considered for various diagnostic and therapeutic applications in brain including their use as contrast agent for magnetic resonance imaging. In delivery application, the critical step is the transport across cell layers and the internalization of NPs into specific cells, a process often limited by poor targeting specificity and low internalization efficiency. The development of the models of brain endothelial cells and choroidal plexus epithelial cells in culture has allowed us to investigate into these mechanisms. Our strategy is aimed at exploring different routes to the entrapment of iron oxide NPs in these brain related cells. Here we demonstrated that not only cells endowed with a good phagocytic activity like activated macrophages but also endothelial brain capillary and choroidal plexus epithelial cells do internalize iron oxide NPs. Our study of the intracellular trafficking of NPs by TEM, and confocal microscopy revealed that NPs are mainly internalized by the endocytic pathway. Iron oxide NPs were dispersed in water and coated with 3,4-dihydroxyl-L-phenylalanine (L-DOPA) using standard procedures. Magnetic lipid NPs were prepared by NANOVECTOR: water in oil in water (W/O/W) microemulsion process has been applied to directly coat different iron based NPs by lipid layer or to encapsulate them into Solid Lipid Nanoparticles (SLNs). By these coating/loading the colloidal stability was improved without strong alteration of the particle size distribution. Magnetic lipid NPs could be reconstituted after freeze drying without appreciable changes in stability. L-DOPA coated NPs are stable in PBS and in MEM (Modified Eagle Medium) medium. The magnetic properties of these NPs were not altered by the coating processes. We investigated the cellular uptake, cytotoxicity, and interaction of these NPs with rat brain capillary endothelial (REB4) and choroidal plexus epithelial (Z310) cells. By means of widefield, confocal

  15. Major involvement of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) in uptake of biotin and pantothenic acid by human brain capillary endothelial cells.

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    Uchida, Yasuo; Ito, Katsuaki; Ohtsuki, Sumio; Kubo, Yoshiyuki; Suzuki, Takashi; Terasaki, Tetsuya

    2015-07-01

    The purpose of this study was to clarify the expression of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) and its contribution to the supply of biotin and pantothenic acid to the human brain via the blood-brain barrier. DNA microarray and immunohistochemical analyses confirmed that SLC5A6 is expressed in microvessels of human brain. The absolute expression levels of SLC5A6 protein in isolated human and monkey brain microvessels were 1.19 and 0.597 fmol/μg protein, respectively, as determined by a quantitative targeted absolute proteomics technique. Using an antibody-free method established by Kubo et al. (2015), we found that SLC5A6 was preferentially localized at the luminal membrane of brain capillary endothelium. Knock-down analysis using SLC5A6 siRNA showed that SLC5A6 accounts for 88.7% and 98.6% of total [(3) H]biotin and [(3) H]pantothenic acid uptakes, respectively, by human cerebral microvascular endothelial cell line hCMEC/D3. SLC5A6-mediated transport in hCMEC/D3 was markedly inhibited not only by biotin and pantothenic acid, but also by prostaglandin E2, lipoic acid, docosahexaenoic acid, indomethacin, ketoprofen, diclofenac, ibuprofen, phenylbutazone, and flurbiprofen. This study is the first to confirm expression of SLC5A6 in human brain microvessels and to provide evidence that SLC5A6 is a major contributor to luminal uptake of biotin and pantothenic acid at the human blood-brain barrier. In humans, it was unclear (not concluded) about what transport system at the blood-brain barrier (BBB) is responsible for the brain uptakes of two vitamins, biotin and pantothenic acid, which are necessary for brain proper function. This study clarified for the first time that the solute carrier 5A6/Na(+) -dependent multivitamin transporter SLC5A6/SMVT is responsible for the supplies of biotin and pantothenic acid into brain across the BBB in humans. DHA, docosahexaenoic acid; NSAID, non-steroidal anti-inflammatory drug; PGE2, prostaglandin E2.

  16. Drug-induced trafficking of p-glycoprotein in human brain capillary endothelial cells as demonstrated by exposure to mitomycin C.

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    Noack, Andreas; Noack, Sandra; Hoffmann, Andrea; Maalouf, Katia; Buettner, Manuela; Couraud, Pierre-Olivier; Romero, Ignacio A; Weksler, Babette; Alms, Dana; Römermann, Kerstin; Naim, Hassan Y; Löscher, Wolfgang

    2014-01-01

    P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. In this study, trafficking of Pgp was investigated in human brain capillary endothelial cells (hCMEC/D3) that were stably transfected with a doxycycline-inducible MDR1-EGFP fusion plasmid. In the presence of doxycycline, these cells exhibited a 15-fold increase in Pgp-EGFP fusion protein expression, which was associated with an increased efflux of the Pgp substrate rhodamine 123 (Rho123). The chemotherapeutic agent mitomycin C (MMC) was used to study drug-induced trafficking of Pgp. Confocal fluorescence microscopy of single hCMEC/D3-MDR1-EGFP cells revealed that Pgp redistribution from intracellular pools to the cell surface occurred within 2 h of MMC exposure. Pgp-EGFP exhibited a punctuate pattern at the cell surface compatible with concentrated regions of the fusion protein in membrane microdomains, i.e., lipid rafts, which was confirmed by Western blot analysis of biotinylated cell surface proteins in Lubrol-resistant membranes. MMC exposure also increased the functionality of Pgp as assessed in three functional assays with Pgp substrates (Rho123, eFluxx-ID Gold, calcein-AM). However, this increase occurred with some delay after the increased Pgp expression and coincided with the release of Pgp from the Lubrol-resistant membrane complexes. Disrupting rafts by depleting the membrane of cholesterol increased the functionality of Pgp. Our data present the first direct evidence of drug-induced Pgp trafficking at the human BBB and indicate that Pgp has to be released from lipid

  17. A large-scale electrophoresis- and chromatography-based determination of gene expression profiles in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties

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    Duban-Deweer Sophie

    2010-11-01

    Full Text Available Abstract Background Brain capillary endothelial cells (BCECs form the physiological basis of the blood-brain barrier (BBB. The barrier function is (at least in part due to well-known proteins such as transporters, tight junctions and metabolic barrier proteins (e.g. monoamine oxidase, gamma glutamyltranspeptidase and P-glycoprotein. Our previous 2-dimensional gel proteome analysis had identified a large number of proteins and revealed the major role of dynamic cytoskeletal remodelling in the differentiation of bovine BCECs. The aim of the present study was to elaborate a reference proteome of Triton X-100-soluble species from bovine BCECs cultured in the well-established in vitro BBB model developed in our laboratory. Results A total of 215 protein spots (corresponding to 130 distinct proteins were identified by 2-dimensional gel electrophoresis, whereas over 350 proteins were identified by a shotgun approach. We classified around 430 distinct proteins expressed by bovine BCECs. Our large-scale gene expression analysis enabled the correction of mistakes referenced into protein databases (e.g. bovine vinculin and constitutes valuable evidence for predictions based on genome annotation. Conclusions Elaboration of a reference proteome constitutes the first step in creating a gene expression database dedicated to capillary endothelial cells displaying BBB characteristics. It improves of our knowledge of the BBB and the key proteins in cell structures, cytoskeleton organization, metabolism, detoxification and drug resistance. Moreover, our results emphasize the need for both appropriate experimental design and correct interpretation of proteome datasets.

  18. Actin filament-associated protein 1 (AFAP-1) is a key mediator in inflammatory signaling-induced rapid attenuation of intrinsic P-gp function in human brain capillary endothelial cells.

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    Hoshi, Yutaro; Uchida, Yasuo; Tachikawa, Masanori; Ohtsuki, Sumio; Terasaki, Tetsuya

    2017-01-23

    The purpose of this study was to identify regulatory molecule(s) involved in the inflammatory signaling-induced decrease in P-glycoprotein (P-gp) efflux function at the blood-brain barrier (BBB) that may occur in brain diseases. We confirmed that in vivo P-gp efflux activity at the BBB was decreased without any change in P-gp protein expression level in a mouse model of acute inflammation induced by 3 mg/kg lipopolysaccharide. In a human BBB model cell line (human brain capillary endothelial cells; hCMEC/D3), 1-h treatment with 10 ng/mL tumor necrosis factor-α (TNF-α; an inflammatory mediator) rapidly reduced P-gp efflux activity, but had no effect on P-gp protein expression level. To clarify the non-transcriptional mechanism that causes the decrease in intrinsic efflux activity of P-gp in acute inflammation, we applied comprehensive quantitative phosphoproteomics to compare hCMEC/D3 cells treated with TNF-α and vehicle (control). Actin filament-associated protein-1 (AFAP-1), MAPK1, and transcription factor AP-1 (AP-1) were significantly phosphorylated in TNF-α-treated cells, and were selected as candidate proteins. In validation experiments, knockdown of AFAP-1 expression blocked the reduction in P-gp efflux activity by TNF-α treatment, whereas inhibition of MAPK function or knockdown of AP-1 expression did not. Quantitative targeted absolute proteomics revealed that the reduction in P-gp activity by TNF-α did not require any change in P-gp protein expression levels in the plasma membrane. Our results demonstrate that AFAP-1 is a key mediator in the inflammatory signaling-induced, translocation-independent rapid attenuation of P-gp efflux activity in human brain capillary endothelial cells.

  19. Targeting immunoliposomes to transferrin receptors on brain capillary endothelial cells as a mean for cargo transport across the blood-brain barrier

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    Johnsen, Kasper Bendix; Larsen, Annette Burkhart; Bruun, Jonas;

    2016-01-01

    transport further into the CNS. We studied transferrin receptor-targeted (OX26) immunoliposomes containing oxaliplatin with the aim of quantifying the uptake of OX26, liposomes and oxaliplatin in BCECs and the remaining CNS. The uptake of the immunoliposomes and their cargo was studied in 18-dayold rats...... higher both in vitro and in vivo when compared to isotypic IgG-conjugated liposomes. Quantitative analyses after capillary depletion revealed cargo transport from BCECs to the remaining CNS, but not differences could be detected between OX26- conjugated and isotype IgG control liposomes in vivo, whereas...

  20. Human Brain Microvascular Endothelial Cells Derived from the BC1 iPS Cell Line Exhibit a Blood-Brain Barrier Phenotype

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    Katt, Moriah E.; Xu, Zinnia S.; Gerecht, Sharon; Searson, Peter C.

    2016-01-01

    The endothelial cells that form capillaries in the brain are highly specialized, with tight junctions that minimize paracellular transport and an array of broad-spectrum efflux pumps that make drug delivery to the brain extremely challenging. One of the major limitations in blood-brain barrier research and the development of drugs to treat central nervous system diseases is the lack of appropriate cell lines. Recent reports indicate that the derivation of human brain microvascular endothelial...

  1. Brain endothelial dysfunction in cerebral adrenoleukodystrophy.

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    Musolino, Patricia L; Gong, Yi; Snyder, Juliet M T; Jimenez, Sandra; Lok, Josephine; Lo, Eng H; Moser, Ann B; Grabowski, Eric F; Frosch, Matthew P; Eichler, Florian S

    2015-11-01

    See Aubourg (doi:10.1093/awv271) for a scientific commentary on this article.X-linked adrenoleukodystrophy is caused by mutations in the ABCD1 gene leading to accumulation of very long chain fatty acids. Its most severe neurological manifestation is cerebral adrenoleukodystrophy. Here we demonstrate that progressive inflammatory demyelination in cerebral adrenoleukodystrophy coincides with blood-brain barrier dysfunction, increased MMP9 expression, and changes in endothelial tight junction proteins as well as adhesion molecules. ABCD1, but not its closest homologue ABCD2, is highly expressed in human brain microvascular endothelial cells, far exceeding its expression in the systemic vasculature. Silencing of ABCD1 in human brain microvascular endothelial cells causes accumulation of very long chain fatty acids, but much later than the immediate upregulation of adhesion molecules and decrease in tight junction proteins. This results in greater adhesion and transmigration of monocytes across the endothelium. PCR-array screening of human brain microvascular endothelial cells after ABCD1 silencing revealed downregulation of both mRNA and protein levels of the transcription factor c-MYC (encoded by MYC). Interestingly, MYC silencing mimicked the effects of ABCD1 silencing on CLDN5 and ICAM1 without decreasing the levels of ABCD1 protein itself. Together, these data demonstrate that ABCD1 deficiency induces significant alterations in brain endothelium via c-MYC and may thereby contribute to the increased trafficking of leucocytes across the blood-brain barrier as seen in cerebral adrenouleukodystrophy.

  2. Brain microvascular endothelial cell association and distribution of a 5 nm ceria engineered nanomaterial

    Directory of Open Access Journals (Sweden)

    Dan M

    2012-07-01

    with the capillary fraction. Electron microscopy showed the ceria ENM located on the endothelial cell luminal surface.Conclusion: Ceria ENM association with brain capillary endothelial cells saturated between 20 and 60 seconds and ceria ENM brain uptake was not diffusion-mediated. During the 120-second ceria ENM perfusion, ceria ENM predominately associated with the surface of the brain capillary cells, providing the opportunity for its cell uptake or redistribution back into circulating blood.Keywords: ceria engineered nanomaterial, brain microvascular endothelial cell association, in situ brain perfusion, capillary depletion

  3. Transferrin receptor expression and role in transendothelial transport of transferrin in cultured brain endothelial monolayers

    DEFF Research Database (Denmark)

    Hersom, Maria; Helms, Hans Christian; Pretzer, Natasia;

    2016-01-01

    across the endothelial cells by transcytosis. The aim of the present study was to investigate transferrin receptor expression and role in transendothelial transferrin transport in cultured bovine brain endothelial cell monolayers. Transferrin receptor mRNA and protein levels were investigated...... in endothelial mono-cultures and co-cultures with astrocytes, as well as in freshly isolated brain capillaries using qPCR, immunocytochemistry and Western blotting. Transendothelial transport and luminal association of holo-transferrin was investigated using [125I]holo-transferrin or [59Fe......]-transferrin. Transferrin receptor mRNA expression in all cell culture configurations was lower than in freshly isolated capillaries, but the expression slightly increased during six days of culture. The mRNA expression levels were similar in mono-cultures and co-cultures. Immunostaining demonstrated comparable transferrin...

  4. New aspects in fenestrated capillary and tissue dynamics in the sensory circumventricular organs of adult brains.

    Science.gov (United States)

    Miyata, Seiji

    2015-01-01

    The blood-brain barrier (BBB) generally consists of endothelial tight junction barriers that prevent the free entry of blood-derived substances, thereby maintaining the extracellular environment of the brain. However, the circumventricular organs (CVOs), which are located along the midlines of the brain ventricles, lack these endothelial barriers and have fenestrated capillaries; therefore, they have a number of essential functions, including the transduction of information between the blood circulation and brain. Previous studies have demonstrated the extensive contribution of the CVOs to body fluid and thermal homeostasis, energy balance, the chemoreception of blood-derived substances, and neuroinflammation. In this review, recent advances have been discussed in fenestrated capillary characterization and dynamic tissue reconstruction accompanied by angiogenesis and neurogliogenesis in the sensory CVOs of adult brains. The sensory CVOs, including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and area postrema (AP), have size-selective and heterogeneous vascular permeabilities. Astrocyte-/tanycyte-like neural stem cells (NSCs) sense blood- and cerebrospinal fluid-derived information through the transient receptor potential vanilloid 1, a mechanical/osmotic receptor, Toll-like receptor 4, a lipopolysaccharide receptor, and Nax, a Na-sensing Na channel. They also express tight junction proteins and densely and tightly surround mature neurons to protect them from blood-derived neurotoxic substances, indicating that the NSCs of the CVOs perform BBB functions while maintaining the capacity to differentiate into new neurons and glial cells. In addition to neurogliogenesis, the density of fenestrated capillaries is regulated by angiogenesis, which is accompanied by the active proliferation and sprouting of endothelial cells. Vascular endothelial growth factor (VEGF) signaling may be involved in angiogenesis and neurogliogenesis, both of

  5. Influence of curvature on the morphology of brain microvascular endothelial cells

    Science.gov (United States)

    Ye, Mao; Yang, Zhen; Wong, Andrew; Searson, Peter; Searson Group Team

    2013-03-01

    There are hundreds or thousands of endothelial cells around the perimeter of a single artery or vein, and hence an individual cell experiences little curvature. In contrast, a single endothelial cell may wrap around itself to form the lumen of a brain capillary. Curvature plays a key role in many biological, chemical and physical processes, however, its role in dictating the morphology and polarization of brain capillary endothelial cells has not been investigated. We hypothesize that curvature and shear flow play a key role in determining the structure and function of the blood-brain barrier (BBB). We have developed the ``rod'' assay to study the influence of curvature on the morphology of confluent monolayers of endothelial cells. In this assay cells are plated onto glass rods pulled down to the desired diameter in the range from 5 - 500 μm and coated with collagen. We show that curvature has a significant influence on the morphology of endothelial cells and may have an important role in blood-brain barrier function.

  6. Specific Accumulation of Tumor-Derived Adhesion Factor in Tumor Blood Vessels and in Capillary Tube-Like Structures of Cultured Vascular Endothelial Cells

    Science.gov (United States)

    Akaogi, Kotaro; Okabe, Yukie; Sato, Junji; Nagashima, Yoji; Yasumitsu, Hidetaro; Sugahara, Kazuyuki; Miyazaki, Kaoru

    1996-08-01

    Tumor-derived adhesion factor (TAF) was previously identified as a cell adhesion molecule secreted by human bladder carcinoma cell line EJ-1. To elucidate the physiological function of TAF, we examined its distribution in human normal and tumor tissues. Immunochemical staining with an anti-TAF monoclonal antibody showed that TAF was specifically accumulated in small blood vessels and capillaries within and adjacent to tumor nests, but not in those in normal tissues. Tumor blood vessel-specific staining of TAF was observed in various human cancers, such as esophagus, brain, lung, and stomach cancers. Double immunofluorescent staining showed apparent colocalization of TAF and type IV collagen in the vascular basement membrane. In vitro experiments demonstrated that TAF preferentially bound to type IV collagen among various extracellular matrix components tested. In cell culture experiments, TAF promoted adhesion of human umbilical vein endothelial cells to type IV collagen substrate and induced their morphological change. Furthermore, when the endothelial cells were induced to form capillary tube-like structures by type I collagen, TAF and type IV collagen were exclusively detected on the tubular structures. The capillary tube formation in vitro was prevented by heparin, which inhibited the binding of TAF to the endothelial cells. These results strongly suggest that TAF contributes to the organization of new capillary vessels in tumor tissues by modulating the interaction of endothelial cells with type IV collagen.

  7. Ultrastructure and histochemistry of rat myocardial capillary endothelial cells in response to diabetes and hypertension

    Institute of Scientific and Technical Information of China (English)

    Ludmila OKRUHLICOVA; Narcis TRIBULOVA; Peter WEISMANN; Ruzena SOTNIKOVA

    2005-01-01

    Insufficient growth and rarefaction of capillaries,followed by endothelial dysfunction may represent one of the most critical mechanisms involved in heart damage.In this study we examined histochemical and ultrastructural changes in myocardial capillary endothelium in two models of heart failure streptozotocin-induced diabetes mellitus (STZ) and NOdeficient hypertension in male Wistar rats.Diabetes was induced by a single i.v.dose of STZ (45 mg/kg) and chronic 9-week stage was analysed.To induce NO-deficient hypertension,animals were treated with inhibitor of NO synthase Lnitroarginine methylester (L-NAME) (40 mg/kg) for 4 weeks.Left ventricular tissue was processed for enzyme catalytic histochemistry of capillary alkaline phosphatase (AlPh),dipeptidyl peptidase Ⅳ (DPP Ⅳ),and endothelial NO synthase/NADPH-diaphorase (NOS) and for ultrastructural analysis.In diabetic and hypertensive rats,lower/absent AlPh and DPP Ⅳ activities were found in focal micro-areas.NOS activity was significantly reduced and persisted only locally.Quantitative evaluation demonstrated reduction of reaction product intensity of AlPh,DPP and NOS by 49.50%,74.36%,20.05% in diabetic and 62.93%,82.71%,37.65% in hypertensive rats.Subcellular alterations of endothelial cells were found in heart of both groups suggesting injury of capillary function as well as compensatory processes.Endothelial injury was more significant in diabetic animals,in contrast the adaptation was more evident in hypertensive ones.Concluding: both STZ-induced diabetes- and NO-deficient hypertension-related cardiomyopathy were accompanied by similar features of structural remodelling of cardiac capillary network manifested as angiogenesis and angiopathy.The latter was however,predominant and may accelerate disappearance of capillary endothelium contributing to myocardial dysfunction.

  8. Distribution of anionic sites on the capillary endothelium in an experimental brain tumor model.

    Science.gov (United States)

    Vincent, S; DePace, D; Finkelstein, S

    1988-02-01

    The distribution of anionic domains on the capillary endothelium of experimental brain tumors was determined using cationic ferritin (CF) in order to ascertain whether the pattern of these domains is different from that on normal cerebral capillaries. Tumors were induced by stereotaxic injection of cultured neoplastic glial cells, A15A5, into the caudate nucleus of Sprague-Dawley rats. Following a 14-21 day growth period tumors appeared as vascularized, sharply circumscribed masses which caused compression of the surrounding brain tissue. Anionic domains were distributed in a patchy and irregular pattern on the luminal plasma membrane of the endothelia of blood vessels in the tumors. Some variability in this pattern was observed infrequently in limited regions of the tumor where there was either a continuous layer of CF or an absence of CF binding. Plasmalemmal vesicles, coated vesicles, coated pits, multivesicular bodies, and some junctional complexes showed varying degrees of labeling with the probe. Capillaries in the tumor periphery and normal cerebral vessels showed a uniform distribution of anionic groups. These results indicate that there is an altered surface charge on the endothelial luminal plasma membrane of blood vessels in brain tumors. A correlation may exist between the altered surface charge and the degree to which the blood-brain barrier is impaired in these vessels.

  9. In-capillary derivatization and capillary electrophoresis separation of amino acid neurotransmitters from brain microdialysis samples.

    Science.gov (United States)

    Denoroy, Luc; Parrot, Sandrine; Renaud, Louis; Renaud, Bernard; Zimmer, Luc

    2008-09-26

    A new in-capillary derivatization method with naphtalene-2,3-dicarboxyaldehyde (NDA)/CN(-) has been developed for capillary electrophoresis with laser-induced fluorescence detection of brain microdialysate amino acids. Samples are sandwiched between two plugs of reagent mixture at the capillary inlet and subsequently separated. Highest derivatization yields are obtained by using a reagent to sample plug length ratio equal to 4, performing a first electrophoretic mixing followed by a zero potential amplification step before applying the separation voltage and using a NaCN to NDA concentration ratio equal to 1. This new single-step methodology allows the analysis of amino acid neurotransmitters in rat brain microdialysis samples.

  10. Lung endothelial cells strengthen, but brain endothelial cells weaken barrier properties of a human alveolar epithelium cell culture model.

    Science.gov (United States)

    Neuhaus, Winfried; Samwer, Fabian; Kunzmann, Steffen; Muellenbach, Ralf M; Wirth, Michael; Speer, Christian P; Roewer, Norbert; Förster, Carola Y

    2012-11-01

    The blood-air barrier in the lung consists of the alveolar epithelium, the underlying capillary endothelium, their basement membranes and the interstitial space between the cell layers. Little is known about the interactions between the alveolar and the blood compartment. The aim of the present study was to gain first insights into the possible interplay between these two neighbored cell layers. We established an in vitro Transwell model of the alveolar epithelium based on human cell line H441 and investigated the influence of conditioned medium obtained from human lung endothelial cell line HPMEC-ST1.6R on the barrier properties of the H441 layers. As control for tissue specificity H441 layers were exposed to conditioned medium from human brain endothelial cell line hCMEC/D3. Addition of dexamethasone was necessary to obtain stable H441 cell layers. Moreover, dexamethasone increased expression of cell type I markers (caveolin-1, RAGE) and cell type II marker SP-B, whereas decreased the transepithelial electrical resistance (TEER) in a concentration dependent manner. Soluble factors obtained from the lung endothelial cell line increased the barrier significantly proven by TEER values and fluorescein permeability on the functional level and by the differential expression of tight junctional proteins on the molecular level. In contrast to this, soluble factors derived from brain endothelial cells weakened the barrier significantly. In conclusion, soluble factors from lung endothelial cells can strengthen the alveolar epithelium barrier in vitro, which suggests communication between endothelial and epithelial cells regulating the integrity of the blood-air barrier.

  11. Interaction of urokinase with specific receptors stimulates mobilization of bovine adrenal capillary endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Fibbi, G.; Ziche, M.; Morbidelli, L. (Mario Aiazzi Mancini - Viale Morgagni, Firenze (Italy)); Magnelli, L.; Del Rosso, M. (Institute of General Pathology, Viale Morgagni, Firenze (Italy))

    1988-12-01

    On the basis of {sup 125}I-labeled plasminogen activator binding analysis the authors have found that bovine adrenal capillary endothelial cells have specific receptors for human urinary-type plasminogen activator on the cell membrane. Each cell exposes about 37,000 free receptors with a K{sub d} of 0.8958{times}10{sup {minus}12} M. A monoclonal antibody against the 17,500 proteolytic fragment of the A chain of the plasminogen activator, not containing the catalytic site of the enzyme, impaired the specific binding, thus suggesting the involvement of a sequence present on the A chain in the interaction with the receptor, as previously shown in other cell model systems. Both the native molecule and the A chain are able to stimulate endothelial cell motility in the Boyden chamber, when used at nanomolar concentrations. The use of the same monoclonal antibody that can inhibit ligand-receptor interaction can impair the plasminogen activator and A-chain-induced endothelial cell motility, suggesting that under the conditions used in this in vitro model system, the motility of bovine adrenal capillary endothelial cells depends on the specific interaction of the ligand with free receptors on the surface of endothelial cells.

  12. Elongation, proliferation & migration differentiate endothelial cell phenotypes and determine capillary sprouting

    Directory of Open Access Journals (Sweden)

    Popel Aleksander S

    2009-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of capillaries from preexisting blood vessels, has been extensively studied experimentally over the past thirty years. Molecular insights from these studies have lead to therapies for cancer, macular degeneration and ischemia. In parallel, mathematical models of angiogenesis have helped characterize a broader view of capillary network formation and have suggested new directions for experimental pursuit. We developed a computational model that bridges the gap between these two perspectives, and addresses a remaining question in angiogenic sprouting: how do the processes of endothelial cell elongation, migration and proliferation contribute to vessel formation? Results We present a multiscale systems model that closely simulates the mechanisms underlying sprouting at the onset of angiogenesis. Designed by agent-based programming, the model uses logical rules to guide the behavior of individual endothelial cells and segments of cells. The activation, proliferation, and movement of these cells lead to capillary growth in three dimensions. By this means, a novel capillary network emerges out of combinatorially complex interactions of single cells. Rules and parameter ranges are based on literature data on endothelial cell behavior in vitro. The model is designed generally, and will subsequently be applied to represent species-specific, tissue-specific in vitro and in vivo conditions. Initial results predict tip cell activation, stalk cell development and sprout formation as a function of local vascular endothelial growth factor concentrations and the Delta-like 4 Notch ligand, as it might occur in a three-dimensional in vitro setting. Results demonstrate the differential effects of ligand concentrations, cell movement and proliferation on sprouting and directional persistence. Conclusion This systems biology model offers a paradigm closely related to biological phenomena and highlights previously

  13. Tumor endothelial marker 5 expression in endothelial cells during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Vallon, Mario, E-mail: m.vallon@arcor.de [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Rohde, Franziska; Janssen, Klaus-Peter [Chirurgische Klinik und Poliklinik, Technische Universitaet Muenchen, Munich (Germany); Essler, Markus [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany)

    2010-02-01

    Tumor endothelial marker (TEM) 5 is an adhesion G-protein-coupled receptor upregulated in endothelial cells during tumor and physiologic angiogenesis. So far, the mechanisms leading to upregulation of TEM5 and its function during angiogenesis have not been identified. Here, we report that TEM5 expression in endothelial cells is induced during capillary-like network formation on Matrigel, during capillary morphogenesis in a three-dimensional collagen I matrix, and upon confluence on a two-dimensional matrix. TEM5 expression was not induced by a variety of soluble angiogenic factors, including VEGF and bFGF, in subconfluent endothelial cells. TEM5 upregulation was blocked by toxin B from Clostridium difficile, an inhibitor of the small GTPases Rho, Rac, and Cdc42. The Rho inhibitor C3 transferase from Clostridium botulinum did not affect TEM5 expression, whereas the Rac inhibitor NSC23766 suppressed TEM5 upregulation. An excess of the soluble TEM5 extracellular domain or an inhibitory monoclonal TEM5 antibody blocked contact inhibition of endothelial cell proliferation resulting in multilayered islands within the endothelial monolayer and increased vessel density during capillary formation. Based on our results we conclude that TEM5 expression during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of proliferation in endothelial cells.

  14. Brain endothelial TAK1 and NEMO safeguard the neurovascular unit

    Science.gov (United States)

    Ridder, Dirk A.; Wenzel, Jan; Müller, Kristin; Töllner, Kathrin; Tong, Xin-Kang; Assmann, Julian C.; Stroobants, Stijn; Weber, Tobias; Niturad, Cristina; Fischer, Lisanne; Lembrich, Beate; Wolburg, Hartwig; Grand’Maison, Marilyn; Papadopoulos, Panayiota; Korpos, Eva; Truchetet, Francois; Rades, Dirk; Sorokin, Lydia M.; Schmidt-Supprian, Marc; Bedell, Barry J.; Pasparakis, Manolis; Balschun, Detlef; D’Hooge, Rudi; Löscher, Wolfgang; Hamel, Edith

    2015-01-01

    Inactivating mutations of the NF-κB essential modulator (NEMO), a key component of NF-κB signaling, cause the genetic disease incontinentia pigmenti (IP). This leads to severe neurological symptoms, but the mechanisms underlying brain involvement were unclear. Here, we show that selectively deleting Nemo or the upstream kinase Tak1 in brain endothelial cells resulted in death of endothelial cells, a rarefaction of brain microvessels, cerebral hypoperfusion, a disrupted blood–brain barrier (BBB), and epileptic seizures. TAK1 and NEMO protected the BBB by activating the transcription factor NF-κB and stabilizing the tight junction protein occludin. They also prevented brain endothelial cell death in a NF-κB–independent manner by reducing oxidative damage. Our data identify crucial functions of inflammatory TAK1–NEMO signaling in protecting the brain endothelium and maintaining normal brain function, thus explaining the neurological symptoms associated with IP. PMID:26347470

  15. Transport and regulation mechanism of the colloidal gold liposomes in the brain microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    WANG Lipeng; CHANG Yanzhong

    2015-01-01

    Objective:Blood-brain barrier is the key barrier of brain in the innate immune. It can prevent the harmful substances from the blood into the brain. In order to keep the brain in a relatively stable environment and maintain the normal function of the nervous system, it can also pump harmful substances or excess substances outside the brain selectively. Among them, brain microvascular endothelial cell tissue is a key part in the blood-brain barrier's function. The number of the patients with central nervous system ( CNS) diseases increased year by year. The therapeutic drug is usually inhibited by the blood-brain barrier and is difficult to work. Therefore, how to modify the drug and to make it easier to cross the blood brain barrier is the key point to cure CNS. At present, more than 95% research focus only on how nano drugs can enter the cell, the way and efficiency to enter the cell and the research of effect of nano drug etc. For the process of drug carrier in endocytosis, intracellular transport and release and regulation of research are rarely reported. Clathrin and P-glycoprotein are related protein in endo-cytosis and exocytosis with nano drug. Clathrin is located on the plasma membrane. It participates in endocytosis of some nutrients, and maybe the entry into the cell of some drugs. P-glycoprotein is located in the membrane of cer-ebral capillary endothelial cells. It can efflux drugs relying on ATP. Although there is a certain understanding of the cell in the inner swallow and efflux. But the process of the liposome drug is not clear. To solve the above prob-lems, using colloidal gold liposome nano materials to trace liposome's transport and regulation mechanism in brain microvascular endothelial cells, and study endocytosis, release, distribution and regulation mechanism of nano lipo-somes in brain microvascular. The solution of this problem can guide to construct reasonable drug carrier, and look forward to clarifing the molecular basis and mechanism of

  16. Flow distributions and spatial correlations in human brain capillary networks

    Science.gov (United States)

    Lorthois, Sylvie; Peyrounette, Myriam; Larue, Anne; Le Borgne, Tanguy

    2015-11-01

    The vascular system of the human brain cortex is composed of a space filling mesh-like capillary network connected upstream and downstream to branched quasi-fractal arterioles and venules. The distribution of blood flow rates in these networks may affect the efficiency of oxygen transfer processes. Here, we investigate the distribution and correlation properties of blood flow velocities from numerical simulations in large 3D human intra-cortical vascular network (10000 segments) obtained from an anatomical database. In each segment, flow is solved from a 1D non-linear model taking account of the complex rheological properties of blood flow in microcirculation to deduce blood pressure, blood flow and red blood cell volume fraction distributions throughout the network. The network structural complexity is found to impart broad and spatially correlated Lagrangian velocity distributions, leading to power law transit time distributions. The origins of this behavior (existence of velocity correlations in capillary networks, influence of the coupling with the feeding arterioles and draining veins, topological disorder, complex blood rheology) are studied by comparison with results obtained in various model capillary networks of controlled disorder. ERC BrainMicroFlow GA615102, ERC ReactiveFronts GA648377.

  17. Endothelial Expression of Endothelin Receptor A in the Systemic Capillary Leak Syndrome.

    Directory of Open Access Journals (Sweden)

    Albert C Sek

    Full Text Available Idiopathic systemic capillary leak syndrome (SCLS is a rare and potentially fatal vascular disorder characterized by reversible bouts of hypotension and edema resulting from fluid and solute escape into soft tissues. Although spikes in permeability-inducing factors have been linked to acute SCLS flares, whether or not they act on an inherently dysfunctional endothelium is unknown. To assess the contribution of endothelial-intrinsic mechanisms in SCLS, we derived blood-outgrowth endothelial cells (BOEC from patients and healthy controls and examined gene expression patterns. Ednra, encoding Endothelin receptor A (ETA-the target of Endothelin 1 (ET-1-was significantly increased in SCLS BOEC compared to healthy controls. Although vasoconstriction mediated by ET-1 through ETA activation on vascular smooth muscle cells has been well characterized, the expression and function of ETA receptors in endothelial cells (ECs has not been described. To determine the role of ETA and its ligand ET-1 in SCLS, if any, we examined ET-1 levels in SCLS sera and functional effects of endothelial ETA expression. ETA overexpression in EAhy926 endothelioma cells led to ET-1-induced hyper-permeability through canonical mechanisms. Serum ET-1 levels were elevated in acute SCLS sera compared to remission and healthy control sera, suggesting a possible role for ET-1 and ETA in SCLS pathogenesis. However, although ET-1 alone did not induce hyper-permeability of patient-derived BOEC, an SCLS-related mediator (CXCL10 increased Edrna quantities in BOEC, suggesting a link between SCLS and endothelial ETA expression. These results demonstrate that ET-1 triggers classical mechanisms of vascular barrier dysfunction in ECs through ETA. Further studies of the ET-1-ETA axis in SCLS and in more common plasma leakage syndromes including sepsis and filovirus infection would advance our understanding of vascular integrity mechanisms and potentially uncover new treatment strategies.

  18. Nanoparticle accumulation and transcytosis in brain endothelial cell layers

    NARCIS (Netherlands)

    Ye, Dong; Raghnaill, Michelle Nic; Bramini, Mattia; Mahon, Eugene; Åberg, Christoffer; Salvati, Anna; Dawson, Kenneth A

    2013-01-01

    The blood-brain barrier (BBB) is a selective barrier, which controls and limits access to the central nervous system (CNS). The selectivity of the BBB relies on specialized characteristics of the endothelial cells that line the microvasculature, including the expression of intercellular tight juncti

  19. Oxidized low-density lipoprotein alters the effect of matrix stiffness on the formation of endothelial networks and capillary lumens

    Science.gov (United States)

    2013-01-01

    Abstract Formation of new blood vessels is essential for vascular repair and remodeling, and it is known that biomechanical properties of extracellular matrix play a major role in this process. Our earlier studies have also shown that exposing endothelial cells to oxidized modification of low-density lipoproteins (oxLDL) increases endothelial stiffness and facilitates their ability to form cellular networks, suggesting that it facilitates endothelial angiogenic potential. The goal of this study, therefore, was to test the interrelationship between matrix stiffness and oxLDL in the regulation of angiogenesis. Our results show that, as expected, an increase in matrix stiffness inhibited endothelial network formation and that exposure to oxLDL significantly facilitated this process. We also show, however, that oxLDL-induced facilitation of endothelial networks was observed only in stiff (3 mg/mL) but not in soft (1 mg/mL) collagen gels, resulting in blunting the effect of matrix stiffness. Also unexpectedly, we show that an increase in matrix stiffness results in a significant increase in the number of capillary lumens that are formed by single cells or pairs of cells, suggesting that while endothelial connectivity is impaired, formation of single-cell lumens is facilitated. oxLDL facilitates lumen formation, but this effect is also matrix dependent and is observed only in soft gels and not in stiff gels. Finally, an increase in both matrix stiffness and oxLDL exposure results in changes in capillary morphology, with the formation of larger capillary lumens. Overall, our study suggests that oxLDL plays an important role in formation of new capillaries and their morphology and that this effect is critically dependent on the extracellular environment’s compliance, thereby underlining the importance of the interdependence of these parameters. PMID:24618546

  20. Effects of various principles from Chinese herbal medicine on rhodamine123 accumulation in brain capillary endothelial cells%多种中草药单体对脑微血管内皮细胞内罗丹明123积累的影响

    Institute of Scientific and Technical Information of China (English)

    何玲; 刘国卿

    2002-01-01

    目的:寻找新型有效的血脑屏障P-糖蛋白逆转剂.方法:通过测定各化合物对牛脑微血管内皮细胞内罗丹明123积累的影响来考查它们对P-糖蛋白的功能性作用,以此筛选血脑屏障上的P-糖蛋白逆转剂.结果:各化合物浓度依赖性地增加胞内Rh123的累积浓度,作用强弱顺序为:环孢素A(CsA)>粉防己碱(Tet)>长春新碱(VCR)≈氟桂利嗪(Flu)>延胡索乙素(dl-THP)>蝙蝠葛碱(DRC)>阿齐霉素(Azi)>维拉帕米(Vet)≈小檗胺(BBM)>蝙蝠葛苏林碱(DRS)>小檗碱(BBR)>阿霉素(Dox)>左旋四氢巴马汀(l-THP)>川芎嗪(TMP).其中CsA、Tet、Ver、Flu、Azi和dl-THP对胞内罗丹明123的累积的影响是可逆的.结论:多种中药单体,如某些异喹啉类生物碱能逆转血脑屏障上P-糖蛋白的功能,而不使血脑屏障上P-糖蛋白的固有水平发生永久性改变.%AIM: To search for novel effective P-glycoprotein (P-gp) reversal agents in the blood-brain barrier (BBB).METHODS: Using rhodamine123 (Rh123) to examine the functional activity of P-gp in cultured bovine brain capillary endothelial cells (BCEC) and screen various principles on P-gp modulation in BBB. RESULTS:All of tested compounds ( 1 - 10μmol/L) increased the intracellular accumulation of Rh123 in a concentrationdependent manner. The rank order of these agents in increasing Rh123 accumulation in BCEC was: cyclosporin A (CsA) > tetrandrine (Tet) > vincrinstine (VCR) ≈ flunarizine (Flu) > dl-tetrahydropalmatine (dl-THP) > dauricine (DRC) > azithromycin (Azi)> verapamil (Ver) ≈ berbamine (BBM) > daurisoline (DRS) > berberine (BBR) ≈ doxorubicin (Dox) >l-tetrahydropalmatine (l-THP) > tetramethylpyrazine (TMP). These agents at concentration of 10 μmol/L increased Rh123 accumulation by 346 %, 203 %,136%, 129 %, 115 %, 103 %, 92 %, 87 %,81%, 75 %, 67 %, 67 %, 63 %, and 54 %,respectively. The effects of CsA, Tet, Ver, Flu, Azi,and dl-THP on cellular accumulation

  1. Ephrin-A3 and ephrin-A4 contribute to microglia-induced angiogenesis in brain endothelial cells.

    Science.gov (United States)

    Li, Ying; Liu, Dong-Xin; Li, Mei-Yang; Qin, Xiao-Xue; Fang, Wen-Gang; Zhao, Wei-Dong; Chen, Yu-Hua

    2014-10-01

    The association of microglia with brain vasculature during development and the reduced brain vascular complexity in microglia-deficient mice suggest the role of microglia in cerebrovascular angiogenesis. However, the underlying molecular mechanism remains unclear. Here, using an in vitro angiogenesis model, we found the culture supernatant of BV2 microglial cells significantly enhanced capillary-like tube formation and migration of brain microvascular endothelial cells (BMECs). The expression of angiogenic factors, ephrin-A3 and ephrin-A4, were specifically upregulated in BMECs exposed to BV2-derived culture supernatant. Knockdown of ephrin-A3 and ephrin-A4 in BMECs by siRNA significantly attenuated the enhanced angiogenesis and migration of BMECs induced by BV2 supernatant. Our further results indicated that the ability of BV2 supernatant to promote endothelial angiogenesis was caused by the soluble tumor necrosis factor α (TNF-α) released from BV2 microglial cells. Moreover, the upregulations of ephrin-A3 and ephrin-A4 in BMECs in response to BV2 supernatant were effectively abolished by neutralization antibody against TNF-α and TNF receptor 1, respectively. The present study provides evidence that microglia upregulates endothelial ephrin-A3 and ephrin-A4 to facilitate in vitro angiogenesis of brain endothelial cells, which is mediated by microglia-released TNF-α.

  2. Purification of a Factor from Human Placenta That Stimulates Capillary Endothelial Cell Protease Production, DNA Synthesis, and Migration

    Science.gov (United States)

    Moscatelli, David; Presta, Marco; Rifkin, Daniel B.

    1986-04-01

    A protein that stimulates the production of plasminogen activator and latent collagenase in cultured bovine capillary endothelial cells has been purified 106-fold from term human placenta by using a combination of heparin affinity chromatography, ion-exchange chromatography, and gel chromatography. The purified molecule has a molecular weight of 18,700 as determined by NaDodSO4/PAGE under both reducing and nonreducing conditions. The purified molecule stimulates the production of plasminogen activator and latent collagenase in a dose-dependent manner between 0.1 and 10 ng of protein/ml. The purified protein also stimulates DNA synthesis and chemotaxis in capillary endothelial cells in the same concentration range. Thus, this molecule has all of the properties predicted for an angiogenic factor.

  3. Vascular endothelial growth factor A protein level and gene expression in intracranial meningiomas with brain edema

    DEFF Research Database (Denmark)

    Nassehi, Damoun; Dyrbye, Henrik; Andresen, Morten;

    2011-01-01

    Meningiomas are the second most common primary intracranial tumors in adults. Although meningiomas are mostly benign, more than 50% of patients with meningioma develop peritumoral brain edema (PTBE), which may be fatal because of increased intracranial pressure. Vascular endothelial growth factor....... Forty-three patients had primary, solitary, supratentorial meningiomas with PTBE. In these, correlations in PTBE, edema index, VEGF-A protein, VEGF gene expression, capillary length, and tumor water content were investigated. DNA-branched hybridization was used for measuring VEGF gene expression...... in tissue homogenates prepared from frozen tissue samples. The method for VEGF-A analysis resembled an ELISA assay, but was based on chemiluminescence. The edema index was positively correlated to VEGF-A protein (p = 0.014) and VEGF gene expression (p

  4. Ultrastructural localization of cholinergic muscarinic receptors in rat brain cortical capillaries

    NARCIS (Netherlands)

    Luiten, PGM; deJong, GI; VanderZee, EA; vanDijken, H; Dijken, H. van

    1996-01-01

    Cholinergic innervation of the cerebrovasculature is known to regulate vascular tone, perfusion rate and permeability of the microvascular wall. Notably the cholinergic innervation of cerebral capillaries is of interest since these capillaries form the blood-brain barrier. Although there is a genera

  5. Brain microvascular endothelial cell transplantation ameliorates ischemic white matter damage.

    Science.gov (United States)

    Puentes, Sandra; Kurachi, Masashi; Shibasaki, Koji; Naruse, Masae; Yoshimoto, Yuhei; Mikuni, Masahiko; Imai, Hideaki; Ishizaki, Yasuki

    2012-08-21

    Ischemic insults affecting the internal capsule result in sensory-motor disabilities which adversely affect the patient's life. Cerebral endothelial cells have been reported to exert a protective effect against brain damage, so the transplantation of healthy endothelial cells might have a beneficial effect on the outcome of ischemic brain damage. In this study, endothelin-1 (ET-1) was injected into the rat internal capsule to induce lacunar infarction. Seven days after ET-1 injection, microvascular endothelial cells (MVECs) were transplanted into the internal capsule. Meningeal cells or 0.2% bovine serum albumin-Hank's balanced salt solution were injected as controls. Two weeks later, the footprint test and histochemical analysis were performed. We found that MVEC transplantation improved the behavioral outcome based on recovery of hind-limb rotation angle (P<0.01) and induced remyelination (P<0.01) compared with the control groups. Also the inflammatory response was repressed by MVEC transplantation, judging from fewer ED-1-positive activated microglial cells in the MVEC-transplanted group than in the other groups. Elucidation of the mechanisms by which MVECs ameliorate ischemic damage of the white matter may provide important information for the development of effective therapies for white matter ischemia.

  6. Fatty acid transport protein expression in human brain and potential role in fatty acid transport across human brain microvessel endothelial cells.

    Science.gov (United States)

    Mitchell, Ryan W; On, Ngoc H; Del Bigio, Marc R; Miller, Donald W; Hatch, Grant M

    2011-05-01

    The blood-brain barrier (BBB), formed by the brain capillary endothelial cells, provides a protective barrier between the systemic blood and the extracellular environment of the CNS. Passage of fatty acids from the blood to the brain may occur either by diffusion or by proteins that facilitate their transport. Currently several protein families have been implicated in fatty acid transport. The focus of the present study was to identify the fatty acid transport proteins (FATPs) expressed in the brain microvessel endothelial cells and characterize their involvement in fatty acid transport across an in vitro BBB model. The major fatty acid transport proteins expressed in human brain microvessel endothelial cells (HBMEC), mouse capillaries and human grey matter were FATP-1, -4 and fatty acid binding protein 5 and fatty acid translocase/CD36. The passage of various radiolabeled fatty acids across confluent HBMEC monolayers was examined over a 30-min period in the presence of fatty acid free albumin in a 1 : 1 molar ratio. The apical to basolateral permeability of radiolabeled fatty acids was dependent upon both saturation and chain length of the fatty acid. Knockdown of various fatty acid transport proteins using siRNA significantly decreased radiolabeled fatty acid transport across the HBMEC monolayer. Our findings indicate that FATP-1 and FATP-4 are the predominant fatty acid transport proteins expressed in the BBB based on human and mouse expression studies. While transport studies in HBMEC monolayers support their involvement in fatty acid permeability, fatty acid translocase/CD36 also appears to play a prominent role in transport of fatty acids across HBMEC.

  7. Scaling of brain metabolism and blood flow in relation to capillary and neural scaling.

    Science.gov (United States)

    Karbowski, Jan

    2011-01-01

    Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 relating whole body resting metabolism with body mass and several other physiological variables in animals and plants. This article investigates the reasons for brain allometric distinction on a level of its microvessels. Based on collected empirical data it is found that regional cerebral blood flow CBF across gray matter scales with cortical volume V as CBF ~ V(-1/6), brain capillary diameter increases as V(1/12), and density of capillary length decreases as V(-1/6). It is predicted that velocity of capillary blood is almost invariant (~V(ε)), capillary transit time scales as V(1/6), capillary length increases as V(1/6+ε), and capillary number as V(2/3-ε), where ε is typically a small correction for medium and large brains, due to blood viscosity dependence on capillary radius. It is shown that the amount of capillary length and blood flow per cortical neuron are essentially conserved across mammals. These results indicate that geometry and dynamics of global neuro-vascular coupling have a proportionate character. Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.

  8. Scaling of brain metabolism and blood flow in relation to capillary and neural scaling.

    Directory of Open Access Journals (Sweden)

    Jan Karbowski

    Full Text Available Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 relating whole body resting metabolism with body mass and several other physiological variables in animals and plants. This article investigates the reasons for brain allometric distinction on a level of its microvessels. Based on collected empirical data it is found that regional cerebral blood flow CBF across gray matter scales with cortical volume V as CBF ~ V(-1/6, brain capillary diameter increases as V(1/12, and density of capillary length decreases as V(-1/6. It is predicted that velocity of capillary blood is almost invariant (~V(ε, capillary transit time scales as V(1/6, capillary length increases as V(1/6+ε, and capillary number as V(2/3-ε, where ε is typically a small correction for medium and large brains, due to blood viscosity dependence on capillary radius. It is shown that the amount of capillary length and blood flow per cortical neuron are essentially conserved across mammals. These results indicate that geometry and dynamics of global neuro-vascular coupling have a proportionate character. Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.

  9. Bradykinin and histamine-induced cytosolic calcium increase in capillary endothelial cells of bovine adrenal medulla.

    Science.gov (United States)

    Vinet, Raúl; Cortés, Magdalena P; Alvarez, Rocío; Delpiano, Marco A

    2014-09-01

    We have assessed the effect of bradykinin and histamine on the cytosolic free calcium concentration ([Ca(2+)]i ) of bovine adrenal medulla capillary endothelial cells (BAMCECs). To measure [Ca(2+)]i changes in BAMCECs the intracellular fluorescent probe, fluo-3 AM, was used. Bradykinin (3 µM) produced a transient monophasic increase in [Ca(2+)]i , which was depressed by B1650 (0.1 µM), a B2-bradykinin receptor antagonist (D-Arg-[Hyp(3), Thi(5,8) , D-Phe(7)]-Bradykinin). Similarly, increase in [Ca(2+)]i induced by histamine was also depressed by tripolidine (0.1 µM), an H1-histamine receptor antagonist. [Ca(2+)]i increase induced by both agonists was unaffected in the absence of extracellular Ca(2+) or presence of antagonists of voltage operated Ca(2+) channels (VOCCs). Thapsigargin (1 µM) did not abolish the increase of [Ca(2+)]i produced by bradykinin, but abolished that of histamine. In contrast, caffeine (100 µM), abolished the [Ca(2+)]i response induced by bradykinin (3 µM), but did not affect the [Ca(2+)]i increase induced by histamine (100 µM). The results indicate the presence of B2 bradykinin- and H1 histamine-receptors in BAMCECs. Liberation of Ca(2+) induced by both agonists occurs through 2 different intracellular mechanisms. While bradykinin activates a sarco(endo) plasmic reticulum (SER) containing a SER Ca(2+) -ATPase (SERCA) thapsigargin-insensitive, histamine activates a SER containing a SERCA thapsigargin-sensitive. We suggest that the increase in [Ca(2+)]i induced by bradykinin and histamine could be of physiological relevance, modulating adrenal gland microcirculation.

  10. Both actin and polyproline interactions of Profilin-1 are required for migration, invasion and capillary morphogenesis of vascular endothelial cells

    Science.gov (United States)

    Ding, Zhijie; Gau, David; Deasy, Bridget; Wells, Alan; Roy, Partha

    2009-01-01

    The objective of the present study was to evaluate how different ligand interactions of profilin-1 (Pfn1), an actin-binding protein that is upregulated during capillary morphogenesis of vascular endothelial cells (VEC), contribute to migration and capillary forming ability of VEC. We adopted a knockdown-knockin experimental system to stably express either fully-functional or mutants of Pfn1 that are impaired in binding to two of its major ligands, actin (H119E mutant) and proteins containing polyproline domains (H133S mutant), in a human dermal microvascular cell line (HmVEC) against near-null endogenous Pfn1 background. We found that silencing endogenous Pfn1 expression in HmVEC leads to slower random migration, reduced velocity of membrane protrusion and a significant impairment in matrigel-induced cord formation. Only re-expression of fully-functional but not any of the two ligand-binding deficient mutants of Pfn1 rescues the above defects. We further show that loss of Pfn1 expression in VEC inhibits three-dimensional capillary morphogenesis, MMP2 secretion and ECM invasion. VEC invasion through ECM is also inhibited when actin and polyproline interactions of Pfn1 are disrupted. Together, these experimental data demonstrate that Pfn1 regulates VEC migration, invasion and capillary morphogenesis through its interaction with both actin and proline-rich ligands. PMID:19607826

  11. Human Brain Microvascular Endothelial Cells Derived from the BC1 iPS Cell Line Exhibit a Blood-Brain Barrier Phenotype.

    Science.gov (United States)

    Katt, Moriah E; Xu, Zinnia S; Gerecht, Sharon; Searson, Peter C

    2016-01-01

    The endothelial cells that form capillaries in the brain are highly specialized, with tight junctions that minimize paracellular transport and an array of broad-spectrum efflux pumps that make drug delivery to the brain extremely challenging. One of the major limitations in blood-brain barrier research and the development of drugs to treat central nervous system diseases is the lack of appropriate cell lines. Recent reports indicate that the derivation of human brain microvascular endothelial cells (hBMECs) from human induced pluripotent stem cells (iPSCs) may provide a solution to this problem. Here we demonstrate the derivation of hBMECs extended to two new human iPSC lines: BC1 and GFP-labeled BC1. These hBMECs highly express adherens and tight junction proteins VE-cadherin, ZO-1, occludin, and claudin-5. The addition of retinoic acid upregulates VE-cadherin expression, and results in a significant increase in transendothelial electrical resistance to physiological values. The permeabilities of tacrine, rhodamine 123, and Lucifer yellow are similar to values obtained for MDCK cells. The efflux ratio for rhodamine 123 across hBMECs is in the range 2-4 indicating polarization of efflux transporters. Using the rod assay to assess cell organization in small vessels and capillaries, we show that hBMECs resist elongation with decreasing diameter but show progressive axial alignment. The derivation of hBMECs with a blood-brain barrier phenotype from the BC1 cell line highlights that the protocol is robust. The expression of GFP in hBMECs derived from the BC1-GFP cell line provides an important new resource for BBB research.

  12. Neutral amino acid transport across brain microvessel endothelial cell monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Audus, K.L.; Borchardt, R.T.

    1986-03-01

    Brain microvessel endothelial cells (BMEC) which form the blood-brain barrier (BBB) possess an amino acid carrier specific for large neutral amino acids (LNAA). The carrier is important for facilitating the delivery of nutrient LNAA's and centrally acting drugs that are LNAA's, to the brain. Bovine BMEC's were isolated and grown up to complete monolayers on regenerated cellulose-membranes in primary culture. To study the transendothelial transport of leucine, the monolayers were placed in a side-by-side diffusion cell, and transport across the monolayers followed with (/sup 3/H)-leucine. The transendothelial transport of leucine in this in vitro model was determined to be bidirectional, and time-, temperature-, and concentration-dependent. The transport of leucine was saturable and the apparent K/sub m/ and V/sub max/, 0.18 mM and 6.3 nmol/mg/min, respectively. Other LNAA's, including the centrally acting drugs, ..cap alpha..-methyldopa, L-DOPA, ..cap alpha..-methyl-tyrosine, and baclofen, inhibited leucine transport. The leucine carrier was also found to be stereospecific and not sensitive to inhibitors of active transport. These results are consistent with previous in vitro and in vivo studies. Primary cultures of BMEC's appear to be a potentially important tool for investigating at the cellular level, the transport mechanisms of the BBB.

  13. Polylactic Acid Nanoparticles Targeted to Brain Microvascular Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    WANG Huafang; HU Yu; SUN Wangqiang; XIE Changsheng

    2005-01-01

    In this work, blank polylactic acid (PLA) nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells (BMECs) targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can be loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 (T-80) can facilitate BMECs targeting of PLA nanoparticles.

  14. Role of pigment epithelium-derived factor on proliferation and migration of choroidal capillary endothelium induced by vascular endothelial growth factor in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-hua; SUN Xiao-dong; ZHANG Xi; XU Xun; ZHU Qi; HUANG Jian-nan; FAN Ying; GU Qing; LIU Hai-yang

    2007-01-01

    Background Pigment epithelium-derived factor (PEDF) is expressed in several normal organs and identified as an inhibitor of neovascularization. In the present study, we investigated the effect of PEDF in an in vitro model of ocular choroidal neovascularization.Methods Microdissection was used to isolate the human choroidal endothelial cells (CECs), followed by the use of superparamagnetic beads (Dynabeads) coated with the CD31 antibody, which selectively binds to the endothelial cell surface. The mitogenic and motogenic effects of vascular endothelial growth factor (VEGF) on cultured choroidal capillary endothelial cells were examined in the presence or absence of PEDF (1, 10, 100, and 1000 ng/ml) using cell counts and migration assays.Results Cells bound to the beads were isolated using a magnetic particle concentrator and they were successfully cultured and characterized to be endothelial cells that possessed greater than 95% immunoreactivity to von Willebrand factor. PEDF suppressed the proliferation and migration of VEGF-induced choroidal capillary endothelial cells. However,the concentration of PEDF which we used has little effect on normal CECs.Conclusions PEDF played an important role on the growth and migration of VEGF-stimulated choroidal endothelial cell.These findings suggest that PEDF may be an effective approach to the treatment of choroidal neovascular disorders.

  15. Immortalized endothelial cell lines for in vitro blood-brain barrier models: A systematic review.

    Science.gov (United States)

    Rahman, Nurul Adhwa; Rasil, Alifah Nur'ain Haji Mat; Meyding-Lamade, Uta; Craemer, Eva Maria; Diah, Suwarni; Tuah, Ani Afiqah; Muharram, Siti Hanna

    2016-07-01

    Endothelial cells play the most important role in construction of the blood-brain barrier. Many studies have opted to use commercially available, easily transfected or immortalized endothelial cell lines as in vitro blood-brain barrier models. Numerous endothelial cell lines are available, but we do not currently have strong evidence for which cell lines are optimal for establishment of such models. This review aimed to investigate the application of immortalized endothelial cell lines as in vitro blood-brain barrier models. The databases used for this review were PubMed, OVID MEDLINE, ProQuest, ScienceDirect, and SpringerLink. A narrative systematic review was conducted and identified 155 studies. As a result, 36 immortalized endothelial cell lines of human, mouse, rat, porcine and bovine origins were found for the establishment of in vitro blood-brain barrier and brain endothelium models. This review provides a summary of immortalized endothelial cell lines as a guideline for future studies and improvements in the establishment of in vitro blood-brain barrier models. It is important to establish a good and reproducible model that has the potential for multiple applications, in particular a model of such a complex compartment such as the blood-brain barrier.

  16. Changes in the permeability of blood brain barrier and endothelial cell damage after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Ke Liu; Jiansheng Li

    2006-01-01

    OBJECTIVE: To investigate the effect of endothelial cells on the permeability of blood brain barrier (BBB) after brain injury and its effect mechanism.DATA SOURCES: We searched for the articles of permeability of BBB and endothelial cell injury after brain ischemia, which were published between January 1982 and December 2005, with the key words of "cerebral ischemia damage,blood brain barrier ( BBB),permeability,effect of endothelial cell (EC) and its variation mechanism"in English.STUDY SELECTION: The materials were primarily selected. The articles related to the changes in the permeability of BBB and the effect of endothelial cells as well as the change mechanism after cerebral ischemia damage were chosen. Repetitive studies or review articles were excluded.DATA EXTRACTION: Totally 55 related articles were collected, and 35 were excluded due to repetitive or review articles, finally 20 articles were involved.DATA SYNTHESIS: The content or viewpoints of involved literatures were analyzed. Cerebral ischemia had damage for endothelial cells, such as the inflow of a lot of Ca2+, the production of nitrogen monoxide and oxygen free radical, and aggravated destruction of BBB. After acceptors of inflammatory mediators on cerebrovascular endothelial cell membrane, such as histamine, bradykinin , 5-hydroxytryptamine and so on are activated, endothelial cells shrink and the permeability of BBB increases. Its mechanism involves in the inflow of extracellular Ca2+and the release of intracellular Ca2+ in the cells. Glycocalyx molecule on the surface of endothelial cell, having structural polytropy, is the determinative factor of the permeability of BBB. VEGF, intensively increasing the vasopermeability and mainly effecting on postcapillary vein and veinlet, is the strongest known blood vessel permeation reagent. Its chronic overexpression in the brain can lead the destruction of BBB.CONCLUSION: The injury of endothelial cell participants in the pathological mechanism of BBB

  17. Rescue of Brain Function Using Tunneling Nanotubes Between Neural Stem Cells and Brain Microvascular Endothelial Cells.

    Science.gov (United States)

    Wang, Xiaoqing; Yu, Xiaowen; Xie, Chong; Tan, Zijian; Tian, Qi; Zhu, Desheng; Liu, Mingyuan; Guan, Yangtai

    2016-05-01

    Evidence indicates that neural stem cells (NSCs) can ameliorate cerebral ischemia in animal models. In this study, we investigated the mechanism underlying one of the neuroprotective effects of NSCs: tunneling nanotube (TNT) formation. We addressed whether the control of cell-to-cell communication processes between NSCs and brain microvascular endothelial cells (BMECs) and, particularly, the control of TNT formation could influence the rescue function of stem cells. In an attempt to mimic the cellular microenvironment in vitro, a co-culture system consisting of terminally differentiated BMECs from mice in a distressed state and NSCs was constructed. Additionally, engraftment experiments with infarcted mouse brains revealed that control of TNT formation influenced the effects of stem cell transplantation in vivo. In conclusion, our findings provide the first evidence that TNTs exist between NSCs and BMECs and that regulation of TNT formation alters cell function.

  18. Impairment of brain endothelial glucose transporter by methamphetamine causes blood-brain barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Murrin L Charles

    2011-03-01

    Full Text Available Abstract Background Methamphetamine (METH, an addictive psycho-stimulant drug with euphoric effect is known to cause neurotoxicity due to oxidative stress, dopamine accumulation and glial cell activation. Here we hypothesized that METH-induced interference of glucose uptake and transport at the endothelium can disrupt the energy requirement of the blood-brain barrier (BBB function and integrity. We undertake this study because there is no report of METH effects on glucose uptake and transport across the blood-brain barrier (BBB to date. Results In this study, we demonstrate that METH-induced disruption of glucose uptake by endothelium lead to BBB dysfunction. Our data indicate that a low concentration of METH (20 μM increased the expression of glucose transporter protein-1 (GLUT1 in primary human brain endothelial cell (hBEC, main component of BBB without affecting the glucose uptake. A high concentration of 200 μM of METH decreased both the glucose uptake and GLUT1 protein levels in hBEC culture. Transcription process appeared to regulate the changes in METH-induced GLUT1 expression. METH-induced decrease in GLUT1 protein level was associated with reduction in BBB tight junction protein occludin and zonula occludens-1. Functional assessment of the trans-endothelial electrical resistance of the cell monolayers and permeability of dye tracers in animal model validated the pharmacokinetics and molecular findings that inhibition of glucose uptake by GLUT1 inhibitor cytochalasin B (CB aggravated the METH-induced disruption of the BBB integrity. Application of acetyl-L-carnitine suppressed the effects of METH on glucose uptake and BBB function. Conclusion Our findings suggest that impairment of GLUT1 at the brain endothelium by METH may contribute to energy-associated disruption of tight junction assembly and loss of BBB integrity.

  19. Podocyte detachment and reduced glomerular capillary endothelial fenestration promote kidney disease in type 2 diabetic nephropathy

    OpenAIRE

    Weil, E. Jennifer; Lemley, Kevin V; Mason, Clinton C; Yee, Berne; Jones, Lois I.; Blouch, Kristina; Lovato, Tracy; Richardson, Meghan; Myers, Bryan D.; Nelson, Robert G.

    2012-01-01

    Podocyte detachment and reduced endothelial cell fenestration and relationships between these features and the classic structural changes of diabetic nephropathy have not been described in patients with type 2 diabetes. Here we studied these relationships in 37 Pima Indians with type 2 diabetes of whom 11 had normal albuminuria, 16 had microalbuminuria, and 10 had macroalbuminuria. Biopsies from ten kidney donors (not Americans Indians) showed almost undetectable (0.03%) podocyte detachment a...

  20. Irradiation of rat brain reduces P-glycoprotein expression and function

    NARCIS (Netherlands)

    Bart, J.; Nagengast, W.B.; Coppes, R.P.; Wegman, T.D.; Graaf, W.T.A. van der; Groen, H.J.; Vaalburg, W.; Vries, E.G.F. de; Hendrikse, N.H.

    2007-01-01

    The blood-brain barrier (BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P-glycoprotein (P-gp), expressed on brain capillary endothelial cells, is part of the BBB. P-gp expression on capillary endothelium decreases 5 days after brain irradiation,

  1. Irradiation of rat brain reduces P-glycoprotein expression and function

    NARCIS (Netherlands)

    Bart, J.; Nagengast, W. B.; Coppes, R. P.; Wegman, T. D.; van der Graaf, W. T. A.; Groen, H. J. M.; Vaalburg, W.; de Vries, E. G. E.; Hendrikse, N. H.

    2007-01-01

    The blood - brain barrier ( BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P- glycoprotein ( P- gp), expressed on brain capillary endothelial cells, is part of the BBB. P- gp expression on capillary endothelium decreases 5 days after brain irrad

  2. Initial contact of glioblastoma cells with existing normal brain endothelial cells strengthen the barrier function via fibroblast growth factor 2 secretion: a new in vitro blood-brain barrier model.

    Science.gov (United States)

    Toyoda, Keisuke; Tanaka, Kunihiko; Nakagawa, Shinsuke; Thuy, Dinh Ha Duy; Ujifuku, Kenta; Kamada, Kensaku; Hayashi, Kentaro; Matsuo, Takayuki; Nagata, Izumi; Niwa, Masami

    2013-05-01

    Glioblastoma multiforme (GBM) cells invade along the existing normal capillaries in brain. Normal capillary endothelial cells function as the blood-brain barrier (BBB) that limits permeability of chemicals into the brain. To investigate whether GBM cells modulate the BBB function of normal endothelial cells, we developed a new in vitro BBB model with primary cultures of rat brain endothelial cells (RBECs), pericytes, and astrocytes. Cells were plated on a membrane with 8 μm pores, either as a monolayer or as a BBB model with triple layer culture. The BBB model consisted of RBEC on the luminal side as a bottom, and pericytes and astrocytes on the abluminal side as a top of the chamber. Human GBM cell line, LN-18 cells, or lung cancer cell line, NCI-H1299 cells, placed on either the RBEC monolayer or the BBB model increased the transendothelial electrical resistance (TEER) values against the model, which peaked within 72 h after the tumor cell application. The TEER value gradually returned to baseline with LN-18 cells, whereas the value quickly dropped to the baseline in 24 h with NCI-H1299 cells. NCI-H1299 cells invaded into the RBEC layer through the membrane, but LN-18 cells did not. Fibroblast growth factor 2 (FGF-2) strengthens the endothelial cell BBB function by increased occludin and ZO-1 expression. In our model, LN-18 and NCI-H1299 cells secreted FGF-2, and a neutralization antibody to FGF-2 inhibited LN-18 cells enhanced BBB function. These results suggest that FGF-2 would be a novel therapeutic target for GBM in the perivascular invasive front.

  3. Generation of primary cultures of bovine brain endothelial cells and setup of cocultures with rat astrocytes

    DEFF Research Database (Denmark)

    Helms, Hans C; Brodin, Birger

    2014-01-01

    In vitro models of the blood-brain barrier are useful tools to study blood-brain barrier function as well as drug permeation from the systemic circulation to the brain parenchyma. However, a large number of the available in vitro models fail to reflect the tightness of the in vivo blood-brain...... barrier. The present protocol describes the setup of an in vitro coculture model based on primary cultures of endothelial cells from bovine brain microvessels and primary cultures of rat astrocytes. The model displays a high electrical tightness and expresses blood-brain barrier marker proteins....

  4. Brain endothelial cells increase the proliferation of Plasmodium falciparum through production of soluble factors.

    Science.gov (United States)

    Khaw, L T; Ball, H J; Mitchell, A J; Grau, G E; Stocker, R; Golenser, J; Hunt, N H

    2014-10-01

    We here describe the novel finding that brain endothelial cells in vitro can stimulate the growth of Plasmodium falciparum through the production of low molecular weight growth factors. By using a conditioned medium approach, we show that the brain endothelial cells continued to release these factors over time. If this mirrors the in vivo situation, these growth factors potentially would provide an advantage, in terms of enhanced growth, for sequestered parasitised red blood cells in the brain microvasculature. We observed this phenomenon with brain endothelial cells from several sources as well as a second P. falciparum strain. The characteristics of the growth factors included: heat stable, and in part chloroform soluble. Future efforts should be directed at identifying these growth factors, since blocking their production or actions might be of benefit for reducing parasite load and, hence, malaria pathology.

  5. Derivation of blood-brain barrier endothelial cells from human pluripotent stem cells.

    Science.gov (United States)

    Lippmann, Ethan S; Azarin, Samira M; Kay, Jennifer E; Nessler, Randy A; Wilson, Hannah K; Al-Ahmad, Abraham; Palecek, Sean P; Shusta, Eric V

    2012-08-01

    The blood-brain barrier (BBB) is crucial to the health of the brain and is often compromised in neurological disease. Moreover, because of its barrier properties, this endothelial interface restricts uptake of neurotherapeutics. Thus, a renewable source of human BBB endothelium could spur brain research and pharmaceutical development. Here we show that endothelial cells derived from human pluripotent stem cells (hPSCs) acquire BBB properties when co-differentiated with neural cells that provide relevant cues, including those involved in Wnt/β-catenin signaling. The resulting endothelial cells have many BBB attributes, including well-organized tight junctions, appropriate expression of nutrient transporters and polarized efflux transporter activity. Notably, they respond to astrocytes, acquiring substantial barrier properties as measured by transendothelial electrical resistance (1,450 ± 140 Ω cm2), and they possess molecular permeability that correlates well with in vivo rodent blood-brain transfer coefficients.

