Name: assessment of the anticoagulant and anti-inflammatory properties of endothelial cells using 3d cell culture and non-anticoagulated whole blood
Uploaded: 2017-09-05T13:00:00
Description: Watch this Scientific Journal Video about Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood at JoVE.com

This study was supported by the Swiss National Science Foundation (SNSF, Grant No. 320030_156193). The authors thank Dr. Beno&#238;t Werlen for providing the Biosilon microcarrier beads. We also thank Prof. Hans Peter Kohler and Prof. Andr&#233; Haeberli for help with setting up the microcarrier bead model.

German Landrace pigs (wild type bred in a local farmhouse and transgenic bred at the Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilian University, Munich, Germany), weighing between 30 kg to 40 kg, were used in this study. All animals were housed under standard conditions with water and food ad lib. All animal experiments were performed in accordance with the U.K. Animals Act (scientific procedures) and the NIH Guide for the Care and Use of Laboratory Animals, as well as the Swiss anima...

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	<li>Rajendran, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+vascular+endothelium+and+human+diseases.">The vascular endothelium and human diseases.</a> Int. J. Biol. Sci. 9, 1057-1069 (2013).</li><li>Rajwal, S., Richards, M., O'Meara, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+recalcified+citrated+whole+blood+-+a+pragmatic+approach+for+thromboelastography+in+children.">The use of recalcified citrated whole blood - a pragmatic approach for thromboelastography in children.</a> Pediatric Anesthesia. 14, 656-660 (2004).</li><li>Kohler, H. P., Muller, M., Mombeli, M., Mtraub, M. M., Maeberli, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Suppression+of+the+Coagulation+of+Nonanticoagulated+Whole-Blood+in-Vitro+by+Human+Umbilical+Endothelial-Cells+Cultivated+on+Microcarriers+Is+Not+Dependent+on+Protein-C+Activation.">The Suppression of the Coagulation of Nonanticoagulated Whole-Blood in-Vitro by Human Umbilical Endothelial-Cells Cultivated on Microcarriers Is Not Dependent on Protein-C Activation.</a> Thromb. Haemost. 73, 719-724 (1995).</li><li>Biedermann, B., Rosenmund, A., Muller, M., Kohler, H. P., Haeberli, A., Straub, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+endothelial+cells+suppress+prothrombin+activation+in+nonanticoagulated+whole+blood+in+vitro.">Human endothelial cells suppress prothrombin activation in nonanticoagulated whole blood in vitro.</a> J. Lab. Clin. Med. 124, 339-347 (1994).</li><li>Banz, Y., Cung, T., Korchagina, E. Y., Bovin, N. V., Haeberli, A., Rieben, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelial+cell+protection+and+complement+inhibition+in+xenotransplantation:+a+novel+in+vitro+model+using+whole+blood.">Endothelial cell protection and complement inhibition in xenotransplantation: a novel in vitro model using whole blood.</a> Xenotransplantation. 12, 434-443 (2005).</li><li>Cowan, P. J., d'Apice, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complement+activation+and+coagulation+in+xenotransplantation.">Complement activation and coagulation in xenotransplantation.</a> Immunology and Cell Biology. 87, 203-208 (2009).</li><li>Reitsma, S., Slaaf, D. W., Vink, H., van Zandvoort, M. A. M. J., oude Egbrink, M. G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+endothelial+glycocalyx:+composition,+functions,+and+visualization.">The endothelial glycocalyx: composition, functions, and visualization.</a> Pflugers Arch. 454, 345-359 (2007).</li><li>Wiegner, R., Chakraborty, S., Huber-Lang, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complement-coagulation+crosstalk+on+cellular+and+artificial+surfaces.">Complement-coagulation crosstalk on cellular and artificial surfaces.</a> Immunobiology. 221, 1073-1079 (2016).</li><li>Bongoni, A. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+Expression+of+Human+CD46+on+Porcine+Endothelium:+Effect+on+Coagulation+and+Fibrinolytic+Cascades+During+Ex+Vivo+Human-to-Pig+Limb+Xenoperfusions.">Transgenic Expression of Human CD46 on Porcine Endothelium: Effect on Coagulation and Fibrinolytic Cascades During Ex Vivo Human-to-Pig Limb Xenoperfusions.</a> Transplantation. 99, 2061-2069 (2015).</li><li>Miyazaki, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+shear+stress+can+initiate+both+platelet+aggregation+and+shedding+of+procoagulant+containing+microparticles.">High shear stress can initiate both platelet aggregation and shedding of procoagulant containing microparticles.</a> Blood. 88, 3456-3464 (1996).</li><li>Wuensch, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulatory+Sequences+of+the+Porcine+THBD+Gene+Facilitate+Endothelial-Specific+Expression+of+Bioactive+Human+Thrombomodulin+in+Single-and+Multitransgenic+Pigs.">Regulatory Sequences of the Porcine THBD Gene Facilitate Endothelial-Specific Expression of Bioactive Human Thrombomodulin in Single-and Multitransgenic Pigs.</a> Transplantation. 97, 138-147 (2014).</li></ol>

