scholarly journals Towards a Biohybrid Lung: Endothelial Cells Promote Oxygen Transfer through Gas Permeable Membranes

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Sarah Menzel ◽  
Nicole Finocchiaro ◽  
Christine Donay ◽  
Anja Lena Thiebes ◽  
Felix Hesselmann ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Gas Exchange ◽  
Oxygen Transfer ◽  
Umbilical Vein ◽  
Test Fluid ◽  
Gas Transfer ◽  
Extracorporeal Lung Support ◽  
Custom Made ◽  
Lung Endothelial Cells ◽  
Umbilical Vein Endothelial Cells

In patients with respiratory failure, extracorporeal lung support can ensure the vital gas exchange via gas permeable membranes but its application is restricted by limited long-term stability and hemocompatibility of the gas permeable membranes, which are in contact with the blood. Endothelial cells lining these membranes promise physiological hemocompatibility and should enable prolonged application. However, the endothelial cells increase the diffusion barrier of the blood-gas interface and thus affect gas transfer. In this study, we evaluated how the endothelial cells affect the gas exchange to optimize performance while maintaining an integral cell layer. Human umbilical vein endothelial cells were seeded on gas permeable cell culture membranes and cultivated in a custom-made bioreactor. Oxygen transfer rates of blank and endothelialized membranes in endothelial culture medium were determined. Cell morphology was assessed by microscopy and immunohistochemistry. Both setups provided oxygenation of the test fluid featuring small standard deviations of the measurements. Throughout the measuring range, the endothelial cells seem to promote gas transfer to a certain extent exceeding the blank membranes gas transfer performance by up to 120%. Although the underlying principles hereof still need to be clarified, the results represent a significant step towards the development of a biohybrid lung.

Heparan sulfate on endothelial cells mediates the binding ofPlasmodium falciparum–infected erythrocytes via the DBL1α domain of PfEMP1

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2405-2411 ◽  
Author(s):  
Anna M. Vogt ◽  
Antonio Barragan ◽  
Qijun Chen ◽  
Fred Kironde ◽  
Dorothe Spillmann ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heparan Sulfate ◽  
Umbilical Vein ◽  
Severe Disease ◽  
Dependent Manner ◽  
Wild Type ◽  
Platelet Endothelial Cell Adhesion ◽  
Erythrocyte Binding ◽  
Lung Endothelial Cells ◽  
Umbilical Vein Endothelial Cells

Plasmodium falciparum may cause severe forms of malaria when excessive sequestration of infected and uninfected erythrocytes occurs in vital organs. The capacity of wild-type isolates of P falciparum–infected erythrocytes (parasitized red blood cells [pRBCs]) to bind glycosaminoglycans (GAGs) such as heparin has been identified as a marker for severe disease. Here we report that pRBCs of the parasite FCR3S1.2 and wild-type clinical isolates from Uganda adhere to heparan sulfate (HS) on endothelial cells. Binding to human umbilical vein endothelial cells (HUVECs) and to human lung endothelial cells (HLECs) was found to be inhibited by HS/heparin or enzymes that remove HS from cell surfaces.35S-labeled HS extracted from HUVECs bound directly to the pRBCs' membrane. Using recombinant proteins corresponding to the different domains of P falciparum erythrocyte membrane protein 1 (PfEMP1), we identified Duffy-binding–like domain–1α (DBL1α) as the ligand for HS. DBL1α bound in an HS-dependent way to endothelial cells and blocked the adherence of pRBCs in a dose-dependent manner. 35S-labeled HS bound to DBL1α-columns and eluted as a distinct peak at 0.4 mM NaCl.35S-labeled chondroitin sulfate (CS) of HUVECs did not bind to PfEMP1 or to the pRBCs' membrane. Adhesion of pRBCs of FCR3S1.2 to platelet endothelial cell adhesion molecule–1 (PECAM-1)/CD31, mediated by the cysteine-rich interdomain region 1α (CIDR1α), was found be operative with, but independent of, the binding to HS. HS and the previously identified HS-like GAG on uninfected erythrocytes may act as coreceptors in endothelial and erythrocyte binding of rosetting parasites, causing excessive sequestration of both pRBCs and RBCs.

scholarly journals EndOxy: Dynamic Long-Term Evaluation of Endothelialized Gas Exchange Membranes for a Biohybrid Lung

2019 ◽  
Vol 48 (2) ◽  
pp. 747-756 ◽  
Author(s):  
Sarah Klein ◽  
Felix Hesselmann ◽  
Suzana Djeljadini ◽  
Tanja Berger ◽  
Anja Lena Thiebes ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Gas Exchange ◽  
Umbilical Vein ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Gas Transfer ◽  
Exchange Performance ◽  
Porcine Blood ◽  
Short Term Exposure

AbstractIn the concept of a biohybrid lung, endothelial cells seeded on gas exchange membranes form a non-thrombogenic an anti-inflammatory surface to overcome the lacking hemocompatibility of today’s oxygenators during extracorporeal membrane oxygenation. To evaluate this concept, the long-term stability and gas exchange performance of endothelialized RGD-conjugated polydimethylsiloxane (RGD-PDMS) membranes was evaluated. Human umbilical vein endothelial cells (ECs) were cultured on RGD-PDMS in a model system under physiological wall shear stress (WSS) of 0.5 Pa for up to 33 days. Gas exchange performance was tested with three biological replicates under elevated WSS of 2.5 Pa using porcine blood adjusted to venous values following ISO 7199 and blood gas analysis. EC morphology was assessed by immunocytochemistry (n = 3). RGD-PDMS promoted endothelialization and stability of endothelialized membranes was shown for at least 33 days and for a maximal WSS of 2.5 Pa. Short-term exposure to porcine blood did not affect EC integrity. The gas transfer tests provided evidence for the oxygenation and decarboxylation of the blood across endothelialized membranes with a decrease of transfer rates over time that needs to be addressed in further studies with larger sample sizes. Our results demonstrate the general suitability of RGD-PDMS for biohybrid lung applications, which might enable long-term support of patients with chronic lung failure in the future.