  6. Glutathione in Cerebral Microvascular Endothelial Biology and Pathobiology: Implications for Brain Homeostasis

    Directory of Open Access Journals (Sweden)

    Wei Li

    2012-01-01

    Full Text Available The integrity of the vascular endothelium of the blood-brain barrier (BBB is central to cerebrovascular homeostasis. Given the function of the BBB as a physical and metabolic barrier that buffers the systemic environment, oxidative damage to the endothelial monolayer will have significant deleterious impact on the metabolic, immunological, and neurological functions of the brain. Glutathione (GSH is a ubiquitous major thiol within mammalian cells that plays important roles in antioxidant defense, oxidation-reduction reactions in metabolic pathways, and redox signaling. The existence of distinct GSH pools within the subcellular organelles supports an elegant mode for independent redox regulation of metabolic processes, including those that control cell fate. GSH-dependent homeostatic control of neurovascular function is relatively unexplored. Significantly, GSH regulation of two aspects of endothelial function is paramount to barrier preservation, namely, GSH protection against oxidative endothelial cell injury and GSH control of postdamage cell proliferation in endothelial repair and/or wound healing. This paper highlights our current insights and hypotheses into the role of GSH in cerebral microvascular biology and pathobiology with special focus on endothelial GSH and vascular integrity, oxidative disruption of endothelial barrier function, GSH regulation of endothelial cell proliferation, and the pathological implications of GSH disruption in oxidative stress-associated neurovascular disorders, such as diabetes and stroke.

  7. Endothelial cells of the blood-brain barrier: a target for glucocorticoids and estrogens?

    Science.gov (United States)

    Dietrich, Jean-Bernard

    2004-01-01

    Adhesion molecules are involved in the leukocyte recruitment of leukocytes at the blood-brain barrier. For this reason, it is important to understand how the regulation of their gene expression controls lymphocyte adhesion to endothelial cells in microvessels. Indeed, due to their specificity and diversity, adhesion molecules involved in extravasation play an essential role in the recruitment of activated leukocytes and activation of inflammation. Multiple sclerosis results from a chronic inflammation of the CNS which is mediated by infiltration of inflammatory cells from the immune system. Administration of glucocorticoids is a routine method to control multiple sclerosis since naturally derived or synthetic glucocorticoids are potent immunosuppressive and anti-inflammatory agents. Glucocorticoids also have beneficial effects in stabilizing the blood-brain barrier, as steroid hormones regulate the expression of adhesion molecule genes in endothelial cells. Other hormones such as estrogens modulate many endothelial cell biological activities, among them adhesion to leukocytes. They regulate expression of adhesion molecules genes on endothelial cells and are useful for the treatment of experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. The effects of glucocorticoids and estrogens on the expression of adhesion molecules on endothelial cells, including microvascular endothelial cells of the blood-brain barrier, are reviewed in this paper, as well as the involvement of these hormones in the therapy of experimental autoimmune encephalomyelitis and multiple sclerosis.

  8. Pentosan polysulfate protects brain endothelial cells against bacterial lipopolysaccharide-induced damages.

    Science.gov (United States)

    Veszelka, Szilvia; Pásztói, Mária; Farkas, Attila E; Krizbai, István; Ngo, Thi Khue Dung; Niwa, Masami; Abrahám, Csongor S; Deli, Mária A

    2007-01-01

    Peripheral inflammation can aggravate local brain inflammation and neuronal death. The blood-brain barrier (BBB) is a key player in the event. On a relevant in vitro model of primary rat brain endothelial cells co-cultured with primary rat astroglia cells lipopolysaccharide (LPS)-induced changes in several BBB functions have been investigated. LPS-treatment resulted in a dose- and time-dependent decrease in the integrity of endothelial monolayers: transendothelial electrical resistance dropped, while flux of permeability markers fluorescein and albumin significantly increased. Immunostaining for junctional proteins ZO-1, claudin-5 and beta-catenin was significantly weaker in LPS-treated endothelial cells than in control monolayers. LPS also reduced the intensity and changed the pattern of ZO-1 immunostaining in freshly isolated rat brain microvessels. The activity of P-glycoprotein, an important efflux pump at the BBB, was also inhibited by LPS. At the same time production of reactive oxygen species and nitric oxide was increased in brain endothelial cells treated with LPS. Pentosan polysulfate, a polyanionic polysaccharide could reduce the deleterious effects of LPS on BBB permeability, and P-glycoprotein activity. LPS-stimulated increase in the production of reactive oxygen species and nitric oxide was also decreased by pentosan treatment. The protective effect of pentosan for brain endothelium can be of therapeutical significance in bacterial infections affecting the BBB.

  9. Expression of human factor IX in rat capillary endothelial cells: Toward somatic gene therapy for hemophilia B

    Energy Technology Data Exchange (ETDEWEB)

    Shounan Yao; Wilson, J.M.; Nabel, E.G.; Kurachi, Sumiko; Hachiya, H.L.; Kurachi, Kotoku (Univ. of Michigan, Ann Arbor (United States))

    1991-09-15

    In aiming to develop a gene therapy approach for hemophilia B, the authors expressed and characterized human factor IX in rat capillary endothelial cells (CECs). Moloney murine leukemia virus-derived retrovirus vectors that contain human factor IX cDNA linked to heterologous promoters and the neomycin-resistant gene were constructed and employed to prepare recombinant retroviruses. Rat CECs and NIH 3T3 cells infected with these viruses were selected with the neomycin analogue, G418 sulfate, and tested for expression of factor IX. A construct with the factor IX cDNA under direct control by long terminal repeat gave the highest level of expression as quantitated by immunoassays as well as clotting activity assays. A single RNA transcript of 4.4 kilobases predicted by the construct and a recombinant factor IX were found. The recombinant human factor IX produced showed full clotting activity, demonstrating that CECs have an efficient mechanism for posttranslational modifications, including {gamma}-carboxylation, essential for its biological activity. These results, in addition to other properties of the endothelium, including large number of cells, accessibility, and direct contact with the circulating blood, suggest that CECs can serve as an efficient drug delivery vehicle producing factor IX in a somatic gene therapy for hemophilia B.

  10. Glioblastoma cell-secreted interleukin-8 induces brain endothelial cell permeability via CXCR2.

    Directory of Open Access Journals (Sweden)

    Julie Dwyer

    Full Text Available Glioblastoma constitutes the most aggressive and deadly of brain tumors. As yet, both conventional and molecular-based therapies have met with limited success in treatment of this cancer. Among other explanations, the heterogeneity of glioblastoma and the associated microenvironment contribute to its development, as well as resistance and recurrence in response to treatments. Increased vascularity suggests that tumor angiogenesis plays an important role in glioblastoma progression. However, the molecular crosstalk between endothelial and glioblastoma cells requires further investigation. To examine the effects of glioblastoma-derived signals on endothelial homeostasis, glioblastoma cell secretions were collected and used to treat brain endothelial cells. Here, we present evidence that the glioblastoma secretome provides pro-angiogenic signals sufficient to disrupt VE-cadherin-mediated cell-cell junctions and promote endothelial permeability in brain microvascular endothelial cells. An unbiased angiogenesis-specific antibody array screen identified the chemokine, interleukin-8, which was further demonstrated to function as a key factor involved in glioblastoma-induced permeability, mediated through its receptor CXCR2 on brain endothelia. This underappreciated interface between glioblastoma cells and associated endothelium may inspire the development of novel therapeutic strategies to induce tumor regression by preventing vascular permeability and inhibiting angiogenesis.

  11. Analysis of serotonin in brain microdialysates using capillary electrophoresis and native laser-induced fluorescence detection.

    Science.gov (United States)

    Benturquia, Nadia; Couderc, François; Sauvinet, Valérie; Orset, Cyrille; Parrot, Sandrine; Bayle, Christophe; Renaud, Bernard; Denoroy, Luc

    2005-03-01

    Serotonin or 5-hydroxytryptamine (5-HT) is a major neurotransmitter in the central nervous system. In this work, a method for analyzing 5-HT in brain microdialysis samples using a commercially available capillary electrophoresis (CE) system has been developed. A pH-mediated in-capillary preconcentration of samples was performed, and after separation by capillary zone electrophoresis, native fluorescence of 5-HT was detected by a 266 nm solid-state laser. The separation conditions for the analysis of 5-HT in standard solutions and microdialysates have been optimized, and this method has been validated on both pharmacological and analytical bases. Separation of 5-HT was performed using a 80 mmol/L citrate buffer, pH 2.5, containing 20 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and +30 kV voltage. The detection limit was 2.5 x 10(-10) mol/L. This method allows the in vivo brain monitoring of 5-HT using a simple, accurate CE measurement in underivatized microdialysis samples.

  12. Method for isolation and molecular characterization of extracellular microvesicles released from brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Haqqani Arsalan S

    2013-01-01

    Full Text Available Abstract Background In addition to possessing intracellular vesicles, eukaryotic cells also produce extracellular microvesicles, ranging from 50 to 1000 nm in diameter that are released or shed into the microenvironment under physiological and pathological conditions. These membranous extracellular organelles include both exosomes (originating from internal vesicles of endosomes and ectosomes (originating from direct budding/shedding of plasma membranes. Extracellular microvesicles contain cell-specific collections of proteins, glycoproteins, lipids, nucleic acids and other molecules. These vesicles play important roles in intercellular communication by acting as carrier for essential cell-specific information to target cells. Endothelial cells in the brain form the blood–brain barrier, a specialized interface between the blood and the brain that tightly controls traffic of nutrients and macromolecules between two compartments and interacts closely with other cells forming the neurovascular unit. Therefore, brain endothelial cell extracellular microvesicles could potentially play important roles in ‘externalizing’ brain-specific biomarkers into the blood stream during pathological conditions, in transcytosis of blood-borne molecules into the brain, and in cell-cell communication within the neurovascular unit. Methods To study cell-specific molecular make-up and functions of brain endothelial cell exosomes, methods for isolation of extracellular microvesicles using mass spectrometry-compatible protocols and the characterization of their signature profiles using mass spectrometry -based proteomics were developed. Results A total of 1179 proteins were identified in the isolated extracellular microvesicles from brain endothelial cells. The microvesicles were validated by identification of almost 60 known markers, including Alix, TSG101 and the tetraspanin proteins CD81 and CD9. The surface proteins on isolated microvesicles could potentially

  13. Targeted drug delivery to the brain using magnetic nanoparticles.

    Science.gov (United States)

    Thomsen, Louiza Bohn; Thomsen, Maj Schneider; Moos, Torben

    2015-01-01

    Brain capillary endothelial cells denote the blood-brain barrier (BBB), and conjugation of nanoparticles with antibodies that target molecules expressed by these endothelial cells may facilitate their uptake and transport into the brain. Magnetic nanoparticles can be encapsulated in liposomes and carry large molecules with therapeutic potential, for example, siRNA, cDNA and polypeptides. An additional approach to enhance the transport of magnetic nanoparticles across the BBB is the application of extracranially applied magnetic force. Stepwise targeting of magnetic nanoparticles to brain capillary endothelial cells followed by transport through the BBB using magnetic force may prove a novel mechanism for targeted therapy of macromolecules to the brain.

  14. Lipopolysaccharide-induced apoptosis in transformed bovine brain endothelial cells and human dermal microvessel endothelial cells: the role of JNK.

    Science.gov (United States)

    Karahashi, Hisae; Michelsen, Kathrin S; Arditi, Moshe

    2009-06-01

    Stimulation of transformed bovine brain endothelial cells (TBBEC) with LPS leads to apoptosis while human microvessel endothelial cells (HMEC) need the presence of cycloheximide (CHX) with LPS to induce apoptosis. To investigate the molecular mechanism of LPS-induced apoptosis in HMEC or TBBEC, we analyzed the involvement of MAPK and PI3K in TBBEC and HMEC. LPS-induced apoptosis in TBBEC was hallmarked by the activation of caspase 3, caspase 6, and caspase 8 after the stimulation of LPS, followed by poly(ADP-ribose) polymerase cleavage and lactate dehydrogenase release. We also observed DNA cleavage determined by TUNEL staining in TBBEC treated with LPS. Herbimycin A, a tyrosine kinase inhibitor, and SP600125, a JNK inhibitor, suppressed the activation of caspases and lactate dehydrogenase release. Moreover, a PI3K inhibitor (LY294002) suppressed activation of caspases and combined treatment with both SP600125 and LY294002 completely inhibited the activation of caspases. These results suggest that the JNK signaling pathway through the tyrosine kinase and PI3K pathways is involved in the induction of apoptosis in LPS-treated TBBEC. On the other hand, we observed sustained JNK activation in HMEC treated with LPS and CHX, and neither ERK1/2 nor AKT were activated. The addition of SP600125 suppressed phosphorylation of JNK and the activation of caspase 3 in HMEC treated with LPS and CHX. These results suggest that JNK plays an important role in the induction of apoptosis in endothelial cells.

  15. Magnetic particle spectroscopy allows precise quantification of nanoparticles after passage through human brain microvascular endothelial cells

    Science.gov (United States)

    Gräfe, C.; Slabu, I.; Wiekhorst, F.; Bergemann, C.; von Eggeling, F.; Hochhaus, A.; Trahms, L.; Clement, J. H.

    2016-06-01

    Crossing the blood-brain barrier is an urgent requirement for the treatment of brain disorders. Superparamagnetic iron oxide nanoparticles (SPIONs) are a promising tool as carriers for therapeutics because of their physical properties, biocompatibility, and their biodegradability. In order to investigate the interaction of nanoparticles with endothelial cell layers in detail, in vitro systems are of great importance. Human brain microvascular endothelial cells are a well-suited blood-brain barrier model. Apart from generating optimal conditions for the barrier-forming cell units, the accurate detection and quantification of SPIONs is a major challenge. For that purpose we use magnetic particle spectroscopy to sensitively and directly quantify the SPION-specific iron content. We could show that SPION concentration depends on incubation time, nanoparticle concentration and location. This model system allows for further investigations on particle uptake and transport at cellular barriers with regard to parameters including particles’ shape, material, size, and coating.

  16. Leukocytes in capillary flow.

    Science.gov (United States)

    Schmid-Schönbein, G W; Lee, J

    1995-01-01

    During disease, the flow of blood cells through the capillary network is one of the most perilous events in the microcirculation. Capillary distensibility, cytoplasmic activity of endothelial cells, red cells and leukocytes play an important role in capillary perfusion. Occlusion of capillaries is one of the early signs of vascular failure and is encountered in many different conditions and organs. Adhesion of leukocytes to the endothelium via expression of membrane adhesion molecules leads to microvascular entrapment with capillary occlusion.

  17. Pericyte abundance affects sucrose permeability in cultures of rat brain microvascular endothelial cells.

    Science.gov (United States)

    Parkinson, Fiona E; Hacking, Cindy

    2005-07-05

    The blood-brain barrier is a physical and metabolic barrier that restricts diffusion of blood-borne substances into brain. In vitro models of the blood-brain barrier are used to characterize this structure, examine mechanisms of damage and repair and measure permeability of test substances. The core component of in vitro models of the blood-brain barrier is brain microvascular endothelial cells. We cultured rat brain microvascular endothelial cells (RBMEC) from isolated rat cortex microvessels. After 2-14 days in vitro (DIV), immunohistochemistry of these cells showed strong labeling for zona occludens 1 (ZO-1), a tight junction protein expressed in endothelial cells. Pericytes were also present in these cultures, as determined by expression of alpha-actin. The present study was performed to test different cell isolation methods and to compare the resulting cell cultures for abundance of pericytes and for blood-brain barrier function, as assessed by 14C-sucrose flux. Two purification strategies were used. First, microvessels were preabsorbed onto uncoated plastic for 4 h, then unattached microvessels were transferred to coated culture ware. Second, microvessels were incubated with an antibody to platelet-endothelial cell adhesion molecule 1 (PECAM-1; CD31) precoupled to magnetic beads, and a magnetic separation procedure was performed. Our results indicate that immunopurification, but not preadsorption, was an effective method to purify microvessels and reduce pericyte abundance in the resulting cultures. This purification significantly reduced 14C-sucrose fluxes across cell monolayers. These data indicate that pericytes can interfere with the development of blood-brain barrier properties in in vitro models that utilize primary cultures of RBMECs.

  18. Brain endothelial cells control fertility through ovarian-steroid-dependent release of semaphorin 3A

    NARCIS (Netherlands)

    Giacobini, Paolo; Parkash, Jyoti; Campagne, Céline; Messina, Andrea; Casoni, Filippo; Vanacker, Charlotte; Langlet, Fanny; Hobo, Barbara; Cagnoni, Gabriella; Gallet, Sarah; Hanchate, Naresh Kumar; Mazur, Danièle; Taniguchi, Masahiko; Mazzone, Massimiliano; Verhaagen, J.; Ciofi, Philippe; Bouret, Sébastien G; Tamagnone, Luca; Prevot, Vincent

    2014-01-01

    Neuropilin-1 (Nrp1) guides the development of the nervous and vascular systems, but its role in the mature brain remains to be explored. Here we report that the expression of the 65 kDa isoform of Sema3A, the ligand of Nrp1, by adult vascular endothelial cells, is regulated during the ovarian cycle

  19. Transcriptional Profile of HIV-induced Nuclear Translocation of Amyloid β in Brain Endothelial Cells

    Science.gov (United States)

    András, Ibolya E.; Rampersaud, Evadnie; Eum, Sung Yong; Toborek, Michal

    2015-01-01

    Background and Aims Increased amyloid deposition in HIV-infected brains may contribute to the pathogenesis of neurocognitive dysfunction in infected patients. We have previously shown that exposure to HIV results in enhanced amyloid β (Aβ) levels in human brain microvascular endothelial cells, suggesting that brain endothelial cells contribute to accumulation of Aβ in HIV-infected brains. Importantly, Aβ not only accumulates in the cytoplasm of HIV-exposed cells but also enters the nuclei of brain endothelial cells. Methods cDNA microarray analysis was performed in order to examine changes in the transcriptional profile associated with Aβ nuclear entry in the presence of HIV-1. Results Gene network analysis indicated that inhibition of nuclear entry of Aβ resulted in enrichment in gene sets involved in apoptosis and survival, endoplasmic reticulum stress response, immune response, cell cycle, DNA damage, oxidative stress, cytoskeleton remodeling and transforming growth factor b (TGFβ) receptor signaling. Conclusions The obtained data indicate that HIV-induced Aβ nuclear uptake affects several cellular stress-related pathways relevant for HIV-induced Aβ pathology. PMID:25446617

  20. Iron uptake and transport at the blood-brain barrier

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    . The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We......The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved...... in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity...

  1. CXCL1 can be regulated by IL-6 and promotes granulocyte adhesion to brain capillaries during bacterial toxin exposure and encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Roy Monica

    2012-01-01

    Full Text Available Abstract Background Granulocytes generally exert protective roles in the central nervous system (CNS, but recent studies suggest that they can be detrimental in experimental autoimmune encephalomyelitis (EAE, the most common model of multiple sclerosis. While the cytokines and adhesion molecules involved in granulocyte adhesion to the brain vasculature have started to be elucidated, the required chemokines remain undetermined. Methods CXCR2 ligand expression was examined in the CNS of mice suffering from EAE or exposed to bacterial toxins by quantitative RT-PCR and in situ hybridization. CXCL1 expression was analyzed in IL-6-treated endothelial cell cultures by quantitative RT-PCR and ELISA. Granulocytes were counted in the brain vasculature after treatment with a neutralizing anti-CXCL1 antibody using stereological techniques. Results CXCL1 was the most highly expressed ligand of the granulocyte receptor CXCR2 in the CNS of mice subjected to EAE or infused with lipopolysaccharide (LPS or pertussis toxin (PTX, the latter being commonly used to induce EAE. IL-6 upregulated CXCL1 expression in brain endothelial cells by acting transcriptionally and mediated the stimulatory effect of PTX on CXCL1 expression. The anti-CXCL1 antibody reduced granulocyte adhesion to brain capillaries in the three conditions under study. Importantly, it attenuated EAE severity when given daily for a week during the effector phase of the disease. Conclusions This study identifies CXCL1 not only as a key regulator of granulocyte recruitment into the CNS, but also as a new potential target for the treatment of neuroinflammatory diseases such as multiple sclerosis.

  2. Transcriptional profiling of human brain endothelial cells reveals key properties crucial for predictive in vitro blood-brain barrier models.

    Directory of Open Access Journals (Sweden)

    Eduard Urich

    Full Text Available Brain microvascular endothelial cells (BEC constitute the blood-brain barrier (BBB which forms a dynamic interface between the blood and the central nervous system (CNS. This highly specialized interface restricts paracellular diffusion of fluids and solutes including chemicals, toxins and drugs from entering the brain. In this study we compared the transcriptome profiles of the human immortalized brain endothelial cell line hCMEC/D3 and human primary BEC. We identified transcriptional differences in immune response genes which are directly related to the immortalization procedure of the hCMEC/D3 cells. Interestingly, astrocytic co-culturing reduced cell adhesion and migration molecules in both BECs, which possibly could be related to regulation of immune surveillance of the CNS controlled by astrocytic cells within the neurovascular unit. By matching the transcriptome data from these two cell lines with published transcriptional data from freshly isolated mouse BECs, we discovered striking differences that could explain some of the limitations of using cultured BECs to study BBB properties. Key protein classes such as tight junction proteins, transporters and cell surface receptors show differing expression profiles. For example, the claudin-5, occludin and JAM2 expression is dramatically reduced in the two human BEC lines, which likely explains their low transcellular electric resistance and paracellular leakiness. In addition, the human BEC lines express low levels of unique brain endothelial transporters such as Glut1 and Pgp. Cell surface receptors such as LRP1, RAGE and the insulin receptor that are involved in receptor-mediated transport are also expressed at very low levels. Taken together, these data illustrate that BECs lose their unique protein expression pattern outside of their native environment and display a more generic endothelial cell phenotype. A collection of key genes that seems to be highly regulated by the local

  3. Regulation of P-glycoprotein expression in brain capillaries in Huntington's disease and its impact on brain availability of antipsychotic agents risperidone and paliperidone.

    Science.gov (United States)

    Kao, Yu-Han; Chern, Yijuang; Yang, Hui-Ting; Chen, Hui-Mei; Lin, Chun-Jung

    2016-08-01

    Huntington's disease (HD) is a neurodegenerative disease marked by an expanded polyglutamine (polyQ) tract on the huntingtin (HTT) protein that may cause transcriptional dysfunction. This study aimed to investigate the regulation and function of P-glycoprotein, an important efflux transporter, in brain capillaries in HD. The results showed that, compared with the littermate controls, R6/2 HD transgenic mice with the human mutant HTT gene had higher levels of P-glycoprotein mRNA and protein and enhanced NF-κB activity in their brain capillaries. Higher P-glycoprotein expression was also observed in the brain capillaries of human HD patients. Consistent with this enhanced P-glycoprotein expression, brain extracellular levels and brain-to-plasma ratios of the antipsychotic agents risperidone and paliperidone were significantly lower in R6/2 mice than in their littermate controls. Exogenous expression of human mutant HTT protein with expanded polyQ (mHTT-109Q) in HEK293T cells enhanced the levels of P-glycoprotein transcripts and NF-κB activity compared with cells expressing normal HTT-25Q. Treatment with the IKK inhibitor, BMS-345541, decreased P-glycoprotein mRNA level in cells transfected with mHTT-109Q or normal HTT-25Q In conclusion, mutant HTT altered the expression of P-glycoprotein through the NF-κB pathway in brain capillaries in HD and markedly affected the availability of P-glycoprotein substrates in the brain.

  4. Anti-lipid phosphate phosphohydrolase-3 (LPP3 antibody inhibits bFGF- and VEGF-induced capillary morphogenesis of endothelial cells

    Directory of Open Access Journals (Sweden)

    Humtsoe Joseph O

    2005-08-01

    Full Text Available Abstract Background Angiogenesis, or the remodeling of existing vasculature serves as a lifeline to nourish developing embryos and starved tissues, and to accelerate wound healing, diabetic retinopathy, and tumor progression. Recent studies indicate that angiogenesis requires growth factor activity as well as cell adhesion events mediated by α5β1 and αvβ3 integrins. We previously demonstrated that human lipid phosphate phosphohydrolase-3 (LPP3 acts as a cell-associated ligand for α5β1 and αvβ3 integrins. Here, we test the hypothesis that an anti-LPP3 antibody can inhibit basic fibroblast growth factor (bFGF-and vascular endothelial growth factor (VEGF-induced capillary morphogenesis of endothelial cells (ECs. Results We report that bFGF and VEGF up-regulate LPP3 protein expression in ECs. Immunoprecipitation analyses show that LPP3 is a cell surface protein and undergoes N-glycosylation. Fluorescent activated cell sorting (FACS data suggest that anti-LPP3-RGD detects native neoepitope on the surface of activated ECs. Moreover, we demonstrate LPP3 protein expression in tumor endothelium alongside VEGF. The embedding of ECs into three-dimensional type I collagen in the presence of bFGF and VEGF induce capillary formation. Importantly, we show that the addition of an anti-LPP3 antibody specifically and significantly blocks bFGF- and VEGF-induced capillary morphogenesis of ECs. Conclusion These data suggest that activated ECs as well as tumor endothelium express LPP3 protein. In an in vitro assay, the anti-LPP3-RGD specifically blocks bFGF and VEGF induced capillary morphogenesis of ECs. Our results, therefore, suggest a role for LPP3 in angiogenesis.

  5. Galectin-1 suppresses methamphetamine induced neuroinflammation in human brain microvascular endothelial cells: Neuroprotective role in maintaining blood brain barrier integrity.

    Science.gov (United States)

    Parikh, Neil U; Aalinkeel, R; Reynolds, J L; Nair, B B; Sykes, D E; Mammen, M J; Schwartz, S A; Mahajan, S D

    2015-10-22

    Methamphetamine (Meth) abuse can lead to the breakdown of the blood-brain barrier (BBB) integrity leading to compromised CNS function. The role of Galectins in the angiogenesis process in tumor-associated endothelial cells (EC) is well established; however no data are available on the expression of Galectins in normal human brain microvascular endothelial cells and their potential role in maintaining BBB integrity. We evaluated the basal gene/protein expression levels of Galectin-1, -3 and -9 in normal primary human brain microvascular endothelial cells (BMVEC) that constitute the BBB and examined whether Meth altered Galectin expression in these cells, and if Galectin-1 treatment impacted the integrity of an in-vitro BBB. Our results showed that BMVEC expressed significantly higher levels of Galectin-1 as compared to Galectin-3 and -9. Meth treatment increased Galectin-1 expression in BMVEC. Meth induced decrease in TJ proteins ZO-1, Claudin-3 and adhesion molecule ICAM-1 was reversed by Galectin-1. Our data suggests that Galectin-1 is involved in BBB remodeling and can increase levels of TJ proteins ZO-1 and Claudin-3 and adhesion molecule ICAM-1 which helps maintain BBB tightness thus playing a neuroprotective role. Galectin-1 is thus an important regulator of immune balance from neurodegeneration to neuroprotection, which makes it an important therapeutic agent/target in the treatment of drug addiction and other neurological conditions.

  6. Human brain microvascular endothelial cells resist elongation due to shear stress.

    Science.gov (United States)

    Reinitz, Adam; DeStefano, Jackson; Ye, Mao; Wong, Andrew D; Searson, Peter C

    2015-05-01

    Endothelial cells in straight sections of vessels are known to elongate and align in the direction of flow. This phenotype has been replicated in confluent monolayers of bovine aortic endothelial cells and human umbilical vein endothelial cells (HUVECs) in cell culture under physiological shear stress. Here we report on the morphological response of human brain microvascular endothelial cells (HBMECs) in confluent monolayers in response to shear stress. Using a microfluidic platform we image confluent monolayers of HBMECs and HUVECs under shear stresses up to 16 dyne cm(-2). From live-cell imaging we quantitatively analyze the cell morphology and cell speed as a function of time. We show that HBMECs do not undergo a classical transition from cobblestone to spindle-like morphology in response to shear stress. We further show that under shear stress, actin fibers are randomly oriented in the cells indicating that there is no cytoskeletal remodeling. These results suggest that HBMECs are programmed to resist elongation and alignment under shear stress, a phenotype that may be associated with the unique properties of the blood-brain barrier.

  7. The Wnt/planar cell polarity signaling pathway contributes to the integrity of tight junctions in brain endothelial cells

    OpenAIRE

    2013-01-01

    Wnt morphogens released by neural precursor cells were recently reported to control blood–brain barrier (BBB) formation during development. Indeed, in mouse brain endothelial cells, activation of the Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, was shown to stabilize endothelial tight junctions (TJs) through transcriptional regulation of the expression of TJ proteins. Because Wnt proteins activate several distinct β-catenin-dependent and independent signaling path...

  8. Human Brain Microvascular Endothelial Cells and Umbilical Vein Endothelial Cells Differentially Facilitate Leukocyte Recruitment and Utilize Chemokines for T Cell Migration

    Directory of Open Access Journals (Sweden)

    Shumei Man

    2008-01-01

    Full Text Available Endothelial cells that functionally express blood brain barrier (BBB properties are useful surrogates for studying leukocyte-endothelial cell interactions at the BBB. In this study, we compared two different endothelial cellular models: transfected human brain microvascular endothelial cells (THBMECs and human umbilical vein endothelial cells (HUVECs. With each grow under optimal conditions, confluent THBMEC cultures showed continuous occludin and ZO-1 immunoreactivity, while HUVEC cultures exhibited punctate ZO-1 expression at sites of cell-cell contact only. Confluent THBMEC cultures on 24-well collagen-coated transwell inserts had significantly higher transendothelial electrical resistance (TEER and lower solute permeability than HUVECs. Confluent THBMECs were more restrictive for mononuclear cell migration than HUVECs. Only THBMECs utilized abluminal CCL5 to facilitate T-lymphocyte migration in vitro although both THBMECs and HUVECs employed CCL3 to facilitate T cell migration. These data establish baseline conditions for using THBMECs to develop in vitro BBB models for studying leukocyte-endothelial interactions during neuroinflammation.

  9. [Influence of n-hexane on vascular endothelial active substances in brain tissue in mice].

    Science.gov (United States)

    Lin, L; Zhang, Z Q; Zhang, C Z

    2017-01-20

    Objective: To investigate the influence of n-hexane on vascular endothelial active substances in brain tissue in mice and its significance. Methods: A total of 48 healthy Kunming mice were randomly divided into high-dose exposure group, middle-dose exposure group, low-dose exposure group, and control group, with 12 mice in each group. All groups except the control group were exposed to n-hexane via static inhalation (0.035 g/L, 0.018 g/L, and 0.009 g/L for the high-, middle-, and low-dose exposure groups, respectively) 4 hours a day for 21 days. the mice in the control groups were not exposed to n-hexane. After the exposure, the lev-els of endothelin-1 (ET-1) , nitric oxide (NO) , and angiotensin II (Ang II) in brain tissue were measured in all groups. Results: There were significant differences in the levels of ET-1, NO, and Ang II between the three ex-posure groups and the control group (PHexane can affect the vascular endothe-lial active substances in brain tissue in mice, and the changes and imbalance in vascular endothelial active sub-stances may be one of the reasons for central nervous system impairment caused by n-hexane.

  10. Normal saline influences coagulation and endothelial function after traumatic brain injury and hemorrhagic shock in pigs

    DEFF Research Database (Denmark)

    Dekker, Simone E; Sillesen, Martin; Bambakidis, Ted

    2014-01-01

    BACKGROUND: Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of trauma-related deaths. These insults disrupt coagulation and endothelial systems. This study investigated whether previously reported differences in lesion size and brain swelling during normal saline (NS...... of endothelial activation (E-selectin, Intercellular adhesion molecule [ICAM]-1), coagulation activation (prothrombin fragment 1 + 2), and natural anticoagulation (activated protein C [aPC]) were determined in serum and brain whole cell lysates. RESULTS: Serum levels of aPC were greater in the NS group (203 ± 30...... pg/mL) compared with HEX (77 ± 28 pg/mL; P = .02) and FFP (110 ± 28 pg/mL; P = .09), as was PF 1 + 2 in the brain when compared with FFP (PF 1 + 2, 89 ± 46 vs 37 ± 14 ng/mL; P = .035). Brain E-selectin was greater in the NS group compared with FFP (3.36 ± 0.02 vs 3.31 ± 0.01 ng/mL; P = .029...

  11. THE RELATIONSHIP BETWEEN PERITUMORAL BRAIN EDEMA AND VASCULAR ENDOTHELIAL GROWTH FACTOR EXPRESSION IN PATIENTS WITH MENINGIOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To determine whether VEGF plays a role in the development of peritumoral brain edema. Methods 50 meningioma patients and their VEGF expression were studied. We took a mono- clonal antibody from mouse to VEGF to stain the tumor cells, the vascular endothelial cells and the interstitial cells. The severity of brain edema was evaluated according to CT or MR scans by the following equation: edema index = Vtumor+edema/Vtumor. The relationship between VEGF expression and edema index was analyzed statisti- cally. Results VEGF was expressed in meningioma tumor cells, which is usually concentrated at the pe- ripheral sites of the tumor. There was a positive linear correlation between the expression and the brain edema index. Conclusion VEGF may play a role in the development of peritumoral brain edema in meningioma patient.

  12. Low intracellular ATP levels exacerbate carcinogen-induced inflammatory stress response and inhibit in vitro tubulogenesis in human brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Elizabeth Tahanian

    2011-01-01

    Full Text Available Elizabeth Tahanian, Sabrina Peiro, Borhane AnnabiLaboratoire d'Oncologie Moléculaire, Centre de Recherche BioMED, Département de Chimie, Université du Québec à Montréal, Montréal, Québec, CanadaAbstract: Solid tumor development requires angiogenesis and is correlated to the expression of inflammatory markers through cellular metabolic and energetic adaptation. While high glycolysis rates enable the cancer cell compartment to generate adenosine triphosphate (ATP, very little is known about the impact of low intracellular ATP concentrations within the vascular endothelial cell compartment, which is responsible for tumor angiogenesis. Here, we investigated the effect of 2-deoxy-D-glucose (2-DG, a glucose analog that inhibits glycolysis through intracellular ATP depletion, on human brain microvascular endothelial cell (HBMEC angiogenic properties. While preformed capillaries remained unaffected, we found that in vitro tubulogenesis was dose-dependently decreased by 2-DG and that this correlated with reduced intracellular ATP levels. Procarcinogenic signaling was induced with phorbol 12-myristate 13-acetate (PMA and found to trigger the proinflammatory marker cyclooxygenase-2 (COX-2 and endoplasmic reticulum (ER stress marker GRP78 expression, whose inductions were potentiated when PMA was combined with 2-DG treatment. Inversely, PMA-induced matrix-metalloproteinase-9 (MMP-9 gene expression and protein secretion were abrogated in the presence of 2-DG, and this can be partially explained by reduced nuclear factor-κB signaling. Collectively, we provide evidence for an intracellular ATP requirement in order for tubulogenesis to occur, and we link increases in ER stress to inflammation. A better understanding of the metabolic adaptations of the vascular endothelial cells that mediate tumor vascularization will help the development of new drugs and therapies.Keywords: endoplasmic reticulum stress, MMP-9, COX-2, 2-deoxy-D-glucose, endothelial

  13. Circulating endothelial progenitor cells in traumatic brain injury: an emerging therapeutic target?

    Institute of Scientific and Technical Information of China (English)

    WEI Hui-jie; JIANG Rong-cai; LIU Li; ZHANG Jian-ning

    2010-01-01

    Traumatic brain injury (TBI) is a major cause ofmortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide promising opportunities to improve clinical outcomes and brain functional recovery. More and more evidences show that circulating endothelial progenitor cells (EPCs), which have been identified in the peripheral blood, may play an important role in the pathologic and physiological angiogenesis in adults. Moreover, impressive data demonstrate that EPCs are mobilized from bone marrow to blood circulation in response to traumatic or inflammatory stimulations.In this review, we discussed the role of EPCs in the repair of brain injury and the possible therapeutic implication for functional recovery of TBl in the future.

  14. Modeling the ischemic blood-brain barrier; the effects of oxygen-glucose deprivation (OGD) on endothelial cells in culture

    DEFF Research Database (Denmark)

    Tornabene, Erica; Helms, Hans Christian Cederberg; Berndt, Philipp;

    Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming ...

  15. The effect of beta-turn structure on the permeation of peptides across monolayers of bovine brain microvessel endothelial cells

    DEFF Research Database (Denmark)

    Sorensen, M; Steenberg, B; Knipp, G T;

    1997-01-01

    PURPOSE: To investigate the effects of the beta-turn structure of a peptide on its permeation via the paracellular and transcellular routes across cultured bovine brain microvessel endothelial cell (BBMEC) monolayers, an in vitro model of the blood-brain barrier (BBB). METHODS: The effective...

  16. The role of shear stress in Blood-Brain Barrier endothelial physiology

    Directory of Open Access Journals (Sweden)

    Puvenna Vikram

    2011-05-01

    Full Text Available Abstract Background One of the most important and often neglected physiological stimuli contributing to the differentiation of vascular endothelial cells (ECs into a blood-brain barrier (BBB phenotype is shear stress (SS. With the use of a well established humanized dynamic in vitro BBB model and cDNA microarrays, we have profiled the effect of SS in the induction/suppression of ECs genes and related functions. Results Specifically, we found a significant upregulation of tight and adherens junctions proteins and genes. Trans-endothelial electrical resistance (TEER and permeability measurements to know substances have shown that SS promoted the formation of a tight and highly selective BBB. SS also increased the RNA level of multidrug resistance transporters, ion channels, and several p450 enzymes. The RNA level of a number of specialized carrier-mediated transport systems (e.g., glucose, monocarboxylic acid, etc. was also upregulated. RNA levels of modulatory enzymes of the glycolytic pathway (e.g., lactate dehydrogenase were downregulated by SS while those involved in the Krebs cycle (e.g., lactate and other dehydrogenases were upregulated. Measurements of glucose consumption versus lactate production showed that SS negatively modulated the glycolytic bioenergetic pathways of glucose metabolism in favor of the more efficient aerobic respiration. BBB ECs are responsive to inflammatory stimuli. Our data showed that SS increased the RNA levels of integrins and vascular adhesion molecules. SS also inhibited endothelial cell cycle via regulation of BTG family proteins encoding genes. This was paralleled by significant increase in the cytoskeletal protein content while that of membrane, cytosol, and nuclear sub-cellular fractions decreased. Furthermore, analysis of 2D gel electrophoresis (which allows identifying a large number of proteins per sample of EC proteins extracted from membrane sub-cellular endothelial fractions showed that SS increased

  17. Gene delivery of the therapeutic polypeptide erythropoietin to primary brain capillary endothelial cells for protein secretion

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Moos, Torben

    2016-01-01

    , however, recently shown that non-viral gene therapy to non-mitotic BCECs cultured in an in-vitro BBB model was possible without disrupting the barrier properties of the BCECs, and that this was as effective as transfection of dividing BCECs. The transfection efficiency is, however, low, questioning...

  18. Vascular endothelial growth factors enhance the permeability of the mouse blood-brain barrier.

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    Shize Jiang

    Full Text Available The blood-brain barrier (BBB impedes entry of many drugs into the brain, limiting clinical efficacy. A safe and efficient method for reversibly increasing BBB permeability would greatly facilitate central nervous system (CNS drug delivery and expand the range of possible therapeutics to include water soluble compounds, proteins, nucleotides, and other large molecules. We examined the effect of vascular endothelial growth factor (VEGF on BBB permeability in Kunming (KM mice. Human VEGF165 was administered to treatment groups at two concentrations (1.6 or 3.0 µg/mouse, while controls received equal-volume saline. Changes in BBB permeability were measured by parenchymal accumulation of the contrast agent Gd-DTPA as assessed by 7 T magnetic resonance imaging (MRI. Mice were then injected with Evans blue, sacrificed 0.5 h later, and perfused transcardially. Brains were removed, fixed, and sectioned for histological study. Both VEGF groups exhibited a significantly greater signal intensity from the cerebral cortex and basal ganglia than controls (P<0.001. Evans blue fluorescence intensity was higher in the parenchyma and lower in the cerebrovasculature of VEGF-treated animals compared to controls. No significant brain edema was observed by diffusion weighted MRI (DWI or histological staining. Exogenous application of VEGF can increase the permeability of the BBB without causing brain edema. Pretreatment with VEGF may be a feasible method to facilitate drug delivery into the CNS.

  19. Endocytosis and intracellular processing of platelet microparticles by brain endothelial cells.

    Science.gov (United States)

    Faille, Dorothée; El-Assaad, Fatima; Mitchell, Andrew J; Alessi, Marie-Christine; Chimini, Giovanna; Fusai, Thierry; Grau, Georges E; Combes, Valéry

    2012-08-01

    Platelet-derived microparticles (PMP) bind and modify the phenotype of many cell types including endothelial cells. Recently, we showed that PMP were internalized by human brain endothelial cells (HBEC). Here we intend to better characterize the internalization mechanisms of PMP and their intracellular fate. Confocal microscopy analysis of PKH67-labelled PMP distribution in HBEC showed PMP in early endosome antigen 1 positive endosomes and in LysoTracker-labelled lysosomes, confirming a role for endocytosis in PMP internalization. No fusion of calcein-loaded PMP with HBEC membranes was observed. Quantification of PMP endocytosis using flow cytometry revealed that it was partially inhibited by trypsin digestion of PMP surface proteins and by extracellular Ca(2+) chelation by EDTA, suggesting a partial role for receptor-mediated endocytosis in PMP uptake. This endocytosis was independent of endothelial receptors such as intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 and was not increased by tumour necrosis factor stimulation of HBEC. Platelet-derived microparticle internalization was dramatically increased in the presence of decomplemented serum, suggesting a role for PMP opsonin-dependent phagocytosis. Platelet-derived microparticle uptake was greatly diminished by treatment of HBEC with cytochalasin D, an inhibitor of microfilament formation required for both phagocytosis and macropinocytosis, with methyl-β-cyclodextrin that depletes membrane cholesterol needed for macropinocytosis and with amiloride that inhibits the Na(+)/H(+) exchanger involved in macropinocytosis. In conclusion, PMP are taken up by active endocytosis in HBEC, involving mechanisms consistent with both phagocytosis and macropinocytosis. These findings identify new processes by which PMP could modify endothelial cell phenotype and functions.

  20. Modulation of cellular adhesion in bovine brain microvessel endothelial cells by a decapeptide.

    Science.gov (United States)

    Pal, D; Audus, K L; Siahaan, T J

    1997-01-30

    The importance of cell adhesion molecules in maintaining the cellular integrity of the endothelial layer is well recognized, yet their exact participation in regulating the blood-brain barrier (BBB) is poorly understood. Both Ca(2+)-dependent and Ca(2+)-independent cell adhesion molecules are found in endothelial cells. In this study, we used immunofluorescence, ELISA, Western blot and cell adhesion assay to identify a Ca(2+)-dependent cell adhesion molecule, E-cadherin, in bovine brain microvessel endothelial cells (BBMECs). Monoclonal anti-E-cadherin antibody specifically interacted with cultured BBMECs and decorated the cellular junctions with a series of punctate fluorescence spots as seen by indirect immunofluorescence using a confocal microscope. The intensity of these fluorescence spots increased after brief treatment with hIFN-gamma or CPT-cAMP. In the cellular extract of BBMECs, a 120 kDa protein was immunoprecipitated with anti-E-cadherin antibody. BBMECs did not react with anti-N-cadherin antibody, but recognized the FITC-labeled LRAHAVDVNG-NH2, a decapeptide generated from the EC-1 domain of N-cadherin, which decorated the lateral margins of the cells with fluorescence spots. A concentration-dependent binding of this decapeptide was also observed in the flow cytometry assay. BBMECs dissociated with trypsin plus Ca2+ were able to reaggregate only in the presence of Ca2+. However, such cell-cell aggregations of BBMECs were prevented by the presence of either anti-E-cadherin antibody or the decapeptide in the assay medium. These results confirm that BBMECs possess a distinct Ca(2+)-dependent cell adhesion mechanism that can be modulated by the decapeptide. This modulation of cell-cell adhesion in BBMECs by the decapeptide is thought-provoking for creating channels for paracellular drug delivery across the BBB.

  1. Ethanol suppression of peripheral blood mononuclear cell trafficking across brain endothelial cells in immunodeficiency virus infection

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    Lola C Hudson

    2010-01-01

    Full Text Available Lola C Hudson1, Brenda A Colby1, Rick B Meeker21Department of Molecular Biosciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; 2Department of Neurology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USAAbstract: Earlier studies suggested that the combination of alcohol use and immunodeficiency virus infection resulted in more severe neurologic disease than either condition individually. These deleterious interactions could be due to increased immune cell and virus trafficking or may result from interactions between ethanol and human immunodeficiency virus (HIV-associated toxicity within the brain. To determine the extent to which increased trafficking played a role, we examined the effect of ethanol on the migration of different peripheral blood mononuclear cell (PBMCs subsets across a brain endothelial cell monolayer. We utilized combinations of feline brain endothelial cells with astrocytes, and/or microglia with either acute exposure to 0.08 g/dL ethanol, a combination of ethanol and feline immunodeficiency virus (FIV, or FIV alone. Adherence of PBMCs to endothelium was increased in all combinations of cells with the addition of ethanol. Despite increased PBMC adhesion with ethanol treatment, transmigration of B cells, monocytes, CD4 T cells and CD8 T cells was not increased and was actually decreased in the presence of astrocytes. Expression of three common adhesion molecules, intercellular adhesion molecule-1 (ICAM1, ICAM2, and vascular cell adhesion molecule, was unchanged or slightly decreased by ethanol. This indicated that although adherence is increased by ethanol it is not due to an increased expression of adhesion molecules. RANTES, MIP1α, MIP1β, and MCP-1 mRNA expression was also studied in brain endothelial cells, astrocytes and microglia by reverse transcriptase-polymerase chain reaction. Ethanol treatment of astrocytes resulted in modest changes of

  2. Adhesive properties of Enterobacter sakazakii to human epithelial and brain microvascular endothelial cells

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    Pospischil Andreas

    2006-06-01

    Full Text Available Abstract Background Enterobacter sakazakii is an opportunistic pathogen that has been associated with sporadic cases and outbreaks causing meningitis, necrotizing enterocolitis and sepsis especially in neonates. However, up to now little is known about the mechanisms of pathogenicity in E. sakazakii. A necessary state in the successful colonization, establishment and ultimately production of disease by microbial pathogens is the ability to adhere to host surfaces such as mucous membranes, gastric and intestinal epithelial or endothelial tissue. This study examined for the first time the adherence ability of 50 E. sakazakii strains to the two epithelial cell lines HEp-2 and Caco-2, as well as the brain microvascular endothelial cell line HBMEC. Furthermore, the effects of bacterial culture conditions on the adherence behaviour were investigated. An attempt was made to characterize the factors involved in adherence. Results Two distinctive adherence patterns, a diffuse adhesion and the formation of localized clusters of bacteria on the cell surface could be distinguished on all three cell lines. In some strains, a mixture of both patterns was observed. Adherence was maximal during late exponential phase, and increased with higher MOI. The adhesion capacity of E. sakazakii to HBMEC cells was affected by the addition of blood to the bacteria growth medium. Mannose, hemagglutination, trypsin digestion experiments and transmission electron microscopy suggested that the adhesion of E. sakazakii to the epithelial and endothelial cells is mainly non-fimbrial based. Conclusion Adherence experiments show heterogeneity within different E. sakazakii strains. In agreement with studies on E. cloacae, we found no relationship between the adhesive capacities in E. sakazakii and the eventual production of specific fimbriae. Further studies will have to be carried out in order to determine the adhesin(s involved in the interaction of E. sakazakii with cells and to

  3. Modulation of P-glycoprotein function by amlodipine derivatives in brain microvessel endothelial cells of rats

    Institute of Scientific and Technical Information of China (English)

    Bian-sheng JI; Ling HE; Guo-qing LIU

    2005-01-01

    Aim: To investigate whether the amlodipine derivatives, CJX1 and CJX2, have a modulative effect on P-glycoprotein (P-gp) function in rat brain microvessel endothelial cells (RBMEC). Methods: Isolated RBMEC were cultured in DMEM/ F1 2 (1:1) medium. The amount of intracellular rhodamine (Rh 123) was determined, using a fluorescence spectrophotometer, to evaluate the function of P-gp. Results:The accumulation of Rh123 in RBMEC was potentiated in a concentrationdependent manner after incubation with CJX1 and CJX2 at 1, 2.5, 5, and 10μmol/L (P<0.01), but no accumulation of Rh123 was observed in human umbilical vein endothelial cells after incubation with CJX1 and CJX2 10 μmol/L (P>0.05). Accumulation of intracellular Rh123 was increased and efflux of intracellular Rh123 was decreased in a time-dependent manner from 0-100 min after CJX1 and CXJ2 at 10 μmol/L treatment. The inhibitory effect of CJX1 and CJX2 on P-gp function was reversible and remained even at 120 min after removal of CJX1 and CJX2 at 2.5 μmol/L from the medium. Conclusion: CJX1 and CJX2 exhibited a potent effect in the inhibition of P-gp function in vitro.

  4. Tetramethylpyrazine Protects Retinal Capillary Endothelial Cells (TR-iBRB2 against IL-1β-Induced Nitrative/Oxidative Stress

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    Xue Zhu

    2015-09-01

    Full Text Available Blood-retinal barrier (BRB breakdown is one of the primary causes of diabetic retinopathy (DR. The pro-inflammatory factor interleukin-1β (IL-1β was reported to be involved in the induction of BRB breakdown during the pathogenesis of DR. In the present study, we investigated the protective effect of tetramethylpyrazine (TMP, a major active component of the traditional herb Ligusticum chuanxiong, on IL-1β-induced cell death of the rat retinal capillary endothelial TR-iBRB2 cells. Our results showed that IL-1β-induced cell dysfunction in TR-iBRB2 cells via inducing nitrative/oxidative stress; however, such effect was attenuated with the pre-treatment of TMP. The cellular protective effect of TMP was likely to be mediated through the inhibition of inducible nitric oxide synthase (iNOS expression and leukostasis as well as suppression of reactive oxygen species (ROS generation, mitochondrial dysfunction and MAPKs activation. These findings significantly contribute to a better understanding of the protective effect of TMP in DR and form the basis of the therapeutic development of TMP in treating such disease in the future.

  5. Interesterified fat or palm oil as substitutes for partially hydrogenated fat during the perinatal period produces changes in the brain fatty acids profile and increases leukocyte-endothelial interactions in the cerebral microcirculation from the male offspring in adult life.

    Science.gov (United States)

    Misan, Vanessa; Estato, Vanessa; de Velasco, Patricia Coelho; Spreafico, Flavia Brasil; Magri, Tatiana; Dos Santos, Raísa Magno de Araújo Ramos; Fragoso, Thaiza; Souza, Amanda S; Boldarine, Valter Tadeu; Bonomo, Isabela T; Sardinha, Fátima L C; Oyama, Lila M; Tibiriçá, Eduardo; Tavares do Carmo, Maria das Graças

    2015-08-01

    We investigated whether maternal intake of normolipidic diets with distinct fatty acid (FA) compositions alters the lipidic profile and influences the inflammatory status of the adult offsprings׳ brains. C57BL/6 female mice during pregnancy and lactation received diets containing either soybean oil (CG), partially hydrogenated vegetable fat rich in trans-fatty acids (TG), palm oil (PG), or interesterified fat (IG). After weaning, male offspring from all groups received control diet. The FA profile was measured in the offspring׳s brains at post-natal days 21 and 90. Brain functional capillary density as well as leukocyte-endothelial interactions in the cerebral post-capillary venules was assessed by intravital fluorescence microscopy at post-natal day 90. Inflammation signaling was evaluated through toll-like receptor 4 (TLR4) content in brain of the adult offspring. In the 21-day old offspring, the brains of the TG showed higher levels of trans FA and reduced levels of linoleic acid (LA) and total n-6 polyunsaturated fatty acids (PUFA). At post-natal day 90, TG and IG groups showed reduced levels of eicosapentaenoic acid (EPA) and total n-3 PUFA tended to be lower compared to CG. The offspring׳s brains exhibited an altered microcirculation with increased leukocyte rolling in groups TG, PG and IG and in TG group increased leukocyte adhesion. The TLR4 content of TG, IG and PG groups only tended to increase (23%; 20% and 35%, respectively). Maternal consumption of trans FA, palm oil or interesterified fat during pregnancy and lactation can trigger the initial steps of inflammatory pathways in the brain of offspring in adulthood.

  6. Destruction of human microvascular endothelial cell capillary-like microtubules by Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Quinn, F D; Weyant, R S; Candal, F J; Ades, E W

    1994-01-01

    When grown in the presence of Matrigel, monolayers of an immortalized human microvascular cell line (HMEC-1) form capillary-like microtubule networks. Previous work, using HMEC-1 monolayers, demonstrated a significant difference in in vitro cytotoxicity between Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius (HAE) strains and non-BPF-associated HAE strains. The present study demonstrates that BPF-related cytotoxic differences can also be observed in HMEC-1 microtubule networks. At a multiplicity of infection (MOI) of 2 x 10(-2) bacteria/tissue culture cell, BPF-associated strain F3031 disrupted the microtubule network, producing random clumps of rounded cells at 48 h of incubation. Infection with non-BPF-associated strain F1947 at the same MOI produced no observable microtubule disruption. The ability of HMEC-1 microtubule model to differentiate virulent and avirulent HAE in vitro will further aid in the study of BPF pathogenesis. In addition, the fact that the HMEC-1 cells can be induced to form microtubules make it an excellent model system for the general study of many of the agents of vascular purpura.

  7. Decreased plasma brain-derived neurotrophic factor and vascular endothelial growth factor concentrations during military training.

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    Go Suzuki

    Full Text Available Decreased concentrations of plasma brain-derived neurotrophic factor (BDNF and serum BDNF have been proposed to be a state marker of depression and a biological indicator of loaded psychosocial stress. Stress evaluations of participants in military mission are critically important and appropriate objective biological parameters that evaluate stress are needed. In military circumstances, there are several problems to adopt plasma BDNF concentration as a stress biomarker. First, in addition to psychosocial stress, military missions inevitably involve physical exercise that increases plasma BDNF concentrations. Second, most participants in the mission do not have adequate quality or quantity of sleep, and sleep deprivation has also been reported to increase plasma BDNF concentration. We evaluated plasma BDNF concentrations in 52 participants on a 9-week military mission. The present study revealed that plasma BDNF concentration significantly decreased despite elevated serum enzymes that escaped from muscle and decreased quantity and quality of sleep, as detected by a wearable watch-type sensor. In addition, we observed a significant decrease in plasma vascular endothelial growth factor (VEGF during the mission. VEGF is also neurotrophic and its expression in the brain has been reported to be up-regulated by antidepressive treatments and down-regulated by stress. This is the first report of decreased plasma VEGF concentrations by stress. We conclude that decreased plasma concentrations of neurotrophins can be candidates for mental stress indicators in actual stressful environments that include physical exercise and limited sleep.

  8. The surface-anchored NanA protein promotes pneumococcal brain endothelial cell invasion.

    Science.gov (United States)

    Uchiyama, Satoshi; Carlin, Aaron F; Khosravi, Arya; Weiman, Shannon; Banerjee, Anirban; Quach, Darin; Hightower, George; Mitchell, Tim J; Doran, Kelly S; Nizet, Victor

    2009-08-31

    In humans, Streptococcus pneumoniae (SPN) is the leading cause of bacterial meningitis, a disease with high attributable mortality and frequent permanent neurological sequelae. The molecular mechanisms underlying the central nervous system tropism of SPN are incompletely understood, but include a primary interaction of the pathogen with the blood-brain barrier (BBB) endothelium. All SPN strains possess a gene encoding the surface-anchored sialidase (neuraminidase) NanA, which cleaves sialic acid on host cells and proteins. Here, we use an isogenic SPN NanA-deficient mutant and heterologous expression of the protein to show that NanA is both necessary and sufficient to promote SPN adherence to and invasion of human brain microvascular endothelial cells (hBMECs). NanA-mediated hBMEC invasion depends only partially on sialidase activity, whereas the N-terminal lectinlike domain of the protein plays a critical role. NanA promotes SPN-BBB interaction in a murine infection model, identifying the protein as proximal mediator of CNS entry by the pathogen.

  9. Cocaine inhibits store-operated Ca2+ entry in brain microvascular endothelial cells: critical role for sigma-1 receptors.

    Science.gov (United States)

    Brailoiu, G Cristina; Deliu, Elena; Console-Bram, Linda M; Soboloff, Jonathan; Abood, Mary E; Unterwald, Ellen M; Brailoiu, Eugen

    2016-01-01

    Sigma-1 receptor (Sig-1R) is an intracellular chaperone protein with many ligands, located at the endoplasmic reticulum (ER). Binding of cocaine to Sig-1R has previously been found to modulate endothelial functions. In the present study, we show that cocaine dramatically inhibits store-operated Ca(2+) entry (SOCE), a Ca(2+) influx mechanism promoted by depletion of intracellular Ca(2+) stores, in rat brain microvascular endothelial cells (RBMVEC). Using either Sig-1R shRNA or pharmacological inhibition with the unrelated Sig-1R antagonists BD-1063 and NE-100, we show that cocaine-induced SOCE inhibition is dependent on Sig-1R. In addition to revealing new insight into fundamental mechanisms of cocaine-induced changes in endothelial function, these studies indicate an unprecedented role for Sig-1R as a SOCE inhibitor.

  10. Brain Endothelial Cells Produce Amyloid β from Amyloid Precursor Protein 770 and Preferentially Secrete the O-Glycosylated Form*

    Science.gov (United States)

    Kitazume, Shinobu; Tachida, Yuriko; Kato, Masaki; Yamaguchi, Yoshiki; Honda, Takashi; Hashimoto, Yasuhiro; Wada, Yoshinao; Saito, Takashi; Iwata, Nobuhisa; Saido, Takaomi; Taniguchi, Naoyuki

    2010-01-01

    Deposition of amyloid β (Aβ) in the brain is closely associated with Alzheimer disease (AD). Aβ is generated from amyloid precursor protein (APP) by the actions of β- and γ-secretases. In addition to Aβ deposition in the brain parenchyma, deposition of Aβ in cerebral vessel walls, termed cerebral amyloid angiopathy, is observed in more than 80% of AD individuals. The mechanism for how Aβ accumulates in blood vessels remains largely unknown. In the present study, we show that brain endothelial cells expressed APP770, a differently spliced APP mRNA isoform from neuronal APP695, and produced Aβ40 and Aβ42. Furthermore, we found that the endothelial APP770 had sialylated core 1 type O-glycans. Interestingly, Ο-glycosylated APP770 was preferentially processed by both α- and β-cleavage and secreted into the media, suggesting that O-glycosylation and APP processing involved related pathways. By immunostaining human brain sections with an anti-APP770 antibody, we found that APP770 was expressed in vascular endothelial cells. Because we were able to detect O-glycosylated sAPP770β in human cerebrospinal fluid, this unique soluble APP770β has the potential to serve as a marker for cortical dementias such as AD and vascular dementia. PMID:20952385

  11. Differential roles for endothelial ICAM-1, ICAM-2, and VCAM-1 in shear-resistant T cell arrest, polarization, and directed crawling on blood-brain barrier endothelium.

    Science.gov (United States)

    Steiner, Oliver; Coisne, Caroline; Cecchelli, Roméo; Boscacci, Rémy; Deutsch, Urban; Engelhardt, Britta; Lyck, Ruth

    2010-10-15

    Endothelial ICAM-1 and ICAM-2 were shown to be essential for T cell diapedesis across the blood-brain barrier (BBB) in vitro under static conditions. Crawling of T cells prior to diapedesis was only recently revealed to occur preferentially against the direction of blood flow on the endothelial surface of inflamed brain microvessels in vivo. Using live cell-imaging techniques, we prove that Th1 memory/effector T cells predominantly crawl against the direction of flow on the surface of BBB endothelium in vitro. Analysis of T cell interaction with wild-type, ICAM-1-deficient, ICAM-2-deficient, or ICAM-1 and ICAM-2 double-deficient primary mouse brain microvascular endothelial cells under physiological flow conditions allowed us to dissect the individual contributions of endothelial ICAM-1, ICAM-2, and VCAM-1 to shear-resistant T cell arrest, polarization, and crawling. Although T cell arrest was mediated by endothelial ICAM-1 and VCAM-1, T cell polarization and crawling were mediated by endothelial ICAM-1 and ICAM-2 but not by endothelial VCAM-1. Therefore, our data delineate a sequential involvement of endothelial ICAM-1 and VCAM-1 in mediating shear-resistant T cell arrest, followed by endothelial ICAM-1 and ICAM-2 in mediating T cell crawling to sites permissive for diapedesis across BBB endothelium.

  12. Effects of flow on LOX-1 and oxidized low-density lipoprotein interactions in brain endothelial cell cultures.

    Science.gov (United States)

    Mao, Xiaoou; Xie, Lin; Greenberg, David A

    2015-12-01

    Fluid shear stress and uptake of oxidized low-density lipoprotein (ox-LDL) into the vessel wall both contribute to atherosclerosis, but the relationship between shear stress and ox-LDL uptake is unclear. We examined the effects of flow, induced by orbital rotation of bEnd.3 brain endothelial cell cultures for 1 wk, on ox-LDL receptor (LOX-1) protein expression, ox-LDL uptake and ox-LDL toxicity. Orbitally rotated cultures showed no changes in LOX-1 protein expression, ox-LDL uptake or ox-LDL toxicity, compared to stationary cultures. Flow alone does not modify ox-LDL/LOX-1 signaling in bEnd.3 brain endothelial cells in vitro, suggesting that susceptibility of atheroprone vascular sites to lipid accumulation is not due solely to effects of altered flow on endothelium.

  13. Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes.

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    Chia-Yi Tseng

    Full Text Available Exposure to diesel exhaust particles (DEP is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

  14. Protease activated receptor signaling is required for African trypanosome traversal of human brain microvascular endothelial cells.

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    Dennis J Grab

    Full Text Available BACKGROUND: Using human brain microvascular endothelial cells (HBMECs as an in vitro model for how African trypanosomes cross the human blood-brain barrier (BBB we recently reported that the parasites cross the BBB by generating calcium activation signals in HBMECs through the activity of parasite cysteine proteases, particularly cathepsin L (brucipain. In the current study, we examined the possible role of a class of protease stimulated HBMEC G protein coupled receptors (GPCRs known as protease activated receptors (PARs that might be implicated in calcium signaling by African trypanosomes. METHODOLOGY/PRINCIPAL FINDINGS: Using RNA interference (RNAi we found that in vitro PAR-2 gene (F2RL1 expression in HBMEC monolayers could be reduced by over 95%. We also found that the ability of Trypanosoma brucei rhodesiense to cross F2RL1-silenced HBMEC monolayers was reduced (39%-49% and that HBMECs silenced for F2RL1 maintained control levels of barrier function in the presence of the parasite. Consistent with the role of PAR-2, we found that HBMEC barrier function was also maintained after blockade of Galpha(q with Pasteurella multocida toxin (PMT. PAR-2 signaling has been shown in other systems to have neuroinflammatory and neuroprotective roles and our data implicate a role for proteases (i.e. brucipain and PAR-2 in African trypanosome/HBMEC interactions. Using gene-profiling methods to interrogate candidate HBMEC pathways specifically triggered by brucipain, several pathways that potentially link some pathophysiologic processes associated with CNS HAT were identified. CONCLUSIONS/SIGNIFICANCE: Together, the data support a role, in part, for GPCRs as molecular targets for parasite proteases that lead to the activation of Galpha(q-mediated calcium signaling. The consequence of these events is predicted to be increased permeability of the BBB to parasite transmigration and the initiation of neuroinflammation, events precursory to CNS disease.

  15. Quercetin protects human brain microvascular endothelial cells from fibrillar β-amyloid1–40-induced toxicity

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    Yongjie Li

    2015-01-01

    Full Text Available Amyloid beta-peptides (Aβ are known to undergo active transport across the blood-brain barrier, and cerebral amyloid angiopathy has been shown to be a prominent feature in the majority of Alzheimer׳s disease. Quercetin is a natural flavonoid molecule and has been demonstrated to have potent neuroprotective effects, but its protective effect on endothelial cells under Aβ-damaged condition is unclear. In the present study, the protective effects of quercetin on brain microvascular endothelial cells injured by fibrillar Aβ1–40 (fAβ1–40 were observed. The results show that fAβ1–40-induced cytotoxicity in human brain microvascular endothelial cells (hBMECs can be relieved by quercetin treatment. Quercetin increases cell viability, reduces the release of lactate dehydrogenase, and relieves nuclear condensation. Quercetin also alleviates intracellular reactive oxygen species generation and increases superoxide dismutase activity. Moreover, it strengthens the barrier integrity through the preservation of the transendothelial electrical resistance value, the relief of aggravated permeability, and the increase of characteristic enzyme levels after being exposed to fAβ1–40. In conclusion, quercetin protects hBMECs from fAβ1–40-induced toxicity.

  16. P. falciparum isolate-specific distinct patterns of induced apoptosis in pulmonary and brain endothelial cells.

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    Nadine N'Dilimabaka

    Full Text Available The factors implicated in the transition from uncomplicated to severe clinical malaria such as pulmonary oedema and cerebral malaria remain unclear. It is known that alterations in vascular integrity due to endothelial cell (EC activation and death occur during severe malaria. In this study, we assessed the ability of different P. falciparum clinical isolates to induce apoptosis in ECs derived from human lung and brain. We observed that induction of EC apoptosis was sensitive to the environmental pH and required direct contact between the parasite and the cell, though it was not correlated to the ability of the parasite to cytoadhere. Moreover, the extent of induced apoptosis in the two EC types varied with the isolate. Analysis of parasite genes transcript led us to propose that the activation of different pathways, such as Plasmodium apoptosis-linked pathogenicity factors (PALPF, PALPF-2, PALPF-5 and PF11_0521, could be implied in EC death. These observations provide an experimental framework to decipher the molecular mechanism implicated in the genesis of severe malaria.

  17. Vascular endothelial growth factor-dependent angiogenesis and dynamic vascular plasticity in the sensory circumventricular organs of adult mouse brain.

    Science.gov (United States)

    Morita, Shoko; Furube, Eriko; Mannari, Tetsuya; Okuda, Hiroaki; Tatsumi, Kouko; Wanaka, Akio; Miyata, Seiji

    2015-03-01

    The sensory circumventricular organs (CVOs), which comprise the organum vasculosum of the lamina terminalis (OVLT), the subfornical organ (SFO) and the area postrema (AP), lack a typical blood-brain barrier (BBB) and monitor directly blood-derived information to regulate body fluid homeostasis, inflammation, feeding and vomiting. Until now, almost nothing has been documented about vascular features of the sensory CVOs except fenestration of vascular endothelial cells. We therefore examine whether continuous angiogenesis occurs in the sensory CVOs of adult mouse. The angiogenesis-inducing factor vascular endothelial growth factor-A (VEGF-A) and the VEGF-A-regulating transcription factor hypoxia-inducible factor-1α were highly expressed in neurons of the OVLT and SFO and in both neurons and astrocytes of the AP. Expression of the pericyte-regulating factor platelet-derived growth factor B was high in astrocytes of the sensory CVOs. Immunohistochemistry of bromodeoxyuridine and Ki-67, a nuclear protein that is associated with cellular proliferation, revealed active proliferation of endothelial cells. Moreover, immunohistochemistry of caspase-3 and the basement membrane marker laminin showed the presence of apoptosis and sprouting of endothelial cells, respectively. Treatment with the VEGF receptor-associated tyrosine kinase inhibitor AZD2171 significantly reduced proliferation and filopodia sprouting of endothelial cells, as well as the area and diameter of microvessels. The mitotic inhibitor cytosine-b-D-arabinofuranoside reduced proliferation of endothelial cells and the vascular permeability of blood-derived low-molecular-weight molecules without changing vascular area and microvessel diameter. Thus, our data indicate that continuous angiogenesis is dependent on VEGF signaling and responsible for the dynamic plasticity of vascular structure and permeability.

  18. Exposure to lipopolysaccharide and/or unconjugated bilirubin impair the integrity and function of brain microvascular endothelial cells.

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    Filipa L Cardoso

    Full Text Available BACKGROUND: Sepsis and jaundice are common conditions in newborns that can lead to brain damage. Though lipopolysaccharide (LPS is known to alter the integrity of the blood-brain barrier (BBB, little is known on the effects of unconjugated bilirubin (UCB and even less on the joint effects of UCB and LPS on brain microvascular endothelial cells (BMEC. METHODOLOGY/PRINCIPAL FINDINGS: Monolayers of primary rat BMEC were treated with 1 µg/ml LPS and/or 50 µM UCB, in the presence of 100 µM human serum albumin, for 4 or 24 h. Co-cultures of BMEC with astroglial cells, a more complex BBB model, were used in selected experiments. LPS led to apoptosis and UCB induced both apoptotic and necrotic-like cell death. LPS and UCB led to inhibition of P-glycoprotein and activation of matrix metalloproteinases-2 and -9 in mono-cultures. Transmission electron microscopy evidenced apoptotic bodies, as well as damaged mitochondria and rough endoplasmic reticulum in BMEC by either insult. Shorter cell contacts and increased caveolae-like invaginations were noticeable in LPS-treated cells and loss of intercellular junctions was observed upon treatment with UCB. Both compounds triggered impairment of endothelial permeability and transendothelial electrical resistance both in mono- and co-cultures. The functional changes were confirmed by alterations in immunostaining for junctional proteins β-catenin, ZO-1 and claudin-5. Enlargement of intercellular spaces, and redistribution of junctional proteins were found in BMEC after exposure to LPS and UCB. CONCLUSIONS: LPS and/or UCB exert direct toxic effects on BMEC, with distinct temporal profiles and mechanisms of action. Therefore, the impairment of brain endothelial integrity upon exposure to these neurotoxins may favor their access to the brain, thus increasing the risk of injury and requiring adequate clinical management of sepsis and jaundice in the neonatal period.