The model presented here is suitable for coagulation related studies allowing the analysis of different aspects of coagulation and its interaction with EC.8 In xenotransplantation research, it is a useful system to test the anticoagulant properties of different genetically modified porcine ECs after incubation with human blood 9.
The most critical steps of the protocol are those ensuring complete cell coverage (confluency) of the microbeads befor...

The vascular endothelium consists of a monolayer of endothelial cells (EC) which line the lumen of blood vessels. In a physiological state, quiescent EC are responsible for the maintenance of an anticoagulant and anti-inflammatory environment.1 This is mediated by the expression of anticoagulant and anti-inflammatory proteins on the EC surface. For example, EC activation caused by ischemia/reperfusion injury or vascular rejection of (xeno-)transplanted organs results in a change of the endothelial surface from an anticoagulant and anti-inflammatory state to a pro-coagulant and pro-inflammatory state.1
To study the fascinating and complex interaction between the endothelium and coagulation factors, in vitro models which mimic as closely as possible the in vivo situation are highly desirable. A common limitation which characterizes conventional in vitro coagulation assays is the use of anticoagulated blood which makes the analysis of coagulation-mediated effects arduous and even recalcification of citrated whole blood cannot reproduce results obtainable with fresh non-anticoagulated blood.2 Besides, in traditional flat-bed cell culture systems it is impossible to exploit the anticoagulant properties of the endothelium as a sufficient endothelial cell surface per blood volume cannot be reached. The model presented here overcomes these limitations by culturing EC on the surface of spherical microcarrier beads, so that an EC surface-to-blood ratio of &#62;16 cm2/mL can be reached, which is similar to the situation in small arterioles or veins, and which was described to be sufficient to allow "natural" anticoagulation of the blood by the EC surface.3,4 Whole blood can be used without added anticoagulants in this setting. Blood samples can be collected during the experiment and cytokines, coagulation factors and soluble complement activation markers can be detected and quantified. Furthermore, EC-coated microcarrier beads may be analyzed for complement and immunoglobulin deposition as well as the expression of EC activation markers by confocal microscopy. Another interesting application includes the testing of drugs which are supposed to prevent endothelial cell activation and, thus, coagulation.5 Although this model cannot completely replace animal experimentation, it offers a method to test specific functional hypotheses ex vivo using cells and thus reduce the number of animals used in basic research on ischemia/reperfusion injury or (xeno)transplantation.
The described model was used to mimic a xenotransplantation setting in which porcine aortic endothelial cells (PAEC) are grown on the microcarrier beads and incubated with whole, non-anticoagulated human blood. Different transgenic PAEC, carrying several human genes such as CD46 for the regulation of the complement system and/or thrombomodulin (hTBM) for the regulation of the coagulation system, were analyzed for their anticoagulant properties. Endothelial cell activation, complement, and coagulation systems are tightly controlled and interconnected.6 It is therefore important to understand how the different transgenic cells behave after exposure to human blood with regard to adhesion molecule expression and cytokine release, shedding of the glycocalyx and loss of anticoagulant proteins.7