Single-Chain and Two-Chain Tissue-Type Plasminogen Activator (t-PA) Bind Differently to Cultured Human Endothelial Cells

1989 ◽  
Vol 62 (02) ◽  
pp. 699-703 ◽  
Author(s):  
Rob J Aerts ◽  
Karin Gillis ◽  
Hans Pannekoek
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Tissue Type ◽  
Single Chain ◽  
Human Endothelial Cells ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Umbilical Vein Endothelial Cells

SummaryIt has recently been shown that the fibrinolytic components plasminogen and tissue-type plasminogen activator (t-PA) both bind to cultured human umbilical vein endothelial cells (HUVEC). After cleavage of t-PA by plasmin, “single-chain” t-PA (sct-PA) is converted into “two-chain” t-PA (tct-PA), which differs from the former in a number of respects. We compared binding of sct-PA and tct-PA to the surface of HUVEC. Removal of t-PA bound to HUVEC by a mild treatment with acid and a subsequent quantification of eluted t-PA both by activity- and immunoradiometric assays revealed that, at concentrations between 10 and 500 nM, HUVEC bind about 3-4 times more sct-PA than tct-PA. At these concentrations, both sct-PA and tct-PA remain active when bound to HUVEC. Mutual competition experiments showed that sct-PA and tct-PA can virtually fully inhibit binding of each other to HUVEC, but that an about twofold higher concentration of tct-PA is required to prevent halfmaximal binding of sct-PA than visa versa. These results demonstrate that sct-PA and tct-PA bind with different affinities to the same binding sites on HUVEC.

Studies of the Factor Xa-Dependent Inhibitor of Factor VIIa/Tissue Factor (Extrinsic Pathway Inhibitor) from Cell Supernates of Cultured Human Umbilical Vein Endothelial Cells

1989 ◽  
Vol 61 (01) ◽  
pp. 101-105 ◽  
Author(s):  
Bonnie J Warn-Cramer ◽  
Fanny E Almus ◽  
Samuel I Rapaport
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Phorbol Ester ◽  
Umbilical Vein ◽  
Primary Cultures ◽  
Factor Xa ◽  
Extrinsic Pathway ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

SummaryCultured human umbilical vein endothelial cells (HUVEC) have been reported to produce extrinsic pathway inhibitor (EPI), the factor Xa-dependent inhibitor of factor VHa/tissue factor (TF). We examined the release of this inhibitor from HUVEC as a function of their growth state and in response to the induction of endothelial cell TF activity. HUVEC constitutively produced significant amounts of EPI at all stages of their growth in culture including the post-confluent state. Rate of release varied over a 3-fold range for primary cultures from 12 different batches of pooled umbilical cord cells. Constitutive EPI release was unaltered during a 6 hour period of induction of TF activity with thrombin or phorbol ester but slowed during longer incubation of the cells with phorbol ester. Whereas plasma contains two molecular weight forms of EPI, only the higher of these two molecular weight forms was demonstrable by Western analysis of HUVEC supernatants with 125I-factor Xa as the ligand.

Effect of Lipoprotein(a) and LDL on Plasminogen Binding to Extracellular Matrix and on Matrix-dependent Plasminogen Activation by Tissue Plasminogen Activator

1996 ◽  
Vol 75 (03) ◽  
pp. 497-502 ◽  
Author(s):  
Hadewijch L M Pekelharing ◽  
Henne A Kleinveld ◽  
Pieter F C.C.M Duif ◽  
Bonno N Bouma ◽  
Herman J M van Rijn
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Single Step ◽  
Plasminogen Activation ◽  
Structural Homology ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells

SummaryLp(a) is an LDL-like lipoprotein plus an additional apolipoprotein apo(a). Based on the structural homology of apo(a) with plasminogen, it is hypothesized that Lp(a) interferes with fibrinolysis. Extracellular matrix (ECM) produced by human umbilical vein endothelial cells was used to study the effect of Lp(a) and LDL on plasminogen binding and activation. Both lipoproteins were isolated from the same plasma in a single step. Plasminogen bound to ECM via its lysine binding sites. Lp(a) as well as LDL were capable of competing with plasminogen binding. The degree of inhibition was dependent on the lipoprotein donor as well as the ECM donor. When Lp(a) and LDL obtained from one donor were compared, Lp(a) was always a much more potent competitor. The effect of both lipoproteins on plasminogen binding was reflected in their effect on plasminogen activation. It is speculated that Lp(a) interacts with ECM via its LDL-like lipoprotein moiety as well as via its apo(a) moiety.

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