  19. Effects of Neospora caninum infection on brain microvascular endothelial cells bioenergetics

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    Elsheikha Hany M

    2013-01-01

    Full Text Available Abstract Background The brain is the most commonly affected organ during Neospora caninum infection but the mechanisms utilized by this protozoan parasite for traversal of the blood–brain barrier (BBB are not yet understood. Herein, we investigate the cellular pathogenicity of N. caninum infection on bioenergetics of human brain microvascular endothelial cells (HBMECs, a fundamental component of the BBB. Methods We tracked the growth kinetics of N. caninum in HBMECs. Focusing on cell bioenergetics, oxygen consumption rate (OCR was determined using Clark electrode system and mitochondrial membrane potential (ΔΨm was evaluated using DePsipher staining by fluorescence microscopy in the presence and absence of infection. Results HBMECs provided a receptive environment for parasite proliferation. N. caninum tachyzoites were able to invade and replicate within HBMECs without significantly altering cell proliferation rate, as measured with the MTT assay, up to 24 hr post infection (pi. The oxygen consumption rate (OCR was significantly inhibited (p 6 cell min-1 and from −0.29±0.09 to −0.16±0.1 nmol 106 cell min-1 for uninfected HBMECs and free N. Caninum tachyzoites, respectively]. After normalization for DNA content the basal OCR did not differ between two host cell types: HBMECs and K562. The OCR of HBMECs was significantly elevated 24 hr pi in the absence of substrate, in 10 mM glucose and in the presence of a tetramethyl-p-phenylenediamine (TMPD/ascorbate redox shuttle. Although quantitatively similar results were observed for uninfected K562 cells, there was no effect on their OCR 24 hr pi with N. caninum under any of the above substrate conditions. 6mM azide abolished OCR in all situations. Mitochondrial staining with DePsipher indicated no change in their membrane potential (Δψm up to 24 hr pi. Conclusions N. caninum is able to grow in HBMECs without markedly disrupting their normal proliferation or mitochondrial integrity. However

  20. Irradiation of rat brain reduces P-glycoprotein expression and function

    OpenAIRE

    Bart, J.; Nagengast, W B; Coppes, R P; Wegman, T D; van der Graaf, W T A; Groen, H J M; Vaalburg, W; de Vries, E G E; Hendrikse, N.H.

    2007-01-01

    The blood–brain barrier (BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P-glycoprotein (P-gp), expressed on brain capillary endothelial cells, is part of the BBB. P-gp expression on capillary endothelium decreases 5 days after brain irradiation, which may reduce P-gp function and increase brain levels of P-gp substrates. To elucidate whether radiation therapy reduces P-gp expression and function in the brain, right hemispheres of rats wer...

  1. Endomorphins exit the brain by a saturable efflux system at the basolateral surface of cerebral endothelial cells.

    Science.gov (United States)

    Somogyvari-Vigh, Aniko; Kastin, Abba J; Liao, Jie; Zadina, James E; Pan, Weihong

    2004-05-01

    Endomorphin-1 (EM-1) and endomorphin-2 (EM-2) are two highly selective mu-opiate receptor agonists. We recently demonstrated that EM-1 and EM-2 have a saturable transport system from brain-to-blood in vivo. Since the endothelial cells are the main component of the non-fenestrated microvessels of the blood-brain barrier (BBB), we examined whether these endogenous tetrapeptides have a saturable transport system in cultured cerebral endothelial cells. EM-1 and EM-2 binding and transport were studied in a transwell system in which primary mouse endothelial cells were co-cultured with rat glioma cells. We found that binding of both endomorphins was greater on the basolateral than the apical cell surface. Flux of EM-1 and EM-2 occurred predominantly in the basolateral to apical direction, each showing self-inhibition with an excess of the respective endomorphin. Transport was not influenced by the addition of the P-glycoprotein inhibitor, cyclosporin A. Neither the mu-opiate receptor agonist DAMGO nor the delta-opiate receptor agonist DPDPE had any effect on the transport. Thus, the results show that a saturable transport system for EM-1 and EM-2 occurs at the level of endothelial cells of the BBB, and unlike beta-endorphin and morphine, P-glycoprotein is not needed for the brain-to-blood transport. Cross-inhibition of the transport of each endomorphin by the other suggests a shared transport system that is different from mu- or delta-opiate receptors. As endormorphins are mainly produced in the CNS, the presence of the efflux system at the BBB could play an important role in pain modulation and neuroendocrine control.

  2. Opiates Upregulate Adhesion Molecule Expression in Brain MicroVascular Endothelial Cells (BMVEC: Implications for Altered Blood Brain Barrier (BBB Permeability

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    Madhavan P.N. Nair

    2006-01-01

    Full Text Available The blood-brain barrier (BBB is an intricate cellular system composed of vascular endothelial cells and perivascular astrocytes that restrict the passage of immunocompetent cells into the central nervous system (CNS. Expression of the adhesion molecules, intercellular adhesion molecule 1 (ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1 on brain microvascular endothelial cells (BMVEC and their interaction with human immunodeficiency virus (HIV-1 viral proteins may help enhance viral adhesion and virus-cell fusion resulting in increased infectivity. Additionally, transmigration through the BBB is facilitated by both endothelial and monocyte/macrophage-derived nitric oxide (NO. Dysregulated production of NO by BMVEC due to opiates and HIV-1 viral protein interactions play a pivotal role in brain endothelial injury, resulting in the irreversible loss of BBB integrity, which may lead to enhanced infiltration of virus-carrying cells across the BBB. Opioids act as co-factors in the neuropathogenesis of HIV-1 by facilitating BBB dysfunction however, no studies have been done to investigate the role of opiates alone or in combination with HIV-1 viral proteins on adhesion molecule expression in BMVEC. We hypothesize that opiates such as heroin and morphine in conjunction with the HIV-1 viral protein gp120 increase the expression of adhesion molecules ICAM-1 and VCAM-1 and these effects are mediated via the modulation of NO. Results show that opiates alone and in synergy with gp120 increase both the genotypic and phenotypic expression of ICAM-1 and VCAM-1 by BMVEC, additionally, these opiate induced effects may be the result of increased NO production. These studies will provide a better understanding of how opiate abuse in conjunction with HIV-1 infection facilitates the breakdown of the BBB and exacerbates the neuropathogenesis of HIV-1. Elucidation of the mechanisms of BBB modulation will provide new therapeutic approaches to maintain BBB integrity

  3. Morphine induces expression of platelet-derived growth factor in human brain microvascular endothelial cells: implication for vascular permeability.

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    Hongxiu Wen

    Full Text Available Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Morphine, often abused by HIV-infected patients, is known to accelerate neuroinflammation associated with HIV-1 infection. Detailed molecular mechanisms of morphine action however, remain poorly understood. Platelet-derived growth factor (PDGF has been implicated in a number of pathological conditions, primarily due to its potent mitogenic and permeability effects. Whether morphine exposure results in enhanced vascular permeability in brain endothelial cells, likely via induction of PDGF, remains to be established. In the present study, we demonstrated morphine-mediated induction of PDGF-BB in human brain microvascular endothelial cells, an effect that was abrogated by the opioid receptor antagonist-naltrexone. Pharmacological blockade (cell signaling and loss-of-function (Egr-1 approaches demonstrated the role of mitogen-activated protein kinases (MAPKs, PI3K/Akt and the downstream transcription factor Egr-1 respectively, in morphine-mediated induction of PDGF-BB. Functional significance of increased PDGF-BB manifested as increased breach of the endothelial barrier as evidenced by decreased expression of the tight junction protein ZO-1 in an in vitro model system. Understanding the regulation of PDGF expression may provide insights into the development of potential therapeutic targets for intervention of morphine-mediated neuroinflammation.

  4. Activation of sonic hedgehog signaling attenuates oxidized low-density lipoprotein-stimulated brain microvascular endothelial cells dysfunction in vitro.

    Science.gov (United States)

    Jiang, Xiu-Long; Chen, Ting; Zhang, Xu

    2015-01-01

    The study was performed to investigate the role of sonic hedgehog (SHH) in the oxidized low-density lipoprotein (oxLDL)-induced blood-brain barrier (BBB) disruption. The primary mouse brain microvascular endothelial cells (MBMECs) were exposed to oxLDL. The results indicated that treatment of MBMECs with oxLDL decreased the cell viability, and oxidative stress was involved in oxLDL-induce MBMECs dysfunction with increasing intracellular ROS and MDA formation as well as decreasing NO release and eNOS mRNA expression. In addition, SHH signaling components, such as SHH, Smo and Gli1, mRNA and protein levels were significantly decreased after incubation with increasing concentrations of oxLDL. Treatment with oxLDL alone or SHH loss-of-function significantly increased the permeability of MBMECs, and overexpression of SHH attenuated oxLDL-induced elevation of permeability in MBMECs. Furthermore, SHH gain-of-function could reverse oxLDL-induced apoptosis through inhibition caspase3 and caspase8 levels in MBMECs. Taken together, these results demonstrated that the suppression of SHH in MBMECs might contribute to the oxLDL-induced disruption of endothelial barrier. However, the overexpression of SHH could reverse oxLDL-induced endothelial cells dysfunction in vitro.

  5. Vascular Endothelial Growth Factor and Brain-Derived Neurotropic Factor Levels in Ischemic Stroke Subject

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    Andri Hidayat

    2016-08-01

    Full Text Available BACKGROUND: Vascular endothelial growth factor (VEGF and brain-derived neurotropic factor (BDNF present during early neuronal development and play important roles in the process of neurorepairing includes angiogenesis, neurogenesis and neuronal plasticity after ischemic stroke. In this study, we observed VEGF and BDNF levels of subjects with ischemic stroke in different onset time. METHODS: A cross sectional study was designed. Study subjects were 51 ischemic stroke subjects, aged 30-80 years old, recruited from Gatot Subroto Army Central Hospital, Jakarta, Indonesia. Ischemic stroke was diagnosed by neurologist, based on clinical examination and magnetic resonance imaging (MRI result. Subjects were divided into 3 groups based on onset time of stroke: 30 days (Group C. VEGF and BDNF levels from serum were measured using lumine Magpix. The data was analyzed for comparison and correlation. RESULTS: VEGF and BDNF levels of group B and C were significantly different with p=0.034 and p=0.007, respectively. Group B had the highest VEGF levels, whereas Group C had the highest BDNF level. VEGF and BDNF levels in each group were not significantly correlated. CONCLUSION: Each stage of time after ischemic stroke has different recovery activities like angiogenesis, neurogenesis and plasticity. Angiogenesis process was optimum in 7-30 days after onset. in more than 30 days onset, Low VEGF with high BDNF have important role in a long period of time after the onset of stroke in the regeneration and repair, such as maintaining neuronal survival and plasticity. KEYWORDS: ischemic stroke, VEGF, BDNF

  6. Effect of curcumin on the adhesion of platelets to brain microvascular endothelial cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Zhen-lun GU; Zheng-hong QIN; Zhong-qin LIANG

    2008-01-01

    Aim: To determine whether curcumin prevents the adhesion of platelets to brain microvascular endothelial cells (BMECs) cultured in vitro. Methods: [3H]Ad-chine-labeled platelets were incubated with BMECs to investigate the role of curcumin in the adhesion of platelets to BMECs. The number of platelets adher-ing to the BMECs monolayer was determined by liquid scintillation spectroscopy. The thrombin-induced expression of platelets P-selectin, glycoprotein Ⅱb (GPⅡb), and glycoprotein Ⅲa (GPⅢa) on the cell surface, was measured by flow cytometry. P-selectin mRNA levels of BMECs were determined by RT-PCR. The TNF-α-induced expressions of P-selectin and E-selectin on the surface of BMECs were determined by Western blotting. Results: The adhesion between thrombin-acti-vated platelets and normal BMECs, and that of TNF-α-activated BMECs and normal platelets were significantly increased, and this increase could be inhibited by curcumin (30-240 μmol/L) in a concentration-dependant manner. The platelets activated with thrombin and BMECs stimulated by TNF-α demonstrated an upregulated expressions of P-selectin and E-selectin, and this increase, when pretreated with curcumin for 30 min, could be restrained dose dependently. Curcumin also inhibited the increase of the GPⅡb/GPⅢa expression of thrombin-activated platelets in a concentration-dependent manner. Conclusion: Curcumin can inhibit the platelets to BMECs. This effect may be related to the decreased expressions of P-selectin, E-selectin, and GPⅡb/GPⅢa on platelets and BMECs.

  7. Reversal of ApoE4-Driven Brain Pathology by Vascular Endothelial Growth Factor Treatment.

    Science.gov (United States)

    Salomon-Zimri, Shiran; Glat, Micaela Johanna; Barhum, Yael; Luz, Ishai; Boehm-Cagan, Anat; Liraz, Ori; Ben-Zur, Tali; Offen, Daniel; Michaelson, Daniel M

    2016-06-30

    Apolipoprotein E4 (ApoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), is associated with increased neurodegeneration and vascular impairments. Vascular endothelial growth factor (VEGF), originally described as a key angiogenic factor, has recently been shown to play a crucial role in the nervous system. The objective of this research is to examine the role of VEGF in mediating the apoE4-driven pathologies. We show that hippocampal VEGF levels are lower in apoE4 targeted replacement mice compared to the corresponding apoE3 mice. This effect was accompanied by a specific decrease in both VEGF receptor-2 and HIF1-α. We next set to examine whether upregulation of VEGF can reverse apoE4-driven pathologies, namely the accumulation of hyperphosphorylated tau (AT8) and Aβ42, and reduced levels of the pre-synaptic marker, VGluT1, and of the ApoE receptor, ApoER2. This was first performed utilizing intra-hippocampal injection of VEGF-expressing-lentivirus (LV-VEGF). This revealed that LV-VEGF treatment reversed the apoE4-driven cognitive deficits and synaptic pathologies. The levels of Aβ42 and AT8, however, were increased in apoE3 mice, masking any potential effects of this treatment on the apoE4 mice. Follow-up experiments utilizing VEGF-expressing adeno-associated-virus (AAV-VEGF), which expresses VEGF specifically under the GFAP astrocytic promoter, prevented this effects on apoE3 mice, and reversed the apoE4-related increase in Aβ42 and AT8. Taken together, these results suggest that apoE4-driven pathologies are mediated by a VEGF-dependent pathway, resulting in cognitive impairments and brain pathology. These animal model findings suggest that the VEGF system is a promising target for the treatment of apoE4 carriers in AD.

  8. Mononuclear phagocyte intercellular crosstalk facilitates transmission of cell-targeted nanoformulated antiretroviral drugs to human brain endothelial cells

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    Kanmogne GD

    2012-05-01

    Full Text Available Georgette D Kanmogne1, Sangya Singh1, Upal Roy1, Xinming Liu1, JoEllyn McMillan1, Santhi Gorantla1, Shantanu Balkundi1, Nathan Smith1, Yazen Alnouti2, Nagsen Gautam2, You Zhou3, Larisa Poluektova1, Alexander Kabanov2, Tatiana Bronich2, Howard E Gendelman11Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, 2Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE; 3Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE, USAAbstract: Despite the successes of antiretroviral therapy (ART, HIV-associated neurocognitive disorders remain prevalent in infected people. This is due, in part, to incomplete ART penetration across the blood–brain barrier (BBB and lymph nodes and to the establishment of viral sanctuaries within the central nervous system. In efforts to improve ART delivery, our laboratories developed a macrophage-carriage system for nanoformulated crystalline ART (nanoART (atazanavir, ritonavir, indinavir, and efavirenz. We demonstrate that nanoART transfer from mononuclear phagocytes (MP to human brain microvascular endothelial cells (HBMEC can be realized through cell-to-cell contacts, which can facilitate drug passage across the BBB. Coculturing of donor MP containing nanoART with recipient HBMEC facilitates intercellular particle transfer. NanoART uptake was observed in up to 52% of HBMEC with limited cytotoxicity. Folate coating of nanoART increased MP to HBMEC particle transfer by up to 77%. To translate the cell assays into relevant animal models of disease, ritonavir and atazanavir nanoformulations were injected into HIV-1-infected NOD/scid-γcnull mice reconstituted with human peripheral blood lymphocytes. Atazanavir and ritonavir levels in brains of mice treated with folate-coated nanoART were three- to four-fold higher than in mice treated with noncoated particles. This was associated with decreased viral load in the spleen and

  9. T11TS inhibits Angiopoietin-1/Tie-2 signaling, EGFR activation and Raf/MEK/ERK pathway in brain endothelial cells restraining angiogenesis in glioma model.

    Science.gov (United States)

    Bhattacharya, Debanjan; Chaudhuri, Suhnrita; Singh, Manoj Kumar; Chaudhuri, Swapna

    2015-06-01

    Malignant gliomas represent one of the most aggressive and hypervascular primary brain tumors. Angiopoietin-1, the peptide growth factor activates endothelial Tie-2 receptor promoting vessel maturation and vascular stabilization steps of angiogenesis in glioma. Epidermal growth factor receptor (EGFR) and Tie-2 receptor on endothelial cells once activated transmits signals through downstream Raf/MEK/ERK pathway promoting endothelial cell proliferation and migration which are essential for angiogenesis induction. The in vivo effect of sheep erythrocyte membrane glycopeptide T11-target structure (T11TS) on angiopoietin-1/Tie-2 axis, EGFR signaling and Raf/MEK/ERK pathway in glioma associated endothelial cells has not been investigated previously. The present study performed with rodent glioma model aims to investigate the effect of T11TS treatment on angiopoietin-1/Tie-2 signaling, EGFR activity and Raf/MEK/ERK pathway in glioma associated endothelial cells within glioma milieu. T11TS administration in rodent glioma model inhibited angiopoietin-1 expression and attenuated Tie-2 expression and activation in glioma associated brain endothelial cells. T11TS treatment also downregulated total and phosphorylated EGFR expression in glioma associated endothelial cells. Additionally T11TS treatment inhibited Raf-1 expression, MEK-1 and ERK-1/2 expression and phosphorylation in glioma associated brain endothelial cells. Thus T11TS therapy remarkably inhibits endothelial angiopoietin-1/Tie-2 signaling associated with vessel maturation and simultaneously antagonizes endothelial cell proliferation signaling by blocking EGFR activation and components of Raf/MEK/ERK pathway. Collectively, the findings demonstrate a multi-targeted anti-angiogenic activity of T11TS which augments the potential for clinical translation of T11TS as an effective angiogenesis inhibitor for glioma treatment.

  10. Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier

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    Shakila Tobwala

    2014-06-01

    Full Text Available Oxidative stress, which is the loss of balance between antioxidant defense and oxidant production in the cells, is implicated in the molecular mechanism of heavy metal-induced neurotoxicity. Given the key role of lead (Pb and cadmium (Cd in inducing oxidative stress, we investigated their role in disrupting the integrity and function of immortalized human brain microvascular endothelial cells (hCMEC/D3. To study this, hCMEC/D3 cells were exposed to control media or to media containing different concentrations of Pb or Cd. Those exposed to Pb or Cd showed significantly higher oxidative stress than the untreated group, as indicated by cell viability, reactive oxygen species (ROS, glutathione (GSH levels, and catalase enzyme activity. Pb also induced oxidative stress-related disruption of the hCMEC/D3 cell monolayer, as measured by trans-endothelial electrical resistance (TEER, the dextran permeability assay, and the level of tight junction protein, zona occluden protein (ZO-2. However, no significant disruption in the integrity of the endothelial monolayer was seen with cadmium at the concentrations used. Taken together, these results show that Pb and Cd induce cell death and dysfunction in hCMEC/D3 cells and, in the case of Pb, barrier disruption. This suggests blood brain barrier (BBB dysfunction as a contributing mechanism in Pb and Cd neurotoxicities.

  11. Quantification of vascular endothelial growth factor and neuropilins mRNAs during rat brain maturation by real-time PCR.

    Science.gov (United States)

    Adris, Soraya; Ojeda, Elizabeth; Genero, Mario; Argibay, Pablo

    2005-09-01

    1. Vascular endothelial growth factor (VEGF) has been related with several brain functions such as angiogenesis, neuroprotection, and neurogenesis. 2. We studied the mRNA expression of the two most important isoforms of VEGF (VEGF120 and VEGF164) as well as one type of VEGF receptors, neuropilins (NRP), during maturation in the rat brain using real-time PCR. 3. Today, real-time PCR is the method of choice for rapid and reliable quantification of mRNA transcription. 4. VEGF120 has little changes in its expression between P5 and P30. 5. However, VEGF164 increased its expression 2-folds at P15 in comparison to P5, remaining at this level in the adult brain (P30). 6. Both types of NRP, NRP-1 and NRP-2, which only bind VEGF164, increased their expression about 2-folds only at P30, at levels similar to those observed for VEGF164.

  12. Simultaneous determination of vigabatrin and amino acid neurotransmitters in brain microdialysates by capillary electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Benturquia, Nadia; Parrot, Sandrine; Sauvinet, Valérie; Renaud, Bernard; Denoroy, Luc

    2004-07-01

    Capillary electrophoresis with laser-induced fluorescence detection (CE-LIFD) coupled to in vivo microdialysis sampling was used in order to monitor simultaneously a drug and several neurotransmitters in the brain extracellular fluid. Determination of the antiepileptic drug vigabatrin and the amino acid neurotransmitters glutamate (Glu), l-aspartate (l-Asp) and gamma-aminobutyric acid (GABA) was performed on low-concentration samples which were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) and separated using a pH 9.2 75 mM sodium borate running buffer containing 60 mM sodium dodecyl sulfate (SDS) and 5mM hydroxypropyl-beta-cyclodextrin (HP-beta-CD). Glu, l-Asp and vigabatrin derivatized at a concentration of 1.0 x 10(-9) M, and GABA derivatized at a concentration of 5.0 x 10(-9) M, produced peaks with signal-to-noise ratios of 8:1, 8:1, 4:1 and 5:1, respectively. The nature of the neurotransmitter peaks found in rat brain microdialysates was confirmed by both electrophoretic and pharmacological validations. This method was used for monitoring vigabatrin and amino acid neurotransmitters in microdialysates from the rat striatum during intracerebral infusion of the drug and revealed rapid vigabatrin-induced changes in GABA and Glu levels. This original application of CE-LIFD coupled to microdialysis represents a powerful tool for pharmacokinetic/pharmacodynamic investigations.

  13. Shear Stress Induces Differentiation of Endothelial Lineage Cells to Protect Neonatal Brain from Hypoxic-Ischemic Injury through NRP1 and VEGFR2 Signaling

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    Chia-Wei Huang

    2015-01-01

    Full Text Available Neonatal hypoxic-ischemic (HI brain injuries disrupt the integrity of neurovascular structure and lead to lifelong neurological deficit. The devastating damage can be ameliorated by preserving the endothelial network, but the source for therapeutic cells is limited. We aim to evaluate the beneficial effect of mechanical shear stress in the differentiation of endothelial lineage cells (ELCs from adipose-derived stem cells (ASCs and the possible intracellular signals to protect HI injury using cell-based therapy in the neonatal rats. The ASCs expressed early endothelial markers after biochemical stimulation of endothelial growth medium. The ELCs with full endothelial characteristics were accomplished after a subsequential shear stress application for 24 hours. When comparing the therapeutic potential of ASCs and ELCs, the ELCs treatment significantly reduced the infarction area and preserved neurovascular architecture in HI injured brain. The transplanted ELCs can migrate and engraft into the brain tissue, especially in vessels, where they promoted the angiogenesis. The activation of Akt by neuropilin 1 (NRP1 and vascular endothelial growth factor receptor 2 (VEGFR2 was important for ELC migration and following in vivo therapeutic outcomes. Therefore, the current study demonstrated importance of mechanical factor in stem cell differentiation and showed promising protection of brain from HI injury using ELCs treatment.

  14. Calcium antagonists decrease capillary wall damage in aging hypertensive rat brain

    NARCIS (Netherlands)

    Farkas, E.; de Jong, G.I.; Apro, E.; Keuker, J.I.H.; Luiten, P.G.M.

    2001-01-01

    Chronic hypertension during aging is a serious threat to the cerebral vasculature. The larger brain arteries can react to hypertension with an abnormal wall thickening, a loss of elasticity and a narrowed lumen. However, little is known about the hypertension-induced alterations of cerebral capillar

  15. NADPH OXIDASE AND LIPID RAFT-ASSOCIATED REDOX SIGNALING ARE REQUIRED FOR PCB153-INDUCED UPREGULATION OF CELL ADHESION MOLECULES IN HUMAN BRAIN ENDOTHELIAL CELLS

    Science.gov (United States)

    Eum, Sung Yong; Andras, Ibolya; Hennig, Bernhard; Toborek, Michal

    2009-01-01

    Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), can lead to chronic inflammation and the development of vascular diseases. Because cell adhesion molecules (CAMs) of the cerebrovascular endothelium regulate infiltration of inflammatory cells into the brain, we have explored the molecular mechanisms by which ortho-substituted polychlorinated biphenyls (PCBs), such as PCB153, can upregulate CAMs in brain endothelial cells. Exposure to PCB153 increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as elevated adhesion of leukocytes to brain endothelial cells. These effects were impeded by inhibitors of EGFR, JAKs, or Src activity. In addition, pharmacological inhibition of NADPH oxidase or disruption of lipid rafts by cholesterol depleting agents blocked PCB153-induced phosphorylation of JAK and Src kinases and upregulation of CAMs. In contrast, silencing of caveolin-1 by siRNA interference did not affect upregulation of ICAM-1 and VCAM-1 in brain endothelial cells stimulated by PCB153. Results of the present study indicate that lipid raft-dependent NADPH oxidase/JAK/EGFR signaling mechanisms regulate the expression of CAMs in brain endothelial cells and adhesion of leukocytes to endothelial monolayers. Due to its role in leukocyte infiltration, induction of CAMs may contribute to PCB-induced cerebrovascular disorders and neurotoxic effects in the CNS. PMID:19632255

  16. Human brain endothelial cells endeavor to immunoregulate CD8 T cells via PD-1 ligand expression in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Pittet Camille L

    2011-11-01

    Full Text Available Abstract Background Multiple sclerosis (MS, an inflammatory disease of the central nervous system (CNS, is characterized by blood-brain barrier (BBB disruption and massive infiltration of activated immune cells. Engagement of programmed cell death-1 (PD-1 expressed on activated T cells with its ligands (PD-L1 and PD-L2 suppresses T cell responses. We recently demonstrated in MS lesions elevated PD-L1 expression by glial cells and absence of PD-1 on many infiltrating CD8 T cells. We have now investigated whether human brain endothelial cells (HBECs, which maintain the BBB, can express PD-L1 or PD-L2 and thereby modulate T cells. Methods We used primary cultures of HBECs isolated from non-tumoral CNS tissue either under basal or inflamed conditions. We assessed the expression of PD-L1 and PD-L2 using qPCR and flow cytometry. Human CD8 T cells were isolated from peripheral blood of healthy donors and co-cultured with HBECs. Following co-culture with HBECs, proliferation and cytokine production by human CD8 T cells were measured by flow cytometry whereas transmigration was determined using a well established in vitro model of the BBB. The functional impact of PD-L1 and PD-L2 provided by HBECs was determined using blocking antibodies. We performed immunohistochemistry for the detection of PD-L1 or PD-L2 concurrently with caveolin-1 (a cell specific marker for endothelial cells on post-mortem human brain tissues obtained from MS patients and normal controls. Results Under basal culture conditions, PD-L2 is expressed on HBECs, whilst PD-L1 is not detected. Both ligands are up-regulated under inflammatory conditions. Blocking PD-L1 and PD-L2 leads to increased transmigration and enhanced responses by human CD8 T cells in co-culture assays. Similarly, PD-L1 and PD-L2 blockade significantly increases CD4 T cell transmigration. Brain endothelium in normal tissues and MS lesions does not express detectable PD-L1; in contrast, all blood vessels in normal

  17. Abnormalities in three-dimensional capillary architecture and imbalance between vascular endothelial growth factor-A and thrombospondin-1 in soleus muscle of ovariectomized rat.

    Science.gov (United States)

    Tanaka, Masayuki; Kanazashi, Miho; Maezawa, Toshiyuki; Kondo, Hiroyo; Fujino, Hidemi

    2015-09-01

    Reduced ovarian hormone levels associated with menopause or ovariectomy (OVX) not only result in vascular dysfunction but also lead to structural abnormalities in capillaries. Therefore, the effect of OVX on the three-dimensional (3-D) architecture of capillary networks and the underlying molecular mechanisms were investigated in rat soleus muscle. Seven-week-old female Wistar rats were divided into the OVX and sham-treated (Sham) groups. The OVX group exhibited lower endurance exercise capacity compared to the sham group and resulted in decreased capillary diameter, number of anastomoses and capillary/anastomosis volume in soleus muscle, indicating 3-D structural abnormalities of capillary networks. Furthermore, OVX led to increased concentrations of thrombospondin-1 (TSP-1) protein and a decreased VEGF-A/TSP-1 ratio, an indicator of angio-adaptations, in soleus muscle compared with the Sham group. These results indicate OVX may induce 3-D capillary regression in soleus muscle through an imbalance between VEGF-A and TSP-1 expression, possibly associated with decreased exercise tolerance in ovariectomized rats.

  18. Reorganization of endothelial cord-like structures on basement membrane complex (Matrigel): involvement of transforming growth factor beta 1.

    Science.gov (United States)

    Kuzuya, M; Kinsella, J L

    1994-11-01

    The formation of capillary-like network structures by cultured vascular endothelial cells on reconstituted basement membrane matrix, Matrigel, models endothelial cell differentiation, the final step of angiogenesis (Kubota et al., 1988; Grant et al., 1989). When endothelial cells derived from bovine aorta and brain capillaries were plated on Matrigel, DNA synthesis was suppressed and a network of capillary-like structures rapidly formed in 8-12 h. With time, the network broke down, resulting in dense cellular cords radiating from multiple cellular clusters in 16-24 h. Finally, multicellular aggregates of cells were formed as the network underwent further retraction. Network regression was prevented when either dithiothreitol (DTT) or anti-TGF-beta 1 antibodies were added during the assay. The addition of exogenous TGF-beta 1 promoted the regression of endothelial cells into the clusters. This response to TGF-beta 1 was blocked by potent serine threonine protein kinase inhibitors, H-7 and HA100. TGF-beta 1 was released from polymerized Matrigel by incubation with Dulbecco's modified eagle's medium (DMEM) in the absence of cells. The Matrigel-conditioned DMEM inhibited endothelial DNA synthesis even in the presence of anti-TGF-beta 1 antibodies. These results suggest that TGF-beta 1 and possibly other soluble factors from Matrigel may be important for differentiation and remodeling of endothelial cells in a capillary network with possible implications for wound healing and development.

  19. Fucoidan Extracted from Hijiki Protects Brain Microvessel Endothelial Cells Against Diesel Exhaust Particle Exposure-Induced Disruption.

    Science.gov (United States)

    Choi, Young-Sook; Eom, Sang-Yong; Kim, In-Soo; Ali, Syed F; Kleinman, Michael T; Kim, Yong-Dae; Kim, Heon

    2016-05-01

    This study was performed to evaluate the protective effects of fucoidan against the decreased function of primary cultured bovine brain microvessel endothelial cells (BBMECs) after exposure to diesel exhaust particles (DEPs). BBMECs were extracted from bovine brains and cultured until confluent. To evaluate the function of BBMECs, we performed a permeability test using cell-by-cell equipment and by Western blot analysis for zonular occludens-1 (ZO-1), which is a tight junction protein of BMECs, and evaluated oxidative stress in BBMECs using the DCFH-DA assay and the CUPRAC-BCS assay. The increased oxidative stress in BBMECs following DEP exposure was suppressed by fucoidan. In addition, permeability of BBMECs induced by DEP exposure was decreased by fucoidan treatment. Our results showed that fucoidan protects against BBMEC disruption induced by DEP exposure. This study provides evidence that fucoidan might protect the central nervous system (CNS) against DEP exposure.

  20. Hypoxia inducible factor-1alpha mediates protection of DL-3-n-butylphthalide in brain microvascular endothelial cells against oxygen glucose deprivation-induced injury

    Institute of Scientific and Technical Information of China (English)

    Weihong Yang; Ling Li; Ruxun Huang; Zhong Pei; Songjie Liao; Jinsheng Zeng

    2012-01-01

    Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on oxygen glucose deprivation -induced hypoxia inducible factor-1α expression. In this study, we hypothesized that DL-3-n-butylphthalide can protect against oxygen glucose deprivation-induced injury of newborn rat brain microvascular endothelial cells by means of upregulating hypoxia inducible factor-1α expression. MTT assay and Hoechst staining results showed that DL-3-n-butylphthalide protected brain microvascular endothelial cells against oxygen glucose deprivation-induced injury in a dose-dependent manner. Western blot and immunofluorescent staining results further confirmed that the protective effect was related to upregulation of hypoxia inducible factor-1α. Real-time RT-PCR reaction results showed that DL-3-n-butylphthalide reduced apoptosis by inhibiting downregulation of pro-apoptotic gene caspase-3 mRNA expression and upregulation of apoptosis-executive protease bcl-2 mRNA expression; however, DL-3-n-butylphthalide had no protective effects on brain microvascular endothelial cells after knockdown of hypoxia inducible factor-1α by small interfering RNA. These findings suggest that DL-3-n-butylphthalide can protect brain microvascular endothelial cells against oxygen glucose deprivation-induced injury by upregulating bcl-2 expression and downregulating caspase-3 expression though hypoxia inducible factor-1α pathway.

  1. B7-H1 shapes T-cell–mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity

    Science.gov (United States)

    Klotz, Luisa; Kuzmanov, Ivan; Hucke, Stephanie; Gross, Catharina C.; Posevitz, Vilmos; Dreykluft, Angela; Schulte-Mecklenbeck, Andreas; Janoschka, Claudia; Lindner, Maren; Herold, Martin; Schwab, Nicholas; Ludwig-Portugall, Isis; Kurts, Christian; Meuth, Sven G.; Kuhlmann, Tanja; Wiendl, Heinz

    2016-01-01

    Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood–brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4+ T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immune-regulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity. PMID:27671636

  2. High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-08-01

    Full Text Available We previously demonstrated that in normal glucose (5 mM, methylglyoxal (MG, a model of carbonyl stress induced brain microvascular endothelial cell (IHEC dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC. Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia; moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation. Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes.

  3. Platelets alter gene expression profile in human brain endothelial cells in an in vitro model of cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Mathieu Barbier

    Full Text Available Platelet adhesion to the brain microvasculature has been associated with cerebral malaria (CM in humans, suggesting that platelets play a role in the pathogenesis of this syndrome. In vitro co-cultures have shown that platelets can act as a bridge between Plasmodium falciparum-infected red blood cells (pRBC and human brain microvascular endothelial cells (HBEC and potentiate HBEC apoptosis. Using cDNA microarray technology, we analyzed transcriptional changes of HBEC in response to platelets in the presence or the absence of tumor necrosis factor (TNF and pRBC, which have been reported to alter gene expression in endothelial cells. Using a rigorous statistical approach with multiple test corrections, we showed a significant effect of platelets on gene expression in HBEC. We also detected a strong effect of TNF, whereas there was no transcriptional change induced specifically by pRBC. Nevertheless, a global ANOVA and a two-way ANOVA suggested that pRBC acted in interaction with platelets and TNF to alter gene expression in HBEC. The expression of selected genes was validated by RT-qPCR. The analysis of gene functional annotation indicated that platelets induce the expression of genes involved in inflammation and apoptosis, such as genes involved in chemokine-, TREM1-, cytokine-, IL10-, TGFβ-, death-receptor-, and apoptosis-signaling. Overall, our results support the hypothesis that platelets play a pathogenic role in CM.

  4. Vascular Endothelial Growth Factor Increases during Blood-Brain Barrier-Enhanced Permeability Caused by Phoneutria nigriventer Spider Venom

    Directory of Open Access Journals (Sweden)

    Monique C. P. Mendonça

    2014-01-01

    Full Text Available Phoneutria nigriventer spider accidental envenomation provokes neurotoxic manifestations, which when critical, results in epileptic-like episodes. In rats, P. nigriventer venom (PNV causes blood-brain barrier breakdown (BBBb. The PNV-induced excitotoxicity results from disturbances on Na+, K+ and Ca2+ channels and glutamate handling. The vascular endothelial growth factor (VEGF, beyond its angiogenic effect, also, interferes on synaptic physiology by affecting the same ion channels and protects neurons from excitotoxicity. However, it is unknown whether VEGF expression is altered following PNV envenomation. We found that adult and neonates rats injected with PNV showed immediate neurotoxic manifestations which paralleled with endothelial occludin, β-catenin, and laminin downregulation indicative of BBBb. In neonate rats, VEGF, VEGF mRNA, and Flt-1 receptors, glutamate decarboxylase, and calbindin-D28k increased in Purkinje neurons, while, in adult rats, the BBBb paralleled with VEGF mRNA, Flk-1, and calbindin-D28k increases and Flt-1 decreases. Statistically, the variable age had a role in such differences, which might be due to age-related unequal maturation of blood-brain barrier (BBB and thus differential cross-signaling among components of the glial neurovascular unit. The concurrent increases in the VEGF/Flt-1/Flk-1 system in the cerebellar neuron cells and the BBBb following PNV exposure might imply a cytokine modulation of neuronal excitability consequent to homeostatic perturbations induced by ion channels-acting PNV neuropeptides. Whether such modulation represents neuroprotection needs further investigation.

  5. Chronic exposure to nicotine and saquinavir decreases endothelial Notch-4 expression and disrupts blood-brain barrier integrity.

    Science.gov (United States)

    Manda, Vamshi K; Mittapalli, Rajendar K; Geldenhuys, Werner J; Lockman, Paul R

    2010-10-01

    Since the advent of HAART, there have been substantial improvements in HIV patient survival; however, the prevalence of HIV associated dementia has increased. Importantly, HIV positive individuals who smoke progress to HIV associated neurological conditions faster than those who do not. Recent in vitro data have shown that pharmacological levels of saquinavir causes endothelial oxidative stress and significantly decreases Notch-4 expression, a primary protein involved in maintaining stability of blood-brain barrier (BBB) endothelium. This is concerning as nicotine can also generate reactive oxygen species in endothelium. It is largely unknown if pharmacological doses of these drugs can cause a similar in vivo down-regulation of Notch-4 and if there is a concurrent destabilization of the integrity of the BBB. The data herein show: (i) nicotine and protease inhibitors cause an additive oxidative stress burden in endothelium; (ii) that the integrity of the BBB is disrupted after concurrent chronic nicotine and protease inhibitor administration; and (iii) that BBB endothelial dysfunction is correlated with a decrease in Notch-4 and ZO-1 expression. Considering the high prevalence of smoking in the HIV infected population (3- to 4-fold higher than in the general population) this data must be followed up to determine if all protease inhibitors cause a similar BBB disruption or if there is a safer alternative. In addition, this data may suggest that the induced BBB disruption may allow foreign molecules to gain access to brain and be a contributing factor to the slow progression of HIV associated dementia.

  6. Comparison between capillary, venous and arterial levels of protein S100B in patients with severe brain pathology

    DEFF Research Database (Denmark)

    Astrand, Ramona; Romner, Bertil; Reinstrup, Peter

    2012-01-01

    Protein S100B is soon in clinical use as a sensitive marker after mild traumatic head injury in adults. Initial studies of S100B in pediatric head injury have shown promising results. Venous sampling can be challenging in children and capillary samples are often a preferred option. The aim...... of the study was to investigate the relation between capillary, venous and arterial measurements of protein S100B, primarily by determining whether capillary S100B differ from venous and if capillary S100B can predict venous S100B levels, and secondarily, if arterial S100B samples can substitute venous samples...

  7. Cancer-associated fibroblast promote transmigration through endothelial brain cells in three-dimensional in vitro models.

    Science.gov (United States)

    Choi, Yoon Pyo; Lee, Joo Hyun; Gao, Ming-Qing; Kim, Baek Gil; Kang, Suki; Kim, Se Hoon; Cho, Nam Hoon

    2014-11-01

    Brain metastases are associated with high morbidity as well as with poor prognosis and survival in breast cancer patients. Despite its clinical importance, metastasis of breast cancer cells through the blood-brain barrier (BBB) is poorly understood. The objective of our study was to investigate whether cancer-associated fibroblasts (CAFs) play crucial roles in breast cancer brain metastasis. Using a cell adhesion assays, in vitro BBB permeability and transmigration assays and soft agar colony formation assays, we investigated the physical roles of CAFs in breast cancer brain metastasis. We also performed immunofluorescence, flow cytometric analysis, Droplet Digital PCR and Simon™ Simple Western System to confirm changes in expression levels. We established two novel three-dimensional (3D) culture systems using a perpendicular slide chamber and applying 3D embedded culture method to reflect brain metastasis conditions. With a newly developed device, CAFs was proven to promote cell adhesion to human brain microvascular endothelial cells, in vitro BBB permeability and transmigration and colony formation of breast cancer cells. Furthermore, CAFs enhanced the invasive migration of breast cancer cells in two kinds of 3D cultures. These 3D models also reliably recapitulate the initial steps of BBB transmigration, micro-metastasis and colonization. Expression of integrin α5β1 and αvβ3, c-MET and α2,6-siayltransferase was increased in breast cancer cells that migrated through the BBB. In conclusion, based on our in vitro BBB and co-culture models, our data suggest that CAFs may play a role in breast cancer brain metastasis.

  8. Interactions of primary neuroepithelial progenitor and brain endothelial cells: distinct effect on neural progenitor maintenance and differentiation by soluble factors and direct contact

    Institute of Scientific and Technical Information of China (English)

    Miguel A Gama Sosa; Rita De Gasperi; Anne B Rocher; Gissel M Perez; Keila Simons; Daniel E Cruz; Patrick R Hof; Gregory A Elder

    2007-01-01

    Neurovascular interactions are crucial for the normal development of the central nervous system. To study such interactions in primary cultures, we developed a procedure to simultaneously isolate neural progenitor and endothelial cell fractions from embryonic mouse brains. Depending on the culture conditions endothelial cells were found to favor maintenance of the neuroprogenitor phenotype through the production of soluble factors, or to promote neuronal differentiation of neural progenitors through direct contact. These apparently opposing effects could reflect differential cellular interactions needed for the proper development of the brain.

  9. Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2

    Science.gov (United States)

    Eum, Sung Yong; Jaraki, Dima; András, Ibolya E.; Toborek, Michal

    2015-01-01

    Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1 h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2) after 24 h h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs. PMID:26080028

  10. Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2.

    Science.gov (United States)

    Eum, Sung Yong; Jaraki, Dima; András, Ibolya E; Toborek, Michal

    2015-09-15

    Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2) after 24h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs.

  11. Influence of mild hypothermia on vascular endothelial growth factor and infarct volume in brain tissues after cerebral ischemia in rats

    Institute of Scientific and Technical Information of China (English)

    Fei Ye; Gangming Xi; Biyong Qin; Shifeng Wang; Chengyan Li

    2006-01-01

    BACKGROUND: It has been demonstrated that mild hypothermia has obvious protective effect on both whole and local cerebral ischemia. However, the definite mechanism is still unclear for the brain protection of mild hypothermia on cerebral edema, inhibiting inflammatory reaction, stabilizing blood brain barrier, etc.OBJECTIVE: To investigate the effect of mild hypothermia on the expression of vascular endothelial growth factor and the infarct volume after cerebral ischemia in rats, and analyze the brain protective mechanism of mild hypothermia.DESIGN: A randomized grouping and controlled animal trial.SETTING: Department of Neurology, People's Hospital of Yunyang Medical College.MATERIALS: Twenty adult male SD rats of clean degree, weighing (250±30) g, were provided by the animal experimental center, School of Medicine, Wuhan University. The kits for SP immunohistochemistry were purchased from Beijing Zhongshan Golden Bridge Biotechnology Co., Ltd.METHODS: The experiments were carried out in the laboratory of Department of Neurology, Renmen Hospital of Wuhan University from May to July 2005. ① The 20 rats were divided randomly into normal temperature group (n =10) and mild hypothermia group (n =10). Models of permanent middle cerebral artery occlusion were established with modified nylon suture embolization. The rats were assessed with the Longa standards: O point for without nerve dysfunction; 1 for mild neurological deficit (fore claws could no extend completely); 2 for moderate neurological deficit (circling towards the affected side); 3 for severe neurological deficit (tilting towards the affected side); 4 for coma and unconscious; 1 -3 points represented that models were successfully established. The rats of the normal temperature group were fed at room temperature, and those in the mild hypothermia group were induced by hypothermia from 2 hours postoperatively, and the rectal temperature was kept at 34-35 ℃ for 72 hours. ② Measurement of infarct volume

  12. Exogenous arachidonic acid mediates permeability of human brain microvessel endothelial cells through prostaglandin E2 activation of EP3 and EP4 receptors.

    Science.gov (United States)

    Dalvi, Siddhartha; Nguyen, Hieu H; On, Ngoc; Mitchell, Ryan W; Aukema, Harold M; Miller, Donald W; Hatch, Grant M

    2015-12-01

    The blood-brain barrier, formed by microvessel endothelial cells, is the restrictive barrier between the brain parenchyma and the circulating blood. Arachidonic acid (ARA; 5,8,11,14-cis-eicosatetraenoic acid) is a conditionally essential polyunsaturated fatty acid [20:4(n-6)] and is a major constituent of brain lipids. The current study examined the transport processes for ARA in confluent monolayers of human brain microvascular endothelial cells (HBMEC). Addition of radioactive ARA to the apical compartment of HBMEC cultured on Transwell(®) inserts resulted in rapid incorporation of radioactivity into the basolateral medium. Knock down of fatty acid transport proteins did not alter ARA passage into the basolateral medium as a result of the rapid generation of prostaglandin E2 (PGE2 ), an eicosanoid known to facilitate opening of the blood-brain barrier. Permeability following ARA or PGE2 exposure was confirmed by an increased movement of fluorescein-labeled dextran from apical to basolateral medium. ARA-mediated permeability was attenuated by specific cyclooxygenase-2 inhibitors. EP3 and EP4 receptor antagonists attenuated the ARA-mediated permeability of HBMEC. The results indicate that ARA increases permeability of HBMEC monolayers likely via increased production of PGE2 which acts upon EP3 and EP4 receptors to mediate permeability. These observations may explain the rapid influx of ARA into the brain previously observed upon plasma infusion with ARA. The blood-brain barrier, formed by microvessel endothelial cells, is a restrictive barrier between the brain parenchyma and the circulating blood. Radiolabeled arachidonic acid (ARA) movement across, and monolayer permeability in the presence of ARA, was examined in confluent monolayers of primary human brain microvessel endothelial cells (HBMECs) cultured on Transwell(®) plates. Incubation of HBMECs with ARA resulted in a rapid increase in HBMEC monolayer permeability. The mechanism was mediated, in part

  13. Functional expression of choline transporter like-protein 1 (CTL1) and CTL2 in human brain microvascular endothelial cells.

    Science.gov (United States)

    Iwao, Beniko; Yara, Miki; Hara, Naomi; Kawai, Yuiko; Yamanaka, Tsuyoshi; Nishihara, Hiroshi; Inoue, Takeshi; Inazu, Masato

    2016-02-01

    In this study, we examined the molecular and functional characterization of choline transporter in human brain microvascular endothelial cells (hBMECs). Choline uptake into hBMECs was a saturable process that was mediated by a Na(+)-independent, membrane potential and pH-dependent transport system. The cells have two different [(3)H]choline transport systems with Km values of 35.0 ± 4.9 μM and 54.1 ± 8.1 μM, respectively. Choline uptake was inhibited by choline, acetylcholine (ACh) and the choline analog hemicholinium-3 (HC-3). Various organic cations also interacted with the choline transport system. Choline transporter-like protein 1 (CTL1) and CTL2 mRNA were highly expressed, while mRNA for high-affinity choline transporter 1 (CHT1) and organic cation transporters (OCTs) were not expressed in hBMECs. CTL1 and CTL2 proteins were localized to brain microvascular endothelial cells in human brain cortical sections. Both CTL1 and CTL2 proteins were expressed on the plasma membrane and mitochondria. CTL1 and CTL2 proteins are mainly expressed in plasma membrane and mitochondria, respectively. We conclude that choline is mainly transported via an intermediate-affinity choline transport system, CTL1 and CTL2, in hBMECs. These transporters are responsible for the uptake of extracellular choline and organic cations. CTL2 participate in choline transport mainly in mitochondria, and may be the major site for the control of choline oxidation.

  14. Effect of low-dose methylprednisolone on peripheral blood endothelial progenitor cells and its significance in rats after brain injury

    Directory of Open Access Journals (Sweden)

    Bin ZHANG

    2011-05-01

    Full Text Available Objective To explore the effects of low-dose methylprednisolone(MP treatment after traumatic brain injury(TBI in rats on the number of peripheral blood endothelial progenitor cells(EPCs and injury area of the brain.Methods One hundred and fifty-four adult male Wistar rats were involved in the present study,and they were randomly divided into normal control group(n=18,TBI control group(n=38,MP control group(n=30,MP+TBI group(n=30 and TBI+MP group(n=38.The TBI model was reproduced by fluid percussion injury(FPI.MP(5mg/kg was intraperitoneally administered once a day for 4 days.Peripheral venous blood samples were taken on day 1,3,7 and 14,and the counts of EPCs were determined by flow cytometry.The rats were sacrificed on day 1 and 3,brain edema was estimated by dry-wet weight method,and the blood-brain barrier(BBB permeability was determined by Evans-blue extravasation.Results The counts of peripheral blood EPCs were significantly higher in MP control group,MP+TBI group and TBI+MP group on day 1,3 and 7 than that in normal control and TBI control group,and it returned to the level of normal control group on day 14.The BBB permeability was improved and brain edema alleviated in MP+TBI and TBI+MP group on day 3.Conclusion The administration of low-dose MP may increase the count of peripheral blood EPCs in rats,decrease BBB damage,and alleviate brain edema.

  15. Protection of the blood-brain barrier by pentosan against amyloid-β-induced toxicity.

    Science.gov (United States)

    Deli, Mária A; Veszelka, Szilvia; Csiszár, Boglárka; Tóth, Andrea; Kittel, Agnes; Csete, Mária; Sipos, Aron; Szalai, Anikó; Fülöp, Lívia; Penke, Botond; Abrahám, Csongor S; Niwa, Masami

    2010-01-01

    Endothelial cells of brain capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer's disease. Amyloid-β (Aβ) peptides are key pathological elements in the development of the disease. A blood-brain barrier model, based on primary rat brain endothelial cells was used in which the barrier properties were induced by glial cells. The effects of amyloid peptides have been tested on cell viability and barrier functions. Aβ showed toxic effects on primary rat brain endothelial cells measured by MTT dye conversion and the lactate dehydrogenase release. Morphologically cytoplasmic vacuolization, disruption of the structure of cytoplasmic organelles and tight junctions could be observed in brain endothelial cells. Treatment with Aβ1-42 decreased the electrical resistance, and increased the permeability of brain endothelial cell monolayers for both fluorescein and albumin. Serum amyloid P component which stabilizes Aβ fibrils in cortical amyloid plaques and cerebrovascular amyloid deposits significantly potentiated the barrier-weakening effect of Aβ1-42. Sulfated polysaccharide pentosan could decrease the toxic effects of Aβ peptides in brain endothelial cells. It could also significantly protect the barrier integrity of monolayers from damaging actions of peptides. Pentosan modified the size, and significantly decreased the number of amyloid aggregates demonstrated by atomic force microscopy. The present data further support the toxic effects of amyloid peptides on brain endothelial cells, and can contribute to the development of molecules protecting the blood-brain barrier in Alzheimer's disease.

  16. Correlation of vascular endothelial growth factor to permeability of blood-brain barrier and brain edema during high-altitude exposure

    Institute of Scientific and Technical Information of China (English)

    Qiquan Zhou; Chang'e Liu; Jing Wang; Yunli Wang; Bo Zhou

    2009-01-01

    BACKGROUND:Many studies have evaluated the role of vascular endothelial growth factor (VEGF) in traumatic brain edema and hemorrhagic brain edema.OBJECTIVE:To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure,and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure.DESIGN,TIME AND SETTING:The randomized,controlled,animal study was performed at the Tanggula Etape,Central Laboratory of Chengdu Medical College,and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA,China,from July 2003 to November 2004.MATERIALS:Quantitative RT-PCR kit (Sigma,USA),VEGF ELISA kit (Biosource,USA),and Evans blue (Jingchun,China) were acquired for this study.METHODS:A total of 180 Wistar rats were equally and randomly assigned to 15 groups:low-altitude (500 m),middle-altitude (2 880 m),high-altitude (4 200 m),super-high-altitude (5 000 m),1,3,5,7,9,11,13,15,17,19,and 21 days of super high-altitude exposure.Wistar rats were exposed to various altitude gradients to establish a hypoxia model.MAIN OUTCOME MEASURES:Brain water content was calculated according to the wet-to-dry weight ratio.BBB permeability to Evans blue was determined by colorimetric method.VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA.RESULTS:Brain water content,BBB permeability to Evans blue,and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude.The greatest increase was determined on day 9 upon ascending 5 000 m.Simultaneously,VEGF expression positively correlated to BBB permeability of Evans blue and brain water content (r=0.975,0.917,P<0.01).CONCLUSION:Increased VEGF protein and mRNA expression was responsible for increased BBB permeability,which may be an important mechanism

  17. β2 integrin-mediated crawling on endothelial ICAM-1 and ICAM-2 is a prerequisite for transcellular neutrophil diapedesis across the inflamed blood-brain barrier.

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    Gorina, Roser; Lyck, Ruth; Vestweber, Dietmar; Engelhardt, Britta

    2014-01-01

    In acute neuroinflammatory states such as meningitis, neutrophils cross the blood-brain barrier (BBB) and contribute to pathological alterations of cerebral function. The mechanisms that govern neutrophil migration across the BBB are ill defined. Using live-cell imaging, we show that LPS-stimulated BBB endothelium supports neutrophil arrest, crawling, and diapedesis under physiological flow in vitro. Investigating the interactions of neutrophils from wild-type, CD11a(-/-), CD11b(-/-), and CD18(null) mice with wild-type, junctional adhesion molecule-A(-/-), ICAM-1(null), ICAM-2(-/-), or ICAM-1(null)/ICAM-2(-/-) primary mouse brain microvascular endothelial cells, we demonstrate that neutrophil arrest, polarization, and crawling required G-protein-coupled receptor-dependent activation of β2 integrins and binding to endothelial ICAM-1. LFA-1 was the prevailing ligand for endothelial ICAM-1 in mediating neutrophil shear resistant arrest, whereas Mac-1 was dominant over LFA-1 in mediating neutrophil polarization on the BBB in vitro. Neutrophil crawling was mediated by endothelial ICAM-1 and ICAM-2 and neutrophil LFA-1 and Mac-1. In the absence of crawling, few neutrophils maintained adhesive interactions with the BBB endothelium by remaining either stationary on endothelial junctions or displaying transient adhesive interactions characterized by a fast displacement on the endothelium along the direction of flow. Diapedesis of stationary neutrophils was unchanged by the lack of endothelial ICAM-1 and ICAM-2 and occurred exclusively via the paracellular pathway. Crawling neutrophils, although preferentially crossing the BBB through the endothelial junctions, could additionally breach the BBB via the transcellular route. Thus, β2 integrin-mediated neutrophil crawling on endothelial ICAM-1 and ICAM-2 is a prerequisite for transcellular neutrophil diapedesis across the inflamed BBB.

  18. Lipid raft/caveolae signaling is required for Cryptococcus neoformans invasion into human brain microvascular endothelial cells

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    Long Min

    2012-02-01

    Full Text Available Abstract Background Cryptococcus neoformans has a predilection for central nervous system infection. C. neoformans traversal of the blood brain barrier, composed of human brain microvascular endothelial cells (HBMEC, is the crucial step in brain infection. However, the molecular mechanism of the interaction between Cryptococcus neoformans and HBMEC, relevant to its brain invasion, is still largely unknown. Methods In this report, we explored several cellular and molecular events involving the membrane lipid rafts and caveolin-1 (Cav1 of HBMEC during C. neoformans infection. Immunofluorescence microscopy was used to examine the roles of Cav1. The knockdown of Cav1 by the siRNA treatment was performed. Phosphorylation of Cav1 relevant to its invasion functions was investigated. Results We found that the host receptor CD44 colocalized with Cav1 on the plasma membrane, and knockdown of Cav1 significantly reduced the fungal ability to invade HBMEC. Although the CD44 molecules were still present, HBMEC membrane organization was distorted by Cav1 knockdown. Concomitantly, knockdown of Cav1 significantly reduced the fungal crossing of the HBMEC monolayer in vitro. Upon C. neoformans engagement, host Cav1 was phosphorylated in a CD44-dependent manner. This phosphorylation was diminished by filipin, a disrupter of lipid raft structure. Furthermore, the phosphorylated Cav1 at the lipid raft migrated inward to the perinuclear localization. Interestingly, the phospho-Cav1 formed a thread-like structure and colocalized with actin filaments but not with the microtubule network. Conclusion These data support that C. neoformans internalization into HBMEC is a lipid raft/caveolae-dependent endocytic process where the actin cytoskeleton is involved, and the Cav1 plays an essential role in C. neoformans traversal of the blood-brain barrier.

  19. Exosomes contribute to the transmission of anti-HIV activity from TLR3-activated brain microvascular endothelial cells to macrophages

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    Sun, Li; Wang, Xu; Zhou, Yu; Zhou, Run-Hong; Ho, Wen-Zhe; Li, Jie-Liang

    2017-01-01

    Human brain microvascular endothelial cells (HBMECs), the major cell type in the blood-brain barrier (BBB), play a key role in maintaining brain homeostasis. However, their role in the BBB innate immunity against HIV invasion of the central nervous system (CNS) remains to be determined. Our early work showed that TLR3 signaling of HBMECs could produce the antiviral factors that inhibit HIV replication in macrophages. The present study examined whether exosomes from TLR3-activated HBMECs mediate the intercellular transfer of antiviral factors to macrophages. Primary human macrophages could take up exosomes from TLR3-activated HBMECs. HBMECs-derived exosomes contained multiple antiviral factors, including several key IFN-stimulated genes (ISGs; ISG15, ISG56, and Mx2) at mRNA and protein levels. The depletion of exosomes from TLR3-activated HBMECs culture supernatant diminished HBMECs-mediated anti-HIV activity in macrophages. In conclusion, we demonstrate that exosomes shed by HBMECs are able to transport the antiviral molecules to macrophages. This finding suggests the possibility that HIV nonpermissive BBB cells (HBMECs) can help to restore the antiviral state in HIV-infected macrophages, which may be a defense mechanism against HIV neuroinvasion. PMID:27496004

  20. CJZ3,a lomerizine derivative,modulates P-glycoprotein function in rat brain microvessel endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Bian-sheng JI; Ling HE; Xiao-qu LI; Guo-qing LIU

    2006-01-01

    Aim:To investigate the modulatory effect of CJZ3,a lomerizine derivative,on P-glycoprotein (P-gp) function in rat brain microvessel endothelial cells (RBMEC).Methods:RBMEC were isolated and cultured in Dulbecco's modified Eagle's medium/F12 (1∶1) medium,and the amount of intracellular rhodamine 123 (Rh123) was determined using a fluorescence spectrophotometer to evaluate the modulatory effect of CJZ3 on P-gp function.Results:The accumulation of Rh123 was 190ten. tiated in a concentration-dependent manner after incubation witll CJZ3 for RBMEC.but not for human umbilical vein endothelial cells (HUVEC).CJZ3 caused the accumulation of intracellular Rh 123 in a time.dependent manner and significantly decreased the effiUX of Rhl 23 from the cells.The inhibitory effect of CJZ3 on P-gp function was reversible and remained for 120 min after CJZ3 (2.5 μmol/L) was removed from the medium.Conclusion:CJZ3 has a potent in vitro effect on the inhibition of P-gp function.

  1. EGb761 provides a protective effect against Aβ1-42 oligomer-induced cell damage and blood-brain barrier disruption in an in vitro bEnd.3 endothelial model.

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    Wen-bin Wan

    Full Text Available Alzheimer's disease (AD is the most common form of senile dementia which is characterized by abnormal amyloid beta (Aβ accumulation and deposition in brain parenchyma and cerebral capillaries, and leads to blood-brain barrier (BBB disruption. Despite great progress in understanding the etiology of AD, the underlying pathogenic mechanism of BBB damage is still unclear, and no effective treatment has been devised. The standard Ginkgo biloba extract EGb761 has been widely used as a potential cognitive enhancer for the treatment of AD. However, the cellular mechanism underlying the effect remain to be clarified. In this study, we employed an immortalized endothelial cell line (bEnd.3 and incubation of Aβ(1-42 oligomer, to mimic a monolayer BBB model under conditions found in the AD brain. We investigated the effect of EGb761 on BBB and found that Aβ1-42 oligomer-induced cell injury, apoptosis, and generation of intracellular reactive oxygen species (ROS, were attenuated by treatment with EGb761. Moreover, treatment of the cells with EGb761 decreased BBB permeability and increased tight junction scaffold protein levels including ZO-1, Claudin-5 and Occludin. We also found that the Aβ(1-42 oligomer-induced upregulation of the receptor for advanced glycation end-products (RAGE, which mediates Aβ cytotoxicity and plays an essential role in AD progression, was significantly decreased by treatment with EGb761. To our knowledge, we provide the first direct in vitro evidence of an effect of EGb761 on the brain endothelium exposed to Aβ(1-42 oligomer, and on the expression of tight junction (TJ scaffold proteins and RAGE. Our results provide a new insight into a possible mechanism of action of EGb761. This study provides a rational basis for the therapeutic application of EGb761 in the treatment of AD.

  2. Methylmercury Causes Blood-Brain Barrier Damage in Rats via Upregulation of Vascular Endothelial Growth Factor Expression

    Science.gov (United States)

    Takahashi, Tetsuya; Fujimura, Masatake; Koyama, Misaki; Kanazawa, Masato; Usuki, Fusako; Nishizawa, Masatoyo; Shimohata, Takayoshi

    2017-01-01

    Clinical manifestations of methylmercury (MeHg) intoxication include cerebellar ataxia, concentric constriction of visual fields, and sensory and auditory disturbances. The symptoms depend on the site of MeHg damage, such as the cerebellum and occipital lobes. However, the underlying mechanism of MeHg-induced tissue vulnerability remains to be elucidated. In the present study, we used a rat model of subacute MeHg intoxication to investigate possible MeHg-induced blood-brain barrier (BBB) damage. The model was established by exposing the rats to 20-ppm MeHg for up to 4 weeks; the rats exhibited severe cerebellar pathological changes, although there were no significant differences in mercury content among the different brain regions. BBB damage in the cerebellum after MeHg exposure was confirmed based on extravasation of endogenous immunoglobulin G (IgG) and decreased expression of rat endothelial cell antigen-1. Furthermore, expression of vascular endothelial growth factor (VEGF), a potent angiogenic growth factor, increased markedly in the cerebellum and mildly in the occipital lobe following MeHg exposure. VEGF expression was detected mainly in astrocytes of the BBB. Intravenous administration of anti-VEGF neutralizing antibody mildly reduced the rate of hind-limb crossing signs observed in MeHg-exposed rats. In conclusion, we demonstrated for the first time that MeHg induces BBB damage via upregulation of VEGF expression at the BBB in vivo. Further studies are required in order to determine whether treatment targeted at VEGF can ameliorate MeHg-induced toxicity. PMID:28118383

  3. Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2

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    Eum, Sung Yong, E-mail: seum@miami.edu; Jaraki, Dima; András, Ibolya E.; Toborek, Michal

    2015-09-15

    Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1 h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2) after 24 h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs. - Highlights: • PCB153 disturbed human brain endothelial barrier through disruption of occludin. • Lipid raft-associated PP

  4. Oxidative Stress Induced by Cigarette Smoke Extracts in Human Brain Cells (T98G) and Human Brain Microvascular Endothelial Cells (HBMEC) in Mono- and Co-Culture.

    Science.gov (United States)

    Kim, Ju-Hyeong; Cho, Myung-Haing; Choi, Kyung-Chul; Lee, Kyuhong; Kim, Kwang-Sik; Shim, Soon-Mi

    2015-01-01

    The objective of the current study was to examine oxidative stress induced by cigarette smoke extract (CSE) or cigarette smoke condensate (CSC) in human brain cells (T98G) and human brain microvascular endothelial cells (HBMEC) in mono- and co-culture systems. Cell viability of T98G cells exposed to CSC (0.05-4 mg/ml) was significantly decreased compared to CSE (0.025-20%). There were no marked differences between quantities of reactive oxygen species (ROS) generation by either CSE (2, 4, and 10%) or CSC (0.2, 0.4, and 0.8 mg/ml) treatment compared to control. However, a significant effect was noted in ROS generation following CSC incubation at 4mg/ml. Cellular integrity of HBMEC decreased to 74 and 64% within 120 h of exposure at the IC50 value of CSE and CSC, respectively. This study suggests that chronic exposure to cigarette smoking might initiate damage to the blood-brain barrier.

  5. Regulation of Monocarboxylic Acid Transporter 1 Trafficking by the Canonical Wnt/β-Catenin Pathway in Rat Brain Endothelial Cells Requires Cross-talk with Notch Signaling.

    Science.gov (United States)

    Liu, Zejian; Sneve, Mary; Haroldson, Thomas A; Smith, Jeffrey P; Drewes, Lester R

    2016-04-01

    The transport of monocarboxylate fuels such as lactate, pyruvate, and ketone bodies across brain endothelial cells is mediated by monocarboxylic acid transporter 1 (MCT1). Although the canonical Wnt/β-catenin pathway is required for rodent blood-brain barrier development and for the expression of associated nutrient transporters, the role of this pathway in the regulation of brain endothelial MCT1 is unknown. Here we report expression of nine members of the frizzled receptor family by the RBE4 rat brain endothelial cell line. Furthermore, activation of the canonical Wnt/β-catenin pathway in RBE4 cells via nuclear β-catenin signaling with LiCl does not alter brain endothelialMct1mRNA but increases the amount of MCT1 transporter protein. Plasma membrane biotinylation studies and confocal microscopic examination of mCherry-tagged MCT1 indicate that increased transporter results from reduced MCT1 trafficking from the plasma membrane via the endosomal/lysosomal pathway and is facilitated by decreased MCT1 ubiquitination following LiCl treatment. Inhibition of the Notch pathway by the γ-secretase inhibitorN-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester negated the up-regulation of MCT1 by LiCl, demonstrating a cross-talk between the canonical Wnt/β-catenin and Notch pathways. Our results are important because they show, for the first time, the regulation of MCT1 in cerebrovascular endothelial cells by the multifunctional canonical Wnt/β-catenin and Notch signaling pathways.

  6. Restraint stress-induced morphological changes at the blood-brain barrier in adult rats

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    Petra eSántha

    2016-01-01

    Full Text Available Stress is well known to contribute to the development of both neurological and psychiatric diseases. While the role of the blood-brain barrier is increasingly recognised in the development of neurodegenerative disorders, such as Alzheimer’s disease, dysfunction of the blood-brain barrier has been linked to stress-related psychiatric diseases only recently. In the present study the effects of restraint stress with different duration (1, 3 and 21 days were investigated on the morphology of the blood-brain barrier in male adult Wistar rats. Frontal cortex and hippocampus sections were immunostained for markers of brain endothelial cells (claudin-5, occludin and glucose transporter-1 and astroglia (GFAP. Staining pattern and intensity were visualized by confocal microscopy and evaluated by several types of image analysis. The ultrastructure of brain capillaries was investigated by electron microscopy. Morphological changes and intensity alterations in brain endothelial tight junction proteins claudin-5 and occludin were induced by stress. Following restraint stress significant increases in the fluorescence intensity of glucose transporter-1 were detected in brain endothelial cells in the frontal cortex and hippocampus. Significant reductions in GFAP fluorescence intensity were observed in the frontal cortex in all stress groups. As observed by electron microscopy, one-day acute stress induced morphological changes indicating damage in capillary endothelial cells in both brain regions. After 21 days of stress thicker and irregular capillary basal membranes in the hippocampus and edema in astrocytes in both regions were seen. These findings indicate that stress exerts time-dependent changes in the staining pattern of tight junction proteins occludin, claudin-5 and glucose transporter-1 at the level of brain capillaries and in the ultrastructure of brain endothelial cells and astroglial endfeet, which may contribute to neurodegenerative processes

  7. 大鼠液压脑损伤后皮层微血管改变与脑水肿的关系%Association of the changes of cortical capillaries with brain edema after lateral fluid percussion brain injury in adult rat

    Institute of Scientific and Technical Information of China (English)

    马迎辉; 刘绍明; 邢国祥

    2013-01-01

    目的 探讨大鼠液压脑损伤后皮层微血管损伤情况及其与伤后脑水肿的关系.方法 成年SD大鼠30只,随机分为正常组(n=6)、假手术组(n=6)、损伤组(n=18),其中损伤组分为伤后6h、24 h、72 h三亚组,每亚组6只.利用液压冲击法建立大鼠颅脑损伤模型,显微镜下观察直接损伤侧和非直接损伤侧皮层微血管损伤情况,CD34标记血管内皮细胞评价血管密度改变,干湿重法检测脑组织含水量的变化.结果 大鼠皮层微血管损伤后6h可见血管支行迂曲、扩张、充血,伤后24 h可见少量血栓形成,损伤后72 h可见有较多血栓形成.损伤组CD34阳性细胞数明显低于假手术组和对照组(P<0.05),而脑组织含水量明显高于假手术组和对照组(P<0.05),而后两组无统计学差异(P>0.05).损伤组直接损伤侧皮层微血管损伤较非直接损伤组严重,而且伤后24h较伤后6、72 h严重.结论 颅脑损伤后脑微血管损伤为全脑性血管损伤,这可能是伤后脑水肿形成的机制之一.%Objective To investigate the changes of the cortical capillaries and brain edema after lateral fluid percussion brain injury in adult rat and their relationship.Methods Thirty adult Sprague-Dawley rats were randomly divided into three groups,i.e.,normal group (n=6),sham-operated group (n=6) and injured group (n=18).The rat model was made by lateral fluid percussion brain injury with an impact of 2.3 kPa.The rats in injured group were killed 6,24 and 72 hours after injury with six rats in each time point.The pathological changes of cerebral tissues were detected by HE staining.The changes of cortical capillaries were evaluated by counting the number of CD34 marked vascular endothelial cells.The brain water content was calculated by wet and dry method.Results The HE staining showed that many cortical capillaries with no congestion and endothelial cells with normal shape could be seen in normal group and sham-operated group

  8. Trafficking of adeno-associated virus vectors across a model of the blood-brain barrier; a comparative study of transcytosis and transduction using primary human brain endothelial cells.