<table>
	<tbody>
		<tr>
			<td>PAEC</td>
			<td></td>
			<td></td>
			<td>Isolated from pig aorta in our Lab</td>
		</tr>
		<tr>
			<td>Microcarrier beads (Biosilon)</td>
			<td>Thermo Fisher Scientific</td>
			<td>160-250</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagen I, Bovine</td>
			<td>Gibco</td>
			<td>A10644-01</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Gibco</td>
			<td>21885-025</td>
			<td></td>
		</tr>
		<tr>
			<td>Medium 199</td>
			<td>Sigma</td>
			<td>M7528</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI</td>
			<td>Gibco</td>
			<td>32404-014</td>
			<td></td>
		</tr>
		<tr>
			<td>Neutral tubes</td>
			<td>Sarstedt</td>
			<td>02.1726.001</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene tubes</td>
			<td>Simport</td>
			<td>T406-2A</td>
			<td></td>
		</tr>
		<tr>
			<td>Stirrer flasks</td>
			<td>Tecnomara</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biological stirrer</td>
			<td>Brouwer</td>
			<td>MCS-104S</td>
			<td></td>
		</tr>
		<tr>
			<td>Rat anti CD31</td>
			<td>R&#38;D Systems</td>
			<td>MAB33871</td>
			<td>Dilution 1:100</td>
		</tr>
		<tr>
			<td>Goat anti-rat IgG-Cy3</td>
			<td>Jackson Immuno Research</td>
			<td>112-166-003</td>
			<td>Dilution 1:500</td>
		</tr>
		<tr>
			<td>Goat anti VE-cadherin</td>
			<td>Santa Cruz</td>
			<td>sc-6458</td>
			<td>Dilution 1:100</td>
		</tr>
		<tr>
			<td>Rabbit anti vWF</td>
			<td>DAKO</td>
			<td>A0082</td>
			<td>Dilution 1:100</td>
		</tr>
		<tr>
			<td>Dk anti Gt IgG &#8211; Alexa 488</td>
			<td>Molecular Probes</td>
			<td>A11055</td>
			<td>Dilution 1:500</td>
		</tr>
		<tr>
			<td>Goat anti Rabbit - FITC</td>
			<td>Southern Biotech</td>
			<td>4050-02</td>
			<td>Dilution 1:500</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma</td>
			<td>32670-25MG-F</td>
			<td>Dilution 1 &#181;g/mL</td>
		</tr>
		<tr>
			<td>0.05% Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25300-054</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Gibco</td>
			<td>10270-106</td>
			<td>Concentration: 10% in cell culture medium</td>
		</tr>
		<tr>
			<td>Needle</td>
			<td>Becton Dickinson</td>
			<td>367286</td>
			<td>Size: 0.8x19 mm (21&#610; 3/4&#34;)</td>
		</tr>
		<tr>
			<td>Adapter</td>
			<td>Sarstedt</td>
			<td>14.1205</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microscope</td>
			<td>Carl Zeiss</td>
			<td>LSM 710</td>
			<td></td>
		</tr>
		<tr>
			<td>Image analysis software</td>
			<td>Image J</td>
			<td></td>
			<td>Available for free at: https://imagej.net</td>
		</tr>
		<tr>
			<td>Endothelial Cell Growth Medium SupplementMix</td>
			<td>PromoCell</td>
			<td>C-39216</td>
			<td>2mL in 500mL of DMEM</td>
		</tr>
		<tr>
			<td>Penicillin Streptomycin</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td>Concentration: 1% in cell culture medium</td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Gibco</td>
			<td>25030-024</td>
			<td>Concentration: 1% in cell culture medium</td>
		</tr>
		<tr>
			<td>Heparinun natricum</td>
			<td>Drossa Pharm AG</td>
			<td></td>
			<td>Stock concentration: 5000 U.I./ mL</td>
		</tr>
		<tr>
			<td>Chamberslides</td>
			<td>Bioswisstec AG</td>
			<td>30108</td>
			<td></td>
		</tr>
		<tr>
			<td>CaCl2 x 2H2O</td>
			<td>Merck</td>
			<td>2382.0500</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2 x6 H2O</td>
			<td>Merck</td>
			<td>1.5833.1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>Axon Lab AG</td>
			<td>9005-64-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Sigma</td>
			<td>A7030</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycergel mounting medium</td>
			<td>Dako</td>
			<td>C0563</td>
			<td></td>
		</tr>
	</tbody>
</table>

assessment of the anticoagulant and anti-inflammatory properties of endothelial cells using 3d cell culture and non-anticoagulated whole blood

In vivo, endothelial cells are crucial for the natural anticoagulation of circulating blood. Consequently, endothelial cell activation leads to blood coagulation. This phenomenon is observed in many clinical situations, like organ transplantation in the presence of pre-formed anti-donor antibodies, including xenotransplantation, as well as in ischemia/reperfusion injury. In order to reduce animal experimentation according to the 3R standards (reduction, replacement and refinement), in vitro models to study the effect of endothelial cell activation on blood coagulation would be highly desirable. However, common flatbed systems of endothelial cell culture provide a surface-to-volume ratio of 1 - 5 cm2 of endothelium per mL of blood, which is not sufficient for natural, endothelial-mediated anticoagulation. Culturing endothelial cells on microcarrier beads may increase the surface-to-volume ratio to 40 - 160 cm2/mL. This increased ratio is sufficient to ensure the &#34;natural&#34; anticoagulation of whole blood, so that the use of anticoagulants can be avoided. Here an in vitro microcarrier-based system is described to study the effects of genetic modification of porcine endothelial cells on coagulation of whole, non-anticoagulated human blood. In the described assay, primary porcine aortic endothelial cells, either wild type (WT) or transgenic for human CD46 and thrombomodulin, were grown on microcarrier beads and then exposed to freshly drawn non-anticoagulated human blood. This model allows for the measurement and quantification of cytokine release as well as activation markers of complement and coagulation in the blood plasma. In addition, imaging of activated endothelial cell and deposition of immunoglobulins, complement- and coagulation proteins on the endothelialized beads were performed by confocal microscopy. This assay can also be used to test drugs which are supposed to prevent endothelial cell activation and, thus, coagulation. On top of its potential to reduce the number of animals used for such investigations, the described assay is easy to perform and consistently reproducible.