    Science.gov (United States)

    Merkel, Steven F; Andrews, Allison M; Lutton, Evan M; Mu, Dakai; Hudry, Eloise; Hyman, Bradley T; Maguire, Casey A; Ramirez, Servio H

    2017-01-01

    Developing therapies for central nervous system (CNS) diseases is exceedingly difficult because of the blood-brain barrier (BBB). Notably, emerging technologies may provide promising new options for the treatment of CNS disorders. Adeno-associated virus serotype 9 (AAV9) has been shown to transduce cells in the CNS following intravascular administration in rodents, cats, pigs, and non-human primates. These results suggest that AAV9 is capable of crossing the BBB. However, mechanisms that govern AAV9 transendothelial trafficking at the BBB remain unknown. Furthermore, possibilities that AAV9 may transduce brain endothelial cells or affect BBB integrity still require investigation. Using primary human brain microvascular endothelial cells as a model of the human BBB, we performed transduction and transendothelial trafficking assays comparing AAV9 to AAV2, a serotype that does not cross the BBB or transduce endothelial cells effectively in vivo. Results of our in vitro studies indicate that AAV9 penetrates brain microvascular endothelial cells barriers more effectively than AAV2, but has reduced transduction efficiency. In addition, our data suggest that (i) AAV9 penetrates endothelial barriers through an active, cell-mediated process, and (ii) AAV9 fails to disrupt indicators of BBB integrity such as transendothelial electrical resistance, tight junction protein expression/localization, and inflammatory activation status. Overall, this report shows how human brain endothelial cells configured in BBB models can be utilized for evaluating transendothelial movement and transduction kinetics of various AAV capsids. Importantly, the use of a human in vitro BBB model can provide import insight into the possible effects that candidate AVV gene therapy vectors may have on the status of BBB integrity. Read the Editorial Highlight for this article on page 192.

  9. Endothelial cell laminin isoforms, laminins 8 and 10, play decisive roles in T cell recruitment across the blood-brain barrier in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Sixt, M; Engelhardt, B; Pausch, F; Hallmann, R; Wendler, O; Sorokin, L M

    2001-05-28

    An active involvement of blood-brain barrier endothelial cell basement membranes in development of inflammatory lesions in the central nervous system (CNS) has not been considered to date. Here we investigated the molecular composition and possible function of the extracellular matrix encountered by extravasating T lymphocytes during experimental autoimmune encephalomyelitis (EAE). Endothelial basement membranes contained laminin 8 (alpha4beta1gamma1) and/or 10 (alpha5beta1gamma1) and their expression was influenced by proinflammatory cytokines or angiostatic agents. T cells emigrating into the CNS during EAE encountered two biochemically distinct basement membranes, the endothelial (containing laminins 8 and 10) and the parenchymal (containing laminins 1 and 2) basement membranes. However, inflammatory cuffs occurred exclusively around endothelial basement membranes containing laminin 8, whereas in the presence of laminin 10 no infiltration was detectable. In vitro assays using encephalitogenic T cell lines revealed adhesion to laminins 8 and 10, whereas binding to laminins 1 and 2 could not be induced. Downregulation of integrin alpha6 on cerebral endothelium at sites of T cell infiltration, plus a high turnover of laminin 8 at these sites, suggested two possible roles for laminin 8 in the endothelial basement membrane: one at the level of the endothelial cells resulting in reduced adhesion and, thereby, increased penetrability of the monolayer; and secondly at the level of the T cells providing direct signals to the transmigrating cells.

  10. Protection of Vascular Endothelial Growth Factor to Brain Edema Following Intracerebral Hemorrhage and Its Involved Mechanisms: Effect of Aquaporin-4.

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    Heling Chu

    Full Text Available Vascular endothelial growth factor (VEGF has protective effects on many neurological diseases. However, whether VEGF acts on brain edema following intracerebral hemorrhage (ICH is largely unknown. Our previous study has shown aquaporin-4 (AQP4 plays an important role in brain edema elimination following ICH. Meanwhile, there is close relationship between VEGF and AQP4. In this study, we aimed to test effects of VEGF on brain edema following ICH and examine whether they were AQP4 dependent. Recombinant human VEGF165 (rhVEGF165 was injected intracerebroventricularly 1 d after ICH induced by microinjecting autologous whole blood into striatum. We detected perihemotomal AQP4 protein expression, then examined the effects of rhVEGF165 on perihemotomal brain edema at 1 d, 3 d, and 7 d after injection in wild type (AQP4(+/+ and AQP4 knock-out (AQP4(-/- mice. Furthermore, we assessed the possible signal transduction pathways activated by VEGF to regulate AQP4 expression via astrocyte cultures. We found perihemotomal AQP4 protein expression was highly increased by rhVEGF165. RhVEGF165 alleviated perihemotomal brain edema in AQP4(+/+ mice at each time point, but had no effect on AQP4(-/- mice. Perihemotomal EB extravasation was increased by rhVEGF165 in AQP4(-/- mice, but not AQP4(+/+ mice. RhVEGF165 reduced neurological deficits and increased Nissl's staining cells surrounding hemotoma in both types of mice and these effects were related to AQP4. RhVEGF165 up-regulated phospharylation of C-Jun amino-terminal kinase (p-JNK and extracellular signal-regulated kinase (p-ERK and AQP4 protein in cultured astrocytes. The latter was inhibited by JNK and ERK inhibitors. In conclusion, VEGF reduces neurological deficits, brain edema, and neuronal death surrounding hemotoma but has no influence on BBB permeability. These effects are closely related to AQP4 up-regulation, possibly through activating JNK and ERK pathways. The current study may present new insights to

  11. Evaluation of soluble junctional adhesion molecule-A as a biomarker of human brain endothelial barrier breakdown.

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    Axel Haarmann

    Full Text Available BACKGROUND: An inducible release of soluble junctional adhesion molecule-A (sJAM-A under pro-inflammatory conditions was described in cultured non-CNS endothelial cells (EC and increased sJAM-A serum levels were found to indicate inflammation in non-CNS vascular beds. Here we studied the regulation of JAM-A expression in cultured brain EC and evaluated sJAM-A as a serum biomarker of blood-brain barrier (BBB function. METHODOLOGY/PRINCIPAL FINDINGS: As previously reported in non-CNS EC types, pro-inflammatory stimulation of primary or immortalized (hCMEC/D3 human brain microvascular EC (HBMEC induced a redistribution of cell-bound JAM-A on the cell surface away from tight junctions, along with a dissociation from the cytoskeleton. This was paralleled by reduced immunocytochemical staining of occludin and zonula occludens-1 as well as by increased paracellular permeability for dextran 3000. Both a self-developed ELISA test and Western blot analysis detected a constitutive sJAM-A release by HBMEC into culture supernatants, which importantly was unaffected by pro-inflammatory or hypoxia/reoxygenation challenge. Accordingly, serum levels of sJAM-A were unaltered in 14 patients with clinically active multiple sclerosis compared to 45 stable patients and remained unchanged in 13 patients with acute ischemic non-small vessel stroke over time. CONCLUSION: Soluble JAM-A was not suited as a biomarker of BBB breakdown in our hands. The unexpected non-inducibility of sJAM-A release at the human BBB might contribute to a particular resistance of brain EC to inflammatory stimuli, protecting the CNS compartment.

  12. Brain pericytes increase the lipopolysaccharide-enhanced transcytosis of HIV-1 free virus across the in vitro blood–brain barrier: evidence for cytokine-mediated pericyte-endothelial cell crosstalk

    Science.gov (United States)

    2013-01-01

    Background Human immunodeficiency virus-1 (HIV-1) enters the brain by crossing the blood–brain barrier (BBB) as both free virus and within infected immune cells. Previous work showed that activation of the innate immune system with lipopolysaccharide (LPS) enhances free virus transport both in vivo and across monolayer monocultures of brain microvascular endothelial cells (BMECs) in vitro. Methods Here, we used monocultures and co-cultures of brain pericytes and brain endothelial cells to examine the crosstalk between these cell types in mediating the LPS-enhanced permeation of radioactively-labeled HIV-1 (I-HIV) across BMEC monolayers. Results We found that brain pericytes when co-cultured with BMEC monolayers magnified the LPS-enhanced transport of I-HIV without altering transendothelial electrical resistance, indicating that pericytes affected the transcytotic component of HIV-1 permeation. As LPS crosses the BBB poorly if at all, and since pericytes are on the abluminal side of the BBB, we postulated that luminal LPS acts indirectly on pericytes through abluminal secretions from BMECs. Consistent with this, we found that the pattern of secretion of cytokines by pericytes directly exposed to LPS was different than when the pericytes were exposed to the abluminal fluid from LPS-treated BMEC monolayers. Conclusion These results are evidence for a cellular crosstalk in which LPS acts at the luminal surface of the brain endothelial cell, inducing abluminal secretions that stimulate pericytes to release substances that enhance the permeability of the BMEC monolayer to HIV. PMID:23816186

  13. Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations.

    Science.gov (United States)

    Zhao, Zhenjun; Johnson, Michael S; Chen, Biyi; Grace, Michael; Ukath, Jaysree; Lee, Vivienne S; McRobb, Lucinda S; Sedger, Lisa M; Stoodley, Marcus A

    2016-06-01

    OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation

  14. Blood-Brain Barrier Deterioration and Hippocampal Gene Expression in Polymicrobial Sepsis: An Evaluation of Endothelial MyD88 and the Vagus Nerve.

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    Gerard Honig

    Full Text Available Systemic infection can initiate or exacerbate central nervous system (CNS pathology, even in the absence of overt invasion of bacteria into the CNS. Recent epidemiological studies have demonstrated that human survivors of sepsis have an increased risk of long-term neurocognitive decline. There is thus a need for improved understanding of the physiological mechanisms whereby acute sepsis affects the CNS. In particular, MyD88-dependent activation of brain microvascular endothelial cells and a resulting loss of blood-brain barrier integrity have been proposed to play an important role in the effects of systemic inflammation on the CNS. Signaling through the vagus nerve has also been considered to be an important component of CNS responses to systemic infection. Here, we demonstrate that blood-brain barrier permeabilization and hippocampal transcriptional responses during polymicrobial sepsis occur even in the absence of MyD88-dependent signaling in cerebrovascular endothelial cells. We further demonstrate that these transcriptional responses can occur without vagus nerve input. These results suggest that redundant signals mediate CNS responses in sepsis. Either endothelial or vagus nerve activation may be individually sufficient to transmit systemic inflammation to the central nervous system. Transcriptional activation in the forebrain in sepsis may be mediated by MyD88-independent endothelial mechanisms or by non-vagal neuronal pathways.

  15. Up-regulation of COX-2/PGE2 by endothelin-1 via MAPK-dependent NF-κB pathway in mouse brain microvascular endothelial cells

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    Lin Chih-Chung

    2013-01-01

    Full Text Available Abstract Background Endothelin-1 (ET-1 is a proinflammatory mediator and elevated in the regions of several brain injury and inflammatory diseases. The deleterious effects of ET-1 on endothelial cells may aggravate brain inflammation mediated through the regulation of cyclooxygenase-2 (COX-2/prostaglandin E2 (PGE2 system in various cell types. However, the signaling mechanisms underlying ET-1-induced COX-2 expression in brain microvascular endothelial cells remain unclear. Herein we investigated the effects of ET-1 in COX-2 regulation in mouse brain microvascular endothelial (bEnd.3 cells. Results The data obtained with Western blotting, RT-PCR, and immunofluorescent staining analyses showed that ET-1-induced COX-2 expression was mediated through an ETB-dependent transcriptional activation. Engagement of Gi- and Gq-protein-coupled ETB receptors by ET-1 led to phosphorylation of ERK1/2, p38 MAPK, and JNK1/2 and then activated transcription factor NF-κB. Moreover, the data of chromatin immunoprecipitation (ChIP and promoter reporter assay demonstrated that the activated NF-κB was translocated into nucleus and bound to its corresponding binding sites in COX-2 promoter, thereby turning on COX-2 gene transcription. Finally, up-regulation of COX-2 by ET-1 promoted PGE2 release in these cells. Conclusions These results suggested that in mouse bEnd.3 cells, activation of NF-κB by ETB-dependent MAPK cascades is essential for ET-1-induced up-regulation of COX-2/PGE2 system. Understanding the mechanisms of COX-2 expression and PGE2 release regulated by ET-1/ETB system on brain microvascular endothelial cells may provide rationally therapeutic interventions for brain injury or inflammatory diseases.

  16. Focal adhesion kinase is involved in type III group B streptococcal invasion of human brain microvascular endothelial cells.

    Science.gov (United States)

    Shin, Sooan; Paul-Satyaseela, Maneesh; Maneesh, Paul-Satyaseela; Lee, Jong-Seok; Romer, Lewis H; Kim, Kwang Sik

    2006-01-01

    Group B streptococcus (GBS), the leading cause of neonatal meningitis, has been shown to invade human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. GBS invasion of HBMEC has been shown to require the host cell actin cytoskeleton rearrangements. The present study examined the mechanisms underlying actin cytoskeleton rearrangements that are involved in type III GBS invasion of HBMEC. We showed that type III GBS invasion was inhibited by genistein, a general tyrosine kinase inhibitor (mean 54% invasion decrease at 100 microM), and LY294002, a phosphatidylinositol 3 (PI3) kinase inhibitor (mean 70% invasion decrease at 50 microM), but not by PP2, an inhibitor of the Src family tyrosine kinases. We subsequently showed that the focal adhesion kinase (FAK) was the one of the host proteins tyrosine phosphorylated by type III GBS. Over-expression of a dominant negative form of the FAK C-terminal domain significantly decreased type III GBS invasion of HBMEC (mean 51% invasion decrease). In addition, we showed that FAK phosphorylation correlated with its association of paxillin, an adapter protein of actin filament, and PI3-kinase subunit p85. This is the first demonstration that FAK phosphorylation and its association with paxillin and PI3 kinase play a key role in type III GBS invasion of HBMEC.

  17. Reversible Opening of Intercellular Junctions of Intestinal Epithelial and Brain Endothelial Cells With Tight Junction Modulator Peptides.

    Science.gov (United States)

    Bocsik, Alexandra; Walter, Fruzsina R; Gyebrovszki, Andrea; Fülöp, Lívia; Blasig, Ingolf; Dabrowski, Sebastian; Ötvös, Ferenc; Tóth, András; Rákhely, Gábor; Veszelka, Szilvia; Vastag, Monika; Szabó-Révész, Piroska; Deli, Mária A

    2016-02-01

    The intercellular junctions restrict the free passage of hydrophilic compounds through the paracellular clefts. Reversible opening of the tight junctions of biological barriers is investigated as one of the ways to increase drug delivery to the systemic circulation or the central nervous system. Six peptides, ADT-6, HAV-6, C-CPE, 7-mer (FDFWITP, PN-78), AT-1002, and PN-159, acting on different integral membrane and linker junctional proteins were tested on Caco-2 intestinal epithelial cell line and a coculture model of the blood-brain barrier. All peptides tested in nontoxic concentrations showed a reversible tight junctions modulating effect and were effective to open the paracellular pathway for the marker molecules fluorescein and albumin. The change in the structure of cell-cell junctions was verified by immunostaining for occludin, claudin-4,-5, ZO-1, β-catenin, and E-cadherin. Expression levels of occludin and claudins were measured in both models. We could demonstrate a selectivity of C-CPE, ADT-6, and HAV-6 peptides for epithelial cells and 7-mer and AT-1002 peptides for brain endothelial cells. PN-159 was the most effective modulator of junctional permeability in both models possibly acting via claudin-1 and -5. Our results indicate that these peptides can be effectively and selectively used as potential pharmaceutical excipients to improve drug delivery across biological barriers.

  18. Effect of baicalin and berberine on transport of nimodipine on primary-cultured, rat brain microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Dong-mei ZHANG; Hai-yan LIU; Lin XIE; Xiao-dong LIU

    2007-01-01

    Aim: To investigate whether baicalin and berberine affects the transport of nimodipine (NMD) across the blood-brain barrier (BBB). Methods: Primary-cultured, rat brain microvascular endothelial cells (rBMEC) were used as an in vitro model of the BBB. When cells became confluent, the steady-state uptake of NMD by rBMEC with or without baicalin and berberine was measured. The ef-fects of baicalin and berberine on the efflux of NMD from rBMEC were also studied.Results: Baicalin (2-5 μg/mL) increased the uptake of NMD, and baicalin (10-20 μg/mL) decreased the uptake. The steady-state uptake of NMD was higher than that of control group in the presence of 0.01-1 μg/mL berberine, but was lower in the presence of 2-10 μg/mL berberine. Conclusion: The bidirectional effect of baicalin and berberine on the uptake of NMD by rBMEC was found. Higher concentration showed an inhibitory effect, and lower concentration demonstrated an increasing effect.

  19. eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

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    Xing Hua Tang

    Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

  20. Capillary sample

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    ... several times a day using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a limited ... do not constitute endorsements of those other sites. Copyright 1997-2017, A.D.A.M., Inc. Duplication ...

  1. Interactions between antiparkinsonian drugs and ABCB1/P-glycoprotein at the blood-brain barrier in a rat brain endothelial cell model.

    Science.gov (United States)

    Vautier, Sarah; Milane, Aline; Fernandez, Christine; Buyse, Marion; Chacun, Helene; Farinotti, Robert

    2008-09-05

    Parkinson's disease is a neurodegenerative disorder that requires treatment by dopaminergic agonists, which may be responsible for central side effects. We hypothesized that the efflux transporter ABCB1/P-glycoprotein played a role in brain disposition of antiparkinsonian drugs and could control central toxicity. We aimed to evaluate antiparkinsonian drugs as ABCB1 substrates and/or inhibitors in rat brain endothelial cells GPNT, in order to predict potential clinical drug-drug interactions. Among the antiparkinsonian drugs tested, levodopa, bromocriptine, pergolide and pramipexole were ABCB1 substrates. However, only bromocriptine could inhibit ABCB1 functionality with an IC(50) of 6.71 microM on Rhodamine 123 uptake and an IC(50) of 1.71 microM on digoxine uptake. Thus, bromocriptine at 100 microM is responsible for an increase of levodopa intracellular transport of about 2.05-fold versus control. Therefore, we can conclude that bromocriptine is a potent drug for medicinal interactions in vitro. Hence, in patients with Parkinson's disease, these results may be considered to optimise treatments individually.

  2. The role of p-glycoprotein in psychiatric disorders : a reliable guard of the brain?

    NARCIS (Netherlands)

    De Klerk, Onno L; Bosker, Fokko J; Luurtsema, Gert; Nolte, Ilja M; Dierckx, Rudi; Den Boer, Johan A; Potschka, Heidrun

    2011-01-01

    A major component in the protection of the brain against blood-borne toxic influences is the multispecific efflux pump P-glycoprotein. This pump, a 170 kD protein, located at the luminal side of the capillary endothelial cells, has a large capacity and is capable of extruding a wide array of structu

  3. Effect of valproic acid and injury on lesion size and endothelial glycocalyx shedding in a rodent model of isolated traumatic brain injury

    DEFF Research Database (Denmark)

    Jepsen, Cecilie Heerdegen; deMoya, Marc A; Perner, Anders;

    2014-01-01

    BACKGROUND: In isolated traumatic brain injury (TBI), little is known about the endothelial response and the effects of endothelial glycocalyx shedding. We have previously shown that treatment with valproic acid (VPA) improves outcomes following TBI and hemorrhagic shock.In this model, we...... hypothesized that severe isolated TBI would cause shedding of the endothelial glycocalyx, as measured by serum syndecan-1 (sSDC-1) levels. We further hypothesized that VPA treatment would reduce this response and reduce lesion size volume. METHODS: Forty Sprague-Dawley rats were allocated to TBI + VPA (n = 8......), TBI + saline vehicle control infusion (n = 8), sham + saline vehicle control infusion (n = 6), or sham + VPA (n = 8). TBI animals were subjected to severe controlled cortical impact and killed 6 hours after injury. VPA 300 mg/kg was given as an intravenous bolus 30 minutes after injury. Serum samples...

  4. Insulin-like growth factor-1 secreted by brain microvascular endothelial cells attenuates neuron injury upon ischemia.

    Science.gov (United States)

    Wang, Jun; Tang, Yibo; Zhang, Wei; Zhao, Haiping; Wang, Runjun; Yan, Yangyang; Xu, Liwei; Li, Pengtao

    2013-08-01

    Insulin-like growth factor (IGF)-1 is essential for the development of the nervous system, and is present in many cell types. Relatively little is known about IGF-1 expression in brain microvascular endothelial cells (BMECs). For in vivo studies, we examined the expression of IGF-1 and insulin-like growth factor-binding protein (IGFBP)-2 after focal cerebral ischemia for 12 h, 24 h, 3 days and 7 days, utilizing a permanent middle cerebral artery occlusion (MCAO) model in rats. For in vitro studies, we examined the levels of IGF-1 and IGFBP-2 in the culture medium or primary culture of BMECs injured by oxygen-glucose deprivation (OGD). Then, we elucidated the protective effects of IGF-1 on cortical neurons injured by OGD and the possible mechanism. In addition, we investigated the effect of BMEC-conditioned medium on IGF-1 receptor expression in neurons. The results showed that IGF-1 expression increased in serum and brain tissue, whereas IGFBP-2 expression decreased in brain tissue of MCAO-injured rats. In primary culture of BMECs, the expression levels of IGF-1 and IGFBP-2 were significantly higher under OGD conditions in culture. IGF-1 administration improved neuron viability upon normoxia or OGD, and upregulated p-Akt expression. This effect was reversed by LY294002, a specific inhibitor of the phosphoinositide 3-kinase-Akt signaling pathway. Furthermore, conditioned medium from OGD-treated BMECs substantially suppressed neuron viability and the expression of IGF-1 receptor simultaneously. These data demonstrate that therapeutic strategies that prioritize the early recovery of the IGF-1 system in BMECs might be promising in ischemic injury.

  5. The Physiochemistry of Capped Nanosilver Predicts Its Biological Activity in Rat Brain Endothelial Cells (REBEC4)

    Science.gov (United States)

    The “capping” or coating of nanosilver (nanoAg) extends its potency by limiting its oxidation and aggregation and stabilizing its size and shape. The ability of such coated nanoAg to alter the permeability and activate oxidative stress pathways in rat brain endothelia...

  6. Sphingosine 1 Phosphate at the Blood Brain Barrier: Can the Modulation of S1P Receptor 1 Influence the Response of Endothelial Cells and Astrocytes to Inflammatory Stimuli?

    Directory of Open Access Journals (Sweden)

    Simona F Spampinato

    Full Text Available The ability of the Blood Brain Barrier (BBB to maintain proper barrier functions, keeping an optimal environment for central nervous system (CNS activity and regulating leukocytes' access, can be affected in CNS diseases. Endothelial cells and astrocytes are the principal BBB cellular constituents and their interaction is essential to maintain its function. Both endothelial cells and astrocytes express the receptors for the bioactive sphingolipid S1P. Fingolimod, an immune modulatory drug whose structure is similar to S1P, has been approved for treatment in multiple sclerosis (MS: fingolimod reduces the rate of MS relapses by preventing leukocyte egress from the lymph nodes. Here, we examined the ability of S1P and fingolimod to act on the BBB, using an in vitro co-culture model that allowed us to investigate the effects of S1P on endothelial cells, astrocytes, and interactions between the two. Acting selectively on endothelial cells, S1P receptor signaling reduced cell death induced by inflammatory cytokines. When acting on astrocytes, fingolimod treatment induced the release of a factor, granulocyte macrophage colony-stimulating factor (GM-CSF that reduced the effects of cytokines on endothelium. In an in vitro BBB model incorporating shear stress, S1P receptor modulation reduced leukocyte migration across the endothelial barrier, indicating a novel mechanism that might contribute to fingolimod efficacy in MS treatment.

  7. Blood-brain barrier transport of drugs for the treatment of brain diseases.

    Science.gov (United States)

    Gabathuler, Reinhard

    2009-06-01

    The central nervous system is a sanctuary protected by barriers that regulate brain homeostasis and control the transport of endogenous compounds into the brain. The blood-brain barrier, formed by endothelial cells of the brain capillaries, restricts access to brain cells allowing entry only to amino acids, glucose and hormones needed for normal brain cell function and metabolism. This very tight regulation of brain cell access is essential for the survival of neurons which do not have a significant capacity to regenerate, but also prevents therapeutic compounds, small and large, from reaching the brain. As a result, various strategies are being developed to enhance access of drugs to the brain parenchyma at therapeutically meaningful concentrations to effectively manage disease.

  8. Proteomic Analysis of Human Brain Microvascular Endothelial Cells Reveals Differential Protein Expression in Response to Enterovirus 71 Infection

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    Wenying Luo

    2015-01-01

    Full Text Available 2D DIGE technology was employed on proteins prepared from human brain microvascular endothelial cells (HBMEC, to study the differentially expressed proteins in cells at 0 h, 1 h, 16 h, and 24 h after infection. Proteins found to be differentially expressed were identified with matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDITOF/TOF MS analysis. We identified 43 spots showing changes of at least 2.5 fold up- or downregulated expressions in EV71-infected cells at different time when comparing to control, and 28 proteins could be successfully identified by MALDI TOF/TOF mass spectrometry analysis. 4 proteins were significantly upregulated, and 6 proteins were downregulated, another 18 proteins were different expression at different incubation time. We identified changes in the expression of 12 cellular metabolism-related proteins, 5 molecules involved in cytoskeleton, 3 molecules involved in energy metabolism, 2 molecules involved in signal transduction, 1 molecule involved in the ubiquitin-proteasome pathway, 1 molecule involved in cell cycle, 1 molecule involved in apoptosis-related protein, 1 molecular chaperone, and 2 unknown proteins. These findings build up a comprehensive profile of the HBMEC proteome and provide a useful basis for further analysis of the pathogenic mechanism that underlies EV71 infections to induce severe neural complications.

  9. Brain-derived neurotrophic factor increases vascular endothelial growth factor expression and enhances angiogenesis in human chondrosarcoma cells.

    Science.gov (United States)

    Lin, Chih-Yang; Hung, Shih-Ya; Chen, Hsien-Te; Tsou, Hsi-Kai; Fong, Yi-Chin; Wang, Shih-Wei; Tang, Chih-Hsin

    2014-10-15

    Chondrosarcomas are a type of primary malignant bone cancer, with a potent capacity for local invasion and distant metastasis. Brain-derived neurotrophic factor (BDNF) is commonly upregulated during neurogenesis. The aim of the present study was to examine the mechanism involved in BDNF-mediated vascular endothelial growth factor (VEGF) expression and angiogenesis in human chondrosarcoma cells. Here, we knocked down BDNF expression in chondrosarcoma cells and assessed their capacity to control VEGF expression and angiogenesis in vitro and in vivo. We found knockdown of BDNF decreased VEGF expression and abolished chondrosarcoma conditional medium-mediated angiogenesis in vitro as well as angiogenesis effects in vivo in the chick chorioallantoic membrane and Matrigel plug nude mouse models. In addition, in the xenograft tumor angiogenesis model, the knockdown of BDNF significantly reduced tumor growth and tumor-associated angiogenesis. BDNF increased VEGF expression and angiogenesis through the TrkB receptor, PLCγ, PKCα, and the HIF-1α signaling pathway. Finally, we analyzed samples from chondrosarcoma patients by immunohistochemical staining. The expression of BDNF and VEGF protein in 56 chondrosarcoma patients was significantly higher than in normal cartilage. In addition, the high level of BDNF expression correlated strongly with VEGF expression and tumor stage. Taken together, our results indicate that BDNF increases VEGF expression and enhances angiogenesis through a signal transduction pathway that involves the TrkB receptor, PLCγ, PKCα, and the HIF-1α. Therefore, BDNF may represent a novel target for anti-angiogenic therapy for human chondrosarcoma.

  10. Evidence for post-translational processing of vascular endothelial (VE-cadherin in brain tumors: towards a candidate biomarker.

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    Isabelle Vilgrain

    Full Text Available Vessel abnormalities are among the most important features in malignant glioma. Vascular endothelial (VE-cadherin is of major importance for vascular integrity. Upon cytokine challenge, VE-cadherin structural modifications have been described including tyrosine phosphorylation and cleavage. The goal of this study was to examine whether these events occurred in human glioma vessels. We demonstrated that VE-cadherin is highly expressed in human glioma tissue and tyrosine phosphorylated at site Y(685, a site previously found phosphorylated upon VEGF challenge, via Src activation. In vitro experiments showed that VEGF-induced VE-cadherin phosphorylation, preceded the cleavage of its extracellular adhesive domain (sVE, 90 kDa. Interestingly, metalloproteases (MMPs secreted by glioma cell lines were responsible for sVE release. Because VEGF and MMPs are important components of tumor microenvironment, we hypothesized that VE-cadherin proteolysis might occur in human brain tumors. Analysis of glioma patient sera prior treatment confirmed the presence of sVE in bloodstream. Furthermore, sVE levels studied in a cohort of 53 glioma patients were significantly predictive of the overall survival at three years (HR 0.13 [0.04; 0.40] p ≤ 0.001, irrespective to histopathological grade of tumors. Altogether, these results suggest that VE-cadherin structural modifications should be examined as candidate biomarkers of tumor vessel abnormalities, with promising applications in oncology.

  11. Protective Effects of Inducible HO-1 on Oxygen Toxicity in Rat Brain Endothelial Microvessel Cells

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    Seung-Jun Yoo

    2014-09-01

    Full Text Available BackgroundReperfusion in ischemia is believed to generate cytotoxic oxidative stress, which mediates reperfusion injury. These stress conditions can initiate lipid peroxidation and damage to proteins, as well as promote DNA strand breaks. As biliverdin and bilirubin produced by heme oxygenase isoform 1 (HO-1 have antioxidant properties, the production of both antioxidants by HO-1 may help increase the resistance of the ischemic brain to oxidative stress. In the present study, the survival effect of HO-1 was confirmed using hemin.MethodsTo confirm the roles of HO-1, carbon monoxide, and cyclic guanosine monophosphate further in the antioxidant effect of HO-1 and bilirubin, cells were treated with cycloheximide, desferoxamine, and zinc deuteroporphyrin IX 2,4 bis glycol, respectively.ResultsHO-1 itself acted as an antioxidant. Furthermore, iron, rather than carbon monoxide, was involved in the HO-1-mediated survival effect. HO-1 activity was also important in providing bilirubin as an antioxidant.ConclusionOur results suggested that HO-1 helped to increase the resistance of the ischemic brain to oxidative stress.

  12. Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette;

    2017-01-01

    basement membrane proteins such as laminin-411, laminin-511, collagen IV [α1(IV)2 α2(IV)], agrin, perlecan, and nidogen 1 and 2 in vitro. Increased expression of the laminin α5 subunit correlated to the addition of BBB inducing factors (hydrocortisone, Ro 20-1724, and pCPT-cAMP), whereas increased...... expression of collagen IV α1 primarily correlated to increased levels of cAMP. In conclusion, BCECs cultured in vitro coherently form a BBB and express basement membrane proteins as a feature of maturation. This article is protected by copyright. All rights reserved....

  13. Induction of heme oxygenase-1 attenuates lipopolysaccharide-induced cyclooxygenase-2 expression in mouse brain endothelial cells

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    Yang Chuen-Mao

    2010-11-01

    Full Text Available Abstract Background Prostaglandin E2 (PGE2, an arachidonic acid metabolite converted by cyclooxygenase-2 (COX-2, plays important roles in the regulation of endothelial functions in response to bacterial infection. The enzymatic activity of COX-2 can be down-regulated by heme oxygenase-1 (HO-1 induction. However, the mechanisms underlying HO-1 modulating COX-2 protein expression are not known. Objective The aim of the present study was to investigate whether the up-regulation of HO-1 regulates COX-2 expression induced by lipopolysaccharide (LPS, an endotoxin produced by Gram negative bacteria, in mouse brain endothelial cells (bEnd.3 Methods Cultured bEnd.3 cells were used to investigate LPS-induced COX-2 expression and PGE2 production. Cobalt protoporphyrin IX (CoPP, an HO-1 inducer, infection with a recombinant adenovirus carried with HO-1 gene (Adv-HO-1, or zinc protoporphyrin (ZnPP, an HO-1 inhibitor was used to stimulate HO-1 induction or inhibit HO-1 activity. The expressions of COX-2 and HO-1 were evaluated by western blotting. PGE2 levels were detected by an enzyme-linked immunoassay. Hemoglobin (a chelator of carbon monoxide, CO, one of metabolites of HO-1 and CO-RM2 (a CO releasing molecule were used to investigate the mechanisms of HO-1 regulating COX-2 expression. Results We found that LPS-induced COX-2 expression and PGE2 production were mediated through NF-κB (p65 via activation of Toll-like receptor 4 (TLR4. LPS-induced COX-2 expression was inhibited by HO-1 induction by pretreatment with CoPP or infection with Adv-HO-1. This inhibitory effect of HO-1 was reversed by pretreatment with either ZnPP or hemoglobin. Pretreatment with CO-RM2 also inhibited TLR4/MyD88 complex formation, NF-κB (p65 activation, COX-2 expression, and PGE2 production induced by LPS. Conclusions We show here a novel inhibition of HO-1 on LPS-induced COX-2/PGE2 production in bEnd.3. Our results reinforce the emerging role of cerebral endothelium-derived HO-1

  14. Brain-derived neurotrophic factor induces migration of endothelial cells through a TrkB-ERK-integrin αVβ3-FAK cascade.

    Science.gov (United States)

    Matsuda, Shinji; Fujita, Tsuyoshi; Kajiya, Mikihito; Takeda, Katsuhiro; Shiba, Hideki; Kawaguchi, Hiroyuki; Kurihara, Hidemi

    2012-05-01

    Brain-derived neurotrophic factor (BDNF) promotes the regeneration of periodontal tissue. Since angiogenesis is important for tissue regeneration, investigating effect of BDNF on endothelial cell function may help to reveal its mechanism, whereby, BDNF promotes periodontal tissue regeneration. In this study, we examined the influence of BDNF on migration in human microvascular endothelial cells (HMVECs), focusing on the effects on extracellular signal-regulated kinase (ERK), integrin α(V)β(3), and focal adhesion kinase (FAK). The migration of endothelial cells was assessed with a modified Boyden chamber and a wound healing assay. The expression of integrin α(V)β(3) and the phosphorylation of ERK and FAK were analyzed by immunoblotting and immunofluorescence microscopy. BDNF (25 ng/ml) induced cell migration. PD98059, an ERK inhibitor, K252a, a specific inhibitor for TrkB, a high affinity receptor of BDNF, and an anti-integrin α(V)β(3) antibody suppressed the BDNF-induced migration. BDNF increased the levels of integrin α(V)β(3) and phosphorylated ERK1/2 and FAK. The ERK inhibitor and TrkB inhibitor also reduced levels of integrin α(V)β(3) and phosphorylated FAK. We propose that BDNF stimulates endothelial cell migration by a process involving TrkB/ERK/integrin α(V)β(3)/FAK, and this may help to enhance the regeneration of periodontal tissue.

  15. Generation of Brain Microvascular Endothelial-Like Cells from Human Induced Pluripotent Stem Cells by Co-Culture with C6 Glioma Cells.

    Science.gov (United States)

    Minami, Haruka; Tashiro, Katsuhisa; Okada, Atsumasa; Hirata, Nobue; Yamaguchi, Tomoko; Takayama, Kazuo; Mizuguchi, Hiroyuki; Kawabata, Kenji

    2015-01-01

    The blood brain barrier (BBB) is formed by brain microvascular endothelial cells (BMECs) and tightly regulates the transport of molecules from blood to neural tissues. In vitro BBB models from human pluripotent stem cell (PSCs)-derived BMECs would be useful not only for the research on the BBB development and function but also for drug-screening for neurological diseases. However, little is known about the differentiation of human PSCs to BMECs. In the present study, human induced PSCs (iPSCs) were differentiated into endothelial cells (ECs), and further maturated to BMECs. Interestingly, C6 rat glioma cell-conditioned medium (C6CM), in addition to C6 co-culture, induced the differentiation of human iPSC-derived ECs (iPS-ECs) to BMEC-like cells, increase in the trans-endothelial electrical resistance, decreased in the dextran transport and up-regulation of gene expression of tight junction molecules in human iPS-ECs. Moreover, Wnt inhibitors attenuated the effects of C6CM. In summary, we have established a simple protocol of the generation of BMEC-like cells from human iPSCs, and have demonstrated that differentiation of iPS-ECs to BMEC-like cells is induced by C6CM-derived signals, including canonical Wnt signals.

  16. Generation of Brain Microvascular Endothelial-Like Cells from Human Induced Pluripotent Stem Cells by Co-Culture with C6 Glioma Cells.

    Directory of Open Access Journals (Sweden)

    Haruka Minami

    Full Text Available The blood brain barrier (BBB is formed by brain microvascular endothelial cells (BMECs and tightly regulates the transport of molecules from blood to neural tissues. In vitro BBB models from human pluripotent stem cell (PSCs-derived BMECs would be useful not only for the research on the BBB development and function but also for drug-screening for neurological diseases. However, little is known about the differentiation of human PSCs to BMECs. In the present study, human induced PSCs (iPSCs were differentiated into endothelial cells (ECs, and further maturated to BMECs. Interestingly, C6 rat glioma cell-conditioned medium (C6CM, in addition to C6 co-culture, induced the differentiation of human iPSC-derived ECs (iPS-ECs to BMEC-like cells, increase in the trans-endothelial electrical resistance, decreased in the dextran transport and up-regulation of gene expression of tight junction molecules in human iPS-ECs. Moreover, Wnt inhibitors attenuated the effects of C6CM. In summary, we have established a simple protocol of the generation of BMEC-like cells from human iPSCs, and have demonstrated that differentiation of iPS-ECs to BMEC-like cells is induced by C6CM-derived signals, including canonical Wnt signals.

  17. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1 -weighted perfusion MRI

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Vestergaard, Mark B; Lindberg, Ulrich

    2017-01-01

    impulse response function was compatible with the adiabatic tissue homogeneity model. In two patients with complete occlusion of the internal carotid artery and in the patient with a brain tumor CTH was increased with values up to 6 s in the affected brain tissue, with an exponential like residue impulse...

  18. Interactions of Pseudomonas aeruginosa and Corynebacterium spp. with non-phagocytic brain microvascular endothelial cells and phagocytic Acanthamoeba castellanii.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Lakhundi, Sahreena; Khan, Naveed Ahmed

    2015-06-01

    Several lines of evidence suggest that Acanthamoeba interact with bacteria, which may aid in pathogenic bacterial transmission to susceptible hosts, and these interactions may have influenced evolution of bacterial pathogenicity. In this study, we tested if Gram-negative Pseudomonas aeruginosa and Gram-positive Corynebacterium spp. can associate/invade and survive inside Acanthamoeba castellanii trophozoites and cysts, as well as non-phagocytic human brain microvascular endothelial cells. The results revealed that both Corynebacterium spp. and P. aeruginosa were able to associate as well as invade and/or taken up by the phagocytic A. castellanii trophozoite. In contrast, P. aeruginosa exhibited higher association as well as invasion of non-phagocytic HBMEC compared with Corynebacterium spp. Notably, P. aeruginosa remained viable during the encystment process and exhibited higher levels of recovery from mature cysts (74.54 bacteria per amoebae) compared with Corynebacterium spp. (2.69 bacteria per amoeba) (P < 0.05). As Acanthamoeba cysts can be airborne, these findings suggest that Acanthamoeba is a potential vector in the transmission of P. aeruginosa to susceptible hosts. When bacterial-ridden amoebae were exposed to favourable (nutrient-rich) conditions, A. castellanii emerged as vegetative trophozoites and remained viable, and likewise viable P. aeruginosa were also observed but rarely any Corynebacterium spp. were observed. Correspondingly, P. aeruginosa but not Corynebacterium spp. exhibited higher cytotoxicity to non-phagocytic HBMEC, producing more than 75% cell death in 24 h, compared to 20% cell death observed with Corynebacterium spp. Additionally, it was observed that the bacterial conditioned medium had no negative effect on A. castellanii growth. Further characterization of amoebal and bacterial interactions will assist in identifying the role of Acanthamoeba in the transmission and evolution of pathogenic bacteria.

  19. Ammonia inhibits the C-type natriuretic peptide-dependent cyclic GMP synthesis and calcium accumulation in a rat brain endothelial cell line.

    Science.gov (United States)

    Konopacka, Agnieszka; Zielińska, Magdalena; Albrecht, Jan

    2008-05-01

    Recently we reported a decrease of C-type natriuretic peptide (CNP)-dependent, natriuretic peptide receptor 2 (NPR2)-mediated cyclic GMP (cGMP) synthesis in a non-neuronal compartment of cerebral cortical slices of hyperammonemic rats [Zielińska, M., Fresko, I., Konopacka, A., Felipo, V., Albrecht, J., 2007. Hyperammonemia inhibits the natriuretic peptide receptor 2 (NPR2)-mediated cyclic GMP synthesis in the astrocytic compartment of rat cerebral cortex slices. Neurotoxicology 28, 1260-1263]. Here we accounted for the possible involvement of cerebral capillary endothelial cells in this response by measuring the effect of ammonia on the CNP-mediated cGMP formation and intracellular calcium ([Ca2+]i) accumulation in a rat cerebral endothelial cell line (RBE-4). We first established that stimulation of cGMP synthesis in RBE-4 cells was coupled to protein kinase G (PKG)-mediated Ca2+ influx from the medium which was inhibited by an L-type channel blocker nimodipine. Ammonia treatment (1h, 5mM NH4Cl) evoked a substantial decrease of CNP-stimulated cGMP synthesis which was related to a decreased binding of CNP to NPR2 receptors, and depressed the CNP-dependent [Ca2+]i accumulation in these cells. Ammonia also abolished the CNP-dependent Ca2+ accumulation in the absence of Na+. In cells incubated with ammonia in the absence of Ca2+ a slight CNP-dependent increase of [Ca2+]i was observed, most likely representing Ca2+ release from intracellular stores. Depression of CNP-dependent cGMP-mediated [Ca2+]i accumulation may contribute to cerebral vascular endothelial dysfunction associated with hyperammonemia or hepatic encephalopathy.

  20. Matrix metalloproteinase 2 (MMP-2) degrades soluble vasculotropic amyloid-beta E22Q and L34V mutants, delaying their toxicity for human brain microvascular endothelial cells.

    Science.gov (United States)

    Hernandez-Guillamon, Mar; Mawhirt, Stephanie; Fossati, Silvia; Blais, Steven; Pares, Mireia; Penalba, Anna; Boada, Merce; Couraud, Pierre-Olivier; Neubert, Thomas A; Montaner, Joan; Ghiso, Jorge; Rostagno, Agueda

    2010-08-27

    Patients carrying mutations within the amyloid-beta (Abeta) sequence develop severe early-onset cerebral amyloid angiopathy with some of the related variants manifesting primarily with hemorrhagic phenotypes. Matrix metalloproteases (MMPs) are typically associated with blood brain barrier disruption and hemorrhagic transformations after ischemic stroke. However, their contribution to cerebral amyloid angiopathy-related hemorrhage remains unclear. Human brain endothelial cells challenged with Abeta synthetic homologues containing mutations known to be associated in vivo with hemorrhagic manifestations (AbetaE22Q and AbetaL34V) showed enhanced production and activation of MMP-2, evaluated via Multiplex MMP antibody arrays, gel zymography, and Western blot, which in turn proteolytically cleaved in situ the Abeta peptides. Immunoprecipitation followed by mass spectrometry analysis highlighted the generation of specific C-terminal proteolytic fragments, in particular the accumulation of Abeta-(1-16), a result validated in vitro with recombinant MMP-2 and quantitatively evaluated using deuterium-labeled internal standards. Silencing MMP-2 gene expression resulted in reduced Abeta degradation and enhanced apoptosis. Secretion and activation of MMP-2 as well as susceptibility of the Abeta peptides to MMP-2 degradation were dependent on the peptide conformation, with fibrillar elements of AbetaE22Q exhibiting negligible effects. Our results indicate that MMP-2 release and activation differentially degrades Abeta species, delaying their toxicity for endothelial cells. However, taking into consideration MMP ability to degrade basement membrane components, these protective effects might also undesirably compromise blood brain barrier integrity and precipitate a hemorrhagic phenotype.

  1. Inhibition of glutathione synthesis in brain endothelial cells lengthens S-phase transit time in the cell cycle: Implications for proliferation in recovery from oxidative stress and endothelial cell damage

    Directory of Open Access Journals (Sweden)

    Carmina Buşu

    2013-01-01

    Full Text Available Oxidative stress-induced decrease in tissue or systemic glutathione (GSH and damage to the vascular endothelium of the blood-brain barrier such as occurs in diabetes or stroke will have important implications for brain homeostasis. Endothelial proliferation or repair is crucial to preserving barrier function. Cell proliferation has been associated with increased intracellular GSH, but the kinetic and distribution of GSH during cell cycle is poorly understood. Here, we determined the influence of cellular GSH status on the early dynamics of nuclear-to-cytosol (N-to-C GSH distribution (6-h interval during proliferation in a human brain microvascular endothelial cell line (IHEC. Control IHECs exhibited two peak S-phases of the cell cycle at 48 and 60 h post seeding that temporally corresponded to peak nuclear GSH levels and expression of cdk1, the S-to-G2-to-M checkpoint controller, suggesting a link between cell cycle progression and nuclear GSH. Sustained inhibition of GSH synthesis delayed S-to-G2/M cell transition; cell arrest in the S-phase was correlated with decreased total nuclear GSH and increased nuclear expressions of chk2/phospho-chk2 and GADPH. The temporal correspondence of nuclear chk2 activation and GAPDH expression with S-phase prolongation is consistent with enhanced DNA damage response and extended time for DNA repair. Strikingly, when GSH synthesis was restored, cell transit time through S-phase remained delayed. Significantly, total nuclear GSH remained depressed, indicating a time lag between restored cellular GSH synthetic capacity and recovery of the nuclear GSH status. Interestingly, despite a delay in cell cycle recovery, nuclear expressions of chk2/phospho-chk2 and GAPDH resembled those of control cells. This means that restoration of nuclear DNA integrity preceded normalization of the cell cycle. The current results provide important insights into GSH control of endothelial proliferation with implications for cell

  2. Flavonoids targeting of IκB phosphorylation abrogates carcinogen-induced MMP-9 and COX-2 expression in human brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Tahanian E

    2011-05-01

    Full Text Available Elizabeth Tahanian¹, Luis Arguello Sanchez¹, Tze Chieh Shiao², René Roy², Borhane Annabi¹¹Centre de Recherche BioMED, ²Centre de Recherche PharmaQAM, Département de chimie, Université du Québec à Montréal, QC, CanadaAbstract: Brain endothelial cells play an essential role as structural and functional components of the blood–brain barrier (BBB. Increased BBB breakdown and brain injury are associated with neuroinflammation and are thought to trigger mechanisms involving matrix metalloproteinase upregulation. Emerging evidence also indicates that cyclooxygenase (COX inhibition limits BBB disruption, but the mechanisms linking metalloproteinase to COX remain unknown. In this study, we sought to investigate the nuclear factor-kappa B (NF-κB signaling pathway, a common pathway in both the regulation of matrix metalloproteinase-9 (MMP-9 and COX-2 expression, and the inhibitory properties of several chemopreventive flavonoids. Human brain microvascular endothelial cells were treated with a combination of phorbol 12-myristate 13-acetate (PMA, a carcinogen documented to increase MMP-9 and COX-2 through NF-κB, and several naturally occurring flavonoids. Among the molecules tested, we found that fisetin, apigenin, and luteolin specifically and dose-dependently antagonized PMA-induced COX-2 and MMP-9 gene and protein expressions as assessed by qRT-PCR, immunoblotting, and zymography respectively. We further demonstrate that flavonoids impact on IκK-mediated phosphorylation activity as demonstrated by the inhibition of PMA-induced IκB phosphorylation levels. Our results suggest that BBB disruption during neuroinflammation could be pharmacologically reduced by a specific class of flavonoids acting as NF-κB signal transduction inhibitors.Keywords: blood–brain barrier, flavonoids, neuroinflammation, NF-κB signal transduction inhibitors

  3. Endothelial cells derived from the blood-brain barrier and islets of Langerhans differ in their response to the effects of bilirubin on oxidative stress under hyperglycemic conditions

    Directory of Open Access Journals (Sweden)

    Jaime eKapitulnik

    2012-07-01

    Full Text Available Unconjugated bilirubin (UCB is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS. High glucose levels (hyperglycemia generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB. In the current study we show that UCB (1-40 M induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langherans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM glucose levels. While UCB (0.1-40 M did not alter ROS production in cells exposed to normal glucose, relatively low ('physiological' UCB concentrations (0.1-5 M attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20-40 M increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

  4. Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

    Science.gov (United States)

    Jayakumar, Arumugam R; Tong, Xiao Y; Curtis, Kevin M; Ruiz-Cordero, Roberto; Abreu, Maria T; Norenberg, Michael D

    2014-03-01

    Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents.

  5. Oxidative and pro-inflammatory impact of regular and denicotinized cigarettes on blood brain barrier endothelial cells: is smoking reduced or nicotine-free products really safe?

    Science.gov (United States)

    2014-01-01

    Background Both active and passive tobacco smoke (TS) potentially impair the vascular endothelial function in a causative and dose-dependent manner, largely related to the content of reactive oxygen species (ROS), nicotine, and pro-inflammatory activity. Together these factors can compromise the restrictive properties of the blood–brain barrier (BBB) and trigger the pathogenesis/progression of several neurological disorders including silent cerebral infarction, stroke, multiple sclerosis and Alzheimer’s disease. Based on these premises, we analyzed and assessed the toxic impact of smoke extract from a range of tobacco products (with varying levels of nicotine) on brain microvascular endothelial cell line (hCMEC/D3), a well characterized human BBB model. Results Initial profiling of TS showed a significant release of reactive oxygen (ROS) and reactive nitrogen species (RNS) in full flavor, nicotine-free (NF, “reduced-exposure” brand) and ultralow nicotine products. This release correlated with increased oxidative cell damage. In parallel, membrane expression of endothelial tight junction proteins ZO-1 and occludin were significantly down-regulated suggesting the impairment of barrier function. Expression of VE-cadherin and claudin-5 were also increased by the ultralow or nicotine free tobacco smoke extract. TS extract from these cigarettes also induced an inflammatory response in BBB ECs as demonstrated by increased IL-6 and MMP-2 levels and up-regulation of vascular adhesion molecules, such as VCAM-1 and PECAM-1. Conclusions In summary, our results indicate that NF and ultralow nicotine cigarettes are potentially more harmful to the BBB endothelium than regular tobacco products. In addition, this study demonstrates that the TS-induced toxicity at BBB ECs is strongly correlated to the TAR and NO levels in the cigarettes rather than the nicotine content. PMID:24755281

  6. Synergy of endothelial and neural progenitor cells from adipose-derived stem cells to preserve neurovascular structures in rat hypoxic-ischemic brain injury.

    Science.gov (United States)

    Hsueh, Yuan-Yu; Chang, Ya-Ju; Huang, Chia-Wei; Handayani, Fitri; Chiang, Yi-Lun; Fan, Shih-Chen; Ho, Chien-Jung; Kuo, Yu-Min; Yang, Shang-Hsun; Chen, Yuh-Ling; Lin, Sheng-Che; Huang, Chao-Ching; Wu, Chia-Ching

    2015-10-08

    Perinatal cerebral hypoxic-ischemic (HI) injury damages the architecture of neurovascular units (NVUs) and results in neurological disorders. Here, we differentiated adipose-derived stem cells (ASCs) toward the progenitor of endothelial progenitor cells (EPCs) and neural precursor cells (NPCs) via microenvironmental induction and investigated the protective effect by transplanting ASCs, EPCs, NPCs, or a combination of EPCs and NPCs (E+N) into neonatal HI injured rat pups. The E+N combination produced significant reduction in brain damage and cell apoptosis and the most comprehensive restoration in NVUs regarding neuron number, normal astrocytes, and vessel density. Improvements in cognitive and motor functions were also achieved in injured rats with E+N therapy. Synergistic interactions to facilitate transmigration under in vitro hypoxic microenvironment were discovered with involvement of the neuropilin-1 (NRP1) signal in EPCs and the C-X-C chemokine receptor 4 (CXCR4) and fibroblast growth factor receptor 1 (FGFR1) signals in NPCs. Therefore, ASCs exhibit great potential for cell sources in endothelial and neural lineages to prevent brain from HI damage.

  7. Interactions of Neuropathogenic Escherichia coli K1 (RS218 and Its Derivatives Lacking Genomic Islands with Phagocytic Acanthamoeba castellanii and Nonphagocytic Brain Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Farzana Abubakar Yousuf

    2014-01-01

    Full Text Available Here we determined the role of various genomic islands in E. coli K1 interactions with phagocytic A. castellanii and nonphagocytic brain microvascular endothelial cells. The findings revealed that the genomic islands deletion mutants of RS218 related to toxins (peptide toxin, α-hemolysin, adhesins (P fimbriae, F17-like fimbriae, nonfimbrial adhesins, Hek, and hemagglutinin, protein secretion system (T1SS for hemolysin, invasins (IbeA, CNF1, metabolism (D-serine catabolism, dihydroxyacetone, glycerol, and glyoxylate metabolism showed reduced interactions with both A. castellanii and brain microvascular endothelial cells. Interestingly, the deletion of RS218-derived genomic island 21 containing adhesins (P fimbriae, F17-like fimbriae, nonfimbrial adhesins, Hek, and hemagglutinin, protein secretion system (T1SS for hemolysin, invasins (CNF1, metabolism (D-serine catabolism abolished E. coli K1-mediated HBMEC cytotoxicity in a CNF1-independent manner. Therefore, the characterization of these genomic islands should reveal mechanisms of evolutionary gain for E. coli K1 pathogenicity.

  8. Neisseria meningitidis causes cell cycle arrest of human brain microvascular endothelial cells at S phase via p21 and cyclin G2.

    Science.gov (United States)

    Oosthuysen, Wilhelm F; Mueller, Tobias; Dittrich, Marcus T; Schubert-Unkmeir, Alexandra

    2016-01-01

    Microbial pathogens have developed several mechanisms to modulate and interfere with host cell cycle progression. In this study, we analysed the effect of the human pathogen Neisseria meningitidis on cell cycle in a brain endothelial cell line as well as in primary brain endothelial cells. We found that N.  Meningitidis causes an accumulation of cells in the S phase early at 3 and at 24 h post-infection that was paralleled by a decrease of cells in G2/M phase. Importantly, the outer membrane proteins of the colony opacity-associated (Opa) protein family as well as the Opc protein proved to trigger the accumulation of cells in the S phase. A focused cell cycle reverse transcription quantitative polymerase chain reaction-based array and integrated network analysis revealed changes in the abundance of several cell cycle regulatory mRNAs, including the cell cycle inhibitors p21(WAF1/CIP1) and cyclin G2. These alterations were reflected in changes in protein expression levels and/or relocalization in N. meningitidis-infected cells. Moreover, an increase in p21(WAF1/CIP1) expression was found to be p53 independent. Genetic ablation of p21(WAF1/CIP1) and cyclin G2 abrogated N. meningitidis-induced S phase accumulation. Finally, by measuring the levels of the biomarker 8-hydroxydeoxyguanosine and phosphorylation of the histone variant H2AX, we provide evidence that N. meningitidis induces oxidative DNA damage in infected cells.

  9. Effect of TM4SF1 on capillary-like tube formation in human umbilical vein endothelial cells%TM4SF1对人脐静脉内皮细胞管腔形成的影响

    Institute of Scientific and Technical Information of China (English)

    曹佳; 贺思佳; 徐雷鸣; 李兆申

    2014-01-01

    目的:研究TM4SF1对内皮细胞体外管腔形成的影响。方法应用qRT-PCR方法检测人脐静脉内皮细胞(HUVECs)中TM4SF1的mRNA表达量;应用siRNA方法瞬时转染HUVECs,采用qRT-PCR方法检测转染48 h与72 h后TM4SF1的沉默效果,选择最佳的转染时间,应用In Vitro Angiogenesis Assay Kit观察siControl与siTM4SF1转染后HUVECs体外管腔形成情况。结果 qRT-PCR实验结果显示,HUVECs中表达TM4SF1的RQ值为(0.71±0.11),已知高表达TM4SF1胰腺癌细胞株MPanc96表达TM4SF1的RQ值为(0.56±0.13),两种细胞中TM4SF1表达量差异无统计学意义(P>0.05);siRNA瞬时转染HUVECs 48 h与72 h后,TM4SF1表达分别下降了47.06%与93.14%,HUVECs瞬时转染72 h后进行体外管腔形成实验,通过对管腔形成情况进行评级,siControl转染后HUVECs管腔形成情况为5级(多个闭合管状结构相连形成筛状),siTM4SF1转染后为2级(细胞排列形成夹角)。结论 TM4SF1在HUVECs中高表达,沉默TM4SF1后可以明显抑制HUVECs的体外管腔形成,提示TM4SF1与肿瘤血管形成相关。%Objective To investigate the effect of TM4SF1 on capillary-like tube formation in human umbili-cal vein endothelial cells (HUVECs) in vitro. Methods The mRNA expression of TM4SF1 in HUVECs was detected by quantitative reverse transcription-PCR (qRT-PCR). HUVECs were transiently transfected with siRNA, and the si-lence of TM4SF1 was determined by qRT-PCR at 48 h or 72 h after transfection to confirm the time of the best silenc-ing effect. The capillary-like tube formation was detected by In Vitro Angiogenesis Assay Kit and compared between siControl and siTM4SF1. Results The results of qRT-PCR showed the expression of TM4SF1 in HUVECs and in MPanc96, a pancreatic cancer cell line, as well. There were no significant difference in RQ values between HUVECs and MPanc96 by Mann-Whitney U test [(0.71±0.11)vs (0.56±0.13), P>0.05]. The expressions of TM4SF1 in HUVECs decreased by 47

  10. Aquaporin 4 expression and ultrastructure of the blood-brain barrier following cerebral contusion injury

    Institute of Scientific and Technical Information of China (English)

    Xinjun Li; Yangyun Han; Hong Xu; Zhongshu Sun; Zengjun Zhou; Xiaodong Long; Yumin Yang; Linbo Zou

    2013-01-01

    This study aimed to investigate aquaporin 4 expression and the ultrastructure of the blood-brain barrier at 2–72 hours following cerebral contusion injury, and correlate these changes to the formation of brain edema. Results revealed that at 2 hours after cerebral contusion and laceration injury, aquaporin 4 expression significantly increased, brain water content and blood-brain barrier permeability increased, and the number of pinocytotic vesicles in cerebral microvascular endothelial cells increased. In addition, the mitochondrial accumulation was observed. As contusion and laceration injury became aggravated, aquaporin 4 expression continued to increase, brain water content and blood-brain barrier permeability gradually increased, brain capillary endothelial cells and astrocytes swelled, and capillary basement membrane injury gradually increased. The above changes were most apparent at 12 hours after injury, after which they gradually attenuated. Aquaporin 4 expression positively correlated with brain water content and the blood-brain barrier index. Our experimental findings indicate that increasing aquaporin 4 expression and blood-brain barrier permeability after cerebral contusion and laceration injury in humans is involved in the formation of brain edema.

  11. Quantitation of dopamine, serotonin and adenosine content in a tissue punch from a brain slice using capillary electrophoresis with fast-scan cyclic voltammetry detection.

    Science.gov (United States)

    Fang, Huaifang; Pajski, Megan L; Ross, Ashley E; Venton, B Jill

    2013-01-01

    Methods to determine neurochemical concentrations in small samples of tissue are needed to map interactions among neurotransmitters. In particular, correlating physiological measurements of neurotransmitter release and the tissue content in a small region would be valuable. HPLC is the standard method for tissue content analysis but it requires microliter samples and the detector often varies by the class of compound being quantified; thus detecting molecules from different classes can be difficult. In this paper, we develop capillary electrophoresis with fast-scan cyclic voltammetry detection (CE-FSCV) for analysis of dopamine, serotonin, and adenosine content in tissue punches from rat brain slices. Using field-amplified sample stacking, the limit of detection was 5 nM for dopamine, 10 nM for serotonin, and 50 nM for adenosine. Neurotransmitters could be measured from a tissue punch as small as 7 µg (7 nL) of tissue, three orders of magnitude smaller than a typical HPLC sample. Tissue content analysis of punches in successive slices through the striatum revealed higher dopamine but lower adenosine content in the anterior striatum. Stimulated dopamine release was measured in a brain slice, then a tissue punch collected from the recording region. Dopamine content and release had a correlation coefficient of 0.71, which indicates much of the variance in stimulated release is due to variance in tissue content. CE-FSCV should facilitate measurements of tissue content in nanoliter samples, leading to a better understanding of how diseases or drugs affect dopamine, serotonin, and adenosine content.

  12. The protective role of isorhamnetin on human brain microvascular endothelial cells from cytotoxicity induced by methylglyoxal and oxygen-glucose deprivation.

    Science.gov (United States)

    Li, Wenlu; Chen, Zhigang; Yan, Min; He, Ping; Chen, Zhong; Dai, Haibin

    2016-02-01

    As the first target of stroke, cerebral endothelial cells play a key role in brain vascular repair and maintenance, and their function is impeded in diabetes. Methylglyoxal (MGO), a reactive dicarbonyl produced during glucose metabolism, accumulates in diabetic patients. MGO and MGO-induced advanced glycation end-products (AGEs) could ameliorate stroke-induced brain vascular damage, closely related with ECs dysfunction. Using MGO plus oxygen-glucose deprivation (OGD) to mimic diabetic stroke, we reported the protective effect of isorhamnetin on OGD-induced cytotoxicity after MGO treatment on primary human brain microvascular endothelial cells (HBMEC) and explored the underlying mechanisms. Treatment of MGO for 24 h significantly enhanced 3-h OGD-induced HBMEC toxic effect, which was inhibited by pretreatment of isorhamnetin (100 μmol/L). Moreover, the protective effect of isorhamnetin is multiple function dependent, which includes anti-inflammation, anti-oxidative stress and anti-apoptosis effects. Besides its well-known inhibition on the mitochondria-dependent or intrinsic apoptotic pathway, isorhamnetin also reduced activation of the extrinsic apoptotic pathway, as characterized by the decreased expression and activity of caspase 3 and caspase 8. Furthermore, pretreatment with isorhamnetin specifically inhibited FAS/FASL expression and suppressed nuclear factor-kappa B nuclear translocation. Taken together, our results indicated that isorhamnetin protected against OGD-induced cytotoxicity after MGO treatment in cultured HBMEC due to its multiple protective effects and could inhibit Fas-mediated extrinsic apoptosis. Therefore, isorhamnetin is a promising reagent for the treatment of hyperglycemia and ischemia-induced cerebral vascular degeneration. A proposed model of the potential protective mechanism of isorhamnetin, a metabolite of quercetin, on methylglyoxal (MGO) treatment plus oxygen-glucose deprivation (OGD) exposure-induced cytotoxicity in cultured human

  13. Capillary origami

    OpenAIRE

    Py, Charlotte; Reverdy, Paul; Doppler, L.; J. Bico; Roman, B.; Baroud, Charles,

    2007-01-01

    International audience; The hairs of a wet dog rushing out from a pond assemble into bundles; this is a common example of the effect of capillary forces on flexible structures. From a practical point of the deformation and adhesion of compliant structures induced by interfacial forces may lead to disastrous effects in mechanical microsystems.

  14. Activation of melatonin receptor (MT1/2) promotes P-gp transporter in methamphetamine-induced toxicity on primary rat brain microvascular endothelial cells.

    Science.gov (United States)

    Jumnongprakhon, Pichaya; Sivasinprasasn, Sivanan; Govitrapong, Piyarat; Tocharus, Chainarong; Tocharus, Jiraporn

    2017-02-20

    Melatonin has been known as a neuroprotective agent for the central nervous system (CNS) and the blood-brain barrier (BBB), which is the primary structure that comes into contact with several neurotoxins including methamphetamine (METH). Previous studies have reported that the activation of melatonin receptors (MT1/2) by melatonin could protect against METH-induced toxicity in brain endothelial cells via several mechanisms. However, its effects on the P-glycoprotein (P-gp) transporter, the active efflux pump involved in cell homeostasis, are still unclear. Thus, this study investigated the role of melatonin and its receptors on the METH-impaired P-gp transporter in primary rat brain microvascular endothelial cells (BMVECs). The results showed that METH impaired the function of the P-gp transporter, significantly decreasing the efflux of Rho123 and P-gp expression, which caused a significant increase in the intracellular accumulation of Rho123, and these responses were reversed by the interaction of melatonin with its receptors. Blockade of the P-gp transporter by verapamil caused oxidative stress, apoptosis, and cell integrity impairment after METH treatment, and these effects could be reversed by melatonin. Our results, together with previous findings, suggest that the interaction of melatonin with its receptors protects against the effects of the METH-impaired P-gp transporter and that the protective role in METH-induced toxicity was at least partially mediated by the regulation of the P-gp transporter. Thus, melatonin and its receptors (MT1/2) are essential for protecting against BBB impairment caused by METH.

  15. Adapting coculture in vitro models of the blood-brain barrier for use in cancer research: maintaining an appropriate endothelial monolayer for the assessment of transendothelial migration.

    Science.gov (United States)

    Vandenhaute, Elodie; Drolez, Aurore; Sevin, Emmanuel; Gosselet, Fabien; Mysiorek, Caroline; Dehouck, Marie-Pierre

    2016-05-01

    Although brain metastases are the most common brain tumors in adults, there are few treatment options in this setting. To colonize the brain, circulating tumor cells must cross the blood-brain barrier (BBB), which is situated within specialized, restrictive microvascular endothelium. Understanding how cancer cells manage to transmigrate through the BBB might enable this process to be prevented. In vitro models are dedicated tools for characterizing the cellular and molecular mechanisms that underlie transendothelial migration process, as long as they accurately mimic the brain endothelium's in vivo characteristics. The objective of the present study was to adapt an existing in vitro model of the human BBB for use in studying cancer cell transmigration. The model is based on the coculture of endothelial cells (ECs, derived from cord blood hematopoietic stem cells) and brain pericytes. To allow the migration of cancer cells into the lower compartment, our model had to be transposed onto inserts with a larger pore size. However, we encountered a problem when culturing ECs on large (3-μm)-pore inserts: the cells crossed the membrane and formed a non-physiological second layer on the lower face of the insert. Using 3-μm-pore inserts (in a 12-well plate format), we report here on a method that enables the maintenance of a single monolayer of ECs on the insert's upper face only. Under these chosen conditions, the ECs exhibited typical BBB properties found in the original model (including restricted paracellular permeability and the expression of continuous tight junctions). This modified in vitro model of the human BBB enabled us to investigate the migratory potential of the MDA-MB-231 cell line (derived from highly metastatic human breast cancer cells). Last, the results obtained were compared with the rate of transmigration through endothelia with no BBB features.

  16. In vitro model of cerebral ischemia by using brain microvascular endothelial cells derived from human induced pluripotent stem cells.

    Science.gov (United States)

    Kokubu, Yasuhiro; Yamaguchi, Tomoko; Kawabata, Kenji

    2017-04-29

    Brain-derived microvascular endothelial cells (BMECs), which play a central role in blood brain barrier (BBB), can be used for the evaluation of drug transport into the brain. Although human BMEC cell lines have already been reported, they lack original properties such as barrier integrity. Pluripotent stem cells (PSCs) can be used for various applications such as regenerative therapy, drug screening, and pathological study. In the recent study, an induction method of BMECs from PSCs has been established, making it possible to more precisely study the in vitro human BBB function. Here, using induced pluripotent stem (iPS) cell-derived BMECs, we examined the effects of oxygen-glucose deprivation (OGD) and OGD/reoxygenation (OGD/R) on BBB permeability. OGD disrupted the barrier function, and the dysfunction was rapidly restored by re-supply of the oxygen and glucose. Interestingly, TNF-α, which is known to be secreted from astrocytes and microglia in the cerebral ischemia, prevented the restoration of OGD-induced barrier dysfunction in an apoptosis-independent manner. Thus, we could establish the in vitro BBB disease model that mimics the cerebral ischemia by using iPS cell-derived BMECs.

  17. Real-time imaging of trapping and urease-dependent transmigration of Cryptococcus neoformans in mouse brain.

    Science.gov (United States)

    Shi, Meiqing; Li, Shu Shun; Zheng, Chunfu; Jones, Gareth J; Kim, Kwang Sik; Zhou, Hong; Kubes, Paul; Mody, Christopher H

    2010-05-01

    Infectious meningitis and encephalitis is caused by invasion of circulating pathogens into the brain. It is unknown how the circulating pathogens dynamically interact with brain endothelium under shear stress, leading to invasion into the brain. Here, using intravital microscopy, we have shown that Cryptococcus neoformans, a yeast pathogen that causes meningoencephalitis, stops suddenly in mouse brain capillaries of a similar or smaller diameter than the organism, in the same manner and with the same kinetics as polystyrene microspheres, without rolling and tethering to the endothelial surface. Trapping of the yeast pathogen in the mouse brain was not affected by viability or known virulence factors. After stopping in the brain, C. neoformans was seen to cross the capillary wall in real time. In contrast to trapping, viability, but not replication, was essential for the organism to cross the brain microvasculature. Using a knockout strain of C. neoformans, we demonstrated that transmigration into the mouse brain is urease dependent. To determine whether this could be amenable to therapy, we used the urease inhibitor flurofamide. Flurofamide ameliorated infection of the mouse brain by reducing transmigration into the brain. Together, these results suggest that C. neoformans is mechanically trapped in the brain capillary, which may not be amenable to pharmacotherapy, but actively transmigrates to the brain parenchyma with contributions from urease, suggesting that a therapeutic strategy aimed at inhibiting this enzyme could help prevent meningitis and encephalitis caused by C. neoformans infection.

  18. Neuron-specific enolase expression in a rat model of radiation-induced brain injury following vascular endothelial growth factor-modified neural stem cell transplantation

    Institute of Scientific and Technical Information of China (English)

    Songhua Xiao; Chaohui Duan; Qingyu Shen; Yigang Xing; Ying Peng; Enxiang Tao; Jun Liu

    2009-01-01

    BACKGROUND:Previous studies have shown that transplantation of vascular endothelial growth factor (VEGF)-modified neural stem cells (NSC) provides better outcomes,compared with neural stem cells,in the treatment of brain damage.OBJECTIVE:To compare the effects of VEGF-modified NSC transplantation and NSC transplantation on radiation-induced brain injury,and to determine neuron-specific enolase (NSE) expression in the brain.DESIGN,TIME,AND SETTING:The randomized,controlled study was performed at the Linbaixin Experimental Center,Second Affiliated Hospital,Sun Yat-sen University,China from November 2007 to October 2008.MATERIALS:VEGF-medified C17.2 NSCs were supplied by Harvard Medical School,USA.Streptavidin-biotin-peroxidase-complex kit (Boster,China) and 5,6-carboxyfluorescein diacetate succinimidyl ester (Fluka,USA) were used in this study.METHODS:A total of 84 Sprague Dawley rats were randomly assigned to a blank control group (n=20),model group (n=20),NSC group (n=20),and a VEGF-modified NSC group (n=24).Rat models of radiation-induced brain injury were established in the model,NSC,and VEGF-modified NSC groups.At 1 week following model induction,10 μL (5×10~4 cells/μL) VEGF-modified NSCs or NSCs were respectively infused into the striatum and cerebral cortex of rats from the VEGF-modified NSC and NSC groups.A total of 10 μL saline was injected into rats from the blank control and model groups.MAIN OUTCOME MEASURES:NSE expression in the brain was detected by immunohistochemistry following VEGF-modified NSC transplantation.RESULTS:NSE expression was significantly decreased in the brains of radiation-induced brain injury rats (P<0.05).The number of NSE-positive neurons significantly increased in the NSC and VEGF-modified NSC groups,compared with the model group (P<0.05).NSE expression significantly increased in the VEGF-modified NSC group,compared with the NSC group,at 6 weeks following transplantation (P<0.05).CONCLUSION:VEGF-modified NSC

  19. Induction of cyclooxygenase-2 expression during HIV-1-infected monocyte-derived macrophage and human brain microvascular endothelial cell interactions

    NARCIS (Netherlands)

    Pereira, CF; Boven, LA; Middel, J; Verhoef, J; Nottet, HSLM

    2000-01-01

    Human immunodeficiency virus type-1 (HIV-1)-associated dementia (HAD) is a neurodegenerative disease characterized by HIV infection and replication in brain tissue. HIV-1-infected monocytes overexpress inflammatory molecules that facilitate their entry into the brain. Prostanoids are lipid mediators

  20. Nanomolar aluminum induces expression of the inflammatory systemic biomarker C-reactive protein (CRP) in human brain microvessel endothelial cells (hBMECs).

    Science.gov (United States)

    Alexandrov, Peter N; Kruck, Theodore P A; Lukiw, Walter J

    2015-11-01

    C-reactive protein (CRP; also known as pentraxin 1, PTX1), a 224 amino acid soluble serum protein organized into a novel pentameric ring-shaped structure, is a highly sensitive pathogenic biomarker for systemic inflammation. High CRP levels are found in practically every known inflammatory state, and elevated CRP levels indicate an increased risk for several common age-related human degenerative disorders, including cardiovascular disease, cancer, diabetes, and Alzheimer's disease (AD). While the majority of CRP is synthesized in the liver for secretion into the systemic circulation, it has recently been discovered that an appreciable amount of CRP is synthesized in highly specialized endothelial cells that line the vasculature of the brain and central nervous system (CNS). These highly specialized cells, the major cell type lining the human CNS vasculature, are known as human brain microvessel endothelial cells (hBMECs). In the current pilot study we examined (i) CRP levels in human serum obtained from AD and age-matched control patients; and (ii) analyzed the effects of nanomolar aluminum sulfate on CRP expression in primary hBMECs. The three major findings in this short communication are: (i) that CRP is up-regulated in AD serum; (ii) that CRP serum levels increased in parallel with AD progression; and (iii) for the first time show that nanomolar aluminum potently up-regulates CRP expression in hBMECs to many times its 'basal abundance'. The results suggest that aluminum-induced CRP may in part contribute to a pathophysiological state associated with a chronic systemic inflammation of the human vasculature.

  1. Increased vesicular and vacuolar transendothelial transport in traumatic human brain oedema. A review.

    Science.gov (United States)

    Castejón, Orlando J

    2013-01-01

    The endothelial vacuolar and vesicular transports in traumatic human brain oedema have been reviewed and compared with experimental brain oedema in order to establish their role in both oedema formation and oedema resolution. Normal or "non-activated" and "activated" capillaries are found. The activated capillaries showed predominantly an enhanced abluminally orientated vesicular transport by means of small, medium and large uncoated and clathrin coated vesicles, as well as the presence of endothelial tubular structures. Activation of the endothelial nuclear zone is featured by the increased amount of micropinocytotic vesicles. Vesicles internalizing to the hypertrophic Golgi complex, lysosomes and multivesicular bodies are observed. The protein vacuolar transport is predominant in most cortical capillaries. A wide spectrum of endothelial cell mechanisms is observed increasing the vesicular and vacuolar transport, such as deep invaginations of the luminal surface, large coated vesicles, tubular structures, and transient and incomplete transendothelial channels formed either by chained plasmalemmal vesicles or elongated protein-containing vacuoles. Uncoated vesicles are seen surrounding lysosomes. Vesicular transport might be discriminated between abluminally orientated or transendothelial transport (oedema formation) and intraendothelial transport (oedema resolution) directed towards cell lysosomes to be degraded by lysosomal enzymes. The transendothelial passage via large vacuoles is mainly caused by macromolecular protein transport.

  2. A novel method for culture of bovine retinal capillary endothelial cells%一种高选择性、高效的牛视网膜微血管内皮细胞培养方法

    Institute of Scientific and Technical Information of China (English)

    王征; 齐炜炜; 陈少波; 戴智育; 陈大伟; 程锐; 高国全; 杨霞

    2012-01-01

    目的 建立一种高效、可行、特异性高的牛视网膜微血管内皮细胞(BREC)培养方法.方法 取新鲜牛眼,分离视网膜并用DMEM进行冲洗、匀浆剪碎,过75μm筛,将滤网上滤渣转移至50 ml离心管,用I型胶原酶、DNaseI及蛋白酶等多种酶混合液消化20 min,人血清中和后,过46μm网筛并冲洗,离心5 min,将组织扣在培养皿中,转入15 ml离心管,用10%人血清含生长因子ECGS的DMEM培养液培养于25 cm2,选择性培养视网膜血管内皮细胞,接种于明胶包被培养瓶中,采用ECGS配合肝素培养液促进内皮细胞生长,观察细胞形状生长特性,并用免疫化学荧光方法进行鉴定.结果 选择性培养视网膜微血管内皮细胞成单层、镶嵌铺路石状生长,Ⅷ因子相关抗原免疫荧光检测为阳性纯度均大于95%以上,将细胞种在凝固的基质胶表面,12~18 h形成官腔结构.结论 本方法过程简单、可靠,培养的内皮细胞纯度高,生长状态良好,稳定传代,为视网膜血管生成疾病研究建立了模型.%Objective To provide an efficient, practicable and high specificity method for culture of bovine retinal capillary endothelial cells (BRCEC). Methods Fresh bovine eyes were obtained from a local market. The retinas were removed and washed several times in DMEM. Subsequently retinas were homogenized and the resultant pellet was resuspended in an isolation medium. Microvesseles were trapped on an 75 ftm nylon mesh and transferred to a 50 ml centrifuge tube containing 10 ml enzyme cocktail which includes collagenase I , Dnase I and pronase and treated for 20 min. The resultant vessel fragments were trapped on a 46 p.m nylon mesh,washed with the isolation medium and centrifuged for 5 min. For selective culture of BRCECs, the resultant pellet was resuspended in 2 ml of the BRCEC growth medium and transferred into 25 cm2 gelatin-coated plastic tissue culture flasks. BRCECs were identified by immunohistochemical method of

  3. 肿瘤坏死因子α对豚鼠耳蜗血管纹微血管内皮细胞通透性的影响%Effect of tumor necrosis factor-alpha on the permeability of strial capillary endothelial cells in guinea pig cochlea

    Institute of Scientific and Technical Information of China (English)

    李琪; 袁伟; 魏运军; 张学渊

    2008-01-01

    Objective To perform an initial study on possible molecular regulatory mechanisms of TNF-α to the permeability of strial capillary endothelial cells in guinea pig cochlea. Methods Strial capillary endothelial cells in guinea pig cochlea was dissociated and cuhureed to establish a model for its permeability in vitro.,The animals were divided into TNF-α,TNF-α+L-arginine (L-Arg),TNF-α +NG-minomethyl-L-arginine(L-NMMA) and control groups.In order to measure the altemations of permeation rate,Evans blue was used in different time by different concentrations to detect contents of F-actin in each group under immunofluorescence laser scanning confocal micrescope.Results TNF-α increased permeability of Blrial capillary endothelial cells notablely,and permeation rate to Evans blue heightened siguificandy (P<0.01) and increased under higher concentrations of TNF-α as well as lengthened the durations.Being as a NO donator,L-Arg siguitlcanfly enhanced the ability of TNF-α which increasing permeability of strial capillary cndothelial cells;permeation rate to Evans blue beightened significantly(P<0.01),which obviously rose up when the concentration of Evans blue added.L-NMMA,NO inhibitor,was able to weaken the ability of TNF-α which increasing permeability of strial capillary endothelial cells:permeation rate to Evans blue decreased siguificantly (P<0.01),which obviously fell down when the concentration of L-NMMA added.TNF-α decreased F-actin in strial capillary endothelisl cells(P<0.01).more TNF-α, less F-actin;L-Arg could be further the inhibition to F-actin content(P<0.05);L-NMMA held back the trend(P<0.05).Conclusions TNF-α can increase permeability of strial capillary endothelial cells of suinca pig cochlea.NO may be one of the important molecular regulators to permeability of strial capillary endothelial cells by TNF-α,and changes of F-actin content probably relate to the regulation in these cells.%目的 探讨肿瘤坏死因子α(TNF-α)对豚鼠

  4. Brain iron homeostasis.

    Science.gov (United States)

    Moos, Torben

    2002-11-01

    Iron is essential for virtually all types of cells and organisms. The significance of the iron for brain function is reflected by the presence of receptors for transferrin on brain capillary endothelial cells. The transport of iron into the brain from the circulation is regulated so that the extraction of iron by brain capillary endothelial cells is low in iron-replete conditions and the reverse when the iron need of the brain is high as in conditions with iron deficiency and during development of the brain. Whereas there is good agreement that iron is taken up by means of receptor-mediated uptake of iron-transferrin at the brain barriers, there are contradictory views on how iron is transported further on from the brain barriers and into the brain extracellular space. The prevailing hypothesis for transport of iron across the BBB suggests a mechanism that involves detachment of iron from transferrin within barrier cells followed by recycling of apo-transferrin to blood plasma and release of iron as non-transferrin-bound iron into the brain interstitium from where the iron is taken up by neurons and glial cells. Another hypothesis claims that iron-transferrin is transported into the brain by means of transcytosis through the BBB. This thesis deals with the topic "brain iron homeostasis" defined as the attempts to maintain constant concentrations of iron in the brain internal environment via regulation of iron transport through brain barriers, cellular iron uptake by neurons and glia, and export of iron from brain to blood. The first part deals with transport of iron-transferrin complexes from blood to brain either by transport across the brain barriers or by uptake and retrograde axonal transport in motor neurons projecting beyond the blood-brain barrier. The transport of iron and transport into the brain was examined using radiolabeled iron-transferrin. Intravenous injection of [59Fe-125]transferrin led to an almost two-fold higher accumulation of 59Fe than of

  5. Mixed Capillary Venous Retroperitoneal Hemangioma

    Directory of Open Access Journals (Sweden)

    Mohit Godar

    2013-01-01

    Full Text Available We report a case of mixed capillary venous hemangioma of the retroperitoneum in a 61-year-old man. Abdominal ultrasonography showed a mass to be hypoechoic with increased flow in color Doppler imaging. Dynamic contrast-enhanced computed tomography revealed a centripetal filling-in of the mass, located anterior to the left psoas muscle at the level of sacroiliac joint. On the basis of imaging features, preoperative diagnosis of hemangioma was considered and the mass was excised by laparoscopic method. Immunohistochemical studies were strongly positive for CD31 and CD34, and negative for calretinin, EMA, WT1, HMB45, Ki67, synaptophysin, and lymphatic endothelial cell marker D2–40. Histologically, the neoplasm was diagnosed as mixed capillary venous hemangioma.

  6. The Role of the Blood-Brain Barrier in the Pathogenesis of Senile Plaques in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    J. Provias

    2014-01-01

    Full Text Available The accumulation of beta-amyloid [Aβ] within senile plaques [SP] is characteristic of these lesions in Alzheimer’s disease. The accumulation of Aβ42, in particular, in the superior temporal [ST] cortex may result from an inability of the blood brain barrier (BBB to regulate the trans-endothelial transport and clearance of the amyloid. Lipoprotein receptor-related protein [LRP] and P-glycoprotein [P-gp] facilitate the efflux of Aβ out of the brain, whereas receptor for advanced glycation end products [RAGE] facilitates Aβ influx. Additionally, vascular endothelial growth factor [VEGF] and endothelial nitric oxide synthase [eNOS] may influence the trans-BBB transport of Aβ. In this study we examined ST samples and compared SP burden of all types with the capillary expression of LRP, p-gp, RAGE, VEGF, and e-NOS in samples from 15 control and 15 Alzheimer brains. LRP, P-gp, RAGE, VEGF, and eNOS positive capillaries and Aβ42 plaques were quantified and statistical analysis of the nonparametric data was performed using the Mann-Whitney and Kruskal-Wallis tests. In the Alzheimer condition P-gp, VEGF, and eNOS positive capillaries were negatively correlated with SP burden, but LRP and RAGE were positively correlated with SP burden. These results indicate altered BBB function in the pathogenesis of SPs in Alzheimer brains.

  7. Hypertonic saline protects brain endothelial cells against hypoxia correlated to the levels of estimated glomerular filtration rate and interleukin-1β

    Science.gov (United States)

    Chen, Sheng-Long; Deng, Yi-Yu; Wang, Qiao-Sheng; Han, Yong-Li; Jiang, Wen-Qiang; Fang, Ming; Hu, Bei; Wu, Zhi-Xin; Huang, Lin-Qiang; Zeng, Hong-Ke

    2017-01-01

    Abstract Objective: The aim of this study was to verify the protective effect of hypertonic saline (HS) on brain endothelial cells under hypoxic conditions and the relevant underlying mechanism. Methods: bEnd.3 cells were treated with oxygen-glucose deprivation (OGD)-induced injury. To measure HS performance, cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt assay, and cell apoptosis was assessed by flow cytometry and Terminal deoxynucleotidyl transferase UTP nick-end labeling staining. RNA-seq was performed to assess the expression profiles and screen the candidate genes that participated in OGD-induced injury and the HS protective effect. Quantitative real-time polymerase chain reaction (qPCR) and western blot analysis were used to confirm the expression of candidate genes, and enzyme-linked immunosorbent assay was used to measure the level of interleukin (IL)-1β. Overexpression analyses were performed to confirm the functions of the differentially expressed genes. Results: HS with a concentration of 40 mmol/L NaCl had an obvious protective effect on bEnd.3 cells after OGD-induced injury, resulting in increased cell viability and a smaller percentage of apoptotic cells. According to the RNA-seq results, epidermal growth factor receptor (EGFR) was chosen as the differentially expressed gene target in this study. The qPCR and western blot analyses further confirmed that the levels of EGFR/phosphorylated epidermal growth factor receptor and IL-1β were enhanced after OGD-induced injury, but attenuated after treatment with 40 mmol/L of NaCl HS. Overexpressed EGFR reversed the protective effect of HS that caused low viability and high rates of apoptosis in cells. Conclusion: HS can protect endothelial cells against OGD-induced injury, but is affected by the expression of EGFR/p-EGFR and IL-1β. PMID:28072729

  8. HCdc14A is involved in cell cycle regulation of human brain vascular endothelial cells following injury induced by high glucose, free fatty acids and hypoxia.

    Science.gov (United States)

    Su, Jingjing; Zhou, Houguang; Tao, Yinghong; Guo, Zhuangli; Zhang, Shuo; Zhang, Yu; Huang, Yanyan; Tang, Yuping; Hu, Renming; Dong, Qiang

    2015-01-01

    Cell cycle processes play a vital role in vascular endothelial proliferation and dysfunction. Cell division cycle protein 14 (Cdc14) is an important cell cycle regulatory phosphatase. Previous studies in budding yeast demonstrated that Cdc14 could trigger the inactivation of mitotic cyclin-dependent kinases (Cdks), which are required for mitotic exit and cytokinesis. However, the exact function of human Cdc14 (hCdc14) in cell cycle regulation during vascular diseases is yet to be elucidated. There are two HCdc14 homologs: hCdc14A and hCdc14B. In the current study, we investigated the potential role of hCdc14A in high glucose-, free fatty acids (FFAs)-, and hypoxia-induced injury in cultured human brain vascular endothelial cells (HBVECs). Data revealed that high glucose, FFA, and hypoxia down-regulated hCdc14A expression remarkably, and also affected the expression of other cell cycle-related proteins such as cyclin B, cyclin D, cyclin E, and p53. Furthermore, the combined addition of the three stimuli largely blocked cell cycle progression, decreased cell proliferation, and increased apoptosis. We also determined that hCdc14A was localized mainly to centrosomes during interphase and spindles during mitosis using confocal microscopy, and that it could affect the expression of other cycle-related proteins. More importantly, the overexpression of hCdc14A accelerated cell cycle progression, enhanced cell proliferation, and promoted neoplastic transformation, whereas the knockdown of hCdc14A using small interfering RNA produced the opposite effects. Therefore, these findings provide novel evidence that hCdc14A might be involved in cell cycle regulation in cultured HBVECs during high glucose-, FFA-, and hypoxia-induced injury.

  9. Inflammation Modulates RLIP76/RALBP1 Electrophile-Glutathione Conjugate Transporter and Housekeeping Genes in Human Blood-Brain Barrier Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Barbara Bennani-Baiti

    Full Text Available Endothelial cells are often present at inflammation sites. This is the case of endothelial cells of the blood-brain barrier (BBB of patients afflicted with neurodegenerative disorders such as Alzheimer's, Parkinson's, or multiple sclerosis, as well as in cases of bacterial meningitis, trauma, or tumor-associated ischemia. Inflammation is a known modulator of gene expression through the activation of transcription factors, mostly NF-κB. RLIP76 (a.k.a. RALBP1, an ATP-dependent transporter of electrophile-glutathione conjugates, modulates BBB permeability through the regulation of tight junction function, cell adhesion, and exocytosis. Genes and pathways regulated by RLIP76 are transcriptional targets of tumor necrosis factor alpha (TNF-α pro-inflammatory molecule, suggesting that RLIP76 may also be an inflammation target. To assess the effects of TNF-α on RLIP76, we faced the problem of choosing reference genes impervious to TNF-α. Since such genes were not known in human BBB endothelial cells, we subjected these to TNF-α, and measured by quantitative RT-PCR the expression of housekeeping genes commonly used as reference genes. We find most to be modulated, and analysis of several inflammation datasets as well as a metaanalysis of more than 5000 human tissue samples encompassing more than 300 cell types and diseases show that no single housekeeping gene may be used as a reference gene. Using three different algorithms, however, we uncovered a reference geneset impervious to TNF-α, and show for the first time that RLIP76 expression is induced by TNF-α and follows the induction kinetics of inflammation markers, suggesting that inflammation can influence RLIP76 expression at the BBB. We also show that MRP1 (a.k.a. ABCC1, another electrophile-glutathione transporter, is not modulated in the same cells and conditions, indicating that RLIP76 regulation by TNF-α is not a general property of glutathione transporters. The reference geneset

  10. Inflammation Modulates RLIP76/RALBP1 Electrophile-Glutathione Conjugate Transporter and Housekeeping Genes in Human Blood-Brain Barrier Endothelial Cells.

    Science.gov (United States)

    Bennani-Baiti, Barbara; Toegel, Stefan; Viernstein, Helmut; Urban, Ernst; Noe, Christian R; Bennani-Baiti, Idriss M

    2015-01-01

    Endothelial cells are often present at inflammation sites. This is the case of endothelial cells of the blood-brain barrier (BBB) of patients afflicted with neurodegenerative disorders such as Alzheimer's, Parkinson's, or multiple sclerosis, as well as in cases of bacterial meningitis, trauma, or tumor-associated ischemia. Inflammation is a known modulator of gene expression through the activation of transcription factors, mostly NF-κB. RLIP76 (a.k.a. RALBP1), an ATP-dependent transporter of electrophile-glutathione conjugates, modulates BBB permeability through the regulation of tight junction function, cell adhesion, and exocytosis. Genes and pathways regulated by RLIP76 are transcriptional targets of tumor necrosis factor alpha (TNF-α) pro-inflammatory molecule, suggesting that RLIP76 may also be an inflammation target. To assess the effects of TNF-α on RLIP76, we faced the problem of choosing reference genes impervious to TNF-α. Since such genes were not known in human BBB endothelial cells, we subjected these to TNF-α, and measured by quantitative RT-PCR the expression of housekeeping genes commonly used as reference genes. We find most to be modulated, and analysis of several inflammation datasets as well as a metaanalysis of more than 5000 human tissue samples encompassing more than 300 cell types and diseases show that no single housekeeping gene may be used as a reference gene. Using three different algorithms, however, we uncovered a reference geneset impervious to TNF-α, and show for the first time that RLIP76 expression is induced by TNF-α and follows the induction kinetics of inflammation markers, suggesting that inflammation can influence RLIP76 expression at the BBB. We also show that MRP1 (a.k.a. ABCC1), another electrophile-glutathione transporter, is not modulated in the same cells and conditions, indicating that RLIP76 regulation by TNF-α is not a general property of glutathione transporters. The reference geneset uncovered herein should

  11. Assessment of coagulopathy, endothelial injury, and inflammation after traumatic brain injury and hemorrhage in a porcine model

    DEFF Research Database (Denmark)

    Sillesen, Martin; Rasmussen, Lars Simon; Jin, Guang;

    2014-01-01

    Traumatic brain injury (TBI) and hemorrhagic shock (HS) can be associated with coagulopathy and inflammation, but the mechanisms are poorly understood. We hypothesized that a combination of TBI and HS would disturb coagulation, damage the endothelium, and activate inflammatory and complement...

  12. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

    Directory of Open Access Journals (Sweden)

    Ong John M

    2007-03-01

    Full Text Available Abstract Background The blood-brain tumor barrier (BTB impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB permeability in brain tumors, but not in normal brain. Iberiotoxin, a KCa channel antagonist, significantly attenuated NS1619-induced BTB permeability increase. We found KCa channels and bradykinin type 2 receptors (B2R expressed in cultured human metastatic brain tumor cells (CRL-5904, non-small cell lung cancer, metastasized to brain, human brain microvessel endothelial cells (HBMEC and human lung cancer brain metastasis tissues. Potentiometric assays demonstrated the activity of KCa channels in metastatic brain tumor cells and HBMEC. Furthermore, we detected higher expression of KCa channels in the metastatic brain tumor tissue and tumor capillary endothelia as compared to normal brain tissue. Co-culture of metastatic brain tumor cells and brain microvessel endothelial cells showed an upregulation of KCa channels, which may contribute to the overexpression of KCa channels in tumor microvessels and selectivity of BTB opening. Conclusion These findings suggest that KCa channels in metastatic brain tumors may serve as an effective target for biochemical modulation of BTB permeability to enhance selective delivery of chemotherapeutic drugs to metastatic brain tumors.

  13. New aspects of fenestrated vasculature and tissue dynamics in the sensory circumventricular organs of adult brains

    Directory of Open Access Journals (Sweden)

    Seiji eMiyata

    2015-10-01

    Full Text Available The blood–brain barrier (BBB generally consists of endothelial tight junction barriers that prevent the free entry of blood-derived substances, thereby maintaining the extracellular environment of the brain. However, the circumventricular organs (CVOs, which are located along the midlines of the brain ventricles, lack these endothelial barriers and have fenestrated capillaries; therefore, they have a number of essential functions, including the transduction of information between the blood circulation and brain. Previous studies have demonstrated the extensive contribution of the CVOs to body fluid and thermal homeostasis, energy balance, the chemoreception of blood-derived substances, and neuroinflammation. In this review, recent advances have been discussed in fenestrated capillary characterization and dynamic tissue reconstruction accompanied by angiogenesis and neurogliogenesis in the sensory CVOs of adult brains. The sensory CVOs, including the organum vasculosum of the lamina terminalis (OVLT, subfornical organ (SFO, and area postrema (AP, have size-selective and heterogeneous vascular permeabilities. Astrocyte-/tanycyte-like neural stem cells (NSCs sense blood- and cerebrospinal fluid-derived information through the transient receptor potential vanilloid 1, a mechanical/osmotic receptor, Toll-like receptor 4, a lipopolysaccharide receptor, and Nax, a Na-sensing Na channel. They also express tight junction proteins and densely and tightly surround mature neurons to protect them from blood-derived neurotoxic substances, indicating that the NSCs of the CVOs perform BBB functions while maintaining the capacity to differentiate into new neurons and glial cells. In addition to neurogliogenesis, the density of fenestrated capillaries is regulated by angiogenesis, which is accompanied by the active proliferation and sprouting of endothelial cells. Vascular endothelial growth factor (VEGF signaling may be involved in angiogenesis and

  14. Stroke and Drug Delivery--In Vitro Models of the Ischemic Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Tornabene, Erica; Brodin, Birger

    2016-01-01

    Stroke is a major cause of death and disability worldwide. Both cerebral hypoperfusion and focal cerebral infarcts are caused by a reduction of blood flow to the brain, leading to stroke and subsequent brain damage. At present, only few medical treatments of stroke are available, with the Food...... and Drug Administration-approved tissue plasminogen activator for treatment of acute ischemic stroke being the most prominent example. A large number of potential drug candidates for treatment of ischemic brain tissue have been developed and subsequently failed in clinical trials. A deeper understanding...... of permeation pathways across the barrier in ischemic and postischemic brain endothelium is important for development of new medical treatments. The blood-brain barrier, that is, the endothelial monolayer lining the brain capillaries, changes properties during an ischemic event. In vitro models of the blood-brain...

  15. Targeting Potassium Channels for Increasing Delivery of Imaging Agents and Therapeutics to Brain Tumors

    Directory of Open Access Journals (Sweden)

    Nagendra Sanyasihally Ningaraj

    2013-05-01

    Full Text Available Every year in the US, 20,000 new primary and nearly 200,000 metastatic brain tumor cases are reported. The cerebral microvessels/ capillaries that form the blood–brain barrier (BBB not only protect the brain from toxic agents in the blood but also pose a significant hindrance to the delivery of small and large therapeutic molecules. Different strategies have been employed to circumvent the physiological barrier posed by blood-brain tumor barrier (BTB. Studies in our laboratory have identified significant differences in the expression levels of certain genes and proteins between normal and brain tumor capillary endothelial cells. In this study, we validated the non-invasive and clinically relevant Dynamic Contrast Enhancing-Magnetic Resonance Imaging (DCE-MRI method with invasive, clinically irrelevant but highly accurate Quantitative Autoradiography (QAR method using rat glioma model. We also showed that DCE-MRI metric of tissue vessel perfusion-permeability is sensitive to changes in blood vessel permeability following administration of calcium-activated potassium (BKCa channel activator NS-1619. Our results show that human gliomas and brain tumor endothelial cells that overexpress BKCa channels can be targeted for increased BTB permeability for MRI enhancing agents to brain tumors. We conclude that monitoring the outcome of increased MRI enhancing agents’ delivery to microsatellites and leading tumor edges in glioma patients would lead to beneficial clinical outcome.

  16. The permeation of dynorphin A 1-6 across the blood brain barrier and its effect on bovine brain microvessel endothelial cell monolayer permeability.

    Science.gov (United States)

    Sloan, Courtney D Kuhnline; Audus, Kenneth L; Aldrich, Jane V; Lunte, Susan M

    2012-12-01

    Dynorphin A 1-17 (Dyn A 1-17) is an endogenous neuropeptide known to act at the kappa opioid receptor; it has been implicated in a number of neurological disorders, including neuropathic pain, stress, depression, and Alzheimer's and Parkinson's diseases. The investigation of Dyn A 1-17 metabolism at the blood-brain barrier (BBB) is important since the metabolites exhibit unique biological functions compared to the parent compound. In this work, Dyn A 1-6 is identified as a metabolite of Dyn A 1-17 in the presence of bovine brain microvessel endhothelial cells (BBMECs), using LC-MS/MS. The transport of Dyn A 1-6 at the BBB was examined using this in vitro cell culture model of the BBB. Furthermore, the permeation of the BBB by the low molecular weight permeability marker fluorescein was characterized in the presence and absences of Dyn A 1-6.

  17. Prehospital resuscitation with hypertonic saline-dextran modulates inflammatory, coagulation and endothelial activation marker profiles in severe traumatic brain injured patients

    Directory of Open Access Journals (Sweden)

    Morrison Laurie J

    2010-01-01

    Full Text Available Abstract Background Traumatic brain injury (TBI initiates interrelated inflammatory and coagulation cascades characterized by wide-spread cellular activation, induction of leukocyte and endothelial cell adhesion molecules and release of soluble pro/antiinflammatory cytokines and thrombotic mediators. Resuscitative care is focused on optimizing cerebral perfusion and reducing secondary injury processes. Hypertonic saline is an effective osmotherapeutic agent for the treatment of intracranial hypertension and has immunomodulatory properties that may confer neuroprotection. This study examined the impact of hypertonic fluids on inflammatory/coagulation cascades in isolated head injury. Methods Using a prospective, randomized controlled trial we investigated the impact of prehospital resuscitation of severe TBI (GCS vs 0.9% normal saline (NS, on selected cellular and soluble inflammatory/coagulation markers. Serial blood samples were drawn from 65 patients (30 HSD, 35 NS at the time of hospital admission and at 12, 24, and 48-h post-resuscitation. Flow cytometry was used to analyze leukocyte cell-surface adhesion (CD62L, CD11b and degranulation (CD63, CD66b molecules. Circulating concentrations of soluble (sL- and sE-selectins (sL-, sE-selectins, vascular and intercellular adhesion molecules (sVCAM-1, sICAM-1, pro/antiinflammatory cytokines [tumor necrosis factor (TNF-α and interleukin (IL-10], tissue factor (sTF, thrombomodulin (sTM and D-dimers (D-D were assessed by enzyme immunoassay. Twenty-five healthy subjects were studied as a control group. Results TBI provoked marked alterations in a majority of the inflammatory/coagulation markers assessed in all patients. Relative to control, NS patients showed up to a 2-fold higher surface expression of CD62L, CD11b and CD66b on polymorphonuclear neutrophils (PMNs and monocytes that persisted for 48-h. HSD blunted the expression of these cell-surface activation/adhesion molecules at all time-points to

  18. Whole-transcriptome brain expression and exon-usage profiling in major depression and suicide: evidence for altered glial, endothelial and ATPase activity

    Science.gov (United States)

    Pantazatos, Spiro P.; Huang, Yung-yu; Rosoklija, Gorazd B.; Dwork, Andrew J.; Arango, Victoria; Mann, J. John

    2016-01-01

    Brain gene expression profiling studies of suicide and depression using oligonucleotide microarrays have often failed to distinguish these two phenotypes. Moreover, next generation sequencing (NGS) approaches are more accurate in quantifying gene expression and can detect alternative splicing. Using RNA-seq, we examined whole-exome gene and exon expression in non-psychiatric controls (CON, N=29), DSM-IV major depressive disorder suicides (MDD-S, N=21) and MDD non-suicides (MDD, N=9) in dorsal lateral prefrontal cortex (Brodmann Area 9) of sudden-death medication-free individuals postmortem. Using small RNA-seq, we also examined miRNA expression (9 samples per group). DeSeq2 identified thirty-five genes differentially expressed between groups and surviving adjustment for false discovery rate (adjusted p<0.1). In depression, altered genes include humanin like-8 (MTRNRL8), interleukin-8 (IL8), and serpin peptidase inhibitor, clade H (SERPINH1) and chemokine ligand 4 (CCL4), while exploratory gene ontology (GO) analyses revealed lower expression of immune-related pathways such as chemokine receptor activity, chemotaxis and cytokine biosynthesis, and angiogenesis and vascular development in (adjusted p<0.1). Hypothesis-driven GO analysis suggests lower expression of genes involved in oligodendrocyte differentiation, regulation of glutamatergic neurotransmission, and oxytocin receptor expression in both suicide and depression, and provisional evidence for altered DNA-dependent ATPase expression in suicide only. DEXSEq analysis identified differential exon usage in ATPase, class II, type 9B (adjusted p<0.1) in depression. Differences in miRNA expression or structural gene variants were not detected. Results lend further support for models in which deficits in microglial, endothelial (blood-brain barrier), ATPase activity and astrocytic cell functions contribute to MDD and suicide, and identify putative pathways and mechanisms for further study in these disorders. PMID

  19. Tanshinone IIA inhibits endothelin-1 production in TNF-α-induced brain microvascular endothelial cells through suppression of endothelin-converting enzyme-1 synthesis

    Institute of Scientific and Technical Information of China (English)

    Chao TANG; An-hua WU; Hong-li XUE; Yun-jie WANG

    2007-01-01

    Aim: To investigate the effects of tanshinone ⅡA (Tan ⅡA) on the regulation of the production of endothelin (ET)-1 (including large ET-1), mRNA levels of ET-1,endothelin-converting enzyme- 1 (ECE- 1), endothelin-A receptor (ETA) and endothelin-B receptor (ETB) induced by TNF-α in rat brain microvascular endo-thelial cells (BMVEC). Methods: The ET-1 release (including large ET-1) into the culture medium was determined by enzyme immunoassay. The levels of ET-1,ECE- 1, ETA, and ETB mRNA were measured by RT-PCR. Endothelin receptor bind-ing was also tested. Results: The induction of ET- 1 release by TNF-α from cul-tured BMVEC was dose-dependently reduced by Tan IIA, but large ET-1 levels progressively increased in response to Tan IIA; the mRNA expression of ET-1 was unaffected. Tan ⅡA also caused a decrease in ETA receptor mRNA and ECE-1expression in a dose-dependent manner. Endothelin receptor binding was unal-tered in BMVEC stimulated with TNF-α alone or a combination of TNF-α and Tan ⅡA. Conclusion: These findings suggest that Tan ⅡA may inhibit ET-1 produc-tion in TNF-α-induced BMVEC through the suppression of ECE-1 synthesis.

  20. G-CSF Protects Human Brain Vascular Endothelial Cells Injury Induced by High Glucose, Free Fatty Acids and Hypoxia through MAPK and Akt Signaling

    Science.gov (United States)

    Tao, Yinghong; Guo, Jingchun; Guo, Zhuangli; Zhang, Shuo; Zhang, Yu; Huang, Yanyan; Tang, Yuping; Dong, Qiang; Hu, Renming

    2015-01-01

    Granulocyte-colony stimulating factor (G-CSF) has been shown to play a neuroprotective role in ischemic stroke by mobilizing bone marrow (BM)-derived endothelial progenitor cells (EPCs), promoting angiogenesis, and inhibiting apoptosis. Impairments in mobilization and function of the BM-derived EPCs have previously been reported in animal and human studies of diabetes where there is both reduction in the levels of the BM-derived EPCs and its ability to promote angiogenesis. This is hypothesized to account for the pathogenesis of diabetic vascular complications such as stroke. Here, we sought to investigate the effects of G-CSF on diabetes-associated cerebral vascular defect. We observed that pretreatment of the cultured human brain vascular endothelial cells (HBVECs) with G-CSF largely prevented cell death induced by the combination stimulus with high glucose, free fatty acids (FFA) and hypoxia by increasing cell viability, decreasing apoptosis and caspase-3 activity. Cell ultrastructure measured by transmission electron microscope (TEM) revealed that G-CSF treatment nicely reduced combination stimulus-induced cell apoptosis. The results from fluorescent probe Fluo-3/AM showed that G-CSF greatly suppressed the levels of intracellular calcium ions under combination stimulus. We also found that G-CSF enhanced the expression of cell cycle proteins such as human cell division cycle protein 14A (hCdc14A), cyclinB and cyclinE, inhibited p53 activity, and facilitated cell cycle progression following combination stimulus. In addition, activation of extracellular signal-regulated kinase1/2 (ERK1/2) and Akt, and deactivation of c-Jun N terminal kinase (JNK) and p38 were proved to be required for the pro-survival effects of G-CSF on HBVECs exposed to combination stimulus. Overall, G-CSF is capable of alleviating HBVECs injury triggered by the combination administration with high glucose, FFA and hypoxia involving the mitogen-activated protein kinases (MAPK) and Akt signaling

  1. Erythropoietin improves memory function with reducing endothelial dysfunction and amyloid-beta burden in Alzheimer's disease models.

    Science.gov (United States)

    Lee, Soon-Tae; Chu, Kon; Park, Jung-Eun; Jung, Keun-Hwa; Jeon, Daejong; Lim, Ji-Youn; Lee, Sang Kun; Kim, Manho; Roh, Jae-Kyu

    2012-01-01

    Neurovascular degeneration contributes to the pathogenesis of Alzheimer's disease (AD). Because erythropoietin (EPO) promotes endothelial regeneration, we investigated the therapeutic effects of EPO in animal models of AD. In aged Tg2576 mice, EPO receptors (EPORs) were expressed in the cortex and hippocampus. Tg2576 mice were treated with daily injection of EPO (5000 IU/kg/day) for 5 days. At 14 days, EPO improved contextual memory as measured by fear-conditioning test. EPO enhanced endothelial proliferation and the level of synaptophysin expression in the brain. EPO also increased capillary density, and decreased the level of the receptor for advanced glycation endproducts (RAGE) in the brain, while decreasing in the amount of amyloid plaque and amyloid-β (Aβ). In cultured human endothelial cells, EPO enhanced angiogenesis and suppressed the expression of the RAGE. These results show that EPO improves memory and ameliorates endothelial degeneration induced by Aβ in AD models. This pre-clinical evidence suggests that EPO may be useful for the treatment of AD.

  2. A glass capillary microelectrode based on capillarity and its application to the detection of L-glutamate release from mouse brain slices.

    Science.gov (United States)

    Nakajima, Kumiko; Yamagiwa, Takashi; Hirano, Ayumi; Sugawara, Masao

    2003-01-01

    A new glass capillary microelectrode for L-glutamate is described using pulled glass capillaries (tip size, approximately 12.5 microm) with a very small volume (approximately 2 microl) of inner solution containing glutamate oxidase (GluOx) and ascorbate oxidase. The operation of the electrode is based on capillary action that samples L-glutamate into the inner solution. The enzyme reaction by GluOx generates hydrogen peroxide that is detected at an Os-gel-HRP polymer modified Pt electrode in a three-electrode configuration. The amperometric response behavior of the electrode was characterized in terms of the capillarity, response time, sensitivity and selectivity for measurements of L-glutamate. The currents at 0 V vs. Ag/AgCl increased linearly with the L-glutamate concentration from 10 to 150 microM for in vitro and in situ calibrations. The response was highly selective to L-glutamate over ascorbate, dopamine, serotonin and other amino acids. The detection of L-glutamate in the extracellular fluids of different regions of mouse hippocampal slices under stimulation of KCl was demonstrated.

  3. Fumaric Acid Esters Do Not Reduce Inflammatory NF-κB/p65 Nuclear Translocation, ICAM-1 Expression and T-Cell Adhesiveness of Human Brain Microvascular Endothelial Cells.

    Science.gov (United States)

    Haarmann, Axel; Nehen, Mathias; Deiß, Annika; Buttmann, Mathias

    2015-08-13

    Dimethyl fumarate (DMF) is approved for disease-modifying treatment of patients with relapsing-remitting multiple sclerosis. Animal experiments suggested that part of its therapeutic effect is due to a reduction of T-cell infiltration of the central nervous system (CNS) by uncertain mechanisms. Here we evaluated whether DMF and its primary metabolite monomethyl fumarate (MMF) modulate pro-inflammatory intracellular signaling and T-cell adhesiveness of nonimmortalized single donor human brain microvascular endothelial cells at low passages. Neither DMF nor MMF at concentrations of 10 or 50 µM blocked the IL-1β-induced nuclear translocation of NF-κB/p65, whereas the higher concentration of DMF inhibited the nuclear entry of p65 in human umbilical vein endothelium cultured in parallel. DMF and MMF also did not alter the IL-1β-stimulated activation of p38 MAPK in brain endothelium. Furthermore, neither DMF nor MMF reduced the basal or IL-1β-inducible expression of ICAM-1. In accordance, both fumaric acid esters did not reduce the adhesion of activated Jurkat T cells to brain endothelium under basal or inflammatory conditions. Therefore, brain endothelial cells probably do not directly mediate a potential blocking effect of fumaric acid esters on the inflammatory infiltration of the CNS by T cells.

  4. Fumaric Acid Esters Do Not Reduce Inflammatory NF-κB/p65 Nuclear Translocation, ICAM-1 Expression and T-Cell Adhesiveness of Human Brain Microvascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Axel Haarmann

    2015-08-01

    Full Text Available Dimethyl fumarate (DMF is approved for disease-modifying treatment of patients with relapsing-remitting multiple sclerosis. Animal experiments suggested that part of its therapeutic effect is due to a reduction of T-cell infiltration of the central nervous system (CNS by uncertain mechanisms. Here we evaluated whether DMF and its primary metabolite monomethyl fumarate (MMF modulate pro-inflammatory intracellular signaling and T-cell adhesiveness of nonimmortalized single donor human brain microvascular endothelial cells at low passages. Neither DMF nor MMF at concentrations of 10 or 50 µM blocked the IL-1β-induced nuclear translocation of NF-κB/p65, whereas the higher concentration of DMF inhibited the nuclear entry of p65 in human umbilical vein endothelium cultured in parallel. DMF and MMF also did not alter the IL-1β-stimulated activation of p38 MAPK in brain endothelium. Furthermore, neither DMF nor MMF reduced the basal or IL-1β-inducible expression of ICAM-1. In accordance, both fumaric acid esters did not reduce the adhesion of activated Jurkat T cells to brain endothelium under basal or inflammatory conditions. Therefore, brain endothelial cells probably do not directly mediate a potential blocking effect of fumaric acid esters on the inflammatory infiltration of the CNS by T cells.

  5. Physiologic upper limits of pore size of different blood capillary types and another perspective on the dual pore theory of microvascular permeability

    Directory of Open Access Journals (Sweden)

    Sarin Hemant

    2010-08-01

    basement membrane layer continuity or lack thereof. Non-sinusoidal blood capillaries were further sub-classified as non-fenestrated or fenestrated based on the absence or presence of endothelial cells with fenestrations. The sinusoidal blood capillaries of the liver, myeloid (red bone marrow, and spleen were sub-classified as reticuloendothelial or non-reticuloendothelial based on the phago-endocytic capacity of the endothelial cells. Results The physiologic upper limit of pore size for transvascular flow across capillary walls of non-sinusoidal non-fenestrated blood capillaries is less than 1 nm for those with interendothelial cell clefts lined with zona occludens junctions (i.e. brain and spinal cord, and approximately 5 nm for those with clefts lined with macula occludens junctions (i.e. skeletal muscle. The physiologic upper limit of pore size for transvascular flow across the capillary walls of non-sinusoidal fenestrated blood capillaries with diaphragmed fenestrae ranges between 6 and 12 nm (i.e. exocrine and endocrine glands; whereas, the physiologic upper limit of pore size for transvascular flow across the capillary walls of non-sinusoidal fenestrated capillaries with open 'non-diaphragmed' fenestrae is approximately 15 nm (kidney glomerulus. In the case of the sinusoidal reticuloendothelial blood capillaries of myeloid bone marrow, the transvascular transport of non-endogenous macromolecules larger than 5 nm into the bone marrow interstitial space takes place via reticuloendothelial cell-mediated phago-endocytosis and transvascular release, which is the case for systemic bone marrow imaging agents as large as 60 nm in diameter. Conclusions The physiologic upper limit of pore size in the capillary walls of most non-sinusoidal blood capillaries to the transcapillary passage of lipid-insoluble endogenous and non-endogenous macromolecules ranges between 5 and 12 nm. Therefore, macromolecules larger than the physiologic upper limits of pore size in the non

  6. Regulation of Toll-like receptor 2 interaction with Ecgp96 controls Escherichia coli K1 invasion of brain endothelial cells

    Science.gov (United States)

    Krishnan, Subramanian; Chen, Shuang; Turcatel, Gianluca; Arditi, Moshe; Prasadarao, Nemani V.

    2012-01-01

    SUMMARY The interaction of outer membrane protein A (OmpA) with its receptor, Ecgp96 (a homologue of Hsp90β) is critical for the pathogenesis of E. coli K1 meningitis. Since Hsp90 chaperones Toll-like receptors (TLRs), we examined the role of TLRs in E. coli K1 infection. Herein, we show that newborn TLR2−/− mice are resistant to E. coli K1 meningitis, while TLR4−/− mice succumb to infection sooner. In vitro, OmpA+ E. coli infection selectively upregulates Ecgp96 and TLR2 in human brain microvascular endothelial cells (HBMEC), whereas OmpA− E. coli upregulates TLR4 in these cells. Furthermore, infection with OmpA+ E. coli causes Ecgp96 and TLR2 translocate to the plasma membrane of HBMEC as a complex. Immunoprecipitation studies of the plasma membrane fractions from infected HBMEC reveal that the C-termini of Ecgp96 and TLR2 are critical for OmpA+ E. coli invasion. Knockdown of TLR2 using siRNA results in inefficient membrane translocation of Ecgp96 and significantly reduces invasion. In addition, the interaction of Ecgp96 and TLR2 induces a bipartite signal, one from Ecgp96 through PKC-α while the other from TLR2 through MyD88, ERK1/2 and NF-κB. This bipartite signal ultimately culminates in the efficient production of NO, which in turn promotes E. coli K1 invasion of HBMEC. PMID:22963587

  7. Citicoline induces angiogenesis improving survival of vascular/human brain microvessel endothelial cells through pathways involving ERK1/2 and insulin receptor substrate-1

    Directory of Open Access Journals (Sweden)

    Krupinski Jerzy

    2012-12-01

    Full Text Available Abstract Background Citicoline is one of the neuroprotective agents that have been used as a therapy in stroke patients. There is limited published data describing the mechanisms through which it acts. Methods We used in vitro angiogenesis assays: migration, proliferation, differentiation into tube-like structures in Matrigel™ and spheroid development assays in human brain microvessel endothelial cells (hCMEC/D3. Western blotting was performed on protein extraction from hCMEC/D3 stimulated with citicoline. An analysis of citicoline signalling pathways was previously studied using a Kinexus phospho-protein screening array. A staurosporin/calcium ionophore-induced apoptosis assay was performed by seeding hCMEC/D3 on to glass coverslips in serum poor medium. In a pilot in vivo study, transient MCAO in rats was carried out with and without citicoline treatment (1000 mg/Kg applied at the time of occlusion and subsequently every 3 days until euthanasia (21 days. Vascularity of the stroke-affected regions was examined by immunohistochemistry. Results Citicoline presented no mitogenic and chemotactic effects on hCMEC/D3; however, it significantly increased wound recovery, the formation of tube-like structures in Matrigel™ and enhanced spheroid development and sprouting. Citicoline induced the expression of phospho-extracellular-signal regulated kinase (ERK-1/2. Kinexus assays showed an over-expression of insulin receptor substrate-1 (IRS-1. Knock-down of IRS-1 with targeted siRNA in our hCMEC/D3 inhibited the pro-angiogenic effects of citicoline. The percentage of surviving cells was higher in the presence of citicoline. Citicoline treatment significantly increased the numbers of new, active CD105-positive microvessels following MCAO. Conclusions The findings demonstrate both a pro-angiogenic and protective effect of citicoline on hCMEC/D3 in vitro and following middle cerebral artery occlusion (MCAO in vivo.

  8. Investigation of Functionalized Poly(N,N-dimethylacrylamide)-block-polystyrene Nanoparticles As Novel Drug Delivery System to Overcome the Blood-Brain Barrier In Vitro.

    Science.gov (United States)

    Gregori, Maria; Bertani, Daniela; Cazzaniga, Emanuela; Orlando, Antonina; Mauri, Michele; Bianchi, Alberto; Re, Francesca; Sesana, Silvia; Minniti, Stefania; Francolini, Maura; Cagnotto, Alfredo; Salmona, Mario; Nardo, Luca; Salerno, Domenico; Mantegazza, Francesco; Masserini, Massimo; Simonutti, Roberto

    2015-12-01

    In the search of new drug delivery carriers for the brain, self-assembled nanoparticles (NP) were prepared from poly(N,N-dimethylacrylamide)-block-polystyrene polymer. NP displayed biocompatibility on cultured endothelial cells, macrophages and differentiated SH-SY5Y neuronal-like cells. The surface-functionalization of NP with a modified fragment of human Apolipoprotein E (mApoE) enhanced the uptake of NP by cultured human brain capillary endothelial cells, as assessed by confocal microscopy, and their permeability through a Transwell Blood Brain Barrier model made with the same cells, as assessed by fluorescence. Finally, mApoE-NP embedding doxorubicin displayed an enhanced release of drug at low pH, suggesting the potential use of these NP for the treatment of brain tumors.

  9. Expression of Iron-Related Proteins at the Neurovascular Unit Supports Reduction and Reoxidation of Iron for Transport Through the Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Burkhart, Annette; Skjørringe, Tina; Johnsen, Kasper Bendix;

    2015-01-01

    The mechanisms for iron transport through the blood-brain barrier (BBB) remain a controversy. We analyzed for expression of mRNA and proteins involved in oxidation and transport of iron in isolated brain capillaries from dietary normal, iron-deficient, and iron-reverted rats. The expression...... was also investigated in isolated rat brain endothelial cells (RBECs) and in immortalized rat brain endothelial (RBE4) cells grown as monoculture or in hanging culture inserts with defined BBB properties. Transferrin receptor 1, ferrireductases Steap 2 and 3, divalent metal transporter 1 (DMT1...... cells provide the machinery for receptor-mediated uptake of ferric iron-containing transferrin. Ferric iron can then undergo reduction to ferrous iron by ferrireductases inside endosomes followed by DMT1-mediated pumping into the cytosol and subsequently cellular export by ferroportin. The expression...

  10. How Glutamate Is Managed by the Blood–Brain Barrier

    Directory of Open Access Journals (Sweden)

    Richard A. Hawkins

    2016-10-01

    Full Text Available A facilitative transport system exists on the blood–brain barrier (BBB that has been tacitly assumed to be a path for glutamate entry to the brain. However, glutamate is a non-essential amino acid whose brain content is much greater than plasma, and studies in vivo show that glutamate does not enter the brain in appreciable quantities except in those small regions with fenestrated capillaries (circumventricular organs. The situation became understandable when luminal (blood facing and abluminal (brain facing membranes were isolated and studied separately. Facilitative transport of glutamate and glutamine exists only on the luminal membranes, whereas Na+-dependent transport systems for glutamate, glutamine, and some other amino acids are present only on the abluminal membrane. The Na+-dependent cotransporters of the abluminal membrane are in a position to actively transport amino acids from the extracellular fluid (ECF into the endothelial cells of the BBB. These powerful secondary active transporters couple with the energy of the Na+-gradient to move glutamate and glutamine into endothelial cells, whereupon glutamate can exit to the blood on the luminal facilitative glutamate transporter. Glutamine may also exit the brain via separate facilitative transport system that exists on the luminal membranes, or glutamine can be hydrolyzed to glutamate within the BBB, thereby releasing ammonia that is freely diffusible. The γ-glutamyl cycle participates indirectly by producing oxoproline (pyroglutamate, which stimulates almost all secondary active transporters yet discovered in the abluminal membranes of the BBB.

  11. How Glutamate Is Managed by the Blood–Brain Barrier

    Science.gov (United States)

    Hawkins, Richard A.; Viña, Juan R.

    2016-01-01

    A facilitative transport system exists on the blood–brain barrier (BBB) that has been tacitly assumed to be a path for glutamate entry to the brain. However, glutamate is a non-essential amino acid whose brain content is much greater than plasma, and studies in vivo show that glutamate does not enter the brain in appreciable quantities except in those small regions with fenestrated capillaries (circumventricular organs). The situation became understandable when luminal (blood facing) and abluminal (brain facing) membranes were isolated and studied separately. Facilitative transport of glutamate and glutamine exists only on the luminal membranes, whereas Na+-dependent transport systems for glutamate, glutamine, and some other amino acids are present only on the abluminal membrane. The Na+-dependent cotransporters of the abluminal membrane are in a position to actively transport amino acids from the extracellular fluid (ECF) into the endothelial cells of the BBB. These powerful secondary active transporters couple with the energy of the Na+-gradient to move glutamate and glutamine into endothelial cells, whereupon glutamate can exit to the blood on the luminal facilitative glutamate transporter. Glutamine may also exit the brain via separate facilitative transport system that exists on the luminal membranes, or glutamine can be hydrolyzed to glutamate within the BBB, thereby releasing ammonia that is freely diffusible. The γ-glutamyl cycle participates indirectly by producing oxoproline (pyroglutamate), which stimulates almost all secondary active transporters yet discovered in the abluminal membranes of the BBB. PMID:27740595

  12. Effects of Ivabradine and Metoprolol on Cardiac Angiogenesis and Endothelial Dysfunction in Rats With Heart Failure

    NARCIS (Netherlands)

    Ulu, Nadir; Henning, Rob H.; Goris, Maaike; Schoeinaker, Regien G.; van Gilst, Wiek H.

    2009-01-01

    Myocardial infarction (MI)-induced remodeling is associated with disturbed myocardial perfusion through vascular changes, such as reduced capillary density and endothelial dysfunction. Heart rate reduction (HRR) initiated immediately after MI stimulates angiogenesis and attenuates left ventricular d

  13. Impacts of Blood-Brain Barrier in Drug Delivery and Targeting of Brain Tumors

    Directory of Open Access Journals (Sweden)

    Yadollah Omidi

    2012-02-01

    Full Text Available Introduction: Entry of blood circulating agents into the brain is highly selectively controlled by specific transport machineries at the blood brain barrier (BBB, whose excellent barrier restrictiveness make brain drug delivery and targeting very challenging. Methods: Essential information on BBB cellular microenvironment were reviewed and discussed towards impacts of BBB on brain drug delivery and targeting. Results: Brain capillary endothelial cells (BCECs form unique biological structure and architecture in association with astrocytes and pericytes, in which microenvironment the BCECs express restrictive tight junctional complexes that block the paracellular inward/outward traverse of biomolecules/compounds. These cells selectively/specifically control the transportation process through carrier and/or receptor mediated transport machineries that can also be exploited for the delivery of pharmaceuticals into the brain. Intelligent molecular therapies should be designed using such transport machineries for the efficient delivery of designated drugs into the brain. For better clinical outcomes, these smart pharmaceuticals should be engineered as seamless nanosystems to provide simultaneous imaging and therapy (multimodal theranostics. Conclusion: The exceptional functional presence of BBB selectively controls inward and outward transportation mechanisms, thus advanced smart multifunctional nanomedicines are needed for the effective brain drug delivery and targeting. Fully understanding the biofunctions of BBB appears to be a central step for engineering of intelligent seamless therapeutics consisting of homing device for targeting, imaging moiety for detecting, and stimuli responsive device for on-demand liberation of therapeutic agent.

  14. In vivo simultaneous monitoring of gamma-aminobutyric acid, glutamate, and L-aspartate using brain microdialysis and capillary electrophoresis with laser-induced fluorescence detection: Analytical developments and in vitro/in vivo validations.

    Science.gov (United States)

    Sauvinet, Valérie; Parrot, Sandrine; Benturquia, Nadia; Bravo-Moratón, Eva; Renaud, Bernard; Denoroy, Luc

    2003-09-01

    gamma-Aminobutyric acid (GABA), glutamate (Glu), and L-aspartate (L-Asp) are three major amino acid neurotransmitters in the central nervous system. In this work, a method for the separation of these three neurotransmitters in brain microdialysis samples using a commercially available capillary electrophoresis (CE) system has been developed. Molecules were tagged on their primary amine function with the fluorogene agent naphthalene-2,3-dicarboxaldehyde (NDA), and, after separation by micellar electrokinetic chromatography, were detected by laser-induced fluorescence using a 442 nm helium-cadmium laser. The separation conditions for the analysis of derivatized neurotransmitters in standard solutions and microdialysates have been optimized, and this method has been validated on both pharmacological and analytical basis. The separation of GABA, Glu, and L-Asp takes less than 10 min by using a 75 mmol/L borate buffer, pH 9.2, containing 70 mmol/L SDS and 10 mmol/L hydroxypropyl-beta-cyclodextrin and + 25 kV voltage. The detection limits were 3, 15 nmol/L and, 5 nmol/L for GABA, Glu, and L-Asp, respectively. Moreover, submicroliter samples can be analyzed. This method allows a simple, rapid and accurate measurement of the three amino acid neurotransmitters for the in vivo brain monitoring using microdialysis sampling.

  15. Tumor Necrosis Factor Type α , a Potent Inhibitor of Endothelial Cell Growth in vitro, is Angiogenic in vivo

    Science.gov (United States)

    Frater-Schroder, Marijke; Risau, Werner; Hallmann, Rupert; Gautschi, Peter; Bohlen, Peter

    1987-08-01

    Tumor necrosis factor type α (TNF-α ) inhibits endothelial cell proliferation in vitro. Basal cell growth (in the absence of exogenously added growth factor) and fibroblast growth factor (FGF)-stimulated cell proliferation are inhibited in a dose-dependent manner from 0.1 to 10 ng/ml with half-maximal inhibition occurring at 0.5-1.0 ng of TNF-α per ml. Bovine aortic and brain capillary endothelial and smooth muscle cells are similarly affected. TNF-α is a noncompetitive antagonist of FGF-stimulated cell proliferation. Its action on endothelial cells is reversible and noncytotoxic. Surprisingly, TNF-α does not seem to inhibit endothelial cell proliferation in vivo. In the rabbit cornea, even a high dose of TNF-α (10 μ g) does not suppress angiogenesis induced by basic FGF. On the contrary, in this model system TNF-α stimulates neovascularization. The inflammatory response that is seen in the cornea after TNF-α implantation suggests that the angiogenic properties of this agent may be a consequence of leukocyte infiltration.

  16. Salvianolic acid B improves the disruption of high glucose-mediated brain microvascular endothelial cells via the ROS/HIF-1α/VEGF and miR-200b/VEGF signaling pathways.

    Science.gov (United States)

    Yang, Ming-Chao; You, Fu-Li; Wang, Zhe; Liu, Xiang-Nan; Wang, Yan-Feng

    2016-09-06

    The study investigated the roles and mechanisms of Salvianolic acid B (Sal B) on permeability of rat brain microvascular endothelial cells (RBMECs) exposed to high glucose. The results demonstrated that Sal B greatly up-regulated the expression of tight junction (TJ) proteins and decreased the permeability of RBMECs compared with the control group. And the increase of reactive oxidative species (ROS) production, the upregulation of hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) protein induced by high glucose were antagonized by Sal B. In addition, a great decrease of microRNA-200b (miR-200b) was observed in the RBMECs under high-glucose condition, which was significantly increased by Sal B pretreatment. And overexpression of miR-200b markedly attenuated the RBMECs permeability and inhibited the expression of VEGF protein by targeting with 3'-UTR of its mRNA. This led to the conclusion that Sal B-mediated improvement of blood-brain barrier dysfunction induced by high-glucose is related to the ROS/HIF-1α/VEGF and miR-200b/VEGF signaling pathways.

  17. Intramedullary capillary haemangioma.

    LENUS (Irish Health Repository)

    Kelleher, T

    2012-02-03

    Intramedullary capillary haemangioma is extremely rare and only four cases have been previously reported. We describe a further case, outlining the clinical, radiological, surgical and pathological features.

  18. Effects of vascular endothelial growth factor on angiogenesis of the endothelial cells isolated from cavernous malformations

    Institute of Scientific and Technical Information of China (English)

    TAN YuZhen; ZHAO Yao; WANG HaiJie; ZHOU LiangFu; MAO Ying; LIU Rui; SHU Jia; WANG YongFei

    2008-01-01

    Human cerebral cavernous malformation (CM) is a common vascular malformation of the central nervous system. We have investigated the biological characteristics of CM endothelial cells and the cellular and molecular mechanisms of CM angiogenesis to offer new insights into exploring effective measures for treatment of this disease. The endothelial cells were isolated from CM tissue masses dissected during operation and expanded in vitro. Expression of VEGFR-1 and VEGFR-2 was examined with immunocytochemical staining. Proliferation, migration and tube formation of CM endothelial cells were determined using MTT, wounding and transmigration assays, and three-dimensional collagen type Ⅰ gel respectively. The endothelial cells were successfully isolated from the tissue specimens of 25 CMs dissected without dipolar electrocoagulation. The cells show the general characteristics of the vascular endothelial cells. Expression of VEGFR-1 and VEGFR-2 on the cells is higher than that on the normal cerebral microvascular endothelial cells. After treatment with VEGF, numbers of the proliferated and migrated cells, the maximal distance of cell migration and the length and area of capillary-like struc-tures formed in the three-dimensional collagen gel increase significantly. These results demonstrate that expression of VEGFR-1 and VEGFR-2 on CM endothelial cells is up-regulated. By binding to re-ceptors, VEGF may activate the downstream signaling pathways and promote proliferation, migration and tube formation of CM endothelial cells. VEGF/VEGFR signaling pathways play important regulating roles in CM angiogenesis.

  19. Dimethyl fumarate attenuates cerebral edema formation by protecting the blood-brain barrier integrity.

    Science.gov (United States)

    Kunze, Reiner; Urrutia, Andrés; Hoffmann, Angelika; Liu, Hui; Helluy, Xavier; Pham, Mirko; Reischl, Stefan; Korff, Thomas; Marti, Hugo H

    2015-04-01

    Brain edema is a hallmark of various neuropathologies, but the underlying mechanisms are poorly understood. We aim to characterize how tissue hypoxia, together with oxidative stress and inflammation, leads to capillary dysfunction and breakdown of the blood-brain barrier (BBB). In a mouse stroke model we show that systemic treatment with dimethyl fumarate (DMF), an antioxidant drug clinically used for psoriasis and multiple sclerosis, significantly prevented edema formation in vivo. Indeed, DMF stabilized the BBB by preventing disruption of interendothelial tight junctions and gap formation, and decreased matrix metalloproteinase activity in brain tissue. In vitro, DMF directly sustained endothelial tight junctions, inhibited inflammatory cytokine expression, and attenuated leukocyte transmigration. We also demonstrate that these effects are mediated via activation of the redox sensitive transcription factor NF-E2 related factor 2 (Nrf2). DMF activated the Nrf2 pathway as shown by up-regulation of several Nrf2 target genes in the brain in vivo, as well as in cerebral endothelial cells and astrocytes in vitro, where DMF also increased protein abundance of nuclear Nrf2. Finally, Nrf2 knockdown in endothelial cells aggravated subcellular delocalization of tight junction proteins during ischemic conditions, and attenuated the protective effect exerted by DMF. Overall, our data suggest that DMF protects from cerebral edema formation during ischemic stroke by targeting interendothelial junctions in an Nrf2-dependent manner, and provide the basis for a completely new approach to treat brain edema.

  20. High performance capillary electrophoresis analysis of polypeptide in protein hydrolysis ingredients of brain tissue%脑蛋白水解物中多肽组分的高效毛细管电泳分析

    Institute of Scientific and Technical Information of China (English)

    王辰; 黄慧玲; 莫丽冬; 范维佳; 阎维维

    2012-01-01

    目的 利用高效毛细管电泳法比较2种水解方法提纯的脑蛋白水解物中的多肽组分,同时监测进口脑蛋白水解物注射液的多肽组分分布.方法 采用固相萃取法提取脑组织中的多肽成分,以PACE/A5500型高效毛细管电泳仪对进口脑蛋白水解物注射液和本实验室提取的脑组织匀浆物进行比较.结果 进口脑蛋白水解物注射液中多肽成分大部分集中在>14400区域,本实验室提纯的脑蛋白水解物成分中多肽多集中在相对分子质量6000 ~ 14 400区域,且纯度及含量均较高.结论 高效毛细管电泳法可有效地对脑蛋白水解物注射液中多肽组分进行分析和比较,2种提纯方法对脑蛋白的裂解能力相差不大.%Objective To extract the protein hydrolysis ingredients of brain tissue were extracted and to analyze the components of polypeptide in cerebrolysin by using the method of high-performance capillary electrophoresis (HPCE).Methods Brain homogenate were extracted by solid phase extraction method.Cerebrolysin and brain tissue hydrolyzated extracted in lab were detected by HPCE (PACE/A5500,Beckman).Result The result of HPCE showed that the cerebrolysin injections molecular weight of most polypeptides were more than 14 400.The purity and content of cerebrolysin was better and the molecular weights were mainly between 6000 and 14 400.Conclusion The method of HPCE can be effectively used in analyzing components of polypeptides of brain tissue hydrolyzated.There is no difference of protein hydrolysis ingredients of brain tissue extracted by 2 kinds of extraction methods.

  1. The acidic domain of the endothelial membrane protein GPIHBP1 stabilizes lipoprotein lipase activity by preventing unfolding of its catalytic domain

    DEFF Research Database (Denmark)

    Mysling, Simon; Kristensen, Kristian Kølby; Larsson, Mikael;

    2016-01-01

    GPIHBP1 is a glycolipid-anchored membrane protein of capillary endothelial cells that binds lipoprotein lipase (LPL) within the interstitial space and shuttles it to the capillary lumen. The LPL•GPIHBP1 complex is responsible for margination of triglyceride-rich lipoproteins along capillaries and...

  2. Murine cerebrovascular cells as a cell culture model for cerebral amyloid angiopathy: isolation of smooth muscle and endothelial cells from mouse brain.

    Science.gov (United States)

    Gauthier, Sebastien A; Sahoo, Susmita; Jung, Sonia S; Levy, Efrat

    2012-01-01

    The use of murine cerebrovascular endothelial and smooth muscle cells has not been widely employed as a cell culture model for the investigation of cellular mechanisms involved in cerebral amyloid angiopathy (CAA). Difficulties in isolation and propagation of murine cerebrovascular cells and insufficient yields for molecular and cell culture studies have deterred investigators from using mice as a source for cerebrovascular cells in culture. Instead, cerebrovascular cells from larger mammals are preferred and several methods describing the isolation of endothelial and smooth muscle cells from human, canine, rat, and guinea pig have been published. In recent years, several transgenic mouse lines showing CAA pathology have been established; consequently murine cerebrovascular cells derived from these animals can serve as a key cellular model to study CAA. Here, we describe a procedure for isolating murine microvessels that yields healthy smooth muscle and endothelial cell populations and produce sufficient material for experimental purposes. Murine smooth muscle cells isolated using this protocol exhibit the classic "hill and valley" morphology and are immunoreactive for the smooth muscle cell marker α-actin. Endothelial cells display a "cobblestone" pattern phenotype and show the characteristic immunostaining for the von Willebrand factor and the factor VIII-related antigen. In addition, we describe methods designed to preserve these cells by storage in liquid nitrogen and reestablishing viable cell cultures. Finally, we compare our methods with protocols designed to isolate and maintain human cerebrovascular cell cultures.

  3. High temporal resolution for in vivo monitoring of neurotransmitters in awake epileptic rats using brain microdialysis and capillary electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Parrot, Sandrine; Sauvinet, Valérie; Riban, Véronique; Depaulis, Antoine; Renaud, Bernard; Denoroy, Luc

    2004-12-30

    A method for high temporal resolution monitoring of five neurotransmitters, dopamine (DA), noradrenaline (NA), gamma-aminobutyric acid (GABA), glutamate (Glu), l-aspartate (L-Asp), in freely-moving rats using microdialysis and capillary electrophoresis with laser-induced fluorescence detection (CE-LIFD) was developed. An on-line device, including microdialysis and derivatization with naphthalene-2,3-dicarboxaldehyde, mixes the dialysate with derivatization reagents directly in the collection tube, i.e. with no reactor. Thereafter, collected derivatized samples are analyzed off-line with an automated CE system coupled to a LIFD using a 442 nm excitation. The sampling time was limited by the minimal volume required for the analysis by the automated CE system used: neurotransmitters could be determined in 667 nl dialysates (940 nl after derivatization), i.e. in samples collected every 20 s with a flow rate of 2 microl/min. The detection limits at the dialysis probe were 3 x 10(-9), 1 x 10(-9), 1.9 x 10(-8), 4.2 x 10(-7), 2.1 x 10(-7) mol/l for DA, NA, GABA, Glu and L-Asp, respectively. The protocol was validated using in vitro/in vivo tests and the performances--repeatability, linearity, characteristics of the probes--were determined. Finally, the high temporal resolution allowed the simultaneous monitoring of these neurotransmitters in rats with genetic absence epilepsy and revealed, for the first time, increases in GABA concentrations concomitantly with the seizures, detected when our new microdialysis method was combined to electroencephalographic recordings.

  4. Comparison of five different targeting ligands to enhance accumulation of liposomes into the brain.

    Science.gov (United States)

    van Rooy, Inge; Mastrobattista, Enrico; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M

    2011-02-28

    In many different studies nanocarriers modified with targeting ligands have been used to target to the brain. Many ligands have been successful, but it is difficult to compare results from different studies to determine which targeting ligand is the best. Therefore, we selected five targeting ligands (transferrin, RI7217, COG133, angiopep-2, and CRM197) and compared their ability to target liposomes to the brain in vitro and in vivo. In vitro, only CRM197-modified liposomes were able to bind to murine endothelial cells (bEnd.3). Both CRM197 and RI7217-modified liposomes associated with human endothelial cells (hCMEC/D3). In vivo, uptake of targeted liposomes was tested at 12h after iv injection. For some of the ligands, additional time points of 1 and 6h were tested. Only the RI7217 was able to significantly enhance brain uptake in vivo at all time points. Uptake in the brain capillaries was up to 10 times higher compared to untargeted liposomes, and uptake in the brain parenchyma was up to 4.3 times higher. Additionally, these results show that many targeting ligands that have been described for brain targeting, do not target to the brain in vivo when coupled to a liposomal delivery vehicle.

  5. Mesangial cell integrin αvβ8 provides glomerular endothelial cell cytoprotection by sequestering TGF-β and regulating PECAM-1.

    Science.gov (United States)

    Khan, Shenaz; Lakhe-Reddy, Sujata; McCarty, Joseph H; Sorenson, Christine M; Sheibani, Nader; Reichardt, Louis F; Kim, Jane H; Wang, Bingcheng; Sedor, John R; Schelling, Jeffrey R

    2011-02-01

    Integrins are heterodimeric receptors that regulate cell adhesion, migration, and apoptosis. Integrin αvβ8 is most abundantly expressed in kidney and brain, and its major ligand is latent transforming growth factor-β (TGF-β). Kidney αvβ8 localizes to mesangial cells, which appose glomerular endothelial cells and maintain glomerular capillary structure by mechanical and poorly understood paracrine mechanisms. To establish kidney αvβ8 function, mice with homozygous Itgb8 deletion (Itgb8(-/-)) were generated on outbred and C57BL/6 congenic backgrounds. Most Itgb8(-/-) mice died in utero, and surviving Itgb8(-/-) mice failed to gain weight, and rarely survived beyond 6 weeks. A renal glomerular phenotype included azotemia and albuminuria, as well as increased platelet endothelial cell adhesion molecule-1 (PECAM-1) expression, which was surprisingly not associated with conventional functions, such as endothelial cell hyperplasia, hypertrophy, or perivascular inflammation. Itgb8(-/-) mesangial cells demonstrated reduced latent TGF-β binding, resulting in bioactive TGF-β release, which stimulated glomerular endothelial cell apoptosis. Using PECAM-1 gain and loss of function strategies, we show that PECAM-1 provides endothelial cytoprotection against mesangial cell TGF-β. These results clarify a singular mechanism of mesangial-to-endothelial cell cross-talk, whereby mesangial cell αvβ8 homeostatically arbitrates glomerular microvascular integrity by sequestering TGF-β in its latent conformation. Under pathological conditions associated with decreased mesangial cell αvβ8 expression and TGF-β secretion, compensatory PECAM-1 modulation facilitates glomerular endothelial cell survival.

  6. Annexin A1 restores Aβ1-42 -induced blood-brain barrier disruption through the inhibition of RhoA-ROCK signaling pathway.

    Science.gov (United States)

    Park, Jong-Chan; Baik, Sung Hoon; Han, Sun-Ho; Cho, Hyun Jin; Choi, Hyunjung; Kim, Haeng Jun; Choi, Heesun; Lee, Wonik; Kim, Dong Kyu; Mook-Jung, Inhee

    2017-02-01

    The blood-brain barrier (BBB) is composed of brain capillary endothelial cells and has an important role in maintaining homeostasis of the brain separating the blood from the parenchyma of the central nervous system (CNS). It is widely known that disruption of the BBB occurs in various neurodegenerative diseases, including Alzheimer's disease (AD). Annexin A1 (ANXA1), an anti-inflammatory messenger, is expressed in brain endothelial cells and regulates the BBB integrity. However, its role and mechanism for protecting BBB in AD have not been identified. We found that β-Amyloid 1-42 (Aβ42)-induced BBB disruption was rescued by human recombinant ANXA1 (hrANXA1) in the murine brain endothelial cell line bEnd.3. Also, ANXA1 was decreased in the bEnd.3 cells, the capillaries of 5XFAD mice, and the human serum of patients with AD. To find out the mechanism by which ANXA1 recovers the BBB integrity in AD, the RhoA-ROCK signaling pathway was examined in both Aβ42-treated bEnd.3 cells and the capillaries of 5XFAD mice as RhoA was activated in both cases. RhoA inhibitors alleviated Aβ42-induced BBB disruption and constitutively overexpressed RhoA-GTP (active form of RhoA) attenuated the protective effect of ANXA1. When pericytes were cocultured with bEnd.3 cells, Aβ42-induced RhoA activation of bEnd.3 cells was inhibited by the secretion of ANXA1 from pericytes. Taken together, our results suggest that ANXA1 restores Aβ42-induced BBB disruption through inhibition of RhoA-ROCK signaling pathway and we propose ANXA1 as a therapeutic reagent, protecting against the breakdown of the BBB in AD.

  7. Capillary pericytes regulate cerebral blood flow in health and disease

    DEFF Research Database (Denmark)

    Hall, Catherine N; Reynell, Clare; Gesslein, Bodil;

    2014-01-01

    Increases in brain blood flow, evoked by neuronal activity, power neural computation and form the basis of BOLD (blood-oxygen-level-dependent) functional imaging. Whether blood flow is controlled solely by arteriole smooth muscle, or also by capillary pericytes, is controversial. We demonstrate...... blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the blood......-brain barrier. Thus, pericytes are major regulators of cerebral blood flow and initiators of functional imaging signals. Prevention of pericyte constriction and death may reduce the long-lasting blood flow decrease that damages neurons after stroke....

  8. Microvascular endothelial cells of the corpus luteum

    Directory of Open Access Journals (Sweden)

    Spanel-Borowski Katherina

    2003-11-01

    Full Text Available Abstract The cyclic nature of the capillary bed in the corpus luteum offers a unique experimental model to examine the life cycle of endothelial cells, involving discrete physiologically regulated steps of angiogenesis, blood vessel maturation and blood vessel regression. The granulosa cells and theca cells of the developing antral follicle and the steroidogenic cells of the corpus luteum produce and respond to angiogenic factors and vasoactive peptides. Following ovulation the neovascularization during the early stages of corpus luteum development has been compared to the rapid angiogenesis observed during tumor formation. On the other end of the spectrum, the microvascular endothelial cells are the first cells to undergo apoptosis at the onset of corpus luteum regression. Important insights on the morphology and function of luteal endothelial cells have been gained from a combination of in vitro and in vivo studies on endothelial cells. Endothelial cells communicate with cells comprising the functional unit of the corpus luteum, i.e., other vascular cells, steroidogenic cells, and immune cells. This review is designed to provide an overview of the types of endothelial cells present in the corpus luteum and their involvement in corpus luteum development and regression. Available evidence indicates that microvascular endothelial cells of the corpus luteum are not alike, and may differ during the process of angiogenesis and angioregression. The contributions of vasoactive peptides generated by the luteal endothelin-1 and the renin-angiotensin systems are discussed in context with the function of endothelial cells during corpus luteum formation and regression. The ability of two cytokines, tumor necrosis factor alpha and interferon gamma, are evaluated as paracrine mediators of endothelial cell function during angioregression. Finally, chemokines are discussed as a vital endothelial cell secretory products that contribute to the recruitment of

  9. Tissue inhibitor of matrix metalloproteinases-1 loaded poly(lactic-co-glycolic acid nanoparticles for delivery across the blood–brain barrier

    Directory of Open Access Journals (Sweden)

    Chaturvedi M

    2014-01-01

    Full Text Available Mayank Chaturvedi,1 Yves Molino,2 Bojja Sreedhar,3 Michel Khrestchatisky,4 Leszek Kaczmarek1 1Laboratory of Neurobiology, Nencki Institute, Warsaw, Poland; 2Vect-Horus, Marseille, France; 3Indian Institute of Chemical Technology, Hyderabad, India; 4Aix-Marseille Université, CNRS, NICN, UMR7259, Marseille, France Aim: The aim of this study was to develop poly(lactic-co-glycolic acid (PLGA nanoparticles (NPs for delivery of a protein – tissue inhibitor of matrix metalloproteinases 1 (TIMP-1 – across the blood–brain barrier (BBB to inhibit deleterious matrix metalloproteinases (MMPs. Materials and methods: The NPs were formulated by multiple-emulsion solvent-evaporation, and for enhancing BBB penetration, they were coated with polysorbate 80 (Ps80. We compared Ps80-coated and uncoated NPs for their toxicity, binding, and BBB penetration on primary rat brain capillary endothelial cell cultures and the rat brain endothelial 4 cell line. These studies were followed by in vivo studies for brain delivery of these NPs. Results: Results showed that neither Ps80-coated nor uncoated NPs caused significant opening of the BBB, and essentially they were nontoxic. NPs without Ps80 coating had more binding to endothelial cells compared to Ps80-coated NPs. Penetration studies showed that TIMP-1 NPs + Ps80 had 11.21%±1.35% penetration, whereas TIMP-1 alone and TIMP-1 NPs without Ps80 coating did not cross the endothelial monolayer. In vivo studies indicated BBB penetration of intravenously injected TIMP-1 NPs + Ps80. Conclusion: The study demonstrated that Ps80 coating of NPs does not cause significant toxic effects to endothelial cells and that it can be used to enhance the delivery of protein across endothelial cell barriers, both in vitro and in vivo. Keywords: PLGA nanoparticles, drug delivery, protein delivery, sustained release, brain delivery, BBB penetration, RBCEC culture

  10. Protein kinase C-α signals P115RhoGEF phosphorylation and RhoA activation in TNF-α-induced mouse brain microvascular endothelial cell barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Deng Xiaolu

    2011-04-01

    Full Text Available Abstract Background Tumor necrosis factor-α (TNF-α, a proinflammatory cytokine, is capable of activating the small GTPase RhoA, which in turn contributes to endothelial barrier dysfunction. However, the underlying signaling mechanisms remained undefined. Therefore, we aimed to determine the role of protein kinase C (PKC isozymes in the mechanism of RhoA activation and in signaling TNF-α-induced mouse brain microvascular endothelial cell (BMEC barrier dysfunction. Methods Bend.3 cells, an immortalized mouse brain endothelial cell line, were exposed to TNF-α (10 ng/mL. RhoA activity was assessed by pull down assay. PKC-α activity was measured using enzyme assasy. BMEC barrier function was measured by transendothelial electrical resistance (TER. p115RhoGEF phosphorylation was detected by autoradiography followed by western blotting. F-actin organization was observed by rhodamine-phalloidin staining. Both pharmacological inhibitors and knockdown approaches were employed to investigate the role of PKC and p115RhoGEF in TNF-α-induced RhoA activation and BMEC permeability. Results We observed that TNF-α induces a rapid phosphorylation of p115RhoGEF, activation of PKC and RhoA in BMECs. Inhibition of conventional PKC by Gö6976 mitigated the TNF-α-induced p115RhoGEF phosphorylation and RhoA activation. Subsequently, we found that these events are regulated by PKC-α rather than PKC-β by using shRNA. In addition, P115-shRNA and n19RhoA (dominant negative mutant of RhoA transfections had no effect on mediating TNF-α-induced PKC-α activation. These data suggest that PKC-α but not PKC-β acts as an upstream regulator of p115RhoGEF phosphorylation and RhoA activation in response to TNF-α. Moreover, depletion of PKC-α, of p115RhoGEF, and inhibition of RhoA activation also prevented TNF-α-induced stress fiber formation and a decrease in TER. Conclusions Taken together, our results show that PKC-α phosphorylation of p115RhoGEF mediates TNF

  11. Capillary regeneration in scleroderma: stem cell therapy reverses phenotype?

    Directory of Open Access Journals (Sweden)

    Jo N Fleming

    Full Text Available BACKGROUND: Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease. METHODOLOGY/PRINCIPAL FINDINGS: We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue, antiangiogenic interferon alpha (overexpressed in the scleroderma dermis and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon alpha and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal. CONCLUSION/SIGNIFICANCE: These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease

  12. Transport characteristics of tramadol in the blood-brain barrier.

    Science.gov (United States)

    Kitamura, Atsushi; Higuchi, Kei; Okura, Takashi; Deguchi, Yoshiharu

    2014-10-01

    Tramadol is a centrally acting analgesic whose action is mediated by both agonistic activity at opioid receptors and inhibitory activity on neuronal reuptake of monoamines. The purpose of this study was to characterize the blood-brain barrier (BBB) transport of tramadol by means of microdialysis studies in rat brain and in vitro studies with human immortalized brain capillary endothelial cells (hCMEC/D3). The Kp,uu,brain value of tramadol determined by rat brain microdialysis was greater than unity, indicating that tramadol is actively taken up into the brain across the BBB. Tramadol was transported into hCMEC/D3 cells in a concentration-dependent manner. The uptake was inhibited by type II cations (pyrilamine, verapamil, etc.), but not by substrates of organic cation transporter OCTs or OCTN2. It was also inhibited by a metabolic inhibitor but was independent of extracellular sodium or membrane potential. The uptake was altered by changes of extracellular pH, and by ammonium chloride-induced intracellular acidification, suggesting that transport of tramadol is driven by an oppositely directed proton gradient. Thus, our in vitro and in vivo results suggest that tramadol is actively transported, at least in part, from blood to the brain across the BBB by proton-coupled organic cation antiporter.

  13. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  14. Blood Brain Barrier Dysfunction and Delayed Neurological Deficits in Mild Traumatic Brain Injury Induced by Blast Shock Waves

    Directory of Open Access Journals (Sweden)

    Ashok K Shetty

    2014-08-01

    Full Text Available Mild traumatic brain injury (mTBI resulting from exposure to blast shock waves (BSWs is one of the most predominant causes of illnesses among veterans who served in the recent Iraq and Afghanistan wars. Such mTBI can also happen to civilians if exposed to shock waves of bomb attacks by terrorists. While cognitive problems, memory dysfunction, depression, anxiety and diffuse white matter injury have been observed at both early and/or delayed time-points, an initial brain pathology resulting from exposure to BSWs appears to be the dysfunction or disruption of the blood-brain barrier (BBB. Studies in animal models suggest that exposure to relatively milder BSWs (123 kPa initially induces free radical generating enzymes in and around brain capillaries, which enhances oxidative stress resulting in loss of tight junction proteins, edema formation, and leakiness of BBB with disruption or loss of its components pericytes and astrocyte end-feet. On the other hand, exposure to more intense BSWs (145-323 kPa causes acute disruption of the BBB with vascular lesions in the brain. Both of these scenarios lead to apoptosis of endothelial and neural cells and neuroinflammation in and around capillaries, which may progress into chronic traumatic encephalopathy and/or a variety of neurological impairments, depending on brain regions that are afflicted with such lesions. This review discusses studies that examined alterations in the brain milieu causing dysfunction or disruption of the BBB and neuroinflammation following exposure to different intensities of BSWs. Furthermore, potential of early intervention strategies capable of easing oxidative stress, repairing the BBB or blocking inflammation for minimizing delayed neurological deficits resulting from exposure to BSWs is conferred.

  15. Derivatization in Capillary Electrophoresis.

    Science.gov (United States)

    Marina, M Luisa; Castro-Puyana, María

    2016-01-01

    Capillary electrophoresis is a well-established separation technique in analytical research laboratories worldwide. Its interesting advantages make CE an efficient and potent alternative to other chromatographic techniques. However, it is also recognized that its main drawback is the relatively poor sensitivity when using optical detection. One way to overcome this limitation is to perform a derivatization reaction which is intended to provide the analyte more suitable analytical characteristics enabling a high sensitive detection. Based on the analytical step where the CE derivatization takes place, it can be classified as precapillary (before separation), in-capillary (during separation), or postcapillary (after separation). This chapter describes the application of four different derivatization protocols (in-capillary and precapillary modes) to carry out the achiral and chiral analysis of different compounds in food and biological samples with three different detection modes (UV, LIF, and MS).

  16. How Capillary Rafts Sink

    CERN Document Server

    Protiere, S; Aristoff, J; Stone, H

    2010-01-01

    We present a fluid dynamics video showing how capillary rafts sink. Small objects trapped at an interface are very common in Nature (insects walking on water, ant rafts, bubbles or pollen at the water-air interface, membranes...) and are found in many multiphase industrial processes. Thanks to Archimedes principle we can easily predict whether an object sinks or floats. But what happens when several small particles are placed at an interface between two fluids. In this case surface tension also plays an important role. These particles self-assemble by capillarity and thus form what we call a "capillary raft". We show how such capillary rafts sink for varying sizes of particles and define how this parameter affects the sinking process.

  17. Age-related alteration of activity and gene expression of endothelial nitric oxide synthase in different parts of the brain in rats.

    Science.gov (United States)

    Strosznajder, Joanna B; Jeśko, Henryk; Zambrzycka, Agata; Eckert, Anne; Chalimoniuk, Małgorzata

    2004-11-11

    Nitric oxide (NO) plays important roles in aging and neurodegeneration. Our previous results indicated that aging differently affects NOS isoforms. Expression of nNOS mRNA was lower while iNOS was absent at any age. However, total NO synthesis increased in aged cerebral cortex and cerebellum as a consequence of changes of nNOS phosphorylation state. The question arise how aging influences activity and expression of eNOS in different parts of adult and aged brain. The levels of eNOS mRNA, protein and activity were measured using RT-PCR, immuno- and radiochemical methods, respectively. Our studies indicated that after inhibition of nNOS with 7-nitroindazole (7-NI) NO synthesis is lower in all parts of aged brain comparing to adults. However, eNOS activity significantly decreases only in cerebellum. The expression of eNOS determined on mRNA level was enhanced in all investigated aged brain parts to 140-190% of adult value and the data were statistically significant for cerebral cortex and cerebellum. The higher level of mRNA is probably the adaptive response to lower NOS activity. However, the Western-blot signal of eNOS protein was unchanged in aged brain parts comparing to adults suggesting age-related disturbances of protein synthesis and its function. It is also possible that a post-translational modification of the enzyme occurs in the aged rat brain. The lower eNOS activity in aged brain may significantly affects the signal transduction processes on the pathway NO/cGMP/PKG.

  18. Endothelial Proliferation and Increased Blood - Brain Barrier Permeability in the Basal Ganglia in a Rat Model of 3,4-Dihydrozyphenyl-L-Alanine-Induced Dyskinesia

    DEFF Research Database (Denmark)

    Westin, Jenny E.; Lindgren, Hanna S.; Gardi, Jonathan Eyal

    2006-01-01

    3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia is associated with molecular and synaptic plasticity in the basal ganglia, but the occurrence of structural remodeling through cell genesis has not been explored. In this study, rats with 6-hydroxydopamine lesions received injections of th...... of angiogenesis and blood-brain barrier dysfunction in an experimental model of L-DOPA-induced dyskinesia. These microvascular changes are likely to affect the kinetics of L-DOPA entry into the brain, favoring the occurrence of motor complications....

  19. In vitro inhibition of protease-activated receptors 1, 2 and 4 demonstrates that these receptors are not involved in an Acanthamoeba castellanii keratitis isolate-mediated disruption of the human brain microvascular endothelial cells.

    Science.gov (United States)

    Iqbal, Junaid; Naeem, Komal; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2014-11-01

    Granulomatous amoebic encephalitis is a rare but serious human disease leading almost always to death. The pathophysiology of amoebic encephalitis is better understood, while events leading to the constitution of brain infection are largely unknown. Traversal of the blood-brain barrier is a key step in amoebae invasion of the central nervous system and facilitated by amoebic extracellular proteases. By using specific inhibitors of protease-activated receptors 1, 2 and 4, here we studied the role of these host receptors in Acanthamoeba castellanii-mediated damage to human brain microvasculature endothelial cells (HBMEC), which constitute the blood-brain barrier. The primary HBMEC were incubated with A. castellanii-conditioned medium in the presence or absence of FR-171113 (selective inhibitor of protease-activated receptor 1), FSLLRY-NH2 (inhibitor of protease-activated receptor 2), and tcY-NH2 (inhibitor of protease-activated receptor 4). The HBMEC monolayer disruptions were assessed by microscopy using Eosin staining, while host cell cytotoxicity was determined by measuring the release of cytoplasmic lactate dehydrogenase. Zymographic assays were performed to determine the effects of inhibitors of protease-activated receptors on the extracellular proteolytic activities of A. castellanii. A. castellanii-conditioned medium produced severe HBMEC monolayer disruptions within 60 min. The selective inhibitors of protease-activated receptors tested did not affect HBMEC monolayer disruptions. On the contrary, pre-treatment of A. castellanii-conditioned medium with phenylmethylsulfonyl fluoride, a serine protease inhibitor, or heating for 10 min at 95°C abolished HBMEC monolayer disruptions. Additionally, inhibitors of protease-activated receptors tested, failed to block A. castellanii-mediated HBMEC cytotoxicity and did not affect extracellular proteolytic activities of A. castellanii. Protease-activated receptors 1, 2 and 4 do not appear to play a role in A. castellanii

  20. Capillary permeability in adipose tissue

    DEFF Research Database (Denmark)

    Paaske, W P; Nielsen, S L

    1976-01-01

    of about 7 ml/100 g-min. This corresponds to a capillary diffusion capacity of 2.0 ml/100 g-min which is half the value reported for vasodilated skeletal muscle having approximately twice as great capillary surface area. Thus, adipose tissue has about the same capillary permeability during slight metabolic...

  1. Decreases in rat brain aquaporin-4 expression following intracerebroventricular administration of an endothelin ET B receptor agonist.

    Science.gov (United States)

    Koyama, Yutaka; Tanaka, Kazuhiro

    2010-01-29

    Aquaporins (AQPs) comprise a family of water channel proteins, some of which are expressed in brain. Expressions of brain AQPs are altered after brain insults, such as ischemia and head trauma. However, little is known about the regulation of brain AQP expression. Endothelins (ETs), vasoconstrictor peptides, regulate several pathophysiological responses of damaged nerve tissues via ET(B) receptors. To show possible roles of ET(B) receptors in the regulation of brain AQP expression, the effects of intracerebroventricular administration of an ET(B) agonist were examined in rat brain. In the cerebrum, the copy numbers of AQP4 mRNAs were highest among AQP1, 3, 4, 5 and 9. Continuous administration of 500 pmol/day Ala(1,3,11,15)-ET-1, an ET(B) selective agonist, into rat brain for 7 days decreased the level of AQP4 mRNA in the cerebrum, but had no effect on AQP1, 3, 5 and 9 mRNA levels. The level of AQP4 protein in the cerebrum decreased by the administration of Ala(1,3,11,15)-ET-1. Immunohistochemical observations of Ala(1,3,11,15)-ET-1-infused rats showed that GFAP-positive astrocytes, but not neurons, activated microglia or brain capillary endothelial cells, had immunoreactivity for AQP4. These findings indicate that activation of brain ET(B) receptors causes a decrease in AQP4 expression, suggesting that ET down-regulates brain AQP4 via ET(B) receptors.

  2. Myocardial serotonin exchange: negligible uptake by capillary endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Moffett, T.C.; Chan, I.S.; Bassingthwaighte, J.B.

    1988-03-01

    The extraction of serotonin from the blood during transorgan passage through the heart was studied using Langendorff-perfused rabbit hearts. Outflow dilution curves of /sup 131/I- or /sup 125/I-labeled albumin, (/sup 14/C)sucrose, and (3H)serotonin injected simultaneously into the inflow were fitted with an axially distributed blood-tissue exchange model to examine the extraction process. The model fits of the albumin and sucrose outflow dilution curves were used to define flow heterogeneity, intravascular dispersion, capillary permeability, and the volume of the interstitial space, which reduced the degrees of freedom in fitting the model to the serotonin curves. Serotonin extractions, measured against albumin, during single transcapillary passage, ranged from 24 to 64%. The ratio of the capillary permeability-surface area products for serotonin and sucrose, based on the maximum instantaneous extraction, was 1.37 +/- 0.2 (n = 18), very close to the predicted value of 1.39, the ratio of free diffusion coefficients calculated from the molecular weights. This result shows that the observed uptake of serotonin can be accounted for solely on the basis of diffusion between endothelial cells into the interstitial space. Thus it appears that the permeability of the luminal surface of the endothelial cell is negligible in comparison to diffusion through the clefts between endothelial cells. In 18 sets of dilution curves, with and without receptor and transport blockers or competitors (ketanserin, desipramine, imipramine, serotonin), the extractions and estimates of the capillary permeability-surface area product were not reduced, nor were the volumes of distribution. The apparent absence of transporters and receptors in rabbit myocardial capillary endothelium contrasts with their known abundance in the pulmonary vasculature.

  3. 99mTc complex conjugated to insulin: CNS radio-pharmaceuticals design based on principles of blood-brain barrier transport vector

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; FAN Caiyun; ZHANG Jinming; WANG Wushang; LIU Boli

    2005-01-01

    Hydrophilic 99mTc-EC and nonlipophilic 99mTc- MAMA′-BA complexes, owing to the existing of intact blood-brain barrier (BBB) in vivo, cannot cross from blood to brain. Previous studies showed that insulin is selectively transported by receptor-mediated transcytosis through the brain capillary endothelial wall that makes up the BBB. In this paper, based on the characteristic of the insulin receptor enriched in brain capillary, the complexes of hydrophilic 99mTc-EC and nonlipophilic 99mTc-MAMA′-BA are conjugated to insulin respectively. After purification, the radiochemical purity of 99mTc-EC-insulin and 99mTc-MAMA′- BA-insulin was > 90% and the stability in vitro was good. Expectation for the special formulation can be internalized and endocytosed into the capillary membrane by the vector-mediated brain delivery system, and transported 99mTc-labeled conjugate through the BBB in vivo, thus enhancing brain uptake in mice. The biodistribution results of 99mTc-EC-insulin and 99mTc-MAMA′-BA-insulin in mice indicated that the brain uptake was higher than 99mTc-EC and 99mTc-MAMA′-BA to some extent. The ratios of brain uptake of 99mTc-EC-insulin to 99mTc-EC, 99mTc-MAMA′-BA-insulin to 99mTc-MAMA′-BA were 4―6 at 2 and 3 h post-injection respectively. In conclusion, the given results have illustrated a new way of brain uptake enhancing for nonlipophilic like complexes that have BBB delivery problems. It has a potential value for the ongoing development of 99mTc-labeled radiopharmaceuticals for CNS receptors imaging.

  4. Development and Validation of an In-Cell Western for Quantifying P-Glycoprotein Expression in Human Brain Microvascular Endothelial (hCMEC/D3) Cells.

    Science.gov (United States)

    McInerney, Mitchell P; Pan, Yijun; Short, Jennifer L; Nicolazzo, Joseph A

    2017-01-05

    An in-cell western (ICW) protocol detecting the relative expression of P-glycoprotein (P-gp) in human cerebro-microvascular endothelial cells (hCMEC/D3) was developed and optimized, with the intention of improving throughput relative to western blotting (WB). For validation of the ICW protocol, hCMEC/D3 cells were incubated with known P-gp upregulators (10 μM rifampicin and 5 μM SR12813) and treated with siRNA targeted against MDR1, before measuring changes in P-gp expression, using both ICW and WB in parallel. To confirm a relationship between the detected P-gp expression and function, the uptake of the P-gp substrate rhodamine-123 was assessed following SR12813 treatment. Rifampicin and SR12813 significantly upregulated P-gp expression (1.5-fold and 1.9-fold, respectively) compared to control, as assessed by the ICW protocol. WB analysis of the same treatments revealed 1.4-fold and 1.5-fold upregulations. MDR1 siRNA reduced P-gp abundance by 20% and 35% when assessed by ICW and WB, respectively. SR12813 treatment reduced rhodamine-123 uptake by 18%, indicating that the observed changes in P-gp expression by ICW were associated with comparable functional changes. The correlation of P-gp upregulation by WB, rhodamine-123 uptake, and the ICW protocol provide validation of a new ICW method as an alternative method for quantification of P-gp in hCMEC/D3 cells.

  5. [Vascular endothelial Barrier Function].

    Science.gov (United States)

    Ivanov, A N; Puchinyan, D M; Norkin, I A

    2015-01-01

    Endothelium is an important regulator of selective permeability of the vascular wall for different molecules and cells. This review summarizes current data on endothelial barrier function. Endothelial glycocalyx structure, its function and role in the molecular transport and leukocytes migration across the endothelial barrier are discussed. The mechanisms of transcellular transport of macromolecules and cell migration through endothelial cells are reviewed. Special section of this article addresses the structure and function of tight and adherens endothelial junction, as well as their importance for the regulation of paracellular transport across the endothelial barrier. Particular attention is paid to the signaling mechanism of endothelial barrier function regulation and the factors that influence on the vascular permeability.

  6. Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

    Directory of Open Access Journals (Sweden)

    Redzic Zoran

    2011-01-01

    Full Text Available Abstract Efficient processing of information by the central nervous system (CNS represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB, which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF barrier (BCSFB, which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC transport proteins at those two barriers and underlines

  7. due to Capillary Forces

    Directory of Open Access Journals (Sweden)

    Hassen M. Ouakad

    2009-01-01

    Full Text Available We present modeling and analysis for the static behavior and collapse instabilities of doubly-clamped and cantilever microbeams subjected to capillary forces. These forces can be as a result of a volume of liquid trapped underneath the microbeam during the rinsing and drying process in fabrication. The model considers the microbeam as a continuous medium, the capillary force as a nonlinear function of displacement, and accounts for the mid-plane stretching and geometric nonlinearities. The capillary force is assumed to be distributed over a specific length underneath the microbeam. The Galerkin procedure is used to derive a reduced-order model consisting of a set of nonlinear algebraic and differential equations that describe the microbeams static and dynamic behaviors. We study the collapse instability, which brings the microbeam from its unstuck configuration to touch the substrate and gets stuck in the so-called pinned configuration. We calculate the pull-in length that distinguishes the free from the pinned configurations as a function of the beam thickness and gap width for both microbeams. Comparisons are made with analytical results reported in the literature based on the Ritz method for linear and nonlinear beam models. The instability problem, which brings the microbeam from a pinned to adhered configuration is also investigated. For this case, we use a shooting technique to solve the boundary-value problem governing the deflection of the microbeams. The critical microbeam length for this second instability is also calculated.

  8. Dual ligand immunoliposomes for drug delivery to the brain.

    Science.gov (United States)

    Loureiro, Joana A; Gomes, Bárbara; Fricker, Gert; Cardoso, Isabel; Ribeiro, Carlos A; Gaiteiro, Cristiana; Coelho, Manuel A N; Pereira, Maria do Carmo; Rocha, Sandra

    2015-10-01

    Drug delivery systems that can reach brain areas affected by amyloid deposits are still underdeveloped. We propose pegylated liposomes functionalized with two antibodies, the anti-transferrin receptor monoclonal antibody (OX26MAb) and the anti-amyloid beta peptide antibody (19B8MAb), as nanocarriers of drugs for Alzheimer's disease therapy. Two distinct conjugation methods are investigated. In one formulation, the OX26MAb is conjugated to the tip of polyethylene glycol molecules through the maleimide group and the 19B8MAb is bound through the streptavidin-biotin complex. In the second system the conjugation reagents are swapped between the antibodies. Fluorescence spectroscopy experiments on porcine brain capillary endothelial cells show that the cellular uptake of the immunoliposomes is substantially more efficient if OX26MAb antibody is conjugated through the streptavidin-biotin complex instead of the maleimide group. The ability of the immunoliposomes to cross the blood brain barrier was established by in vivo studies in wild type rats. Our results demonstrate the importance of the conjugation method used to bind the antibody that targets the blood brain barrier to immunoliposomes for efficient drug delivery to the brain.

  9. SNS-032 Prevents Tumor Cell-Induced Angiogenesis By Inhibiting Vascular Endothelial Growth Factor

    Directory of Open Access Journals (Sweden)

    M. Aktar Ali

    2007-05-01

    Full Text Available Cell proliferation, migration, and capillary network formation of endothelial cells are the fundamental steps for angiogenesis, which involves the formation of new blood vessels. The purpose of this study is to investigate the effect of a novel aminothiazole SNS-032 on these critical steps for in vitro angiogenesis using a coculture system consisting of human umbilical vein endothelial cells (HUVECs and human glioblastoma cells (U87MG. SNS-032 is a potent selective inhibitor of cyclin-dependent kinases 2, 7, and 9, and inhibits both transcription and cell cycle. In this study, we examined the proliferation and viability of HUVECs and U87MG cells in the presence of SNS-032 and observed a dose-dependent inhibition of cellular proliferation in both cell lines. SNS-032 inhibited threedimensional capillary network formations of endothelial cells. In a coculture study, SNS-032 completely prevented U87MG cell-mediated capillary formation of HUVECs. This inhibitor also prevented the migration of HUVECs when cultured alone or cocultured with U87MG cells. In addition, SNS-032 significantly prevented the production of vascular endothelial growth factor (VEGF in both cell lines, whereas SNS-032 was less effective in preventing capillary network formation and migration of endothelial cells when an active recombinant VEGF was added to the medium. In conclusion, SNS-032 prevents in vitro angiogenesis, and this action is attributable to blocking of VEGF.

  10. Stress failure of pulmonary capillaries: role in lung and heart disease

    Science.gov (United States)

    West, J. B.; Mathieu-Costello, O.

    1992-01-01

    Pulmonary capillaries have extremely thin walls to allow rapid exchange of respiratory gases across them. Recently it has been shown that the wall stresses become very large when the capillary pressure is raised, and in anaesthetised rabbits, ultrastructural damage to the walls is seen at pressures of 40 mm Hg and above. The changes include breaks in the capillary endothelial layer, alveolar epithelial layer, and sometimes all layers of the wall. The strength of the thin part of the capillary wall can be attributed to the type IV collagen in the extracellular matrix. Stress failure of pulmonary capillaries results in a high-permeability form of oedema, or even frank haemorrhage, and is apparently the mechanism of neurogenic pulmonary oedema and high-altitude pulmonary oedema. It also explains the exercise-induced pulmonary haemorrhage that occurs in all racehorses. Several features of mitral stenosis are consistent with stress failure. Overinflation of the lung also leads to stress failure, a common cause of increased capillary permeability in the intensive care environment. Stress failure also occurs if the type IV collagen of the capillary wall is weakened by autoantibodies as in Goodpasture's syndrome. Neutrophil elastase degrades type IV collagen and this may be the starting point of the breakdown of alveolar walls that is characteristic of emphysema. Stress failure of pulmonary capillaries is a hitherto overlooked and potentially important factor in lung and heart disease.

  11. Cellular localization of Y-box binding protein 1 in brain tissue of rats, macaques, and humans

    Directory of Open Access Journals (Sweden)

    Horn Anja

    2009-03-01

    Full Text Available Abstract Background The Y-box binding protein 1 (YB-1 is considered to be one of the key regulators of transcription and translation. However, so far only limited knowledge exists regarding its cellular distribution in the adult brain. Results Analysis of YB-1 immunolabelling as well as double-labelling with the neuronal marker NeuN in rat brain tissue revealed a predominant neuronal expression in the dentate gyrus, the cornu ammonis pyramidal cell layer, layer III of the piriform cortex as well as throughout all layers of the parahippocampal cortex. In the hilus of the hippocampus single neurons expressed YB-1. The neuronal expression pattern was comparable in the hippocampus and parahippocampal cortex of adult macaques and humans. Double-labelling of YB-1 with the endothelial cell marker Glut-1, the multidrug transporter P-glycoprotein, and the astrocytic marker GFAP did not indicate a co-localization. Following status epilepticus in rats, no induction of YB-1 occurred in brain capillary endothelial cells and neurons. Conclusion In conclusion, our study demonstrates that YB-1 is predominantly expressed in neurons in the adult brain of rats, macaques and humans. Lack of a co-localization with Glut-1 and P-glycoprotein argues against a direct role of YB-1 in the regulation of blood-brain barrier P-glycoprotein.

  12. Interaction of human endothelial cells and nickel-titanium materials modified with silicon ions

    Energy Technology Data Exchange (ETDEWEB)

    Lotkov, Aleksandr I., E-mail: lotkov@ispms.tsc.ru; Kashin, Oleg A., E-mail: okashin@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Kudryavtseva, Yuliya A., E-mail: yulia-k1970@mail.ru; Antonova, Larisa V., E-mail: antonova.la@mail.ru; Matveeva, Vera G., E-mail: matveeva-vg@mail.ru; Sergeeva, Evgeniya A., E-mail: sergeewa.ew@yandex.ru [Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, 650002 (Russian Federation); Kudryashov, Andrey N., E-mail: kudryashov@angioline.ru [Angioline Interventional Device Ltd, Novosibirsk, 630090 (Russian Federation)

    2015-10-27

    The paper studies the influence of chemical and phase compositions of NiTi surface layers modified with Si ions by plasma immersion implantation on their interaction with endothelial cells. It is shown that certain technological modes of Si ion implantation enhance the adhesion, proliferation, and viability of endothelial cells. It is found that the Si-modified NiTi surface is capable of stimulating the formation of capillary-like structures in the cell culture.

  13. 重组人脑利钠肽对动脉硬化大鼠血管内皮功能的影响%The effects of Brain Natriuretic Peptide on the function of rats arteriosclerosis model vascular endothelial

    Institute of Scientific and Technical Information of China (English)

    周琳; 张静; 袁天阳; 李扬雪; 徐艳玲; 戴琎

    2013-01-01

    目的 探讨rhBNP对动脉粥样硬化(AS)大鼠模型血管内皮功能的影响.方法 40只健康wistar大鼠,随机分为对照组、模型组、处理组各8只.处理组分别给予硝酸酯类、阿魏酸钠、重组人脑利钠肽皮下注射.采用酶联免疫吸附(ELISA)方法测定各组大鼠处理前后血清中血栓素B2(TXB2)和6-酮前列腺素F1a(6-Keto-PGF1a)的含量,并且光镜下观察各组处理前后大鼠的主动脉内膜细胞的变化.结果 1)处理组药物治疗后,血清中TXB2均下降、6-Keto-PGF1a均升高,与治疗前比较有统计学差异(P0.05);3)光镜的观察结果提示:模型组血管管腔内有附壁斑块;平滑肌细胞排列紊乱;处理组内膜较光滑,局部有MC粘附,偶可见EC缺失,但好于模型组,各处理组之间未见明显差别.结论 rhBNP通过保护血管内皮功能具有抗动脉粥样硬化的作用.%Objective The effects of Brain Natriuretic Pcptidc on the function of rats arteriosclerosis model vascular endothelial. Methods 40 healthy wistar rats, divided into five groups at random, eight rats in contorl group, eight in model group,each of the treatment group of nitratcs(Hua rcn xin shu),Sodium Fcrulatc(Haisi) ., rhBNP (xinhuosu) model group were eight rats. Adopt enzyme-linked immunosorbent adsorption (ELISA) methods to determine each rat treatment and scrum blood TXB2 and 6-Kcto-PGFla content,and light-microscopy each rat before and after processing the aortic lining cells changes. Results a. The treatment group scrum TXB2 and 6-Kcto-PGFla levels obviously different than bcforc(P 0. 05). c. Optical microscope observations, the control group vascular lumen, no calcium sediment, big plaques can be seen. Smooth muscle cells is boom and ectoblast is conjunction tissue, arranging disorganized. The treatment group is smoother,local macrophagc adhesion,visible EC missing,but better than model group,and the treatment group showed no significant difference between. Conclusion rhBNP can not

  14. Inflammation- and tumor-induced anorexia and weight loss require MyD88 in hematopoietic/myeloid cells but not in brain endothelial or neural cells.

    Science.gov (United States)

    Ruud, Johan; Wilhelms, Daniel Björk; Nilsson, Anna; Eskilsson, Anna; Tang, Yan-Juan; Ströhle, Peter; Caesar, Robert; Schwaninger, Markus; Wunderlich, Thomas; Bäckhed, Fredrik; Engblom, David; Blomqvist, Anders

    2013-05-01

    Loss of appetite is a hallmark of inflammatory diseases. The underlying mechanisms remain undefined, but it is known that myeloid differentiation primary response gene 88 (MyD88), an adaptor protein critical for Toll-like and IL-1 receptor family signaling, is involved. Here we addressed the question of determining in which cells the MyD88 signaling that results in anorexia development occurs by using chimeric mice and animals with cell-specific deletions. We found that MyD88-knockout mice, which are resistant to bacterial lipopolysaccharide (LPS)-induced anorexia, displayed anorexia when transplanted with wild-type bone marrow cells. Furthermore, mice with a targeted deletion of MyD88 in hematopoietic or myeloid cells were largely protected against LPS-induced anorexia and displayed attenuated weight loss, whereas mice with MyD88 deletion in hepatocytes or in neural cells or the cerebrovascular endothelium developed anorexia and weight loss of similar magnitude as wild-type mice. Furthermore, in a model for cancer-induced anorexia-cachexia, deletion of MyD88 in hematopoietic cells attenuated the anorexia and protected against body weight loss. These findings demonstrate that MyD88-dependent signaling within the brain is not required for eliciting inflammation-induced anorexia. Instead, we identify MyD88 signaling in hematopoietic/myeloid cells as a critical component for acute inflammatory-driven anorexia, as well as for chronic anorexia and weight loss associated with malignant disease.

  15. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  16. Normal human epithelial cells regulate the size and morphology of tissue-engineered capillaries.

    Science.gov (United States)

    Rochon, Marie-Hélène; Fradette, Julie; Fortin, Véronique; Tomasetig, Florence; Roberge, Charles J; Baker, Kathleen; Berthod, François; Auger, François A; Germain, Lucie

    2010-05-01

    The survival of thick tissues/organs produced by tissue engineering requires rapid revascularization after grafting. Although capillary-like structures have been reconstituted in some engineered tissues, little is known about the interaction between normal epithelial cells and endothelial cells involved in the in vitro angiogenic process. In the present study, we used the self-assembly approach of tissue engineering to examine this relationship. An endothelialized tissue-engineered dermal substitute was produced by adding endothelial cells to the tissue-engineered dermal substitute produced by the self-assembly approach. The latter consists in culturing fibroblasts in the medium supplemented with serum and ascorbic acid. A network of tissue-engineered capillaries (TECs) formed within the human extracellular matrix produced by dermal fibroblasts. To determine whether epithelial cells modify TECs, the size and form of TECs were studied in the endothelialized tissue-engineered dermal substitute cultured in the presence or absence of epithelial cells. In the presence of normal keratinocytes from skin, cornea or uterine cervix, endothelial cells formed small TECs (cross-sectional area estimated at less than 50 microm(2)) reminiscent of capillaries found in the skin's microcirculation. In contrast, TECs grown in the absence of epithelial cells presented variable sizes (larger than 50 microm(2)), but the addition of keratinocyte-conditioned media or exogenous vascular endothelial growth factor induced their normalization toward a smaller size. Vascular endothelial growth factor neutralization inhibited the effect of keratinocyte-conditioned media. These results provide new direct evidence that normal human epithelial cells play a role in the regulation of the underlying TEC network, and advance our knowledge in tissue engineering for the production of TEC networks in vitro.

  17. Differentiation state determines neural effects on microvascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Muffley, Lara A., E-mail: muffley@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Pan, Shin-Chen, E-mail: pansc@mail.ncku.edu.tw [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Smith, Andria N., E-mail: gnaunderwater@gmail.com [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Ga, Maricar, E-mail: marga16@uw.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Hocking, Anne M., E-mail: ahocking@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Gibran, Nicole S., E-mail: nicoleg@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States)

    2012-10-01

    Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells. -- Highlights: Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell proliferation. Black-Right-Pointing-Pointer Neural progenitor cells, not dorsal root ganglion neurons, regulate microvascular endothelial cell migration. Black-Right-Pointing-Pointer Neural progenitor cells and dorsal root ganglion neurons do not effect microvascular endothelial tube formation. Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate

  18. Ultrastructural changes in the optic nerve and capillary vessels during early stages of optic nerve injury

    Institute of Scientific and Technical Information of China (English)

    Xuehong Ju; Xiuyun Li; Xiaoshuang Li; Hongtao Tang; Hongguo Liu

    2008-01-01

    BACKGROUND: Capillaries are the only blood supply for optic nerves, which makes the system more vulnerable to impaired blood circulation. OBJECTIVE: To observe the ultrastructural changes in the optic nerves and capillaries in rabbits following intracanalicular segment injury to the optic nerve. DESIGN, TIME AND SETTING: Comparative, observational, pathological morphology was performed at the Department of Anatomy, Weifang Medical College from September to November 2007. MATERIALS: Models of intracanalicular segment injury to the optic nerve were induced in the right eye of thirty healthy, adult rabbits by a flee-falling metal cylinder. The H-7500 transmission electron microscope was provided by Hitachi, Japan. METHODS: All rabbits were randomly assigned into experimental (n = 25) and control (n = 5) groups. Optic nerve specimens were obtained from the experimental group at 0.5, 6, 12, 48, and 96 hours, respectively, following injury. Uitrastructural changes to the optic nerves and their capillaries were observed by electron microscopy. Optic nerve injury was not established in the control group, but optic nerve specimens were collected similarly to the experimental group. MAIN OUTCOME MEASURES: Ultrastructural changes in the injured optic nerves and their capillaries. RESULTS: Thirty rabbits were included in the final analysis. In the control group, cross-sections of the optic nerves exhibited varied thicknesses with regularly arranged fibers. The axons appeared to be smooth with condensed myelin sheaths and oval mitochondria. The microtubules and mierofilaments were clearly seen. The lumens of the capillaries were regular with densely arranged endothelial cells and visible mitochondria. In the experimental group, 30 minutes after injury to the optic nerves, swollen axons, sparse myelin sheath, disordered microtubules and microfilaments, swollen mitochondria, and a decreased number of pinocytosis vesicles and microfilaments in endothelial cells of the capillaries

  19. 循环内皮细胞与放射性脑损伤相关性实验研究%Correlation between circulating endothelial cells and radiation-induced brain injury

    Institute of Scientific and Technical Information of China (English)

    马代远; 谭榜宪; 李祥攀; 阮林; 甘浪舸; 韦力

    2008-01-01

    Objective To investigate the correlation between circulating endothelial cells (CECs) and radiation-induced brain injury. Methods One hundred and eight SD rats were randomly divided into control group, single-dose 10 Gy 60Co irradiation group and single-dose 30 Gy group. The neurobehavioral changes were observed by Morris water labyrinth at 1 week, 1 month and 3 months after irradiation. The CECs in right ventricular blood were counted after Morrie water test. Hippocamp ultramicrostructure and GFAP positive cell were detected after perfusion of encephalon. Results Neuobehavior change: at 1 month and 3 months after irradiation the swim latency was significantly prolonged (30 Gy group>10 Gy group>control group, P 10 Gy group> 30 Gy group, P 10 Gy group>control group, P10 Gy group>control group, P<0.05). Good correlations between the numbers of CECs and the swim lantency (r10 Gy=0.97, P=0.034; r30 Gy=0.95, P=0.013),and the numbers of GFAP positive cells(r10 Gy=0.94, P=0.037; r30 Gy=0.96, P=0.027) were demonstrated.Conclusion The changes of the CECs numbers are definitely correlated to radiation-induced brain injury, which is more with irradiation dose and duration.%目的 探讨循环内皮细胞(circulating endothelial cegs,CECs)与放射性脑损伤相关性.方法 108只SD大鼠信封法随机分成对照组、实验组(10 Gy组、30 Gy组),分别于照射后1周、1月和3月每组随机抽取9只进行Morris水迷宫行为测试,心脏取血计数CECs,取脑观察海马形态和结构.结果 神经行为改变:照射1和3个月后平台潜伏期延长、穿越平台象限时间及次数明显减少.海马齿状回形态改变:照射1和3个月后实验组神经胶质酸性蛋白(glial fibfillary acidic protein,GFAP)阳性细胞数量明显高于对照组,30 Gy组高于10 Gy组;照射1和3个月后超微结构变化为毛细血管内皮细胞变薄、内皮细胞吞饮小泡明显增多、内皮细胞间紧密连接破坏,毛细血管基膜外星形胶质细胞

  20. Hyperosmotic stimulus induces reversible angiogenesis within the hypothalamic magnocellular nuclei of the adult rat: a potential role for neuronal vascular endothelial growth factor

    Directory of Open Access Journals (Sweden)

    Vincent Anne

    2005-03-01

    Full Text Available Abstract Background In mammals, the CNS vasculature is established during the postnatal period via active angiogenesis, providing different brain regions with capillary networks of various densities that locally supply adapted metabolic support to neurons. Thereafter this vasculature remains essentially quiescent excepted for specific pathologies. In the adult rat hypothalamus, a particularly dense network of capillary vessels is associated with the supraoptic (SON and paraventricular (PVN nuclei containing the magnocellular neurons secreting vasopressin and oxytocin, two neurohormones involved in the control of the body fluid homoeostasis. In the seventies, it was reported that proliferation of astrocytes and endothelial cells occurs within these hypothalamic nuclei when strong metabolic activation of the vasopressinergic and oxytocinergic neurons was induced by prolonged hyperosmotic stimulation. The aim of the present study was to determine whether such proliferative response to osmotic stimulus is related to local angiogenesis and to elucidate the cellular and molecular mechanisms involved. Results Our results provide evidence that cell proliferation occurring within the SON of osmotically stimulated adult rats corresponds to local angiogenesis. We show that 1 a large majority of the SON proliferative cells is associated with capillary vessels, 2 this proliferative response correlates with a progressive increase in density of the capillary network within the nucleus, and 3 SON capillary vessels exhibit an increased expression of nestin and vimentin, two markers of newly formed vessels. Contrasting with most adult CNS neurons, hypothalamic magnocellular neurons were found to express vascular endothelial growth factor (VEGF, a potent angiogenic factor whose production was increased by osmotic stimulus. When VEGF was inhibited by dexamethasone treatment or by the local application of a blocking antibody, the angiogenic response was strongly

  1. Infection of hepatitis B virus in extrahepatic endothelial tissues mediated by endothelial progenitor cells

    Directory of Open Access Journals (Sweden)

    Zhang Lili

    2007-04-01

    Full Text Available Abstract Background Hepatitis B virus (HBV replication has been reported to be involved in many extrahepatic viral disorders; however, the mechanism by which HBV is trans-infected into extrahepatic tissues such as HBV associated myocarditis remains largely unknown. Results In this study, we showed that human cord blood endothelial progenitor cells (EPCs, but not human umbilical vein endothelial cells (HUVECs could be effectively infected by uptake of HBV in vitro. Exposure of EPCs with HBV resulted in HBV DNA and viral particles were detected in EPCs at day 3 after HBV challenge, which were peaked around day 7 and declined in 3 weeks. Consistently, HBV envelope surface and core antigens were first detected in EPCs at day 3 after virus challenge and were retained to be detectable for 3 weeks. In contrast, HBV covalently closed circular DNA was not detected in EPCs at any time after virus challenge. Intravenous transplantation of HBV-treated EPCs into myocardial infarction and acute renal ischemia mouse model resulted in incorporation of HBV into injured heart, lung, and renal capillary endothelial tissues. Conclusion These results strongly support that EPCs serve as virus carrier mediating HBV trans-infection into the injured endothelial tissues. The findings might provide a novel mechanism for HBV-associated myocarditis and other HBV-related extrahepatic diseases as well.

  2. Tapered capillary optics

    Science.gov (United States)

    Hirsch, Gregory

    1998-01-01

    A metal or glass wire is etched with great precision into a very narrowly tapering cone which has the shape of the desired final capillary-optics bore. By controlling the rate of removal of the wire from an etchant bath, a carefully controlled taper is produced. A sensor measures the diameter of the wire as it leaves the surface of the etchant. This signal is used for feedback control of the withdrawal speed. The etched wire undergoes a treatment to produce an extremely low surface-roughness. The etched and smoothed wire is coated with the material of choice for optimizing the reflectivity of the radiation being focused. This could be a vacuum evaporation, sputtering, CVD or aqueous chemical process. The coated wire is either electroplated, built up with electroless plating, or encapsulated in a polymer cylinder such as epoxy to increase the diameter of the wire for easier handling and greater robustness. During this process, the wire is vertically oriented and tensioned to assure that the wire is absolutely straight. The coated and electroformed wire is bonded to a flat, rigid substrate and is then periodically segmented by cutting or etching a series of narrow slits or grooves into the wire. The wire is vertically oriented and tensioned during the bonding process to assure that it is straight. The original wire material is then chemically etched away through the slits or otherwise withdrawn to leave the hollow internal bore of the final tapered-capillary optical element.

  3. An immunocytochemical study of the germinal layer vasculature in the developing fetal brain using Ulex europaeus 1 lectin.

    Science.gov (United States)

    Gould, S J; Howard, S

    1988-10-01

    The characteristics of the germinal matrix vasculature were studied in the developing fetal brain using immunocytochemical methods. A preliminary comparative immunocytochemical study was made on six fetal brains to compare endothelial staining by Ulex europaeus I lectin with that of antibody to Factor VIII related antigen. Ulex was found to stain germinal layer vessels better than Factor VIII related antigen. Subsequently, the germinal layers of a further 15 fetal and preterm infant brains ranging from 13 to 35 weeks' gestation were stained with Ulex europaeus I to demonstrate the vasculature. With increasing gestation, there was a gradual increase in vessel density, particularly of capillaries. This was not a uniform process. A plexus of capillaries was prominent immediately beneath the ependyma while the more central parts of the germinal matrix contained fewer, but often larger diameter, vessels. The variation in vessel density which was a feature of the later gestation brains may have implications for local blood flow and may be a factor in haemorrhage at this site.

  4. Update on pulmonary edema: the role and regulation of endothelial barrier function.

    Science.gov (United States)

    Patterson, C E; Lum, H

    2001-01-01

    Discovery of the pathophysiologic mechanisms leading to pulmonary edema and identification of effective strategies for prevention remain significant clinical concerns. Endothelial barrier function is a key component for maintenance of the integrity of the vascular boundary in the lung, particularly since the gas exchange surface area of the alveolar-capillary membrane is large. This review is focused on new insights in the pulmonary endothelial response to injury and recovery, reversible activation by edemagenic agents, and the biochemical/structural basis for regulation of endothelial barrier function. This information is discussed in the context of fundamental concepts of lung fluid balance and pulmonary function.

  5. Capillaries modified by noncovalent anionic polymer adsorption for capillary zone electrophoresis, micellar electrokinetic capillary chromatography and capillary electrophoresis mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L; Hansen, S H; Gammelgaard, Bente

    2001-01-01

    A simple coating procedure for generation of a high and pH-independent electroosmotic flow in capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) is described. The bilayer coating was formed by noncovalent adsorption of the ionic polymers Polybrene...

  6. Brain pericytes from stress-susceptible pigs increase blood-brain barrier permeability in vitro

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    Vandenhaute Elodie

    2012-06-01

    Full Text Available Abstract Background The function of pericytes remains questionable but with improved cultured technique and the use of genetically modified animals, it has become increasingly clear that pericytes are an integral part of blood–brain barrier (BBB function, and the involvement of pericyte dysfunction in certain cerebrovascular diseases is now emerging. The porcine stress syndrome (PSS is the only confirmed, homologous model of malignant hyperthermia (MH in veterinary medicine. Affected animals can experience upon slaughter a range of symptoms, including skeletal muscle rigidity, metabolic acidosis, tachycardia and fever, similar to the human syndrome. Symptoms are due to an enhanced calcium release from intracellular stores. These conditions are associated with a point mutation in ryr1/hal gene, encoding the ryanodine receptor, a calcium channel. Important blood vessel wall muscle modifications have been described in PSS, but potential brain vessel changes have never been documented in this syndrome. Methods In the present work, histological and ultrastructural analyses of brain capillaries from wild type and ryr1 mutated pigs were conducted to investigate the potential impairment of pericytes, in this pathology. In addition, brain pericytes were isolated from the three porcine genotypes (wild-type NN pigs; Nn and nn pigs, bearing one or two (n mutant ryr1/hal alleles, respectively, and tested in vitro for their influence on the permeability of BBB endothelial monolayers. Results Enlarged perivascular spaces were observed in ryr1-mutant samples, corresponding to a partial or total detachment of the astrocytic endfeet. These spaces were electron lucent and sometimes filled with lipid deposits and swollen astrocytic feet. At the ultrastructural level, brain pericytes did not seem to be affected because they showed regular morphology and characteristics, so we aimed to check their ability to maintain BBB properties in vitro. Our results indicated

  7. Ion guiding in alumina capillaries

    DEFF Research Database (Denmark)

    Juhász, Z.; Sulik, B.; Biri, S.;

    2009-01-01

    Transmission of a few keV impact energy Ne ions through capillaries in anodic alumina membranes has been studied with different ion counting methods using an energy dispersive electrostatic spectrometer, a multichannel plate (MCP) array and sensitive current-measurement. In the present work, we...... focus our attention to the measurements with the MCP array. The alumina capillaries were prepared by electro-chemical oxidation of aluminium foils. For the present experiments guiding of 3-6 keV Ne ions has been studied in two samples with capillary diameter of about 140 nm and 260 nm and with capillary...... length of about 15 μm. At these energies, the ions have been efficiently guided by the capillaries up to few degrees tilt angle. In this work, we compare the results obtained by the energy dispersive spectrometer to those studied by the MCP array. © 2008 Elsevier B.V. All rights reserved....

  8. Biomedical applications of capillary electrophoresis

    Science.gov (United States)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  9. Blood-Brain Barrier Effects of the Fusarium Mycotoxins Deoxynivalenol, 3 Acetyldeoxynivalenol, and Moniliformin and Their Transfer to the Brain

    Science.gov (United States)

    Behrens, Matthias; Hüwel, Sabine; Galla, Hans-Joachim; Humpf, Hans-Ulrich

    2015-01-01

    Background Secondary metabolites produced by Fusarium fungi frequently contaminate food and feed and have adverse effects on human and animal health. Fusarium mycotoxins exhibit a wide structural and biosynthetic diversity leading to different toxicokinetics and toxicodynamics. Several studies investigated the toxicity of mycotoxins, focusing on very specific targets, like the brain. However, it still remains unclear how fast mycotoxins reach the brain and if they impair the integrity of the blood-brain barrier. This study investigated and compared the effects of the Fusarium mycotoxins deoxynivalenol, 3-acetyldeoxynivalenol and moniliformin on the blood-brain barrier. Furthermore, the transfer properties to the brain were analyzed, which are required for risk assessment, including potential neurotoxic effects. Methods Primary porcine brain capillary endothelial cells were cultivated to study the effects of the examined mycotoxins on the blood-brain barrier in vitro. The barrier integrity was monitored by cellular impedance spectroscopy and 14C radiolabeled sucrose permeability measurements. The distribution of the applied toxins between blood and brain compartments of the cell monolayer was analyzed by high performance liquid chromatography-mass spectrometry to calculate transfer rates and permeability coefficients. Results Deoxynivalenol reduced the barrier integrity and caused cytotoxic effects at 10 μM concentrations. Slight alterations of the barrier integrity were also detected for 3-acetyldeoxynivalenol. The latter was transferred very quickly across the barrier and additionally cleaved to deoxynivalenol. The transfer of deoxynivalenol and moniliformin was slower, but clearly exceeded the permeability of the negative control. None of the compounds was enriched in one of the compartments, indicating that no efflux transport protein is involved in their transport. PMID:26600019

  10. Blood-Brain Barrier Effects of the Fusarium Mycotoxins Deoxynivalenol, 3 Acetyldeoxynivalenol, and Moniliformin and Their Transfer to the Brain.

    Directory of Open Access Journals (Sweden)

    Matthias Behrens

    Full Text Available Secondary metabolites produced by Fusarium fungi frequently contaminate food and feed and have adverse effects on human and animal health. Fusarium mycotoxins exhibit a wide structural and biosynthetic diversity leading to different toxicokinetics and toxicodynamics. Several studies investigated the toxicity of mycotoxins, focusing on very specific targets, like the brain. However, it still remains unclear how fast mycotoxins reach the brain and if they impair the integrity of the blood-brain barrier. This study investigated and compared the effects of the Fusarium mycotoxins deoxynivalenol, 3-acetyldeoxynivalenol and moniliformin on the blood-brain barrier. Furthermore, the transfer properties to the brain were analyzed, which are required for risk assessment, including potential neurotoxic effects.Primary porcine brain capillary endothelial cells were cultivated to study the effects of the examined mycotoxins on the blood-brain barrier in vitro. The barrier integrity was monitored by cellular impedance spectroscopy and 14C radiolabeled sucrose permeability measurements. The distribution of the applied toxins between blood and brain compartments of the cell monolayer was analyzed by high performance liquid chromatography-mass spectrometry to calculate transfer rates and permeability coefficients.Deoxynivalenol reduced the barrier integrity and caused cytotoxic effects at 10 μM concentrations. Slight alterations of the barrier integrity were also detected for 3-acetyldeoxynivalenol. The latter was transferred very quickly across the barrier and additionally cleaved to deoxynivalenol. The transfer of deoxynivalenol and moniliformin was slower, but clearly exceeded the permeability of the negative control. None of the compounds was enriched in one of the compartments, indicating that no efflux transport protein is involved in their transport.

  11. Compromised Blood-Brain Barrier Competence in Remote Brain Areas in Ischemic Stroke Rats at Chronic Stage

    Science.gov (United States)

    Garbuzova-Davis, Svitlana; Haller, Edward; Williams, Stephanie N.; Haim, Eithan D.; Tajiri, Naoki; Hernandez-Ontiveros, Diana G.; Frisina-Deyo, Aric; Boffeli, Sean M.; Sanberg, Paul R.; Borlongan, Cesario V.

    2014-01-01

    Stroke is a life threatening disease leading to long-term disability in stroke survivors. Cerebral functional insufficiency in chronic stroke might be due to pathological changes in brain areas remote from initial ischemic lesion, i.e. diaschisis. Previously, we showed that the damaged blood-brain barrier (BBB) was implicated in subacute diaschisis. The present study investigated BBB competence in chronic diaschisis using a transient middle cerebral artery occlusion (tMCAO) rat model. Our results demonstrated significant BBB damage mostly in the ipsilateral striatum and motor cortex in rats at 30 days after tMCAO. The BBB alterations were also determined in the contralateral hemisphere via ultrastructural and immunohistochemical analyses. Major BBB pathological changes in contralateral remote striatum and motor cortex areas included: (1) vacuolated endothelial cells containing large autophagosomes, (2) degenerated pericytes displaying mitochondria with cristae disruption, (3) degenerated astrocytes and perivascular edema, (4) Evans Blue extravasation, and (5) appearance of parenchymal astrogliosis. Importantly, discrete analyses of striatal and motor cortex areas revealed significantly higher autophagosome accumulation in capillaries of ventral striatum and astrogliosis in dorsal striatum in both cerebral hemispheres. These widespread microvascular alterations in ipsilateral and contralateral brain hemispheres suggest persistent and/or continued BBB damage in chronic ischemia. The pathological changes in remote brain areas likely indicate chronic ischemic diaschisis, which should be considered in the development of treatment strategies for stroke. PMID:24610730

  12. Endothelial activation, lymphangiogenesis, and humoral rejection of kidney transplants.

    Science.gov (United States)

    Phillips, Sharon; Kapp, Meghan; Crowe, Deborah; Garces, Jorge; Fogo, Agnes B; Giannico, Giovanna A

    2016-05-01

    Antibody-mediated rejection (ABMR) is implicated in 45% of renal allograft failure and 57% of late allograft dysfunction. Peritubular capillary C4d is a specific but insensitive marker of ABMR. The 2013 Banff Conference ABMR revised criteria included C4d-negative ABMR with evidence of endothelial-antibody interaction. We hypothesized that endothelial activation and lymphangiogenesis are increased with C4d-negative ABMR and correlate with intragraft T-regulatory cells and T-helper 17. Seventy-four renal transplant biopsies were selected to include (a) ABMR with C4d Banff scores ≥2 (n = 35), (b) variable microvascular injury and C4d score 0-1 (n = 24), and (c) variable microvascular injury and C4d score = 0 (n = 15). Controls included normal preimplantation donor kidneys (n = 5). Immunohistochemistry for endothelial activation (P- and E-selectins [SEL]), lymphangiogenesis (D2-40), T-regulatory cells (FOXP3), and T-helper 17 (STAT3) was performed. Microvessel and inflammatory infiltrate density was assessed morphometrically in interstitium and peritubular capillaries. All transplants had significantly higher microvessel and lymph vessel density compared with normal. Increased expression of markers of endothelial activation predicted transplant glomerulopathy (P-SEL, P = .003). Increased P-SEL and D2-40 were associated with longer interval from transplant to biopsy (P = .005). All 3 markers were associated with increased interstitial fibrosis, tubular atrophy, and graft failure (P-SEL, P < .001; E-SEL, P = .0011; D2-40, P = .012). There was no association with the intragraft FOXP3/STAT3 ratio. We conclude that endothelial activation and lymphangiogenesis could represent a late response to injury leading to fibrosis and progression of kidney damage, and are independent of the intragraft FOXP3/STAT3 ratio. Our findings support the therapeutic potential of specifically targeting endothelial activation.

  13. Creating capillary networks within human engineered tissues: impact of adipocytes and their secretory products.

    Science.gov (United States)

    Aubin, Kim; Vincent, Caroline; Proulx, Maryse; Mayrand, Dominique; Fradette, Julie

    2015-01-01

    The development of tissue-engineered substitutes of substantial volume is closely associated with the need to ensure rapid vascularization upon grafting. Strategies promoting angiogenesis include the in vitro formation of capillary-like networks within engineered substitutes. We generated both connective and adipose tissues based on a cell sheet technology using human adipose-derived stromal cells. This study evaluates the morphology and extent of the capillary networks that developed upon seeding of human microvascular endothelial cells during tissue production. We posited that adipocyte presence/secretory products could modulate the resulting capillary network when compared to connective substitutes. Analyses including confocal imaging of CD31-labeled capillary-like networks indicated slight differences in their morphological appearance. However, the total volume occupied by the networks as well as the frequency distribution of the structure's volumes were similar between connective and adipose tissues. The average diameter of the capillary structures tended to be 20% higher in reconstructed adipose tissues. Quantification of pro-angiogenic molecules in conditioned media showed greater amounts of leptin (15×), angiopoietin-1 (3.4×) and HGF (1.7×) secreted from adipose than connective tissues at the time of endothelial cell seeding. However, this difference was attenuated during the following coculture period in endothelial cell-containing media, correlating with the minor differences noted between the networks. Taken together, we developed a protocol allowing reconstruction of both connective and adipose tissues featuring well-developed capillary networks in vitro. We performed a detailed characterization of the network architecture within engineered tissues that is relevant for graft assessment before implantation as well as for in vitro screening of angiogenic modulators using three-dimensional models.

  14. Endothelial nitric oxide: protector of a healthy mind.

    Science.gov (United States)

    Katusic, Zvonimir S; Austin, Susan A

    2014-04-01

    Endothelial nitric oxide (NO) is generated by constitutively active endothelial nitric oxide synthase (eNOS), an essential enzyme responsible for cardiovascular homeostasis. Historically, endothelial NO was first recognized as a major vasodilator involved in control of vasomotor function and local blood flow. In this review, our attention is focused on the emerging role of endothelial NO in linking cerebrovascular function with cognition. We will discuss the recognized ability of endothelial NO to modulate processing of amyloid precursor protein (APP), influence functional status of microglia, and affect cognitive function. Existing evidence suggests that the loss of NO in cultured human cerebrovascular endothelium causes increased expression of APP and β-site APP-cleaving enzyme 1 (BACE1) thereby resulting in increased secretion of amyloid β peptides (Aβ1-40 and Aβ1-42). Furthermore, increased expression of APP and BACE1 as well as increased production of Aβ peptides was detected in the cerebral microvasculature and brain tissue of eNOS-deficient mice. Since Aβ peptides are considered major cytotoxic molecules responsible for the pathogenesis of Alzheimer's disease, these observations support the concept that a loss of endothelial NO might significantly contribute to the initiation and progression of cognitive decline. In addition, genetic inactivation of eNOS causes activation of microglia and promotes a pro-inflammatory phenotype in the brain. Behavioural analysis revealed that eNOS-deficient mice exhibit impaired cognitive performance thereby indicating that selective loss of endothelial NO has a detrimental effect on the function of neuronal cells. Together with findings from prior studies demonstrating the ability of endothelial NO to affect synaptic plasticity, mitochondrial biogenesis, and function of neuronal progenitor cells, it is becoming apparent that the role of endothelial NO in the control of central nervous system function is very complex. We

  15. A D-peptide ligand of nicotine acetylcholine receptors for brain-targeted drug delivery.

    Science.gov (United States)

    Wei, Xiaoli; Zhan, Changyou; Shen, Qing; Fu, Wei; Xie, Cao; Gao, Jie; Peng, Chunmei; Zheng, Ping; Lu, Weiyue

    2015-03-01

    Lysosomes of brain capillary endothelial cells are implicated in nicotine acetylcholine receptor (nAChR)-mediated transcytosis and act as an enzymatic barrier for the transport of peptide ligands to the brain. A D-peptide ligand of nAChRs (termed (D)CDX), which binds to nAChRs with an IC50 value of 84.5 nM, was developed by retro-inverso isomerization. (D)CDX displayed exceptional stability in lysosomal homogenate and serum, and demonstrated significantly higher transcytosis efficiency in an in vitro blood-brain barrier monolayer compared with the parent L-peptide. When modified on liposomal surface, (D)CDX facilitated significant brain-targeted delivery of liposomes. As a result, brain-targeted delivery of (D)CDX modified liposomes enhanced therapeutic efficiency of encapsulated doxorubicin for glioblastoma. This study illustrates the importance of ligand stability in nAChRs-mediated transcytosis, and paves the way for developing stable brain-targeted entities.

  16. Capillaries for use in a multiplexed capillary electrophoresis system

    Science.gov (United States)

    Yeung, E.S.; Chang, H.T.; Fung, E.N.

    1997-12-09

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  17. Multidimensional capillary electrophoresis.

    Science.gov (United States)

    Grochocki, Wojciech; Markuszewski, Michał J; Quirino, Joselito P

    2015-01-01

    Multidimensional separation where two or more orthogonal displacement mechanisms are combined is a promising approach to increase peak capacity in CE. The combinations allow dramatic improvement of analytical performance since the total peak capacity is given by a product of the peak capacities of all methods. The initial reports were concentrated on the construction of effective connections between capillaries for 2D analysis. Today, 2D and 3D CE systems are now able to separate real complex biological or environmental mixtures with good repeatability, improved resolution with minimal loss of sample. This review will present the developments in the field of multidimensional CE during the last 15 years. The endeavors in this specific field were on the development of interfaces, interface-free techniques including integrated separations, microdevices, and on-line sample concentration techniques to improve detection sensitivity.

  18. Exercise Training Could Improve Age-Related Changes in Cerebral Blood Flow and Capillary Vascularity through the Upregulation of VEGF and eNOS

    Directory of Open Access Journals (Sweden)

    Sheepsumon Viboolvorakul

    2014-01-01

    Full Text Available This study aimed to investigate the effect of exercise training on age-induced microvascular alterations in the brain. Additionally, the association with the protein levels of vascular endothelial growth factor (VEGF and endothelial nitric oxide synthase (eNOS was also assessed. Male Wistar rats were divided into four groups: sedentary-young (SE-Young, n=5, sedentary aged (SE-Aged, n=8, immersed-aged (IM-Aged, n=5, and exercise trained-aged (ET-Aged, 60 minutes/day and 5 days/week for 8 weeks, n=8 rats. The MAPs of all aged groups, SE-Aged, IM-Aged, and ET-Aged, were significantly higher than that of the SE-Young group. The regional cerebral blood flow (rCBF in the SE-Aged and IM-Aged was significantly decreased as compared to SE-Young groups. However, rCBF of ET-Aged group was significantly higher than that in the IM-Aged group (P<0.05. Moreover, the percentage of capillary vascularity (%CV and the levels of VEGF and eNOS in the ET-Aged group were significantly increased compared to the IM-Aged group (P<0.05. These results imply that exercise training could improve age-induced microvascular changes and hypoperfusion closely associated with the upregulation of VEGF and eNOS.

  19. Anesthetic propofol overdose causes endothelial cytotoxicity in vitro and endothelial barrier dysfunction in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ming-Chung [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Department of Anesthesiology, Chi Mei Medical Center, Liouying, Tainan, Taiwan (China); Chen, Chia-Ling [Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Yang, Tsan-Tzu; Choi, Pui-Ching [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Hsing, Chung-Hsi [Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan (China); Department of Anesthesiology, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Lin, Chiou-Feng, E-mail: cflin@mail.ncku.edu.tw [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China)

    2012-12-01

    An overdose and a prolonged treatment of propofol may cause cellular cytotoxicity in multiple organs and tissues such as brain, heart, kidney, skeletal muscle, and immune cells; however, the underlying mechanism remains undocumented, particularly in vascular endothelial cells. Our previous studies showed that the activation of glycogen synthase kinase (GSK)-3 is pro-apoptotic in phagocytes during overdose of propofol treatment. Regarding the intravascular administration of propofol, we therefore hypothesized that propofol overdose also induces endothelial cytotoxicity via GSK-3. Propofol overdose (100 μg/ml) inhibited growth in human arterial and microvascular endothelial cells. After treatment, most of the endothelial cells experienced caspase-independent necrosis-like cell death. The activation of cathepsin D following lysosomal membrane permeabilization (LMP) determined necrosis-like cell death. Furthermore, propofol overdose also induced caspase-dependent apoptosis, at least in part. Caspase-3 was activated and acted downstream of mitochondrial transmembrane potential (MTP) loss; however, lysosomal cathepsins were not required for endothelial cell apoptosis. Notably, activation of GSK-3 was essential for propofol overdose-induced mitochondrial damage and apoptosis, but not necrosis-like cell death. Intraperitoneal administration of a propofol overdose in BALB/c mice caused an increase in peritoneal vascular permeability. These results demonstrate the cytotoxic effects of propofol overdose, including cathepsin D-regulated necrosis-like cell death and GSK-3-regulated mitochondrial apoptosis, on endothelial cells in vitro and the endothelial barrier dysfunction by propofol in vivo. Highlights: ► Propofol overdose causes apoptosis and necrosis in endothelial cells. ► Propofol overdose triggers lysosomal dysfunction independent of autophagy. ► Glycogen synthase kinase-3 facilitates propofol overdose-induced apoptosis. ► Propofol overdose causes an increase

  20. Electrical detachment of cells for engineering capillary-like structures in a photocrosslinkable hydrogel.

    Science.gov (United States)

    Osaki, Tatsuya; Kakegawa, Takahiro; Suzuki, Hiroaki; Fukuda, Junji

    2011-01-01

    A major challenge in tissue engineering is the fabrication of vascular networks capable of delivering oxygen and nutrients throughout tissue constructs. Because cells located more than a few hundred micrometers away from the nearest capillaries are susceptible to oxygen shortages, it is crucial to develop microscale technologies for engineering a vascular structure in three-dimensionally thick tissues. This study describes an electrochemical approach for fabricating capillary-like structures precisely aligned within micrometer distances, the internal surfaces of which are covered with vascular endothelial cells in a photocrosslinkable hydrogel.

  1. 大鼠局灶性脑缺血再灌注后内皮细胞对不同缺血时间的耐受性%Endothelial cell endurance to various courses of focal brain ischemia-reperfusional injury in rats

    Institute of Scientific and Technical Information of China (English)

    褚晓凡; 付学军; 亓传洁; 马可夫; 肖学长; 彭健

    2005-01-01

    转化,出血转化多发生于再灌注后的缺血中心区.%BACKGROUND: Endothelial cell structural and functional integrity is importnat decisive fatcor for ischemic time-window and hemorragic transformation follwing brain ischemic injury.OBJECTIVE: To investiagte the endotheliocyt endurance to various course of ischemic injury basing on dynamical observation of morphological and ultrastructural changes of endotheliocyte during IR injury.DESIGN: Randomized controlled experiment.SETTING:Neurological Internal Department of the Second Affiliated Hospital of Jinan University.MATERIALS: This experiment was carried out in the Animal Experimental Laboratory of the Second Affiliated Hospital of Jinan University from March 1998 to March 1999. Totally 53 SD rats were randomly dihours of 6 rats.METHODS: Thread-bolt occlusion method was used to establish focal brain ischemia model on rats. Brain tissue was evenly cut into five coronary segments: namely A, B, C, D and E, segments C underwent TTC staining for marginal region location. segments D was taken for routine dehydration, transparency, envelop, slice and HE staining,optical microscopic observation. Ischemic surrounding area and central brain tissues was obtained from slice B, fixed and enveloped before cutting into ultrathin slices that was observed under transmission electron microscope.the occurring time of hemorrhagic infarction at different ischemic time cell vacuolization degree in foot process layer at different ischemic time points.RESULTS: Totally 53 rats were enrolled in this experiment and all data was entered into results analysis. Under optical microscope: Neuropil loose and small vascular surrounding edema was observed at ischemia 3 hours.Small arterial broken and hemorrhage occurred at ischemia 12 hours reperfusion 3 hours. Under electron microscope: Capillary endothelial nuclear swelling was observed at ischemia 3 hours, with cytoplasmic pinocytosi increasing and vacuolization in foot process layer

  2. Capillary flow solder wettability test

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Rejent, J.A.

    1996-01-01

    A test procedure was developed to assess the capillary flow wettability of solders inside of a confined geometry. The test geometry was comprised of two parallel plates with a controlled gap of constant thickness (0.008 cm, 0.018 cm, 0.025 cm, and 0.038 cm). Capillary flow was assessed by: (1) the meniscus or capillary rise of the solder within the gap, (2) the extent of void formation in the gap, and (3) the time-dependence of the risen solder film. Tests were performed with the lead-free solders.

  3. Structural and functional aspects of porcine endometrial capillaries on days 13 and 15 after oestrus or mating.

    Science.gov (United States)

    Laforest, J P; King, G J

    1992-01-01

    The permeability of subepithelial capillaries in porcine endometrium was studied during midcycle and early pregnancy. Gilts were slaughtered on Day 13 or Day 15 of the oestrous cycle or pregnancy, 15 min after injection through the ear vein of 11.1 MBq of 125I-labelled human albumin in phosphate-buffered saline. The radioactivity of endometrial strips taken along the mesometrial and antimesometrial aspects of the uterine horn varied on average from 270 to 701 c.p.m./g and no difference (P greater than 0.05) was found between reproductive status, days of slaughter or sampling sites. The majority of the subepithelial capillaries showed ultrastructural evidence of increased vascular permeability, such as marked thinning of the capillary walls, especially on the side proximal to the epithelial basal lamina, multilayering and partial disparition of the endothelial basal lamina and abundant endothelial vesicles. Fenestrated pores were observed, but were rare. There was no obvious difference between reproductive status, days of sampling or sampling sites inside the uterus, suggesting that on Days 13-15 after oestrus the ultrastructural characteristics of porcine endometrial capillaries are little affected by the presence of attaching blastocysts and supporting the results obtained with radioactive albumin. Ferritin injected directly into a uterine artery of one gilt on Day 15 of pregnancy was carried through the capillary wall by endothelial vesicles, showing ultrastructural evidence of increased permeability.

  4. Lymphocyte migration in the micro-channel of splenic sheathed capillaries in Chinese soft-shelled turtles, Pelodiscus sinensis.

    Science.gov (United States)

    Zhang, Qian; Ullah, Shakeeb; Liu, Yi; Yang, Ping; Chen, Bing; Waqas, Yasir; Bao, Huijun; Hu, Lisi; Li, Quanfu; Chen, Qiusheng

    2016-01-01

    The structural characteristics of the splenic sheathed capillary were investigated using light microscopy and transmission electron microscopy (TEM). This study mainly focused on lymphocyte migration to the splenic white pulp via micro-channels in Chinese soft-shelled turtles, Pelodiscus sinensis. The results showed that the sheathed capillaries in the turtle spleen were high endothelial venule (HEV)-like vessels. These capillaries consist of micro-channels that facilitate lymphocyte migration to the splenic white pulp. The micro-channel is a dynamic structure comprising processes of endothelial cells, supporting cells, and ellipsoid-associated cells (EACs), which provides a microenvironment for lymphocyte migration. The pattern of lymphocyte migration in the micro-channel of the turtle spleen includes the following steps: (i) lymphocyte first adheres to the endothelium of the sheathed capillary, passes through the endothelial cells, and traverses through the basement membrane of the sheathed capillary; (ii) it then enters into the ellipsoid combined with supporting cells and EACs; and (iii) lymphocyte migrates from the ellipsoid to the periellipsoidal lymphatic sheath (PELS) via the micro-channel. This study provides morphological evidence for lymphocyte migration in the micro-channels of turtle spleens and also an insight into the mechanism of lymphocyte homing to the splenic white pulp of reptiles.

  5. The Glycoprofile Patterns of Endothelial Cells in Usual Interstitial Pneumonia

    Directory of Open Access Journals (Sweden)

    A Barkhordari

    2014-09-01

    Full Text Available [THIS ARTICLE HAS BEEN RETRACTED FOR DUPLICATE PUBLICATION] Background: The pathological classification of cryptogenic fibrosing alveolitis has been a matter of debate and controversy for histopathologists.Objective: To identify and specify the glycotypes of capillary endothelial cells in usual interstitial pneumonia (UIP compared to those found in normal tissue.Methods: Sections of formalin-fixed, paraffin-embedded blocks from 16 cases of UIP were studied by lectin histochemistry with a panel of 27 biotinylated lectins and an avidin-peroxidase revealing system.Results: High expression of several classes of glycan was seen de novo in capillary endothelial cells from patients with UIP including small complex and bi/tri-antennary bisected complex N-linked sequences bolund by Concanavalin A and erythro-phytohemagglutinin, respectively, GalNAca1 residues bound by Helix pomatia and Maclura pomifera agglutinins, and L-fucosylated derivatives of type II glycan chains recognized by Ulex europaeus agglutinin-I. Glycans bound by agglutinins from Lycopersicon esculentum (β1,4GlcNAc and Wisteria floribunda (GalNAc as well as GlcNAc oligomers bound by Phytolacca americana and succinylated Wheat Germ agglutinin were also seen in the capillary endothelial cells of UIP. In contrast, L-fucosylated derivatives of type I glycan chains were absent in cells from cases of UIP when Anguilla anguilla agglutinin was applied, unlike the situation in normal tissue.Conclusion: These results may indicate existence of two distinct populations of endothelial cell in UIP with markedly different patterns of glycosylation, reflecting a pattern of differentiation and angiogenesis, which is not detectable morphologically.

  6. Analysis of Capillary Rise in Asymmetric Branch-Like Capillary

    Science.gov (United States)

    Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Yang, Zhihui; Su, Shuai; Ren, Kai; Huang, Heyu

    2016-05-01

    Transport in porous media is common in nature, attracting many attentions for a long time. Tree-like network model is often used as a simplification for porous space, expressing the complexity of pore spaces instead of capillary bundle. To investigate spontaneous imbibition characteristics in this network, a dynamic asymmetric branch-like capillary model is used to represent basic network structure, using fractal method to represent tortuosity. This work investigates the influence of parameters on imbibition process in the branch-like capillary model. An analytical equation for the imbibition mass versus time is derived. Parameters from capillary structures to liquid properties are taken into account and analyzed based on the numerical solution of the equation. It is found that the imbibition process in asymmetric branch-like capillary model can be recognized by four sections and brunching tubes are positive for imbibition process. Concomitantly, meniscus arrest event is simulated and discussed. Moreover, the influence of parameters on imbibition process is discussed. These parameters can be classified as static and dynamic. Static parameters mainly change the capillary force, which are related to the ultimate imbibition mass or imbibition ability, while dynamic parameters mainly have influence on resistance of flowing fluid, which are related to the imbibition speed in the imbibition process.

  7. Mesodermal Pten inactivation leads to alveolar capillary dysplasia- like phenotype.

    Science.gov (United States)

    Tiozzo, Caterina; Carraro, Gianni; Al Alam, Denise; Baptista, Sheryl; Danopoulos, Soula; Li, Aimin; Lavarreda-Pearce, Maria; Li, Changgong; De Langhe, Stijn; Chan, Belinda; Borok, Zea; Bellusci, Saverio; Minoo, Parviz

    2012-11-01

    Alveolar capillary dysplasia (ACD) is a congenital, lethal disorder of the pulmonary vasculature. Phosphatase and tensin homologue deleted from chromosome 10 (Pten) encodes a lipid phosphatase controlling key cellular functions, including stem/progenitor cell proliferation and differentiation; however, the role of PTEN in mesodermal lung cell lineage formation remains unexamined. To determine the role of mesodermal PTEN in the ontogeny of various mesenchymal cell lineages during lung development, we specifically deleted Pten in early embryonic lung mesenchyme in mice. Pups lacking Pten died at birth, with evidence of failure in blood oxygenation. Analysis at the cellular level showed defects in angioblast differentiation to endothelial cells and an accompanying accumulation of the angioblast cell population that was associated with disorganized capillary beds. We also found decreased expression of Forkhead box protein F1 (Foxf1), a gene associated with the ACD human phenotype. Analysis of human samples for ACD revealed a significant decrease in PTEN and increased activated protein kinase B (AKT). These studies demonstrate that mesodermal PTEN has a key role in controlling the amplification of angioblasts as well as their differentiation into endothelial cells, thereby directing the establishment of a functional gas exchange interface. Additionally, these mice could serve as a murine model of ACD.

  8. DNA typing by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, N.

    1997-10-08

    Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.

  9. Selectivity in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Zeeuw, R.A; de Jong, G.J.; Ensing, K

    1999-01-01

    This review gives a survey of selectivity modes in capillary electrophoresis separations in pharmaceutical analysis and bioanalysis. Despite the high efficiencies of these separation techniques, good selectivity is required to allow quantitation or identification of a Chemistry and Toxicology, parti

  10. Ultrasensitive quantification of cerebral capillary flow networks and dynamics

    Science.gov (United States)

    You, Jiang; Park, Ki; Du, Congwu; Pan, Yingtian

    2015-03-01

    Ultra-high resolution optical Doppler coherence tomography (μODT) is a promising tool for brain functional imaging. However, its sensitivity for detecting slow flows in capillary beds may limit its utility in visualizing and quantifying subtle changes in brain microcirculation. To address this limitation, we developed a novel method called contrast-enhanced μODT (c-μODT) in which intralipid is injected into mouse tail vein to enhance μODT detection sensitivity. We demonstrate that after intralipid injection, the flow detection sensitivity of μODT is dramatically enhanced by 230% as quantified by the fill factor (FF) of microvasculature. More importantly, we show that c-μODT preserves the quantitative properties for flow imaging, i.e., showing a comparable change ratio of hypercapnia-induced flow increase in the capillary network before and after injecting intralipid.

  11. The interaction of carbon nanotubes with an in vitro blood-brain barrier model and mouse brain in vivo

    Science.gov (United States)

    Kafa, Houmam; Wang, Julie Tzu-Wen; Rubio, Noelia; Venner, Kerrie; Anderson, Glenn; Pach, Elzbieta; Ballesteros, Belén; Preston, Jane E.; Abbott, N. Joan; Al-Jamal, Khuloud T.

    2015-01-01

    Carbon nanotubes (CNTs) are a novel nanocarriers with interesting physical and chemical properties. Here we investigate the ability of amino-functionalized multi-walled carbon nanotubes (MWNTs-NH3+) to cross the Blood-Brain Barrier (BBB) in vitro using a co-culture BBB model comprising primary porcine brain endothelial cells (PBEC) and primary rat astrocytes, and in vivo following a systemic administration of radiolabelled f-MWNTs. Transmission Electron microscopy (TEM) confirmed that MWNTs-NH3+ crossed the PBEC monolayer via energy-dependent transcytosis. MWNTs-NH3+ were observed within endocytic vesicles and multi-vesicular bodies after 4 and 24 h. A complete crossing of the in vitro BBB model was observed after 48 h, which was further confirmed by the presence of MWNTs-NH3+ within the astrocytes. MWNT-NH3+ that crossed the PBEC layer was quantitatively assessed using radioactive tracers. A maximum transport of 13.0 ± 1.1% after 72 h was achieved using the co-culture model. f-MWNT exhibited significant brain uptake (1.1  ±  0.3% injected dose/g) at 5 min after intravenous injection in mice, after whole body perfusion with heparinized saline. Capillary depletion confirmed presence of f-MWNT in both brain capillaries and parenchyma fractions. These results could pave the way for use of CNTs as nanocarriers for delivery of drugs and biologics to the brain, after systemic administration. PMID:25890741

  12. Defining the critical hypoxic threshold that promotes vascular remodeling in the brain.

    Science.gov (United States)

    Boroujerdi, Amin; Milner, Richard

    2015-01-01

    In animal models, hypoxic pre-conditioning confers protection against subsequent neurological insults, mediated in part through an extensive vascular remodeling response. In light of the therapeutic potential of this effect, the goal of this study was to establish the dose-response relationship between level of hypoxia and the extent of cerebrovascular modeling, and to define the mildest level of hypoxia that promotes remodeling. Mice were exposed to different levels of continuous hypoxia (8-21% O2) for seven days before several aspects of vascular remodeling were evaluated, including endothelial proliferation, total vascular area, arteriogenesis, and fibronectin/α5β1 integrin expression. For most events, the threshold level of hypoxia that stimulated remodeling was 12-13% O2. Interestingly, many parameters displayed a biphasic dose-response curve, with peak levels attained at 10% O2, but declined thereafter. Further analysis in the 12-13% O2 range revealed that vascular remodeling occurs by two separate mechanisms: (i) endothelial hyperplasia, triggered by a hypoxic threshold of 13% O2, which leads to increased capillary growth, and (ii) endothelial hypertrophy, triggered by a more severe hypoxic threshold of 12% O2, which leads to expansion of large vessels and arteriogenesis. Taken together, these results define the hypoxic thresholds for vascular remodeling in the brain, and point to two separate mechanisms mediating this process.

  13. CXC Chemokine Receptor 7 (CXCR7) Regulates CXCR4 Protein Expression and Capillary Tuft Development in Mouse Kidney

    Science.gov (United States)

    Haege, Sammy; Mueller, Wiebke; Nietzsche, Sandor; Lupp, Amelie; Mackay, Fabienne; Schulz, Stefan; Stumm, Ralf

    2012-01-01

    Background The CXCL12/CXCR4 axis is involved in kidney development by regulating formation of the glomerular tuft. Recently, a second CXCL12 receptor was identified and designated CXCR7. Although it is established that CXCR7 regulates heart and brain development in conjunction with CXCL12 and CXCR4, little is known about the influence of CXCR7 on CXCL12 dependent kidney development. Methodology/Principal Findings We provided analysis of CXCR7 expression and function in the developing mouse kidney. Using in situ hybridization, we identified CXCR7 mRNA in epithelial cells including podocytes at all nephron stages up to the mature glomerulus. CXCL12 mRNA showed a striking overlap with CXCR7 mRNA in epithelial structures. In addition, CXCL12 was detected in stromal cells and the glomerular tuft. Expression of CXCR4 was complementary to that of CXCR7 as it occurred in mesenchymal cells, outgrowing ureteric buds and glomerular endothelial cells but not in podocytes. Kidney examination in CXCR7 null mice revealed ballooning of glomerular capillaries as described earlier for CXCR4 null mice. Moreover, we detected a severe reduction of CXCR4 protein but not CXCR4 mRNA within the glomerular tuft and in the condensed mesenchyme. Malformation of the glomerular tuft in CXCR7 null mice was associated with mesangial cell clumping. Conclusions/Significance We established that there is a similar glomerular pathology in CXCR7 and CXCR4 null embryos. Based on the phenotype and the anatomical organization of the CXCL12/CXCR4/CXCR7 system in the forming glomerulus, we propose that CXCR7 fine-tunes CXCL12/CXCR4 mediated signalling between podocytes and glomerular capillaries. PMID:22880115

  14. Comparison of Capillary Architecture between Slow and Fast Muscles in Rats Using a Confocal Laser Scanning Microscope

    Directory of Open Access Journals (Sweden)

    Kumagishi,Kanae

    2010-02-01

    Full Text Available The skeletal muscle is classified into 2 types, slow oxidative or fast glycolytic muscle. For further characterization, we investigated the capillary architecture in slow and fast muscles. The rat soleus and extensor digitorum longus (EDL muscles were used as representatives of slow and fast muscles, respectively. To investigate capillary density, sections of both types of muscle were stained with alkaline phosphatase;the soleus muscle showed more intense reactivity, indicating that it had a denser capillary structure than the EDL muscle. We then injected fluorescent contrast medium into samples of both muscle types for light and confocal-laser microscopic evaluation. The capillary density and capillary-to-fiber ratio were significantly higher, and the course of the capillaries was more tortuous, in the soleus muscle than in the EDL muscle. Capillary coursed more tortuously in the soleus than in the EDL muscle. Succinate dehydrogenase (SDH activity, an indicator of mitochondrial oxidative capacity, and vascular endothelial growth factor (VEGF expression were also significantly higher in the soleus muscle. Thus, we conclude that slow oxidative muscle possess a rich capillary structure to provide demanded oxygen, and VEGF might be involved in the formation and/or maintenance of this highly capillarized architecture.

  15. Acquired capillary hemangioma of the eyelid in a 49-year-old woman from Turkey

    Directory of Open Access Journals (Sweden)

    Sertac Argun Kivanc

    2014-01-01

    Full Text Available A 49-year-old woman developed a dark brown nodular mass in the lower eyelid. The lesion had grown fast for 2 months and then had remained stable in size. Excisional biopsy was performed. Histopathological examination of an excisional biopsy specimen pointed to proliferative vessels lined by increased endothelial cells without nuclear atypism. The nodular mass evaluated as a capillary hemangioma.

  16. Fine structure of capillaries in the conus papillaris of the limbless lizard, Ophisaurus apodus (anguidae, lacertilia).

    Science.gov (United States)

    Jasiński, A

    1977-08-26

    The conus papillaris of Ophisaurus apodus consists of blood vessels and pigment cells. The capillary walls are formed by endothelial cells, scarce pericytes and basal laminae. The cell bodies are attenuated and the plasmalemma of their luminal and abluminal surfaces forms microvilli. The perivascular space is well developed, containing nerve fibers and their terminals. Similar localization and ultrastructure of avian pecten oculi and lacertilian conus papillaris suggest homology of these structures.

  17. Cyclodextrins, blood-brain barrier, and treatment of neurological diseases.

    Science.gov (United States)

    Vecsernyés, Miklós; Fenyvesi, Ferenc; Bácskay, Ildikó; Deli, Mária A; Szente, Lajos; Fenyvesi, Éva

    2014-11-01

    Biological barriers are the main defense systems of the homeostasis of the organism and protected organs. The blood-brain barrier (BBB), formed by the endothelial cells of brain capillaries, not only provides nutrients and protection to the central nervous system but also restricts the entry of drugs, emphasizing its importance in the treatment of neurological diseases. Cyclodextrins are increasingly used in human pharmacotherapy. Due to their favorable profile to form hydrophilic inclusion complexes with poorly soluble active pharmaceutical ingredients, they are present as excipients in many marketed drugs. Application of cyclodextrins is widespread in formulations for oral, parenteral, nasal, pulmonary, and skin delivery of drugs. Experimental and clinical data suggest that cyclodextrins can be used not only as excipients for centrally acting marketed drugs like antiepileptics, but also as active pharmaceutical ingredients to treat neurological diseases. Hydroxypropyl-β-cyclodextrin received orphan drug designation for the treatment of Niemann-Pick type C disease. In addition to this rare lysosomal storage disease with neurological symptoms, experimental research revealed the potential therapeutic use of cyclodextrins and cyclodextrin nanoparticles in neurodegenerative diseases, stroke, neuroinfections and brain tumors. In this context, the biological effects of cyclodextrins, their interaction with plasma membranes and extraction of different lipids are highly relevant at the level of the BBB.

  18. Two-dimensional capillary electrophoresis using tangentially connected capillaries.

    Science.gov (United States)

    Sahlin, Eskil

    2007-06-22

    A novel type of fused silica capillary system is described where channels with circular cross-sections are tangentially in contact with each other and connected through a small opening at the contact area. Since the channels are not crossing each other in the same plane, the capillaries can easily be filled with different solutions, i.e. different solutions will be in contact with each other at the contact point. The system has been used to perform different types of two-dimensional separations and the complete system is fully automated where a high voltage switch is used to control the location of the high voltage in the system. Using two model compounds it is demonstrated that a type of two-dimensional separation can be performed using capillary zone electrophoresis at two different pH values. It is also shown that a compound with acid/base properties can be concentrated using a dynamic pH junction mechanism when transferred from the first separation to the second separation. In addition, the system has been used to perform a comprehensive two-dimensional capillary electrophoresis separation of tryptic digest of bovine serum albumin using capillary zone electrophoresis followed by micellar electrokinetic chromatography.

  19. Synergism of matrix stiffness and vascular endothelial growth factor on mesenchymal stem cells for vascular endothelial regeneration.

    Science.gov (United States)

    Wingate, Kathryn; Floren, Michael; Tan, Yan; Tseng, Pi Ou Nancy; Tan, Wei

    2014-09-01

    Mesenchymal stem cells (MSCs) hold tremendous potential for vascular tissue regeneration. Research has demonstrated that individual factors in the cell microenvironment such as matrix elasticity and growth factors regulate MSC differentiation to vascular lineage. However, it is not well understood how matrix elasticity and growth factors combine to direct the MSC fate. This study examines the combined effects of matrix elasticity and vascular endothelial growth factor (VEGF) on both MSC differentiation into endothelial lineage and MSC paracrine signaling. MSCs were seeded in soft nanofibrous matrices with or without VEGF, and in Petri dishes with or without VEGF. Only MSCs seeded in three-dimensional soft matrices with VEGF showed significant increases in the expression of endothelial markers (vWF, eNOS, Flt-1, and Flk-1), while eliminating the expression of smooth muscle marker (SM-α-actin). MSCs cultured in VEGF alone on two-dimensional dishes showed increased expression of both early-stage endothelial and smooth muscle markers, indicating immature vascular differentiation. Furthermore, MSCs cultured in soft matrices with VEGF showed faster upregulation of endothelial markers compared with MSCs cultured in VEGF alone. Paracrine signaling studies found that endothelial cells cultured in the conditioned media from MSCs differentiated in the soft matrix and VEGF condition exhibited increased migration and formation of capillary-like structures. These results demonstrate that VEGF and soft matrix elasticity act synergistically to guide MSC differentiation into mature endothelial phenotype while enhancing paracrine signaling. Therefore, it is critical to control both mechanical and biochemical factors to safely regenerate vascular tissues with MSCs.

  20. 细胞饥饿及 TNF-α干预后内皮细胞膜微粒对人脑微血管内皮细胞的影响%Effects of cell starvation and TNF-αderived endothelial microvesicles on human brain microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    潘群文; 何彩霞; 刘雅静; 张惠婷; 王艳; 戴炳琰; 马晓瑭

    2015-01-01

    目的:探讨饥饿及TNF-α刺激条件下,内皮细胞膜微粒( EMVs )对人脑微血管内皮细胞( HBMECs )增殖、迁移及血管生成功能的影响。方法体外培养HBMECs,分为PBS组、饥饿组、TNF-α组。于饥饿24 h后提取饥饿后产生的EMVs( sHB-MVs),于TNF-α刺激24 h后提取TNF-α刺激下产生的EMVs(αHB-MVs)。将sHB-MVs与αHB-MVs按照1×108个/mL、每孔10μL分别与饥饿组及TNF-α组HBMECs共培养,PBS组给予10μL PBS处理。采用MTT法测定各组HBMECs增殖能力,倒置显微镜下测定HBMECs迁移距离,观察血管形成数。结果饥饿组增殖能力高于PBS组(P<0.01),TNF-α组HBMECs增殖能力低于PBS组(P<0.01)。饥饿组迁移距离长于PBS组(P<0.05),TNF-α组迁移距离短于PBS组(P<0.01)。饥饿组血管生成数多于PBS组(P<0.01),TNF-α组血管生成数少于PBS组(P<0.01)。结论饥饿刺激下产生的EMVs可促进HBMECs增殖、迁移及血管生成功能,TNF-α刺激下产生的EMVs可抑制HBMECs增殖、迁移及血管生成功能。%Objective To investigate the effects of cell starvation and TNF-αderived endothelial microvesicles (EMVs) on the proliferation, migration and angiogenesis of human brain microvascular endothelial cells (HBMECs) in vitro.Methods HBMECs were cultured and were divided into the PBS group, starvation group and TNF-αgroup.EMVs were extracted from HB-MECs cultured in a serum deprivation (SD) medium (starving stress, sHB-MVs) or SD medium containing tumor necrosis fac-tor-(TNF-α) (apoptotic stress,αHB-MVs).The HBMECs of the starvation group and TNF-αgroup were cultured with sHB-MVs andαHB-MVs (1 ×108/mL, 10μL each hole), respectively;and the PBS group was treated with 10μL PBS.The prolif-eration of HBMECs in each group was determined by MTT, the migration distance of HBMECs was measured by inverted micro-scope and the number of angiogenesis was observed under the

  1. Apigenin Isolated from the Medicinal Plant Elsholtzia rugulosa Prevents β-Amyloid 25–35-Induces Toxicity in Rat Cerebral Microvascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Qingshan Liu

    2011-05-01

    Full Text Available Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone is a plant flavonoid and pharmacologically active agent that can be isolated from several plant species. In the present study, effects of apigenin obtained from the medicinal plant Elsholtzia rugulosa (Labiatae on primary cultured rat cerebral microvascular endothelial cells (CMECs mediated by amyloid-β peptide 25–35 (Aβ25–35 were examined. Aβ25–35 showed toxic effects on CMECs, involving reduction of cell viability, release of lactate dehydrogenase (LDH, increase of nuclear condensation, over-production of intracellular reactive oxygen species (ROS, decrease of superoxide dismutase (SOD activity, and breakage of the barrier integrity and function. Based on this model, we demonstrated that apigenin from the medicinal plant Elsholtzia rugulosa protected cultured rat CMECs by increasing cell viability, reducing LDH release, relieving nuclear condensation, alleviating intracellular ROS generation, increasing SOD activity, and strengthening the barrier integrity through the preservation of transendothelial electrical resistance, permeability property and characteristic enzymatic activity after being exposed to Aβ25–35. In conclusion, apigenin isolated from Elsholtzia rugulosa has the ability to protect rat CMECs against Aβ25–35-induced toxicity.

  2. In Vivo Vascularization of Endothelial Cells Derived from Bone Marrow Mesenchymal Stem Cells in SCID Mouse Model

    Directory of Open Access Journals (Sweden)

    Allameh Abdolamir

    2016-07-01

    Full Text Available Objective In vivo and in vitro stem cell differentiation into endothelial cells is a promising area of research for tissue engineering and cell therapy. Materials and Methods We induced human mesenchymal stem cells (MSCs to differentiate to endothelial cells that had the ability to form capillaries on an extracellular matrix (ECM gel. Thereafter, the differentiated endothelial cells at early stage were characterized by expression of specific markers such as von Willebrand factor (vWF, vascular endothelial growth factor (VEGF receptor 2, and CD31. In this experimental model, the endothelial cells were transplanted into the groins of severe combined immunodeficiency (SCID mice. After 30 days, we obtained tissue biopsies from the transplantation sites. Biopsies were processed for histopathological and double immunohistochemistry (DIHC staining. Results Endothelial cells at the early stage of differentiation expressed endothelial markers. Hematoxylin and eosin (H&E staining, in addition to DIHC demonstrated homing of the endothelial cells that underwent vascularization in the injected site. Conclusion The data clearly showed that endothelial cells at the early stage of differentiation underwent neovascularization in vivo in SCID mice. Endothelial cells at their early stage of differentiation have been proven to be efficient for treatment of diseases with impaired vasculogenesis.

  3. Adenosine receptor signaling modulates permeability of the blood-brain barrier.

    Science.gov (United States)

    Carman, Aaron J; Mills, Jeffrey H; Krenz, Antje; Kim, Do-Geun; Bynoe, Margaret S

    2011-09-14

    The blood-brain barrier (BBB) is comprised of specialized endothelial cells that form the capillary microvasculature of the CNS and is essential for brain function. It also poses the greatest impediment in the treatment of many CNS diseases because it commonly blocks entry of therapeutic compounds. Here we report that adenosine receptor (AR) signaling modulates BBB permeability in vivo. A(1) and A(2A) AR activation facilitated the entry of intravenously administered macromolecules, including large dextrans and antibodies to β-amyloid, into murine brains. Additionally, treatment with an FDA-approved selective A(2A) agonist, Lexiscan, also increased BBB permeability in murine models. These changes in BBB permeability are dose-dependent and temporally discrete. Transgenic mice lacking A(1) or A(2A) ARs showed diminished dextran entry into the brain after AR agonism. Following treatment with a broad-spectrum AR agonist, intravenously administered anti-β-amyloid antibody was observed to enter the CNS and bind β-amyloid plaques in a transgenic mouse model of Alzheimer's disease (AD). Selective AR activation resulted in cellular changes in vitro including decreased transendothelial electrical resistance, increased actinomyosin stress fiber formation, and alterations in tight junction molecules. These results suggest that AR signaling can be used to modulate BBB permeability in vivo to facilitate the entry of potentially therapeutic compounds into the CNS. AR signaling at brain endothelial cells represents a novel endogenous mechanism of modulating BBB permeability. We anticipate these results will aid in drug design, drug delivery and treatment options for neurological diseases such as AD, Parkinson's disease, multiple sclerosis and cancers of the CNS.

  4. Establishment of an in vitro blood-brain barrier model by co-culturing rat brain microvascular endothelial cells,pericytes and astrocytes%大鼠脑微血管内皮细胞与周细胞、星形胶质细胞共培养建立体外血脑屏障模型

    Institute of Scientific and Technical Information of China (English)

    查雨锋; 傅晓钟; 张顺; 罗敏; 欧瑜; 董永喜; 王爱民; 王永林

    2015-01-01

    目的:应用原代培养的大鼠脑微血管内皮细胞(brain-microvessel endothelial cells,BMECs )与脑微血管周细胞(brain-microvessel pericytes,BMPC )、星形胶质细胞(astro-cytes,AS)共培养建立可模拟在体状态的体外血脑屏障(blood-brain barrier,BBB)模型。方法原代分离、纯化和培养大鼠BMECs、BMPC和AS,通过细胞形态学和免疫细胞化学染色方法鉴定原代培养的细胞,应用Millicell细胞培养插(孔径0.4μm)建立5种不同类型的体外BBB模型,经跨内皮电阻值(transendothelial electrical resistance,TEER)、荧光素钠通透性(sodium fluorescent,Na-FLU )、碱性磷酸酶(AKP)和γ-谷氨酰转肽酶(γ-GT1)的表达测定以及阳性药在体内和体外BBB通透量的相似性,比较评价其屏障功能。结果原代培养的BMECs呈典型的铺路卵石样结构,BMPC胞体较大且呈分枝状,AS 有细长突触,胞质较浅;免疫细胞化学染色证实原代细胞为目标细胞;BMECs与BMPC、AS共培养后TEER值可达(478±25)Ω·cm2,Na-FLU 的表观渗透系数为[(8.23±0.78)×10-6]cm·s-1,AKP和γ-GT1表达分别为(6.90±0.27)金氏单位· g-1 Pro,(4.39±0.32)μg·g-1 Pro;阳性药在体外BBB的表观渗透系数(apparent permeability coefficient,Papp )与在体数据具有较好的相关性(R2=0.92)。结论原代培养的大鼠BMECs与BMPC、AS共培养建立的体外BBB模型在形态、结构及屏障功能方面具备BBB的基本特征,为研究BBB的生理学、病理学以及筛选化合物提供了一种有用工具。%Aim To establish in vitro blood-brain barrier (BBB) model with characteristics of simulation of in vivo BBB by primi-tive co-culture of brain-microvessel endothelial cells (BMECs) with brain-microvessel pericytes (BMPC)and astrocytes (AS). Methods BMECs,BMPC and AS from SD rats were primitively isolated,purified and cultured,and then

  5. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  6. Non-Aqueous Capillary Electrophoresis

    Science.gov (United States)

    Szumski, Michał; Buszewski, Bogusław

    Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.

  7. Capillary imbibition in parallel tubes

    Science.gov (United States)

    McRae, Oliver; Ramakrishnan, T. S.; Bird, James

    2016-11-01

    In modeling porous media two distinct approaches can be employed; the sample can be examined holistically, using global variables such as porosity, or it can be treated as a network of capillaries connected in series to various intermediate reservoirs. In forced imbibition this series-based description is sufficient to characterize the flow, due to the presence of an externally maintained pressure difference. However, in spontaneous imbibition, flow is driven by an internal capillary pressure, making it unclear whether a series-based model is appropriate. In this talk, we show using numerical simulations the dynamics of spontaneous imbibition in concentrically arranged capillary tubes. This geometry allows both tubes access to a semi-infinite reservoir but with inlets in close enough proximity to allow for interference. We compare and contrast the results of our simulations with theory and previous experiments. Schlumberger-Doll Research.

  8. Thalidomide effect in endothelial cell of acute radiation proctitis

    Institute of Scientific and Technical Information of China (English)

    Ki-Tae Kim; Hiun-Suk Chae; Jin-Soo Kim; Hyung-Keun Kim; Young-Seok Cho; Whang Choi; Kyu-Yong Choi; Sang-Young Rho; Suk-Jin Kang

    2008-01-01

    AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used:six in the radiation group,six in the thalidomide group,and two in normal controls.The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure.The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation.All animals were sacrificed and the rectums were removed on day 8 after irradiation.The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM),yon Willebrand Factor (vWF),and vascular endothelial growth factor (VEGF).RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups,but both were higher than in the control group.Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001).The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7),and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5,P < 0.001).The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003).CONCLUSION: The mechanisms of acute radiationinduced proctitis in the rats are related to endothelial cell injury of microvessel,which may be attenuated with thalidomide.

  9. Erythropoietin has a mitogenic and positive chemotactic effect on endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostou, A.; Kessimian, N.; Steiner, M. (Memorial Hospital of Rhode Island, Pawtucket (USA) Brown Univ. Program in Medicine, Providence, RH (USA)); Lee, Eun Sun (Memorial Hospital of Rhode Island, Pawtucket (USA)); Levinson, R. (Brown Univ. Program in Medicine, Providence, RI (USA))

    1990-08-01

    Erythropoietin is known to be a hematopoietic growth factor with a singularly specific action on the proliferation and differentiation of erythroid progenitor cells. The authors have observed a dose-dependent proliferative action of human recombinant erythropoietin on human umbilical vein endothelial cells and bovine adrenal capillary endothelial cells. Binding studies with radioiodinated recombinant human erythropoietin revealed a large number ({approx}27,000) of an apparent single class of receptors with an affinity in the 10{sup {minus}9} M range. Linkage of the radiolabeled ligand to its receptor via a bifunctional crosslinking agent allowed them to identify an endothelial cell protein of 45 kDa as the principal receptor associated with this mitogenic effect of erythropoietin. Recombinant human erythropoietin also enhanced the migration of endothelial cells.

  10. Microdialysis monitoring of catecholamines and excitatory amino acids in the rat and mouse brain: recent developments based on capillary electrophoresis with laser-induced fluorescence detection--a mini-review.

    Science.gov (United States)

    Parrot, Sandrine; Bert, Lionel; Mouly-Badina, Laurence; Sauvinet, Valérie; Colussi-Mas, Joyce; Lambás-Señas, Laura; Robert, Frédéric; Bouilloux, Jean-Pierre; Suaud-Chagny, Marie-Françoise; Denoroy, Luc; Renaud, Bernard

    2003-10-01

    1. Although microdialysis is a widely used approach for in vivo monitoring extracellular neurotransmitter concentrations, it has been previously limited in many cases by its poor temporal resolution. It is clear that when 10-30-min sampling is performed, short-lasting changes in extracellular neurotransmitter concentrations can be overlooked. Such a low sampling rate is necessary when combining microdialysis with the conventional analytical methods like high performance liquid chromatography. 2. Since capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIFD) allows the detection of attomoles of neurotransmitters, the temporal resolution of microdialysis may be significantly improved: high sampling rates, in the range of 5 s to 1 min, have been already reported by our group and others using CE-LIFD for simultaneously analyzing catecholamines and amino acids in microdialysates. 3. The power of combining microdialyis and CE-LIFD is shown, using examples of physiological and pharmacological studies dealing with the dynamics of in vivo efflux processes and/or interactions between neurotransmitters.

  11. Capillary interactions in Pickering emulsions

    Science.gov (United States)

    Guzowski, J.; Tasinkevych, M.; Dietrich, S.

    2011-09-01

    The effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically. Pair potentials between capillary monopoles and dipoles, corresponding to particles floating on a droplet with a fixed center of mass and subjected to external forces and torques, respectively, exhibit a repulsion at large angular separations and an attraction at smaller separations, with the latter resembling the typical behavior for flat interfaces. This change of character is not observed for quadrupoles, corresponding to free particles on a mechanically isolated droplet. The analytical results are compared with the numerical minimization of the surface free energy of the droplet in the presence of spherical or ellipsoidal particles.

  12. In vitro modeling of endothelial interaction with macrophages and pericytes demonstrates Notch signaling function in the vascular microenvironment.

    Science.gov (United States)

    Tattersall, Ian W; Du, Jing; Cong, Zhuangzhuang; Cho, Bennet S; Klein, Alyssa M; Dieck, Chelsea L; Chaudhri, Reyhaan A; Cuervo, Henar; Herts, James H; Kitajewski, Jan

    2016-04-01

    Angiogenesis is regulated by complex interactions between endothelial cells and support cells of the vascular microenvironment, such as tissue myeloid cells and vascular mural cells. Multicellular interactions during angiogenesis are difficult to study in animals and challenging in a reductive setting. We incorporated stromal cells into an established bead-based capillary sprouting assay to develop assays that faithfully reproduce major steps of vessel sprouting and maturation. We observed that macrophages enhance angiogenesis, increasing the number and length of endothelial sprouts, a property we have dubbed "angiotrophism." We found that polarizing macrophages toward a pro-inflammatory profile further increased their angiotrophic stimulation of vessel sprouting, and this increase was dependent on macrophage Notch signaling. To study endothelial/pericyte interactions, we added vascular pericytes directly to the bead-bound endothelial monolayer. These pericytes formed close associations with the endothelial sprouts, causing increased sprout number and vessel caliber. We found that Jagged1 expression and Notch signaling are essential for the growth of both endothelial cells and pericytes and may function in their interaction. We observed that combining endothelial cells with both macrophages and pericytes in the same sprouting assay has multiplicative effects on sprouting. These results significantly improve bead-capillary sprouting assays and provide an enhanced method for modeling interactions between the endothelium and the vascular microenvironment. Achieving this in a reductive in vitro setting represents a significant step toward a better understanding of the cellular elements that contribute to the formation of mature vasculature.

  13. Contractile proteins of endothelial cells, platelets and smooth muscle.

    Science.gov (United States)

    Becker, C G; Nachman, R L

    1973-04-01

    In experiments described herein it was observed, by direct and indirect immunofluorescence technics, that rabbit antisera to human platelet actomyosin (thrombosthenin) stained mature megakaryocytes, blood platelets, endothelial cells and smooth muscle cells of arteries and veins, endothelial cells of liver sinusoids and certain capillaries, uterine smooth muscle cells, myoepithelial cells, perineurial cells of peripheral nerves and "fibroblastic" cells of granulation tissue. The specificity of immunohistologic staining was confirmed by appropriate absorption and blocking studies and immunodiffusional analysis in agarose gel. It was also observed by immunodiffusional analysis in agarose gel, electrophoresis of actomyosin fragments in polyacrylamide gels, immune inhibition of actomyosin ATPase activity and immune aggregation of platelets that uterine and platelet actomyosin are partially, but not completely, identical.

  14. Endothelial Repair in Childhood Arterial Ischaemic Stroke with Cerebral Arteriopathy

    Directory of Open Access Journals (Sweden)

    Despina Eleftheriou

    2015-06-01

    Full Text Available Background: We have previously shown that recurrent arterial ischaemic stroke (AIS in children with cerebral arteriopathy is associated with increased circulating endothelial cells and endothelial microparticles, consistent with ongoing endothelial injury. To date, however, little is known about endothelial repair responses in childhood AIS. We examined the relationship between the number and function of circulating endothelial progenitor cells (EPC, the levels of brain-derived neurotrophic factor (BDNF and AIS recurrence. Methods: Flow cytometry was used to identify peripheral blood mononuclear cells positive for CD34/kinase insert domain-containing receptor (KDR. In a subgroup of patients (5 in each group selected at random, monocytic EPC function was assessed by colony-forming unit (EPC-CFU capacity and incorporation into endothelial cell networks in Matrigel. BDNF was measured using ELISA. Results: Thirty-five children, aged 12 years (range: 5-16.5; 9 males, with AIS and cerebral arteriopathy were studied; 10 had recurrent AIS. CD34+/KDR+ cells were significantly higher in recurrent AIS compared to non-recurrent AIS patients (p = 0.005 and controls (p = 0.0002. EPC-CFU and EPC incorporation into endothelial cell networks were significantly reduced in recurrent compared to non-recurrent AIS patients (p = 0.04 and p = 0.01, respectively. Levels of BDNF were significantly higher in recurrent compared to non-recurrent AIS patients (p = 0.0008 and controls (p = 0.0002. Conclusions: Children with recurrent AIS and cerebral arteriopathy had increased circulating CD34+/KDR+ cells and BDNF consistent with an endothelial repair response. However, EPC function was impaired. Future studies are needed to examine whether suboptimal endothelial repair contributes to childhood AIS recurrence.

  15. Nano carriers for drug transport across the blood-brain barrier.

    Science.gov (United States)

    Li, Xinming; Tsibouklis, John; Weng, Tingting; Zhang, Buning; Yin, Guoqiang; Feng, Guangzhu; Cui, Yingde; Savina, Irina N; Mikhalovska, Lyuba I; Sandeman, Susan R; Howel, Carol A; Mikhalovsky, Sergey V

    2017-01-01

    Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully

  16. Ex Vivo Behaviour of Human Bone Tumor Endothelial Cells

    Energy Technology Data Exchange (ETDEWEB)

    Infante, Teresa [SDN-Foundation, Institute of Diagnostic and Nuclear Development, IRCCS, 80143 Naples (Italy); Cesario, Elena [Department of Biochemistry and Biophysics, Second University of Naples, 80138 Naples (Italy); Gallo, Michele; Fazioli, Flavio [Division of Skeletal Muscles Oncology Surgery, National Cancer Institute, Pascale Foundation, 80131 Naples (Italy); De Chiara, Annarosaria [Anatomic Pathology Unit, National Cancer Institute, Pascale Foundation, 80131 Naples (Italy); Tutucci, Cristina; Apice, Gaetano [Medical Oncology of Bone and Soft Sarcoma tissues Unit, National Cancer Institute, Pascale Foundation, 80131 Naples (Italy); Nigris, Filomena de, E-mail: filomena.denigris@unina2.it [Department of Biochemistry and Biophysics, Second University of Naples, 80138 Naples (Italy)

    2013-04-11

    Cooperation between endothelial cells and bone in bone remodelling is well established. In contrast, bone microvasculature supporting the growth of primary tumors and metastasis is poorly understood. Several antiangiogenic agents have recently been undergoing trials, although an extensive body of clinical data and experimental research have proved that angiogenic pathways differ in each tumor type and stage. Here, for the first time, we characterize at the molecular and functional level tumor endothelial cells from human bone sarcomas at different stages of disease and with different histotypes. We selected a CD31{sup +} subpopulation from biopsies that displayed the capability to grow as adherent cell lines without vascular endothelial growth factor (VEGF). Our findings show the existence in human primary bone sarcomas of highly proliferative endothelial cells expressing CD31, CD44, CD105, CD146 and CD90 markers. These cells are committed to develop capillary-like structures and colony formation units, and to produce nitric oxide. We believe that a better understanding of tumor vasculature could be a valid tool for the design of an efficacious antiangiogenic therapy as adjuvant treatment of sarcomas.

  17. Flow through flexible cylinders inspired by the endothelial glycocalyx

    Science.gov (United States)

    Cooper, Lauren; Fovargue, Daniel; Miller, Laura

    2009-11-01

    Inspired by the recent shift in hypertension research, we present a new computational model to better examine blood flow induced shear stress in the endothelial surface layer (ESL). The ESL is the luminal side barrier between blood and the endothelial cells that line the vessel wall and has been of interest due to its function as a mechanotransducer.footnotetextSquire, J. M., Chew, M., Nneji, G., Neal, C., Barry, J. & Michel, C. C., 2001. Quasi-periodic substructure in the microvessel endothelial glycocalyx: a possible explanation for molecular filtering? J. Struct. Bio. 136, 239-255. Further, it is believed that shear stress seen by the ESL, induced by blood flow, is converted to chemical responses such as blood pressure regulation. We utilize the Immersed Boundary method to simulate blood flow through a vessel and examine the shear stress at the ESL over different heights and flexibilities. We compare our results in the Reynolds number regime of a canine capillary with previous computational modelsfootnotetextWeinbaum, S., Tarbell, J., Damiano, E., 2000. The Structure and Function of the Endothelial Glycocalyx Layer. Pfl"ugers Arch. -- Eur. J. Physiol. 440, 653--666. and experimental results.

  18. Filling of charged cylindrical capillaries

    NARCIS (Netherlands)

    Das, Siddhartha; Chanda, Sourayon; Eijkel, J.C.T.; Tas, N.R.; Chakraborty, Suman; Mitra, Sushanta K.

    2014-01-01

    We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because

  19. Capillary thinning of polymeric filaments

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Szabo, Peter

    1999-01-01

    The capillary thinning of filaments of a Newtonian polybutene fluid and a viscoelastic polyisobutylene solution are analyzed experimentally and by means of numerical simulation. The experimental procedure is as follows. Initially, a liquid sample is placed between two cylindrical plates. Then, th...... and quantified. (C) 1999 The Society of Rheology. [S0148-6055(99)00103-0]....

  20. Influence of Chronobiology on the Nanoparticle-Mediated Drug Uptake into the Brain

    Directory of Open Access Journals (Sweden)

    Jörg Kreuter

    2015-02-01

    Full Text Available Little attention so-far has been paid to the influence of chronobiology on the processes of nanoparticle uptake and transport into the brain, even though this transport appears to be chronobiologically controlled to a significant degree. Nanoparticles with specific surface properties enable the transport across the blood–brain barrier of many drugs that normally cannot cross this barrier. A clear dependence of the central antinociceptive (analgesic effects of a nanoparticle-bound model drug, i.e., the hexapeptide dalargin, on the time of day was observable after intravenous injection in mice. In addition to the strongly enhanced antinociceptive effect due to the binding to the nanoparticles, the minima and maxima of the pain reaction with the nanoparticle-bound drug were shifted by almost half a day compared to the normal circadian nociception: The maximum in the pain reaction after i.v. injection of the nanoparticle-bound dalargin occurred during the later rest phase of the animals whereas the normal pain reaction and that of a dalargin solution was highest during the active phase of the mice in the night. This important shift could be caused by an enhanced endo- and exocytotic particulates transport activity of the brain capillary endothelial cells or within the brain during the rest phase.

  1. Influence of chronobiology on the nanoparticle-mediated drug uptake into the brain.

    Science.gov (United States)

    Kreuter, Jörg

    2015-02-03

    Little attention so-far has been paid to the influence of chronobiology on the processes of nanoparticle uptake and transport into the brain, even though this transport appears to be chronobiologically controlled to a significant degree. Nanoparticles with specific surface properties enable the transport across the blood-brain barrier of many drugs that normally cannot cross this barrier. A clear dependence of the central antinociceptive (analgesic) effects of a nanoparticle-bound model drug, i.e., the hexapeptide dalargin, on the time of day was observable after intravenous injection in mice. In addition to the strongly enhanced antinociceptive effect due to the binding to the nanoparticles, the minima and maxima of the pain reaction with the nanoparticle-bound drug were shifted by almost half a day compared to the normal circadian nociception: The maximum in the pain reaction after i.v. injection of the nanoparticle-bound dalargin occurred during the later rest phase of the animals whereas the normal pain reaction and that of a dalargin solution was highest during the active phase of the mice in the night. This important shift could be caused by an enhanced endo- and exocytotic particulates transport activity of the brain capillary endothelial cells or within the brain during the rest phase.

  2. The use of adipose mesenchymal stem cells and human umbilical vascular endothelial cells on a fibrin matrix for endothelialized skin substitute.

    Science.gov (United States)

    Sánchez-Muñoz, Isabel; Granados, Rosario; Holguín Holgado, Purificación; García-Vela, José Antonio; Casares, Celia; Casares, Miguel

    2015-01-01

    In recent years, the reconstruction of human skin by tissue engineering represents a clinical challenge and has offered a therapeutic alternative. Avascular engineered skin equivalents have been available for several years and used to treat wounds due to burns, nonhealing ulcers, and surgical excisions. They are constituted by different types of cultured cells included in a three-dimensional structure that permits cellular proliferation to create tissue substitutes. The major drawback of these artificial skin substitutes is their lack of blood supply, since the endurance and cell proliferation of the substitute depend on an adequate oxygen and nutrient supply and on toxin removal. These functions are served by the vascular system. We have produced a new model of endothelialized skin substitute that promotes the formation of capillary-like structures by seeding human umbilical vein endothelial cells (HUVECs) with dermal fibroblasts and human adipose-derived mesenchymal stem cells (hADMSCs) in a fibrin matrix. Dermal fibroblasts and hADMSCs produce extracellular matrix that stimulates cellular growth and proliferation. hADMSCs secrete significant quantities of angiogenic and antiapoptotic factors (vascular endothelial growth factor and hepatocyte growth factor), which induce in vitro differentiation of these cells into endothelial cells promoting angiogenesis and participating in tissue repair and skin regeneration processes. We obtained the artificial skin substitute with similar structure to native skin, including dermis and epidermis. We demonstrated that endothelial cells (CD31 and von Willebrand factor positive) proliferated and organized themselves into capillary-like structures within the fibrin matrix. The epidermis showed a complete epithelization by squamous cells (AE1/AE3 cytokeratin positive) with intracytoplasmic keratohyalin granules, hyperkeratosis, and parakeratosis. We have established a novel artificial skin substitute that facilitates the formation

  3. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  4. Aberrant production of extracellular matrix proteins and dysfunction in kidney endothelial cells with a short duration of diabetes.

    Science.gov (United States)

    Grutzmacher, Cathy; Park, SunYoung; Zhao, Yun; Morrison, Margaret E; Sheibani, Nader; Sorenson, Christine M

    2013-01-01

    Diabetic nephropathy is the most common cause of end-stage renal disease and is a major risk factor for cardiovascular disease. In the United States, microvascular complications during diabetic nephropathy contribute to high morbidity and mortality rates. However, the cell-autonomous impact of diabetes on kidney endothelial cell function requires further investigation. Male Akita/+ [autosomal dominant mutation in the insulin II gene (Ins2)] mice reproducibly develop diabetes by 4 wk of age. Here, we examined the impact a short duration of diabetes had on kidney endothelial cell function. Kidney endothelial cells were prepared from nondiabetic and diabetic mice (4 wk of diabetes) to delineate the early changes in endothelial cell function. Kidney endothelial cells from Akita/+ mice following 4 wk of diabetes demonstrated aberrant expression of extracellular matrix proteins including decreased osteopontin and increased fibronectin expression which correlated with increased α5-integrin expression. These changes were associated with the attenuation of migration and capillary morphogenesis. Kidney endothelial cells from Akita/+ mice had decreased VEGF levels but increased levels of endothelial nitric oxide synthase(eNOS) and NO, suggesting uncoupling of VEGF-mediated NO production. Knocking down eNOS expression in Akita/+ kidney endothelial cells increased VEGF expression, endothelial cell migration, and capillary morphogenesis. Furthermore, attenuation of sprouting angiogenesis of aortas from Akita/+ mice with 8 wk of diabetes was restored in the presence of the antioxidant N-acetylcysteine. These studies demonstrate that aberrant endothelial cell function with a short duration of diabetes may set the stage for vascular dysfunction and rarefaction at later stages of diabetes.

  5. Capillary growth in human skeletal muscle: physiological factors and the balance between pro-angiogenic and angiostatic factors

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Hoier, Birgitte

    2014-01-01

    In human skeletal muscle, the capillary net readily adapts according to the level of muscular activity to allow for optimal diffusion conditions for oxygen from the blood to the muscle. Animal studies have demonstrated that stimulation of capillary growth in skeletal muscle can occur either...... by mechanical or by chemical signalling. Mechanical signals originate from shear stress forces on the endothelial cell layer induced by the blood flowing through the vessel, but include also mechanical stretch and compression of the vascular structures and the surrounding tissue, as the muscle contracts...

  6. Atorvastatin prevents Plasmodium falciparum cytoadherence and endothelial damage

    Directory of Open Access Journals (Sweden)

    Soubrier Florent

    2011-02-01

    Full Text Available Abstract Background The adhesion of Plasmodium falciparum parasitized red blood cell (PRBC to human endothelial cells (EC induces inflammatory processes, coagulation cascades, oxidative stress and apoptosis. These pathological processes are suspected to be responsible for the blood-brain-barrier and other organs' endothelial dysfunctions observed in fatal cases of malaria. Atorvastatin, a drug that belongs to the lowering cholesterol molecule family of statins, has been shown to ameliorate endothelial functions and is widely used in patients with cardiovascular disorders. Methods The effect of this compound on PRBC induced endothelial impairments was assessed using endothelial co-culture models. Results Atorvastatin pre-treatment of EC was found to reduce the expression of adhesion molecules and P. falciparum cytoadherence, to protect cells against PRBC-induced apoptosis and to enhance endothelial monolayer integrity during co-incubation with parasites. Conclusions These results might suggest a potential interest use of atorvastatin as a protective treatment to interfere with the pathophysiological cascades leading to severe malaria.

  7. [Changes of ultrastructure of the capillary endotheliocytes of ischemized and nonaffected muscular tissue after transplantation of human hemopoietic stem cells of fetal liver in experiment in vivo].

    Science.gov (United States)

    Saliutin, R V; Zadorozhna, T D; Medvets'kyĭ, E B; Driuk, M F; Petrenko, A Iu

    2010-04-01

    In experiment was investigated ultrastructure of the capillaries endothelial cells and histological peculiarities of muscular tissue on various stages after transplantation of hemopoietic stem cells of fetal liver (HSCFL). There was proved, that in ischemic environment HSCFL stimulate processes of angiogenesis, and in the case of transplantation into intact muscular tissue they are differentiating into the tissue macrophages, not interfering with muscular tissue structure.

  8. Breast cancer cells stimulate osteoprotegerin (OPG production by endothelial cells through direct cell contact

    Directory of Open Access Journals (Sweden)

    Holen Ingunn

    2009-07-01

    Full Text Available Abstract Background Angiogenesis, the sprouting of capillaries from existing blood vessels, is central to tumour growth and progression, however the molecular regulation of this process remains to be fully elucidated. The secreted glycoprotein osteoprotegerin (OPG is one potential pro-angiogenic factor, and clinical studies have demonstrated endothelial cells within a number of tumour types to express high levels of OPG compared to those in normal tissue. Additionally, OPG can increase endothelial cell survival, proliferation and migration, as well as induce endothelial cell tube formation in vitro. This study aims to elucidate the processes involved in the pro-angiogenic effects of OPG in vitro, and also how OPG levels may be regulated within the tumour microenvironment. Results It has previously been demonstrated that OPG can induce tube formation on growth factor reduced matrigel. In this study, we demonstrate that OPG enhances the pro-angiogenic effects of VEGF and that OPG does not stimulate endothelial cell tube formation through activation of the VEGFR2 receptor. We also show that cell contact between HuDMECs and the T47D breast cancer cell line increases endothelial cell OPG mRNA and protein secretion levels in in vitro co-cultures. These increases in endothelial cell OPG secretion were dependent on ανβ3 ligation and NFκB activation. In contrast, the pro-angiogenic factors VEGF, bFGF and TGFβ had no effect on HuDMEC OPG levels. Conclusion These findings suggest that the VEGF signalling pathway is not involved in mediating the pro-angiogenic effects of OPG on endothelial cells in vitro. Additionally, we show that breast cancer cells cause increased levels of OPG expression by endothelial cells, and that direct contact between endothelial cells and tumour cells is required in order to increase endothelial OPG expression and secretion. Stimulation of OPG secretion was shown to involve ανβ3 ligation and NFκB activation.

  9. Blood-Brain Barrier Changes in High Altitude.

    Science.gov (United States)

    Lafuente, José V; Bermudez, Garazi; Camargo-Arce, Lorena; Bulnes, Susana

    2016-01-01

    Cerebral syndromes related to high-altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully understood. The classical "tight-fit hypothesis" posits that there are some anatomical variations that would obstruct the sinovenous outflow and worsen vasogenic edema and intracranial hypertension reactive to hypoxia. This could explain microhemorrhages seen in autopsies. However, recent magnetic resonance imaging studies have demonstrated some components of cytotoxic edema in HACE absent in AMS, suggesting a dysfunction in water balance at the cellular level. Currently, the "red-ox theory" supports trigemino-vascular system activation by free radicals formed after hypoxia and the consequent oxidative stress cascades. Apart from trigemino-vascular system activation, free radicals can also provoke membrane destabilisation mediated by lipid peroxidation, inflammation, and local hypoxia inducible factor-1α and vascular endothelial growth factor activation, resulting in gross blood-brain barrier (BBB) dysfunction. Besides alterations in endothelial cells such as increased pinocytotic vesicles and disassembly of interendothelial tight junction proteins, capillary permeability may also increase with subsequent swelling of astrocyte end-feet. In conclusion, although the pathophysiology of AMS and HACE is not completely understood, recent evidence proposes a multifactorial entity, with brain swelling and compromise of the BBB considered to play an important role. A fuller comprehension of these processes is crucial to reduce and prevent BBB alterations during high-altitude exposure.

  10. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    Directory of Open Access Journals (Sweden)

    Ravi Kant Upadhyay

    2014-01-01

    Full Text Available Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.

  11. The distribution of the anti-HIV drug, tenofovir (PMPA, into the brain, CSF and choroid plexuses

    Directory of Open Access Journals (Sweden)

    Gibbs Julie E

    2006-01-01

    Full Text Available Abstract Background Tenofovir disoproxil fumarate, a prodrug of the nucleotide reverse transcriptase inhibitor, tenofovir (9-[9(R-2-(phosphonomethoxypropyl]adenine; PMPA, was recently approved for use in the combination therapy of human immunodeficiency virus (HIV-1 infection. This study was undertaken to understand PMPA distribution to the virus sanctuary sites located in the brain, CSF and choroid plexuses and to clarify its possible role in reducing the neurological problems associated with HIV infection. Methods The methods used included an established bilateral carotid artery perfusion of [3H]PMPA and a vascular marker, D-[14C]mannitol, in anaesthetised guinea-pigs followed by scintillation counting, HPLC and capillary depletion analyses. Movement of [3H]PMPA into the brain, cisternal CSF and lateral ventricle choroid plexus was also examined in the absence and presence of additional anti-HIV drugs and a transport inhibitor. Control and test groups were compared by ANOVA or Student's t-test, as appropriate. Results The distribution of [3H]PMPA in the cerebrum, cerebellum, pituitary gland and cerebral capillary endothelial cells was not significantly different to that measured for D-[14C]mannitol. However, [3H]PMPA accumulation was significantly higher than that of D-[14C]mannitol in the choroid plexus and CSF. Further experiments revealed no cross-competition for transport of [3H]PMPA by probenecid, a non-specific inhibitor of organic anion transport, or the nucleoside reverse transcriptase inhibitors into any of the CNS regions studied. The octanol-saline partition coefficient measurement for [3H]PMPA was 0.0134 ± 0.00003, which is higher that the 0.002 ± 0.0004 measured for D-[14C]mannitol in an earlier study. Conclusion There is negligible transport of [3H]PMPA across the blood-brain barrier, but it can cross the blood-CSF barrier. This is a reflection of the differing physiological and functional characteristics of the blood

  12. Deficiency of tenascin-C and attenuation of blood-brain barrier disruption following experimental subarachnoid hemorrhage in mice.

    Science.gov (United States)

    Fujimoto, Masashi; Shiba, Masato; Kawakita, Fumihiro; Liu, Lei; Shimojo, Naoshi; Imanaka-Yoshida, Kyoko; Yoshida, Toshimichi; Suzuki, Hidenori

    2016-06-01

    OBJECT Tenascin-C (TNC), a matricellular protein, is induced in the brain following subarachnoid hemorrhage (SAH). The authors investigated if TNC causes brain edema and blood-brain barrier (BBB) disruption following experimental SAH. METHODS C57BL/6 wild-type (WT) or TNC knockout (TNKO) mice were subjected to SAH by endovascular puncture. Ninety-seven mice were randomly allocated to WT sham-operated (n = 16), TNKO sham-operated (n = 16), WT SAH (n = 34), and TNKO SAH (n = 31) groups. Mice were examined by means of neuroscore and brain water content 24-48 hours post-SAH; and Evans blue dye extravasation and Western blotting of TNC, matrix metalloproteinase (MMP)-9, and zona occludens (ZO)-1 at 24 hours post-SAH. As a separate study, 16 mice were randomized to WT sham-operated, TNKO sham-operated, WT SAH, and TNKO SAH groups (n = 4 in each group), and activation of mitogen-activated protein kinases (MAPKs) was immunohistochemically evaluated at 24 hours post-SAH. Moreover, 40 TNKO mice randomly received an intracerebroventricular injection of TNC or phosphate-buffered saline, and effects of exogenous TNC on brain edema and BBB disruption following SAH were studied. RESULTS Deficiency of endogenous TNC prevented neurological impairments, brain edema formation, and BBB disruption following SAH; it was also associated with the inhibition of both MMP-9 induction and ZO-1 degradation. Endogenous TNC deficiency also inhibited post-SAH MAPK activation in brain capillary endothelial cells. Exogenous TNC treatment abolished the neuroprotective effects shown in TNKO mice with SAH. CONCLUSIONS Tenascin-C may be an important mediator in the development of brain edema and BBB disruption following SAH, mechanisms for which may involve MAPK-mediated MMP-9 induction and ZO-1 degradation. TNC could be a molecular target against which to develop new therapies for SAH-induced brain injuries.

  13. Endothelial binding of beta toxin to small intestinal mucosal endothelial cells in early stages of experimentally induced Clostridium perfringens type C enteritis in pigs.

    Science.gov (United States)

    Schumacher, V L; Martel, A; Pasmans, F; Van Immerseel, F; Posthaus, H

    2013-07-01

    Beta toxin (CPB) is known to be an essential virulence factor in the development of lesions of Clostridium perfringens type C enteritis in different animal species. Its target cells and exact mechanism of toxicity have not yet been clearly defined. Here, we evaluate the suitability of a neonatal piglet jejunal loop model to investigate early lesions of C. perfringens type C enteritis. Immunohistochemically, CPB was detected at microvascular endothelial cells in intestinal villi during early and advanced stages of lesions induced by C. perfringens type C. This was first associated with capillary dilatation and subsequently with widespread hemorrhage in affected intestinal segments. CPB was, however, not demonstrated on intestinal epithelial cells. This indicates a tropism of CPB toward endothelial cells and suggests that CPB-induced endothelial damage plays an important role in the early stages of C. perfringens type C enteritis in pigs.

  14. High lung volume increases stress failure in pulmonary capillaries

    Science.gov (United States)

    Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

    1992-01-01

    We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological

  15. Mecanotransduction and Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    S.MULLER; JF.; STOLTZ2

    2005-01-01

    1 IntroductionAtherosclerosis preferentially occurs in areas of complex blood flow where there are disturbed flow and low fluid shear stress, whereas laminar blood flow and high shear stress are atheroprotective~([1]). Reports of others and our studies suggest a steady laminar flow decreases some molecules and genes expression of vascular endothelial cells (EC) that may promote atherosclerosis, as well as it can differentially regulate production of many vasoactive factors at the level of gene expression an...

  16. Recovering endothelial function

    OpenAIRE

    Bryce Moncloa, Alfonso; Médico Cardiólogo, Académico Asociado de la Academia Nacional de Medicina, Presidente del Colegio Panamericano del Endotelio, Miembro del Comité Institucional de Investigaciones del Comité Ejecutivo de la Sociedad Latino Americana de Hipertensión Arterial y del Colegio Americano de Cardiología (ACC).; Morales Villegas, Enrique C.; Médico Internista y Cardiólogo, Fundador y Director del Centro de Investigación Cardiometabólica de Aguascalientes. México; Urquiaga Calderón, Juan; Médico Internista y Cardiólogo, Fundador y Director del Centro de Investigación Cardiometabólica de Aguascalientes. México; Larrauri Vigna, Cesar; Médico Cardiólogo, Miembro de la Sociedad Peruana de Cardiología, Sociedad Peruana de Hipertensión, Sociedad Peruana de Medicina Interna, Colegio Panamericano del Endotelio.

    2014-01-01

    Atherosclerosis starts early in life. The presence of risk factors like hypertension, smoking, dyslipidemia and diabetes as well as obesity and metabolic syndrome accelerates its progress. These factors generate endothelial dysfunction, oxidative stress and inflammation, with early appearance of foamy cells, fatty streaks and atheromatous plaques. These plaques are vulnerable to erosion and rupture, the so called atherothrombotic phenomenon, leading to acute vascular events like acute coronar...

  17. Quantitative analysis using ELISA of vascular endothelial growth factor and basic fibroblast growth factor in human colorectal cancer, liver metastasis of colorectal cancer and hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Muriel Mathonnet; Bernard Descottes; Denis Valleix; Fran(c)ois Labrousse; Véronique Truffinet; Yves Denizot

    2006-01-01

    @@ TO THE EDITOR Angiogenesis consists of the sprouting of capillaries from pre-existing vessels[1]. It is well-known that tumor growth is angiogenesis-dependent. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)stimulated vascular endothelial cell proliferation and are involved in the neoplastic angiogenesis of several types of tumors including those of the intestinal tract[1-5].

  18. 大鼠原代脑微血管内皮细胞体外分离与培养的实验研究%In Vitro Isolation and Culture of Primary Rat Brain Microvascular Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    李振; 刘云会; 薛一雪; 刘丽波; 王萍

    2012-01-01

    目的 探讨获取大鼠脑微血管内皮细胞(BMEC)的简单、有效方法,为构建体外血肿瘤屏障(BTB)模型提供材料.方法 采集出生3~5 d的Wistar胎鼠大脑皮质,应用酶消化法及葡聚糖离心法获得脑微血管段后,接种于培养皿中进行原代培养,采用倒置显微镜对所培养的细胞进行形态学观察;以Ⅷ因子相关抗原免疫组化染色法鉴定细胞;将BMEC与C6脑胶质瘤细胞共培养,构建体外BTB模型,并采用免疫组化法和免疫荧光法检测BMEC间紧密连接相关蛋白occludin的表达.结果 体外培养2h时脑微血管段贴壁,12~48 h见圆形生发中心形成,2~3d单层内皮细胞自生发中心长出,4~5 d见较大单层内皮细胞团,5~7 d可见融合成片的内皮细胞单层,外观呈“铺路石”样;第Ⅷ因子免疫组化结果显示“铺路石”样细胞胞质呈棕黄色染色;紧密连接相关蛋白occludin的免疫组化和荧光结果证明共培养的BMEC间表达BTB的特性.结论 本方法能成功地进行大鼠原代BMEC培养,构建大鼠体外BTB模型,进而应用于BTB的生理、生化及药理学研究.%Objective To explore a simple and reprodueable method lor the in vitro isolation and eulture of rat brain microvascular endothelial cells (BMEC), so as to provide materials for the construction of in vilro blood tumor barrier ( BTB) models. Methods Relative!* pure cerebral microvessel fragments were obtained from the cortex of 3-5 days old wistar rats through dissection,enzyme digestion,and dex-tran centrifugation. Then, these fragments were seeded on dishes for primary culture. The morphology of BMEC was observed under an invert microscope. BMEC were identified by immunohistoehemistry with factor VIII-associated antigen. In vitro BTB models were constructed by co-cultivation of BMEC with C6 glioma cells. The expression of tight junction-related protein oeeludin in BMEC of BTB was measured by immunohistoehemistry and

  19. CURRENT METHODS OF ENDOTHELIAL DYSFUNCTION ASSESSMENT AND THEIR POSSIBLE USE IN THE PRACTICAL MEDICINE

    Directory of Open Access Journals (Sweden)

    A. V. Shabrov

    2016-01-01

    Full Text Available A review contains a description of the most common methods of evaluation and monitoring of "endothelial dysfunction" that are assessed in terms of their information content and applicability in the practice of medicine. The term "endothelial function" is interpreted primarily as a function of the regulation of capillary blood flow, carried out by the expense of the dynamic change of the phase of vasoconstriction and vasodilatation in vessels of resistive type (in accordance with the changing needs of cellular metabolism. Assessment of endothelial dysfunction is understood as a generalized indicator of the extent and nature of violations of the regulation of peripheral circulation. It includes an assessment of imbalances between endotheliumdependent vasoconstrictor and vasodilating factors or mismatch of the local and central regulation of capillary blood flow in response to various functional tests or other effects (eg, cold test, or test with local ischemia. All methods of endothelial dysfunction assessment in the survey are divided into invasive and non-invasive. The main feature of invasive methods lies in the direct effect on the endothelium of the coronary or other vessels by introducing into these vessels vasoactive substances such as acetylcholine. Response to the test (vasoconstriction or vasodilation is evaluated by coronary angiography or by ultrasound. Non-invasive methods of the assessment of endothelial dysfunction or functions of regulation of the peripheral circulation are regarded as the most promising for widespread use. There are two basic methods that underlie functional tests: methods PAT (peripheral arterial tone and PHG (polyhepatography. Assessment of endothelial dysfunction in many modern scientific researches is important. They are regarded as the causative factors of many different diseases. Such assessments can be useful in everyday medical practice. Assessment of endothelial function provides the clinician with

  20. Capillary electrophoresis systems and methods

    Science.gov (United States)

    Dorairaj, Rathissh; Keynton, Robert S.; Roussel, Thomas J.; Crain, Mark M.; Jackson, Douglas J.; Walsh, Kevin M.; Naber, John F.; Baldwin, Richard P.; Franco, Danielle B.

    2011-08-02

    An embodiment of the invention is directed to a capillary electrophoresis apparatus comprising a plurality of separation micro-channels. A sample loading channel communicates with each of the plurality of separation channels. A driver circuit comprising a plurality of electrodes is configured to induce an electric field across each of the plurality of separation channels sufficient to cause analytes in the samples to migrate along each of the channels. The system further comprises a plurality of detectors configured to detect the analytes.

  1. Capillary electrophoresis in food authenticity.

    Science.gov (United States)

    Kvasnicka, Frantisek

    2005-06-01

    Food authenticity is a term which simply refers to whether the food purchased by the consumer matches its description. False description can occur in many forms, from the undeclared addition of water or other cheaper materials, or the wrong declaration of the amount of a particular ingredient in the product, to making false statements about the source of ingredients i.e., their geographic, plant, or animal origin. The aim of this review is to summarize applications of capillary electrophoresis in food authentication.

  2. Capillary Electrophoresis - Optical Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sepaniak, M. J.

    2001-08-06

    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  3. Capillary stretching of elastic fibers

    Science.gov (United States)

    Protiere, Suzie; Stone, Howard A.; Duprat, Camille

    2014-11-01

    Fibrous media consisting of constrained flexible fibers can be found in many engineered systems (membranes in filters, woven textile, matted paper). When such materials interact with a liquid, the presence of liquid/air interfaces induces capillary forces that deform the fibers. To model this interaction we study the behaviour of a finite volume of liquid deposited on two parallel flexible fibers clamped at both ends. A tension along the fibers is imposed and may be varied. We show that the system undergoes various morphological changes as the interfiber distance, the elasticity and the tension of the fibers are varied. For a certain range of parameters, the liquid spreads along the fibers and pulls them together, leading to the ``zipping'' of the fibers. This capillary adhesion can then be enhanced or reduced by changing the tension within the fibers. We will show that balancing stretching and capillary forces allows the prediction of this transition as well as the conditions for which detachment of the fibers occurs. These results may be used to prevent the clogging of fibrous membranes or to optimize the capture of liquids.

  4. Critical Capillary Number of Interfacial Film Displacement in a Capillary Tube

    CERN Document Server

    Yan, Changfei

    2016-01-01

    The role of surface tension and wettability in the dynamics of air-liquid interfaces during immiscible fluid displacement flows in capillary tube driven by pressure has been investigated. The contact angle and capillary number drive the force wetting processes which is controlled by the balance between the capillary and the viscous lubrication forces. The dynamic wetting condition with the critical capillary number is studied analytically and validated experimentally, which demonstrates that the critical capillary number is associated with the contact angle, slip length and capillary radius.

  5. Progression of Diabetic Capillary Occlusion: A Model.

    Directory of Open Access Journals (Sweden)

    Xiao Fu

    2016-06-01

    Full Text Available An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.

  6. Capillary malformation--arteriovenous malformation syndrome: review of the literature, proposed diagnostic criteria, and recommendations for management.

    Science.gov (United States)

    Orme, Charisse M; Boyden, Lynn M; Choate, Keith A; Antaya, Richard J; King, Brett A

    2013-01-01

    Capillary malformation-arteriovenous malformation syndrome is an autosomal dominant disorder caused by mutations in the RASA1 gene and characterized by multiple small, round to oval capillary malformations with or without arteriovenous malformations. Ateriovenous malformations occur in up to one-third of patients and may involve the brain and spine. Although making the diagnosis is straightforward in some patients, there are other patients for whom diagnostic criteria may be helpful in their evaluation. Here we review the literature regarding capillary malformation-arteriovenous malformation syndrome, propose diagnostic criteria, and discuss the care of patients with this condition.

  7. Endothelial RIG-I activation impairs endothelial function

    Energy Technology Data Exchange (ETDEWEB)

    Asdonk, Tobias, E-mail: tobias.asdonk@ukb.uni-bonn.de [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Motz, Inga; Werner, Nikos [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Coch, Christoph; Barchet, Winfried; Hartmann, Gunther [Institute for Clinical Chemistry and Clinical Pharmacology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Nickenig, Georg; Zimmer, Sebastian [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer RIG-I activation impairs endothelial function in vivo. Black-Right-Pointing-Pointer RIG-I activation alters HCAEC biology in vitro. Black-Right-Pointing-Pointer EPC function is affected by RIG-I stimulation in vitro. -- Abstract: Background: Endothelial dysfunction is a crucial part of the chronic inflammatory atherosclerotic process and is mediated by innate and acquired immune mechanisms. Recent studies suggest that pattern recognition receptors (PRR) specialized in immunorecognition of nucleic acids may play an important role in endothelial biology in a proatherogenic manner. Here, we analyzed the impact of endothelial retinoic acid inducible gene I (RIG-I) activation upon vascular endothelial biology. Methods and results: Wild type mice were injected intravenously with 32.5 {mu}g of the RIG-ligand 3pRNA (RNA with triphosphate at the 5 Prime end) or polyA control every other day for 7 days. In 3pRNA-treated mice, endothelium-depended vasodilation was significantly impaired, vascular oxidative stress significantly increased and circulating endothelial microparticle (EMP) numbers significantly elevated compared to controls. To gain further insight in RIG-I dependent endothelial biology, cultured human coronary endothelial cells (HCAEC) and endothelial progenitor cells (EPC) were stimulated in vitro with 3pRNA. Both cells types express RIG-I and react with receptor upregulation upon stimulation. Reactive oxygen species (ROS) formation is enhanced in both cell types, whereas apoptosis and proliferation is not significantly affected in HCAEC. Importantly, HCAEC release significant amounts of proinflammatory cytokines in response to RIG-I stimulation. Conclusion: This study shows that activation of the cytoplasmatic nucleic acid receptor RIG-I leads to endothelial dysfunction. RIG-I induced endothelial damage could therefore be an important pathway in atherogenesis.

  8. RhoB controls endothelial cell morphogenesis in part via negative regulation of RhoA

    Directory of Open Access Journals (Sweden)

    Howe Grant A

    2012-02-01

    Full Text Available Abstract Recent studies have suggested a role for the small GTPase RhoB in the control of processes required for angiogenesis. However, the mechanisms whereby RhoB exerts control over these processes are not well understood. Given the role of vascular endothelial growth factor (VEGF in pathological angiogenesis, we were interested in examining whether RhoB contributed to VEGF-induced angiogenic processes. To assess this, RhoB was specifically depleted in human umbilical vein endothelial cells (HUVEC, using siRNA-targeted strategies. The effects of RhoB depletion on VEGF-induced angiogenic activities were assessed using a variety of standard in vitro angiogenesis assays to assess endothelial cell viability, migration and capillary morphogenesis. Effects of RhoB depletion on signaling from other Rho family member proteins was also assessed using specific activity assays for RhoA and RhoC. We observed that although RhoB appeared dispensable for HUVEC viability, RhoB was required for endothelial cell migration, sprouting, and capillary morphogenesis. We also observed that siRNA-mediated depletion of RhoB in HUVEC resulted in increased RhoA activation in response to VEGF stimulation. This increased RhoA activation contributed to the cellular morphogenesis defects observed in RhoB-depleted cells, as inhibition of RhoA activity using C3 transferase, or inhibition of the activity of the downstream RhoA effectors Rho-dependent kinases I and II (ROCK I and II led to a partial restoration of capillary morphogenesis in the absence of RhoB. Thus our data indicate that RhoB plays a significant role in VEGF-induced endothelial cell morphogenesis in part by negatively regulating the activity of RhoA and the RhoA/ROCK pathway.

  9. Computational micro-scale model of control of extravascular water and capillary perfusion in the air blood barrier.

    Science.gov (United States)

    Mazzuca, Enrico; Aliverti, Andrea; Miserocchi, Giuseppe

    2016-07-01

    A computational model of a morphologically-based alveolar capillary unit (ACU) in the rabbit is developed to relate lung fluid balance to mechanical forces between capillary surface and interstitium during development of interstitial edema. We hypothesize that positive values of interstitial liquid pressure Pliq impact on capillary transmural pressure and on blood flow. ACU blood flow, capillary recruitment and filtration are computed by modulating vascular and interstitial pressures. Model results are compared with experimental data of Pliq increasing from ~-10 (control) up to ~4cmH2O in two conditions, hypoxia and collagenase injection. For hypoxia exposure, fitting data requires a linear increase in hydraulic conductivity Lp and capillary pressure PC, that fulfils the need of increase in oxygen delivery. For severe fragmentation of capillary endothelial barrier (collagenase injection), fitting requires a rapid increase in both hydraulic and protein permeability, causing ACU de-recruitment, followed by an increase in PC as a late response to restore blood flow. In conclusion, the model allows to describe the lung adaptive response to edemagenic perturbations; the increase in Pliq, related to the low interstitial compliance, provides an efficient control of extravascular water, by limiting microvascular filtration.

  10. Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction.

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Scioli

    Full Text Available Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery.We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS reduction, inducible nitric oxide synthase (iNOS and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF, placental growth factor (PlGF and reduction of NADPH-oxidase 4 (Nox4 expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction.PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and

  11. Capillary pumped loop body heat exchanger

    Science.gov (United States)

    Swanson, Theodore D. (Inventor); Wren, deceased, Paul (Inventor)

    1998-01-01

    A capillary pumped loop for transferring heat from one body part to another body part, the capillary pumped loop comprising a capillary evaporator for vaporizing a liquid refrigerant by absorbing heat from a warm body part, a condenser for turning a vaporized refrigerant into a liquid by transferring heat from the vaporized liquid to a cool body part, a first tube section connecting an output port of the capillary evaporator to an input of the condenser, and a second tube section connecting an output of the condenser to an input port of the capillary evaporator. A wick may be provided within the condenser. A pump may be provided between the second tube section and the input port of the capillary evaporator. Additionally, an esternal heat source or heat sink may be utilized.

  12. Measurement of Liquid Viscosities in Tapered or Parabolic Capillaries.

    Science.gov (United States)

    Ershov; Zorin; Starov

    1999-08-01

    The possibility of using tapered or parabolic capillaries for measurement of liquid viscosities is investigated both experimentally and theoretically. It is demonstrated that even small deviations in capillary radius from a constant value may substantially affect measurement results. Equations are derived which allow correct analysis of the measurement results in tapered or parabolic capillaries. The following cases are analyzed: a water imbibition into a tapered or parabolic capillary and displacement of one liquid by another immiscible liquid in tapered or parabolic capillaries. Two possibilities are considered: (a) the narrow end of the capillary as capillary inlet and (b) the wide end of the capillary as capillary inlet. Copyright 1999 Academic Press.

  13. The effects of hyperbaric air and hyperbaric oxygen on blood-brain barrier integrity in rats.

    Science.gov (United States)

    Cevik, Nihal Gunes; Orhan, Nurcan; Yilmaz, Canan Ugur; Arican, Nadir; Ahishali, Bulent; Kucuk, Mutlu; Kaya, Mehmet; Toklu, Akin Savas

    2013-09-19

    Hyperbaric oxygen (HBO) treatment yields conflicting results on blood-brain barrier (BBB) integrity under various pathological conditions and the effects of HBO on healthy brain is poorly understood. In this experimental study, the effects of HBO on BBB integrity were investigated in comparison with hyperbaric air (HBA) in intact rats. Four sessions of HBA or HBO were applied to intact rats in 24h. BBB integrity was functionally and structurally evaluated by determining extravasation of Evans blue (EB) dye and horseradish peroxidase (HRP) tracers. In immunohistochemical evaluation, relative staining intensity for occludin, a tight junction (TJ) protein, and aquaporin 4 (AQP4), a water-channel protein, was detected in the barrier type of microvessels of brain by image analysis. BBB permeability to EB dye significantly increased in animals in HBO treatment group compared to those in HBA and control groups (p<0.05). The immunoreactivity of occludin, a tight junction protein, remained essentially unaltered in capillaries of hippocampus in all groups. In animals exposed to HBO, AQP4 immunoreactivity significantly increased in parietal cortex compared to those in HBA and control groups (p<0.01). Ultrastructurally, frequent vesicles containing HRP reaction products were observed in capillary endothelial cells in cerebral cortex and hippocampus of rats subjected to both HBA and HBO. Our results indicate that the HBO administration to intact rats increased BBB permeability to both EB and HRP while HBA increased only HRP extravasation in these animals. The results of this study suggest that HBA also impairs the BBB integrity in intact rats as well as HBO.

  14. Ovine carotid artery-derived cells as an optimized supportive cell layer in 2-D capillary network assays.

    Directory of Open Access Journals (Sweden)

    Stefan Weinandy

    Full Text Available BACKGROUND: Endothelial cell co-culture assays are differentiation assays which simulate the formation of capillary-like tubules with the aid of a supportive cell layer. Different cell types have been employed as a supportive cell layer, including human pulmonary artery smooth muscle cells (PASMCs and human mammary fibroblasts. However, these sources of human tissue-derived cells are limited, and more readily accessible human or animal tissue-derived cell sources would simplify the endothelial cell co-culture assay. In the present study, we investigated the potential use of alternative, accessible supportive cells for endothelial cell co-culture assay, including human umbilical cord and ovine carotid artery. METHODS AND RESULTS: Human umbilical artery SMCs (HUASMCs and ovine carotid artery-derived cells were seeded into 96-well plates, followed by addition of human umbilical vein endothelial cells (HUVECs. Nine days after co-culture, cells were fixed, immunostained and analysed using an in vitro angiogenesis quantification tool. Capillary-like structures were detected on ovine carotid artery-derived supportive cell layers. The initial cell number, as well as pro- and anti-angiogenic factors (VEGF, PDGF-BB and Bevacizumab, had a positive or negative influence on the number of capillary-like structures. Furthermore, HUVECs from different donors showed distinct levels of VEGF receptor-2, which correlated with the amount of capillary-like structures. In the case of HUASMC supportive cell layers, HUVECs detached almost completely from the surface. CONCLUSIONS: Cells of different origin have a varying applicability regarding the endothelial cell co-culture assay: under the conditions described here, ovine carotid artery-derived cells seem to be more suitable than HUASMCs for an endothelial co-culture assay. Furthermore, the ovine carotid artery-derived cells are easier to obtain and are in more abundant supply than the currently used dermal or breast

  15. In Vitro Endothelialization Test of Biomaterials Using Immortalized Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Ken Kono

    Full Text Available Functionalizing biomaterials with peptides or polymers that enhance recruitment of endothelial cells (ECs can reduce blood coagulation and thrombosis. To assess endothelialization of materials in vitro, primary ECs are generally used, although the characteristics of these cells vary among the donors and change with time in culture. Recently, primary cell lines immortalized by transduction of simian vacuolating virus 40 large T antigen or human telomerase reverse transcriptase have been developed. To determine whether immortalized ECs can substitute for primary ECs in material testing, we investigated endothelialization on biocompatible polymers using three lots of primary human umbilical vein endothelial cells (HUVEC and immortalized microvascular ECs, TIME-GFP. Attachment to and growth on polymer surfaces were comparable between cell types, but results were more consistent with TIME-GFP. Our findings indicate that TIME-GFP is more suitable for in vitro endothelialization testing of biomaterials.

  16. A New Conductivity Detector for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell, the microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring, the ends of microelectrode and capillary were located by a guide with two cross holes. LOD for K+ was 1.5×10-5 mol/L.

  17. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  18. Induction of initial steps of angiogenic differentiation and maturation of endothelial cells by pericytes in vitro and the role of collagen IV.

    Science.gov (United States)

    Zhou, Zhigang; Pausch, Friederike; Schlötzer-Schrehardt, Ursula; Brachvogel, Bent; Pöschl, Ernst

    2016-05-01

    Activation of endothelial cells and recruitment of mural cells define critical steps during the formation of stable vascular elements. Both events are reflected by cocultures of endothelial cells and isolated murine pericyte-like cells and define a versatile platform for the analysis of distinct steps during the angiogenic process in vitro. Isolated pericyte-like cells promote the survival of endothelial cells, induce the assembly of endothelial cells as well as establish direct contacts with forming endothelial alignments. More importantly, they also induce characteristic steps of maturation including the assembly of stable cell-cell junctions, deposition of basement membrane-like matrices and local formation of a central lumen. The presence of pericyte-like cells induces the secretion of extracellular matrices enriched in collagen IV by endothelial cells, which improves endothelial tube formation and provides the adhesive substrate for mural cell recruitment. Collagen-binding integrins contribute differentially to the process, with α1β1 involved in the adhesion of pericyte-like cells to collagen IV and α2β1 mainly involved in endothelial cord formation. These data indicate that pericyte-like cells are essential for the survival of endothelial cells, the efficient formation of endothelial alignments as well as initial steps of maturation of capillary-like structures.

  19. Defining minimum essential factors to derive highly pure human endothelial cells from iPS/ES cells in an animal substance-free system.

    Science.gov (United States)

    Wu, Yu-Ting; I-Shing Yu; Tsai, Kuen-Jer; Shih, Chien-Yu; Hwang, Shiaw-Min; Su, Ih-Jen; Chiang, Po-Min

    2015-04-13

    It is desirable to obtain unlimited supplies of endothelial cells for research and therapeutics. However, current methods of deriving endothelial cells from humans suffer from issues, such as limited supplies, contamination from animal substances, and lengthy/complicated procedures. In this article we developed a way to differentiate human iPS and ES cells to highly pure endothelial cells in 5 days. The chemically defined system is robust, easy to perform, and free of animal substances. Using the system, we verified that combined TGFβ and canonical Wnt agonists are essential and sufficient for iPS/ES cell-to-mesoderm transition. Besides, VEGF-KDR signaling alone is required for endothelial formation at high density while supplementation with FGF allows for colonial endothelial differentiation. Finally, anti-adsorptive agents could enrich the endothelial output by allowing selective attachment of the endothelial precursors. The system was validated to work on multiple iPS/ES cells lines to produce endothelial cells capable of forming capillary-like structures in vitro and integrating into host vasculature in vivo. In sum, the simple yet robust differentiation system permits the unlimited supply of human endothelial cells. The defined and animal substance-free nature of the system is compatible with clinical applications and characterization of endothelial differentiation in an unbiased manner.

  20. Slope wavenumber spectrum models of capillary and capillary-gravity waves

    Institute of Scientific and Technical Information of China (English)

    贾永君; 张杰; 王岩峰

    2010-01-01

    Capillary and capillary-gravity waves possess a random character, and the slope wavenumber spectra of them can be used to represent mean distributions of wave energy with respect to spatial scale of variability. But simple and practical models of the slope wavenumber spectra have not been put forward so far. In this article, we address the accurate definition of the slope wavenumber spectra of water surface capillary and capillary-gravity waves. By combining the existing slope wavenumber models and using th...

  1. PKCε ACTIVATION PROMOTES FGF-2 EXOCYTOSIS AND INDUCES ENDOTHELIAL CELL PROLIFERATION AND SPROUTING

    Science.gov (United States)

    Monti, Martina; Donnini, Sandra; Morbidelli, Lucia; Giachetti, Antonio; Mochly-Rosen, Daria; Mignatti, Paolo; Ziche, Marina

    2013-01-01

    Protein kinase C epsilon (PKCε) activation controls fibroblast growth factor-2 (FGF-2) angiogenic signaling. Here, we examined the effect of activating PKCε on FGF-2 dependent vascular growth and endothelial activation. ψεRACK, a selective PKCε agonist induces pro-angiogenic responses in endothelial cells, including formation of capillary like structures and cell growth. These effects are mediated by FGF-2 export to the cell membrane, as documented by biotinylation and immunofluorescence, and FGF-2/FGFR1 signaling activation, as attested by ERK1/2-STAT-3 phosphorylation and de novo FGF-2 synthesis. Similarly, vascular endothelial growth factor (VEGF) activates PKCε in endothelial cells, and promotes FGF-2 export and FGF-2/FGFR1 signaling activation. ψεRACK fails to elicit responses in FGF-2−/− endothelial cells, and in cells pretreated with methylamine (MeNH2), an exocytosis inhibitor, indicating that both intracellular FGF-2 and its export toward the membrane are required for the ψεRACK activity. In vivo ψεRACK does not induce angiogenesis in the rabbit cornea. However, ψεRACK promotes VEGF angiogenic responses, an effect sustained by endothelial FGF-2 release and synthesis, since anti-FGF-2 antibody strongly attenuates VEGF responses. The results demonstrate that PKCε stimulation promotes angiogenesis and modulates VEGF activity, by inducing FGF-2 release and autocrine signaling. PMID:23880610

  2. Angiogenesis gene expression in murine endothelial cells during post-pneumonectomy lung growth

    Directory of Open Access Journals (Sweden)

    Konerding Moritz A

    2011-07-01

    Full Text Available Abstract Although blood vessel growth occurs readily in the systemic bronchial circulation, angiogenesis in the pulmonary circulation is rare. Compensatory lung growth after pneumonectomy is an experimental model with presumed alveolar capillary angiogenesis. To investigate the genes participating in murine neoalveolarization, we studied the expression of angiogenesis genes in lung endothelial cells. After left pneumonectomy, the remaining right lung was examined on days 3, 6, 14 and 21days after surgery and compared to both no surgery and sham thoracotomy controls. The lungs were enzymatically digested and CD31+ endothelial cells were isolated using flow cytometry cell sorting. The transcriptional profile of the CD31+ endothelial cells was assessed using quantitative real-time polymerase chain reaction (PCR arrays. Focusing on 84 angiogenesis-associated genes, we identified 22 genes with greater than 4-fold regulation and significantly enhanced transcription (p

  3. A Simple Method for Assessing Free Brain/Free Plasma Ratios Using an In Vitro Model of the Blood Brain Barrier

    Science.gov (United States)

    Sevin, Emmanuel; Szorath, Erica; Martinsson, Stefan; Renftel, Mila; Hongmei, Yan; Cecchelli, Romeo; Lundquist, Stefan

    2013-01-01

    Historically, the focus has been to use in vitro BBB models to optimize rate of drug delivery to the CNS, whereas total in vivo brain/plasma ratios have been used for optimizing extent. However, these two parameters do not necessarily show good correlations with receptor occupancy data or other pharmacological readouts. In line with the free drug hypothesis, the use of unbound brain concentrations (Cu,br) has been shown to provide the best correlations with pharmacological data. However, typically the determination of this parameter requires microdialysis, a technique not ideally suited for screening in early drug development. Alternative, and less resource-demanding methodologies to determine Cu,br employ either equilibrium dialysis of brain homogenates or incubations of brain slices in buffer to determine fraction unbound brain (fu,br), which is subsequently multiplied by the total brain concentration to yield Cu,br. To determine Cu,br/Cu,pl ratios this way, still requires both in vitro and in vivo experiments that are quite time consuming. The main objective of this study was to explore the possibility to directly generate Cu,br/Cu,pl ratios in a single in vitro model of the BBB, using a co-culture of brain capillary endothelial and glial cells in an attempt to mimick the in vivo situation, thereby greatly simplifying existing experimental procedures. Comparison to microdialysis brain concentration profiles demonstrates the possibility to estimate brain exposure over time in the BBB model. A stronger correlation was found between in vitro Cu,br/Cu,pl ratios and in vivo Cu,br/Cu,pl obtained using fu,br from brain slice than with fu,br from brain homogenate for a set of 30 drugs. Overall, Cu,br/Cu,pl ratios were successfully predicted in vitro for 88% of the 92 studied compounds. This result supports the possibility to use this methodology for identifying compounds with a desirable in vivo response in the CNS early on in the drug discovery process. PMID:24312489

  4. Endothelial dysfunction: EDCF revisited

    Institute of Scientific and Technical Information of China (English)

    PAUL M Vanhoutte

    2008-01-01

    Endothelial cells can initiate contraction (constriction) of the vascular smooth muscle cells that surround them. Such endothelium-dependent, acute increases in contractile tone can be due to the withdrawal of the production of nitric oxide, to the production of vasoconstrictor peptides (angiotensin Ⅱ, endothelin-1), to the formation of oxygen-derived free radicals(superoxide anions) and/or the release of vasoconstrictor metabolites of arachidonic acid. The latter have been termed endothelium-derived contracting factor (EDCF) as they can contribute to moment-to-moment changes in contractile activity of the underlying vascular smooth muscle cells. To judge from animal experiments, EDCF-mediated responses are exacerbated when the production of nitric oxide is impaired as well as by aging, spontaneous hypertension and diabetes. To judge from human studies, they contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive patients. Since EDCF causes vasoconstriction by activation of the TP-receptors on the vascular smooth muscle cells, selective antagonists at these receptors prevent endothelium-dependent contractions, and curtail the endothelial dysfunction in hypertension and diabetes.

  5. Platelet-derived growth factor B retention is essential for development of normal structure and function of conduit vessels and capillaries

    DEFF Research Database (Denmark)

    Nyström, Henrik C.; Lindblom, Per; Wickman, Anna;

    2006-01-01

    : Passive and active properties of conduit vessels were studied using myograph techniques and histological examination. Capillary structure and function was studied using measurements of capillary density in skeletal muscle and by assessing aerobic physical performance in a treadmill setup. Cardiac function...... was assessed using echocardiography. RESULTS: Myograph experiments revealed an increased diameter and stiffness of the aorta in RetKO. Histological examination showed increased media collagen content and a decreased number of aortic wall layers, however with a similar number of vascular smooth muscle cells....... This outward eutrophic remodelling of the aorta was accompanied by endothelial dysfunction. RetKO showed decreased capillary density in skeletal muscle and signs of a defective delivery of capillary oxygen to skeletal muscle, as shown by a decreased physical performance. In RetKO mice, echocardiography...

  6. Comparative observation with MRI and pathology of brain edema at the early stage of severe burn

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the correlation between MRI features and pathology in brain edema at the early stage of severe burn (50% TBSA Ⅲ degree) in dogs.Methods: Fifty-two dogs were randomized into control, simple burn (SB), burn plus sodium lactate (BSL), and burn plus glucose solution groups (BGS). The manifestation of the brain of control group was compared with that of burn groups at 6, 12, 18 and 24 hours postburn with MRI and pathological examination (gross appearance, electron microscopy and light microscopy).Results: The earliest findings of brain edema were seen at 12 hours after burn in BGS group, in which brain swelling was the main feature of MRI. The decrease of SIR on T1WI was not observed until it was exceeded 10%.Signal of T2WI increased by 8.29% at 24 hours after burn.It was difficult to distinguish the gray matter from the white matter at the boundary line, which became blurred later. Histological changes of brain edema were observed as early as 6 hours after burn, being accompanied by swelling of endothelial cells and peri-vescular astrocytes, and vacuolation took place in neurons at 12 hours after burn, with different degrees of necrosis of capillary endothelimn,neurons, and axons. These changes became more marked with elapse of time. The BGS group showed the most obvious changes mentioned above at 24 hours after burn.Conclusions: The model of the brain edema after severe burn has the feature of both vasogenic edema and cytotoxic edema on the MRI and pathology. Positive MRI findings lagged behind that of the pathomorphological changes.ed

  7. Capillary electrophoresis theory and practice

    CERN Document Server

    Grossman, Paul D

    1992-01-01

    This book is designed to be a practical guide, used by wide audience, including those new to CE, those more experienced, routine users, those interested in technology development, and those involved with applications research. References have been emphasized to allow the reader to explore the detailed specifics and theoretical foundations.This book draws together the rapidly evolving, diverse, and multidisciplinary subject of capillary electrophoresis (CE). It is designed as a practical guide to be used by a wide audience, including those new to CE as well as more experienced users. T

  8. Electromigration dispersion in Capillary Electrophoresis

    CERN Document Server

    Chen, Zhen; 10.1007/s11538-011-9708-7

    2012-01-01

    In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol. 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger's equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data.

  9. Capillary Bridges between Soft Substrates

    Science.gov (United States)

    Wexler, Jason S.; Heard, Tiara M.; Stone, Howard A.

    2014-02-01

    A wetting droplet trapped in the thin gap between two elastic bodies will deflect the bodies towards one another. The deformation increases the total capillary adhesion force by increasing the contact radius and narrowing the gap height. For flat droplets, with a large ratio of radius to gap height, the Laplace pressure causes surface deformations that are orders of magnitude larger than those induced by a sessile droplet of the same radius. We present experiments, scalings, and closed-form solutions that describe the deformation. Using variational techniques, we also show that the problem exhibits a bifurcation, where the gap spontaneously closes due to an incremental increase in drop volume.

  10. The endothelial border to health

    DEFF Research Database (Denmark)

    Hansen, Nina Wærling; Hansen, Anker Jon; Sams, Anette

    2017-01-01

    The endothelial cell (EC) layer constitutes a barrier that controls movements of fluid, solutes and cells between blood and tissue. Further, the endothelial layer regulates vascular tone and directs local humoral and cellular inflammatory processes. The strategic position makes it an important...... for several endothelial dysfunctions. There is also mounting epidemiological evidence that dietary intake of refined sugars is important for the development of a number of diseases beyond obesity and type 2 diabetes. Various diseases involving inflammatory and immunological components are accelerated...... extracellular proteins form epitopes for potential specific antibody formation upon interactions with reducing sugars. This paper reviews the endothelial metabolism, biology, inflammatory processes, physical barrier functions, and summarizes evidence that although stochastic in nature, endothelial responses...

  11. Extract of Indian green mussel, Perna viridis (L.) shows inhibition of blood capillary formation in vitro

    Digital Repository Service at National Institute of Oceanography (India)

    Mirshahi, M.; Mirshahi, P.; Negro, S.; Soria, J.; Sreekumar, P.K.; Kotnala, S.; Therwath, A.; Chatterji, A.

    to the control. No. of capillary tubes formed/ visual field Control 5 mg/mL 1 mg/mL 0,2 mg/mL 0,04 mg/mL Concentrations of GM Crude (mg/mL) 100 80 60 40 20 0 2 Hrs 4 Hrs 6 Hrs Fig. 1: Dose and time dependant effects of the GM crude on the formation... of capillary tubes of human microvascular endothelial cells No. of junctions formed/ visual field Control 5 mg/mL 1 mg/mL 0,2 mg/mL 0,04 mg/mL Concentrations of GM Crude (mg/mL) 180 160 140 120 100 80 60 40 20 0 2 Hrs 4 Hrs 6 Hrs Fig. 2: The dose and time...

  12. Orally Administrated Ascorbic Acid Suppresses Neuronal Damage and Modifies Expression of SVCT2 and GLUT1 in the Brain of Diabetic Rats with Cerebral Ischemia-Reperfusion

    Directory of Open Access Journals (Sweden)

    Naohiro Iwata

    2014-04-01

    Full Text Available Diabetes mellitus is known to exacerbate cerebral ischemic injury. In the present study, we investigated antiapoptotic and anti-inflammatory effects of oral supplementation of ascorbic acid (AA on cerebral injury caused by middle cerebral artery occlusion and reperfusion (MCAO/Re in rats with streptozotocin-induced diabetes. We also evaluated the effects of AA on expression of sodium-dependent vitamin C transporter 2 (SVCT2 and glucose transporter 1 (GLUT1 after MCAO/Re in the brain. The diabetic state markedly aggravated MCAO/Re-induced cerebral damage, as assessed by infarct volume and edema. Pretreatment with AA (100 mg/kg, p.o. for two weeks significantly suppressed the exacerbation of damage in the brain of diabetic rats. AA also suppressed the production of superoxide radical, activation of caspase-3, and expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β in the ischemic penumbra. Immunohistochemical staining revealed that expression of SVCT2 was upregulated primarily in neurons and capillary endothelial cells after MCAO/Re in the nondiabetic cortex, accompanied by an increase in total AA (AA + dehydroascorbic acid in the tissue, and that these responses were suppressed in the diabetic rats. AA supplementation to the diabetic rats restored these responses to the levels of the nondiabetic rats. Furthermore, AA markedly upregulated the basal expression of GLUT1 in endothelial cells of nondiabetic and diabetic cortex, which did not affect total AA levels in the cortex. These results suggest that daily intake of AA attenuates the exacerbation of cerebral ischemic injury in a diabetic state, which may be attributed to anti-apoptotic and anti-inflammatory effects via the improvement of augmented oxidative stress in the brain. AA supplementation may protect endothelial function against the exacerbated ischemic oxidative injury in the diabetic state and improve AA transport through SVCT2 in the cortex.

  13. Stretch and/or oxygen glucose deprivation (OGD in an in vitro traumatic brain injury (TBI model induces calcium alteration and inflammatory cascade

    Directory of Open Access Journals (Sweden)

    Ellaine eSalvador

    2015-08-01

    Full Text Available The blood-brain barrier (BBB, made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI, cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH and nitric oxide (NO into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (IL-6, IL-1α, chemokine (C-C motif ligand 2 (CCL2 and tumor necrosis factor (TNF-α also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glut1 expression and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models.

  14. Stretch and/or oxygen glucose deprivation (OGD) in an in vitro traumatic brain injury (TBI) model induces calcium alteration and inflammatory cascade.

    Science.gov (United States)

    Salvador, Ellaine; Burek, Malgorzata; Förster, Carola Y

    2015-01-01

    The blood-brain barrier (BBB), made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI), cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD) is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH) and nitric oxide (NO) into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (I L)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glut1 expression, and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models.

  15. Targeted liposomes for drug delivery across the blood-brain barrier

    NARCIS (Netherlands)

    van Rooy, I.

    2011-01-01

    Our brain is protected by the blood-brain barrier (BBB). This barrier is formed by specialized endothelial cells of the brain vasculature and prevents toxic substances from entering the brain. The downside of this barrier is that many drugs that have been developed to cure brain diseases cannot cros

  16. Flow and deformation of the capillary glycocalyx in the wake of a leukocyte

    Science.gov (United States)

    Damiano, Edward R.; Stace, Thomas M.

    2005-03-01

    An analysis is presented of the axisymmetric axial and radial flow and deformation fields throughout the endothelial-cell glycocalyx surface layer in the wake region behind a leukocyte moving steadily through a capillary. The glycocalyx, modeled as a thin poroelastic surface layer lining the capillary wall, is assumed to consist of a binary mixture of a linearly viscous fluid constituent and an isotropic, highly compressible, linearly elastic solid constituent having a vanishingly small solid-volume fraction. Invoking the asymptotic approximations of lubrication theory in a frame of reference translating with the leukocyte, closed-form solutions are obtained to the leading-order boundary-value problems governing the axial and radial flow and deformation fields throughout the glycocalyx as well as the axial and radial flow fields throughout the free capillary lumen within the wake. A simple asymptotic expression is obtained for the length lchar of the wake region in terms of the translational speed U0 of the leukocyte, and the equilibrium thickness h0, permeability k0, and aggregate elastic modulus HA of the glycocalyx. The predicted wake length, as seen from an observer moving in a reference frame attached to the leukocyte, is consistent with the recovery time predicted from a one-dimensional analysis of glycocalyx deformation through a quiescent inviscid fluid. The two-dimensional fluid dynamical analysis presented here thus provides the appropriate relationships for extracting estimates of the mechanoelectrochemical properties of the glycocalyx from physiologically realistic constitutive models developed under simplified one-dimensional flow regimes. The directly measurable quantities lchar,U0, and h0, which are obtainable from in vivo observations of the wake region behind a leukocyte moving steadily through a capillary, can therefore be connected, through the results of this analysis, to estimates of the mechanoelectrochemical properties of the glycocalyx on

  17. Differential gene expression analysis of tubule forming and non-tubule forming endothelial cells: CDC42GAP as a counter-regulator in tubule formation

    NARCIS (Netherlands)

    Engelse, M.A.; Laurens, N.; Verloop, R.E.; Koolwijk, P.; Hinsbergh, V.W.M. van

    2008-01-01

    The formation of new tubular structures from a quiescent endothelial lining is one of the hallmarks of sprouting angiogenesis. This process can be mimicked in vitro by inducing capillary-like tubular structures in a three-dimensional (3D) fibrin matrix. We aimed to analyze the differential mRNA expr

  18. IL-17A potentiates TNFα-induced secretion from human endothelial cells and alters barrier functions controlling neutrophils rights of passage

    DEFF Research Database (Denmark)

    Bosteen, Markus H; Tritsaris, Katerina; Hansen, Anker J

    2014-01-01

    Interleukin-17A (IL-17A) is an important pro-inflammatory cytokine that regulates leukocyte mobilization and recruitment. To better understand how IL-17A controls leukocyte trafficking across capillaries in the peripheral blood circulation, we used primary human dermal microvascular endothelial...

  19. Atomic Force Controlled Capillary Electrophoresis

    Science.gov (United States)

    Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham

    2010-03-01

    Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.

  20. Two-dimensional capillary origami

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, N.D., E-mail: nbrubaker@math.arizona.edu; Lega, J., E-mail: lega@math.arizona.edu

    2016-01-08

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

  1. Capillary density and capillary-to-fibre ratio in vastus lateralis muscle of untrained and trained men

    Directory of Open Access Journals (Sweden)

    W. M. Kilarski

    2011-08-01

    Full Text Available Muscle fibre profile area (Af, volume density (Vv, capillary-to-fibre ratio (CF and number of capillaries per fibre square millimetre (CD were determined from needle biopsies of vastus lateralis of twenty-four male volunteers (mean ± SD: age 25.4±5.8 years, height 178.6±5.5 cm, body mass 72.1±7.7 kg of different training background. Seven subjects were untrained students (group A, nine were national and sub-national level endurance athletes (group B with the background of 7.8±2.9 years of specialised training, and eight subjects were sprint-power athletes (group C with 12.8±8.7 years of specialised training. Muscle biopsies of vastus lateralis were analysed histochemically for mATPase. Capillaries were visualized and counted using CD31 antibodies against endothelial cells. There were significant differences in the Vv of type I and type II muscle fibres in both trained groups, B (51.8%; 25.6% and C (50.5%; 26.4%. However, in untrained group A that was treated as a reference group, the difference between Vv of type I and type II fibres was less prominent, nevertheless statistically significant (42.1%; 35.1%. There was also a significant difference in CF: 1.9 in group A and 2.1 in groups B and C. The number of capillaries per mm2 (CD was 245 (group A, 308 (group B and 325 (group C. Significant differences (P<0.05 in CF and CD, were found only between group A (1.9; 245 and both groups of trained men, B and C (2.1; 308 and 325. However, endurance athletes (group B, such as long-distance runners, cyclists and cross country skiers, did not differ from the athletes representing short term, high power output sports (group C such as ice hockey, karate, ski-jumping, volleyball, soccer and modern dance.

  2. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  3. Differential cellular expression of organic anion transporting peptides OATP1A2 and OATP2B1 in the human retina and brain: implications for carrier-mediated transport of neuropeptides and neurosteriods in the CNS.

    Science.gov (United States)

    Gao, Bo; Vavricka, Stephan R; Meier, Peter J; Stieger, Bruno

    2015-07-01

    Organic anion transporting polypeptides (OATPs) are polyspecific organic anion transporters, which are expressed in the blood-brain barrier, the choroid plexus, and other organs. The physiologic function of OATPs in extrahepatic tissues remains ambiguous. In rat retina, members of the OATP family are expressed. We therefore investigated the human retina for the expression of OATP1A2 and OATP2B1 and extended the study to human brain. Furthermore, we searched for peptide neurotransmitters as novel OATP substrates. OATP1A2 displayed a broad expression pattern in human retina as assessed by immunofluorescence localization. It is expressed in photoreceptor bodies and somas of amacrine cells. OATP1B2 expression is restricted to the inner nuclear layer and to the inner plexiform layer. Using paraffin sections from human cortex, cerebellum, and hippocampus, OATP1A2 was localized to neurons and neuronal processes, while OATP2B1 is expressed in endothelial cells of brain capillaries. Substance P and vasoactive intestinal peptide were identified as substrates for OATP1A2 and OATP2B1. Double-labeling immunofluorescence of human retina demonstrated the presence of substance P and of vasoactive intestinal peptides in neurons expressing OATP1A2 and OATP2B1, respectively. The expression of OATP1A2 and OATP2B1 in retinal neurons implies a role of these transporters in the reuptake of peptide neurotransmitters released from retinal neurons. The abundant expression of OATP1A2 in brain neurons points to the possibility that OATP1A2 could be involved in the homeostasis of neurosteroids. The high expression of OATP2B1 in brain capillaries supports an important function of OATPs in substance penetration across the blood-brain barrier.

  4. Capillary waveguide optrodes for Medical applications

    Science.gov (United States)

    Kieslinger, Dietmar; Weigl, Bernhard H.; Draxler, Sonja; Lippitsch, Max E.

    1997-01-01

    Glass capillaries with a chemically sensitive coating on the inner surface are used as optical sensors for medical diagnostics. The capillary simultaneously serves as a sample compartment, a sensor element, and an inhomogeneous optical waveguide. Different optical setups have been investigated and compared regarding its waveguiding properties.

  5. Modeling capillary forces for large displacements

    NARCIS (Netherlands)

    Mastrangeli, M.; Arutinov, G.; Smits, E.C.P.; Lambert, P.

    2014-01-01

    Originally applied to the accurate, passive positioning of submillimetric devices, recent works proved capillary self-alignment as effective also for larger components and relatively large initial offsets. In this paper, we describe an analytic quasi-static model of 1D capillary restoring forces tha

  6. Capillary electrophoresis using core-based hyperbranched polyethyleneimine (CHPEI) static-coated capillaries.

    Science.gov (United States)

    Boonyakong, Cheerapa; Tucker, Sheryl A

    2009-10-01

    With unique 3-D architecture, the application of core-based hyperbranched polyethyleneimine (CHPEI), as a capillary coating in capillary electrophoresis, is demonstrated by manipulation of the electroosmotic mobility (EOF). CHPEI coatings (CHPEI5, M(w) approximately 5000 and CHPEI25, M(w) approximately 25,000) were physically adsorbed onto the inner surface of bare fused-silica capillary (BFS) via electrostatic interaction of the oppositely charged molecules by rinsing the capillaries with different CHPEI aqueous solutions. The EOF values of the coated capillaries were measured over the pH range of 4.0-9.0. At higher pH (pH >6) the coated capillary surface possesses excess negative charges, which causes the reversal of the EOF. The magnitudes of the EOF obtained from the coated capillaries were three-fold lower than that of BFS capillary. Desirable reproducibility of the EOF with % RSD (n = 5) capillaries were successfully utilized to separate phenolic compounds, B vitamins, as well as basic drugs and related compounds with reasonable analysis time (capillary and capillary).

  7. Heme oxygenase and angiogenic activity of endothelial cells: stimulation by carbon monoxide and inhibition by tin protoporphyrin-IX.

    Science.gov (United States)

    Józkowicz, Alicja; Huk, Ihor; Nigisch, Anneliese; Weigel, Guenter; Dietrich, Wolf; Motterlini, Roberto; Dulak, Józef

    2003-04-01

    The activity of heme oxygenase enzymes (HOs) is responsible for the endogenous source of carbon monoxide (CO). Their activities can be inhibited by tin protoporphyrin-IX (SnPPIX). Recent data indicate the involvement of HOs in the regulation of angiogenesis. Here, we investigated the role of the HO pathway in the production and angiogenic activity of vascular endothelial growth factor (VEGF) in endothelial cells treated with SnPPIX, or cultured in the presence of a CO-releasing molecule (CO-RM). Addition of CO-RM or induction of HO-1 by hemin resulted in a threefold elevation in CO production in culture medium (up to 20.3 microg/L) and was associated with a 30% increase in VEGF synthesis. Much higher levels of CO (up to 60 microg/L) and a further increase in VEGF production (by 277%) were measured in cells treated with prostaglandin-J(2), a potent activator of HO-1. SnPPIX prevented the induction of CO generation and inhibited VEGF synthesis. Moreover, SnPPIX reduced the VEGF-elicited angiogenic activities of endothelial cells by decreasing their proliferation (by 26%), migration (by 46%), formation of tubes on Matrigel (by 48%), and outgrowth of capillaries from endothelial spheroids (by 30%). In contrast, overexpression of HO-1 or incubation of cells with CO-RM led to an increase in capillary sprouting. Thus, HO activity up-regulates VEGF production and augments the capability of endothelial cells to respond to exogenous stimulation.

  8. Endothelial dysfunction in morbid obesity.

    Science.gov (United States)

    Mauricio, Maria Dolores; Aldasoro, Martin; Ortega, Joaquin; Vila, José María

    2013-01-01

    Morbid obesity is a chronic multifunctional disease characterized by an accumulation of fat. Epidemiological studies have shown that obesity is associated with cardiovascular and metabolic disorders. Endothelial dysfunction, as defined by an imbalance between relaxing and contractile endothelial factors, plays a central role in the pathogenesis of these cardiometabolic diseases. Diminished bioavailability of nitric oxide (NO) contributes to endothelial dysfunction and impairs endothelium- dependent vasodilatation. But this is not the only mechanism that drives to endothelial dysfunction. Obesity has been associated with a chronic inflammatory process, atherosclerosis, and oxidative stress. Moreover levels of asymmetrical dimethyl-L-arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), are elevated in obesity. On the other hand, increasing prostanoid-dependent vasoconstriction and decreasing vasodilator prostanoids also lead to endothelial dysfunction in obesity. Other mechanisms related to endothelin-1 (ET-1) or endothelium derived hyperpolarizing factor (EDHF) have been proposed. Bariatric surgery (BS) is a safe and effective means to achieve significant weight loss, but its use is limited only to patients with severe obesity including morbid obesity. BS also proved efficient in endothelial dysfunction reduction improving cardiovascular and metabolic comorbidities associated with morbid obesity such as diabetes, coronary artery disease, nonalcoholic fatty liver disease and cancer. This review will provide a brief overview of the mechanisms that link obesity with endothelial dysfunction, and how weight loss is a cornerstone treatment for cardiovascular comorbidities obesity-related. A better understanding of the mechanisms of obesity-induced endothelial dysfunction may help develop new therapeutic strategies to reduce cardiovascular morbidity and mortality.

  9. Calcium Channel Blockade and Peroxisome Proliferator Activated Receptor γ Agonism Diminish Cognitive Loss and Preserve Endothelial Function During Diabetes Mellitus.

    Science.gov (United States)

    Jain, Swati; Sharma, B M; Sharma, Bhupesh

    2016-01-01

    Diabetes mellitus is considered as a main risk factor for vascular dementia. In the past, we have reported the induction of vascular dementia (VaD) by experimental diabetes. This study investigates the efficacy of a nifedipine, a calcium channel blocker and pioglitazone in the pharmacological interdiction of pancreatectomy diabetes (PaD) induced vascular endothelial dysfunction and subsequent VaD in rats. Attentional set shifting (ASST) and Morris water-maze (MWM) test were used for assessment of learning and memory. Vascular endothelial function, blood brain barrier permeability, serum glucose, serum nitrite/nitrate, oxidative stress (viz. aortic superoxide anion, brain thiobarbituric acid reactive species and brain glutathione), brain calcium and inflammation (myeloperoxidase) were also estimated. PaD rats have shown impairment of endothelial function, blood brain barrier permeability, learning and memory along with an increase in brain inflammation, oxidative stress and calcium. Administration of nifedipine and pioglitazone significantly attenuated PaD induced impairment of learning, memory, blood brain barrier permeability, endothelial function and biochemical parameters. It may be concluded that nifedipine, a calcium channel blocker may be considered as a potent pharmacological agent for the management of PaD induced endothelial dysfunction and subsequent VaD.

  10. Effect of ruthenium red, a ryanodine receptor antagonist in experimental diabetes induced vascular endothelial dysfunction and associated dementia in rats.

    Science.gov (United States)

    Jain, Swati; Sharma, Bhupesh

    2016-10-01

    Diabetes mellitus is considered as a main risk factor for vascular dementia. In the past, we have reported the induction of vascular dementia by experimental diabetes. This study investigates the efficacy of a ruthenium red, a ryanodine receptor antagonist and pioglitazone in the pharmacological interdiction of pancreatectomy diabetes (PaD) induced vascular endothelial dysfunction and subsequent vascular dementia in rats. Attentional set shifting and Morris water-maze test were used for assessment of learning and memory. Vascular endothelial function, blood brain barrier permeability, serum glucose, serum nitrite/nitrate, oxidative stress (viz. aortic superoxide anion, brain thiobarbituric acid reactive species and brain glutathione), brain calcium and inflammation (myeloperoxidase) were also estimated. PaD rats have shown impairment of endothelial function, blood brain barrier permeability, learning and memory along with an increase in brain inflammation, oxidative stress and calcium. Administration of ruthenium red and pioglitazone has significantly attenuated PaD induced impairment of learning, memory, blood brain barrier permeability, endothelial function and biochemical parameters. It may be concluded that ruthenium red, a ryanodine receptor antagonist and pioglitazone, a PPAR-γ agonist may be considered as potent pharmacological agent for the management of PaD induced endothelial dysfunction and subsequent vascular dementia. Ryanodine receptor may be explored further for their possible benefits in vascular dementia.

  11. Capillary Discharge XUV Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Nevrkla

    2009-01-01

    Full Text Available A device producing Z-pinching plasma as a source of XUV radiation is described. Here a ceramic capacitor bank pulse-charged up to 100 kV is discharged through a pre-ionized gas-filled ceramic tube 3.2 mm in diameter and 21 cm in length. The discharge current has amplitude of 20 kA and a rise-time of 65 ns. The apparatus will serve as experimental device for studying of capillary discharge plasma, for testing X-ray optics elements and for investigating the interaction of water-window radiation with biological samples. After optimization it will be able to produce 46.9 nm laser radiation with collision pumped Ne-like argon ions active medium. 

  12. Copolymers For Capillary Gel Electrophoresis

    Science.gov (United States)

    Liu, Changsheng; Li, Qingbo

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  13. Two-dimensional capillary origami

    Science.gov (United States)

    Brubaker, N. D.; Lega, J.

    2016-01-01

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid.

  14. Capillary Separation: Micellar Electrokinetic Chromatography

    Science.gov (United States)

    Terabe, Shigeru

    2009-07-01

    Micellar electrokinetic chromatography (MEKC), a separation mode of capillary electrophoresis (CE), has enabled the separation of electrically neutral analytes. MEKC can be performed by adding an ionic micelle to the running solution of CE without modifying the instrument. Its separation principle is based on the differential migration of the ionic micelles and the bulk running buffer under electrophoresis conditions and on the interaction between the analyte and the micelle. Hence, MEKC's separation principle is similar to that of chromatography. MEKC is a useful technique particularly for the separation of small molecules, both neutral and charged, and yields high-efficiency separation in a short time with minimum amounts of sample and reagents. To improve the concentration sensitivity of detection, several on-line sample preconcentration techniques such as sweeping have been developed.

  15. Brain and Retinal Pericytes: Origin, Function and Role

    Directory of Open Access Journals (Sweden)

    Andrea eTrost

    2016-02-01

    Full Text Available Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilisers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy with detrimental consequences for eye sight in millions of patients. In this review we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes.

  16. Alterations of blood brain barrier function in hyperammonemia: an overview.

    Science.gov (United States)

    Skowrońska, Marta; Albrecht, Jan

    2012-02-01

    Ammonia is a neurotoxin involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy, a condition associated with acute--(ALF) or chronic liver failure. This article reviews evidence that apart from directly affecting the metabolism and function of the central nervous system cells, ammonia influences the passage of different molecules across the blood brain barrier (BBB). A brief description is provided of the tight junctions, which couple adjacent cerebral capillary endothelial cells to each other to form the barrier. Ammonia modulates the transcellular passage of low-to medium-size molecules, by affecting their carriers located at the BBB. Ammonia induces interrelated aberrations of the transport of the large neutral amino acids and aromatic amino acids (AAA), whose influx is augmented by exchange with glutamine produced in the course of ammonia detoxification, and maybe also modulated by the extracellularly acting gamma-glutamyl moiety transferring enzyme, gamma-glutamyl-transpeptidase. Impaired AAA transport affects neurotransmission by altering intracerebral synthesis of catecholamines (serotonin and dopamine), and producing "false neurotransmitters" (octopamine and phenylethylamine). Ammonia also modulates BBB transport of the cationic amino acids: the nitric oxide precursor, arginine, and ornithine, which is an ammonia trap, and affects the transport of energy metabolites glucose and creatine. Moreover, ammonia acting either directly or in synergy with liver injury-derived inflammatory cytokines also evokes subtle increases of the transcellular passage of molecules of different size (BBB "leakage"), which appears to be responsible for the vasogenic component of cerebral edema associated with ALF.

  17. Expression and regulation of endothelial nitric oxide synthase.

    Science.gov (United States)

    Sase, K; Michel, T

    1997-01-01

    Endothelium-derived nitric oxide (NO) is a key determinant of blood pressure homeostasis and platelet aggregation and is synthesized by the endothelial isoform of nitric oxide synthase (eNOS). In the vascular wall, eNOS is activated by diverse cell-surface receptors and by increases in blood flow, and the consequent generation of NO leads to vascular smooth-muscle relaxation. Endothelium-dependent vasorelaxation is deranged in a variety of disease states, including hypertension, diabetes, and atherosclerosis, but the roles of eNOS in endothelial dysfunction remain to be clearly defined. The past several years have witnessed important advances in understanding the molecular and cellular biology of eNOS regulation. In endothelial cells, eNOS undergoes a complex series of covalent modifications, including myristoylation, palmitoylation, and phosphorylation. Palmitoylation of eNOS dynamically targets the enzyme to distinct domains of the endothelial plasma membrane termed caveolae; caveolae may serve as sites for the sequestration of signal-transducing proteins and are themselves subject to dynamic regulation by ligands and lipids. Originally thought to be expressed only in endothelial cells, eNOS is now known to be expressed in a variety of tissues, including blood platelets, cardiac myocytes, and brain hippocampus. Paradigms established in endothelial cells for the molecular regulation and subcellular targeting of eNOS are being extended to the investigation of eNOS expressed in nonendothelial tissues. This review summarizes recent advances in understanding the molecular regulation of eNOS and the other NOS isoforms and identifies important parallels between eNOS and other cell-signaling molecules. © 1997, Elsevier Science Inc. (Trends Cardiovasc Med 1997;7:28-37).

  18. Paravascular channels, cisterns, and the subarachnoid space in the rat brain: A single compartment with preferential pathways.

    Science.gov (United States)

    Bedussi, Beatrice; van der Wel, Nicole N; de Vos, Judith; van Veen, Henk; Siebes, Maria; VanBavel, Ed; Bakker, Erik Ntp

    2016-06-15

    Recent evidence suggests an extensive exchange of fluid and solutes between the subarachnoid space and the brain interstitium, involving preferential pathways along blood vessels. We studied the anatomical relations between brain vasculature, cerebrospinal fluid compartments, and paravascular spaces in male Wistar rats. A fluorescent tracer was infused into the cisterna magna, without affecting intracranial pressure. Tracer distribution was analyzed using a 3D imaging cryomicrotome, confocal microscopy, and correlative light and electron microscopy. We found a strong 3D colocalization of tracer with major arteries and veins in the subarachnoid space and large cisterns, attributed to relatively large subarachnoid space volumes around the vessels. Confocal imaging confirmed this colocalization and also revealed novel cisternal connections between the subarachnoid space and ventricles. Unlike the vessels in the subarachnoid space, penetrating arteries but not veins were surrounded by tracer. Correlative light and electron microscopy images indicated that this paravascular space was located outside of the endothelial layer in capillaries and just outside of the smooth muscle cells in arteries. In conclusion, the cerebrospinal fluid compartment, consisting of the subarachnoid space, cisterns, ventricles, and para-arteriolar spaces, forms a continuous and extensive network that surrounds and penetrates the rat brain, in which mixing may facilitate exchange between interstitial fluid and cerebrospinal fluid.

  19. 石杉碱甲保护人脑微血管内皮细胞损伤的体外实验研究%Protect Effects of Huperzine A on Methylglyoxal Induced Injury in the Cultured Human Brain Microvascular Endothelial Cell in Vitro Experimental Study

    Institute of Scientific and Technical Information of China (English)

    姜松国; 徐磊; 柴冬梅; 朱辉武; 林铮

    2015-01-01

    目的 体外实验研究石杉碱甲对人脑微血管内皮细胞(human brain microvascular endothelial cells,HBMEC)损伤的保护作用和机制.方法 在培养的HBMEC上,利用丙酮醛诱导细胞损伤,通过MTT检测细胞活力,LDH、SOD活性试剂盒及caspase-3活性试剂盒检测细胞损伤情况,观察石杉碱甲的作用和机制.结果 石杉碱甲呈浓度依赖地保护MGO诱导的细胞损伤,在10-5 mol·L-1时呈最大保护作用.丙酮醛能诱导HBMEC的SOD活性下降,而石杉碱甲(10-6,10-5mol·L-1)能逆转这种作用.进一步研究发现石杉碱甲能抑制丙酮醛诱导的caspase-3活性上升.结论 石杉碱甲对丙酮醛诱导的HBMEC的损伤具有保护作用,这可能与其抗自由基和抗凋亡作用有关.

  20. Laminin isoforms in endothelial and perivascular basement membranes.

    Science.gov (United States)

    Yousif, Lema F; Di Russo, Jacopo; Sorokin, Lydia

    2013-01-01

    Laminins, one of the major functional components of basement membranes, are found underlying endothelium, and encasing pericytes and smooth muscle cells in the vessel wall. Depending on the type of blood vessel (capillary, venule, postcapillary venule, vein or artery) and their maturation state, both the endothelial and mural cell phenotype vary, with associated changes in laminin isoform expression. Laminins containing the α4 and α5 chains are the major isoforms found in the vessel wall, with the added contribution of laminin α2 in larger vessels. We here summarize current data on the precise localization of these laminin isoforms and their receptors in the different layers of the vessel wall, and their potential contribution to vascular homeostasis.

  1. Nanoparticle-based capillary electroseparation of proteins in polymer capillaries under physiological conditions

    DEFF Research Database (Denmark)

    Nilsson, C.; Harwigsson, I.; Becker, K.

    2010-01-01

    Totally porous lipid-based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas (R), 6.7 cm effective length). In the absence of n...... at protein friendly conditions. The developed capillary-based method facilitates future electrochromatography of proteins on polymer-based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development....

  2. The impact of early aerobic exercise on brain microvascular alterations induced by cerebral hypoperfusion.

    Science.gov (United States)

    Leardini-Tristão, Marina; Borges, Juliana Pereira; Freitas, Felipe; Rangel, Raquel; Daliry, Anissa; Tibiriçá, Eduardo; Estato, Vanessa

    2017-02-15

    The therapeutic potential of early exercise training following cerebral hypoperfusion was investigated on brain perfusion and inflammation in rats with permanent bilateral occlusion of the common carotid arteries (2VO). Wistar rats were subjected to 2VO or sham surgery and each group was then subdivided randomly into sedentary or exercise groups. Early exercise training was initiated after three days of 2VO or sham surgery and consisted of seven days of treadmill training (30min/day at ∼60% of maximal exercise test), composing four groups: 1) Sham sedentary (Sham-Sed), 2) Sham exercised (Sham-Ex), 3) 2VO sedentary (2VO-Sed) and 4) 2VO exercised (2VO-Ex). Microvascular cerebral blood flow (MCBF) and NADPH oxidase and eNOS gene expression were evaluated by laser speckle contrast imaging and RT-PCR, respectively, and brain functional capillary density and endothelial-leukocyte interactions were evaluated by fluorescence intravital video-microscopy. The 2VO-Sed group presented a decrease in MCBF (Sham-Sed: 230.9±12.2 vs. 2VO-Sed: 183.6±10.6 arbitrary perfusion units, Pexercise was able to prevent the cerebral microvascular inflammation by decreasing endothelial-leukocyte interactions (2VO-Ex: 0.9±0.3 vs. 2VO-Sed: 5±0.6cells/min/100μm, Pbrain NADPH oxidase gene expression (2VO-Ex: 1.7±0.1 arbitrary units, Pexercise may represent a means of preventing the microvascular alterations induced by chronic cerebral hypoperfusion.

  3. Effect of photobiomodulation on endothelial cell exposed to Bothrops jararaca venom.

    Science.gov (United States)

    Franco, Ana Tereza Barufi; Silva, Luciana Miato Gonçalves; Costa, Marcília Silva; Zamuner, Silvia Fernanda; Vieira, Rodolfo Paula; de Fatima Pereira Teixeira, Catarina; Zamuner, Stella Regina

    2016-07-01

    Bleeding is a common feature in envenoming caused by Bothrops snake venom due to extensive damage to capillaries and venules, producing alterations in capillary endothelial cell morphology. It has been demonstrated, in vivo, that photobiomodulation (PBM) decreases hemorrhage after venom inoculation; however, the mechanism is unknown. Thus, the objective was to investigate the effects of PBM on a murine endothelial cell line (tEnd) exposed to Bothrops jararaca venom (BjV). Cells were exposed to BjV and irradiated once with either 660- or 780-nm wavelength laser light at energy densities of 4 and 5 J/cm(2), respectively, and irradiation time of 10 s. Cell integrity was analyzed by crystal violet and cell viability/mitochondrial metabolism by MTT assay. The release of lactic dehydrogenase (LDH) was quantified as a measure of cell damage. In addition, cytokine IL1-β levels were measured in the supernatant. PBM at 660 and 780 nm wavelength was able to increase cellular viability and decrease the release of LDH and the loss of cellular integrity. In addition, the concentration of pro-inflammatory cytokine IL1-β was reduced after PBM by both wavelengths. The data reported herein indicates that irradiation with red or near-infrared laser resulted in protection on endothelial cells after exposure to Bothrops venom and could be, at least in part, a reasonable explanation by the beneficial effects of PBM inhibiting the local effects induced by Bothrops venoms, in vivo.

  4. Vascular progenitor cells isolated from human embryonic stem cells give rise to endothelial and smooth muscle like cells and form vascular networks in vivo.

    Science.gov (United States)

    Ferreira, Lino S; Gerecht, Sharon; Shieh, Hester F; Watson, Nicki; Rupnick, Maria A; Dallabrida, Susan M; Vunjak-Novakovic, Gordana; Langer, Robert

    2007-08-03

    We report that human embryonic stem cells contain a population of vascular progenitor cells that have the ability to differentiate into endothelial-like and smooth muscle (SM)-like cells. Vascular progenitor cells were isolated from EBs grown in suspension for 10 days and were characterized by expression of the endothelial/hematopoietic marker CD34 (CD34+ cells). When these cells are subsequently cultured in EGM-2 (endothelial growth medium) supplemented with vascular endothelial growth factor-165 (50 ng/mL), they give rise to