After 7 - 10 days of culture in the spinner flask (Figure 1) the cells were confluent, covering the whole surface of the microcarrier beads (Figure 2). Verification of the confluency state is an important step because a non-confluent monolayer of EC on the microbeads will lead to a marked decrease in the clotting time, given the microcarrier beads&#39; surface is strongly pro-coagulant (clotting time: 4&#160;&#177; 1 min) (<stron...

Watch this Scientific Journal Video about Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood at JoVE.com

Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood

We present an in vitro model which allows the study and analysis of coagulation in whole, non-anticoagulated blood. Anticoagulation in the system depends on the natural anticoagulation effect of healthy endothelial cells and endothelial cell activation will result in clotting.

In vivo, endothelial cells are crucial for the natural anticoagulation of circulating blood. Consequently, endothelial cell activation leads to blood ...

The overall goal of this assay is to assess the anticoagulant properties of endothelial cells, using whole non-anticoagulated blood. This method can be used to answer research questions which are related to cardiovascular research, transportation and surgery related research. Essentially, can be used for all questions which have to do with anti-immunity and the activation of endothelial cells.The main advantage of this technique is that whole blood, without anticoagulants can be used as anticoagulation is guaranteed by endothelial cells. To begin the protocol, mix seven milliliters of microcarrier beads with 42 milliliters of coagulant solution in a 50 milliliter tube and incubate the beads for one hour at room temperature. After incubation, wash the beads with 25 milliliters of phosphate buffered saline or PBS and rinse the beads by pipetting up and down.Wait until the beads settle at the bottom of the tube, before discarding the supernatant and repeating. Next, wash the beads one time with 25 milliliters of Dulbecco's Modified Eagle's Medium, DMEM. Then, cover the beads with 10 milliliters of medium 199 and allow them to equilibrate for 10 minutes before further use.Remove the cell culture media from the T175 flask containing PAEC and add five milliliters of PBS. Then, remove PBS from the T175 flask and replace it with five milliliters of trypsin with 0.05%EDTA. Incubate the cells for three to four minutes at 37 degree celsius.Collect the cells by rinsing the flask with 15 milliliters of cell culture media and transfer the suspension to a 50 milliliter tube. Centrifuge the cells, after centrifugation, remove excess media and re-suspend the pellet in five milliliters of cell culture media. Add 20 milliliters of cell culture media to the cell suspension and re-suspend the cells.Add 20 milliliters of cell culture media without cells into a 500 milliliter magnetic stirrer flask. Add the cells to the washed micro carrier beads and mix the solution carefully with a 25 milliliter serological pipette. Transfer the bead cell mixture into the magnetic spinner flask.Rinse the tube with 10 milliliters of cell culture media to collect the remaining cells. Add an additional 85 milliliters of cell culture media into the spinner flask. Place the flask into the incubator overnight, at 37 degree celsius on a shaker.Add 50 milliliters of cell culture media for a total volume of 200 milliliters. Continue stirring for an additional 24 hours on a shaker. Add colorless rockwell park memorial institute or RPMI media, until 320 milliliters of the total volume is reached.Remove 100 milliliters of the old media and add 100 milliliters of fresh supplemented colorless RPMI, every 48 hours. Culture the cells for five to seven days depending on the confluent state of the cell coated beads. Using a 10 milliliter serological pipette, remove the cell coated beads from the magnetic stirrer flask and transfer them into 12 milliliter round bottom polypropylene tubes.After one to two minutes, when the beads have settled down, remove the excess media. Add more beads to the tubes until each tube contains exactly two millimeters of beads. Next, add five milliliters of clear RPMI to each tube and mix the solution carefully with a 10 milliliter serological pipette.Let the beads settle down and remove excess media. Repeat the washing procedure one more time with RPMI and remove all excess medium. Carefully and slowly draw blood from a healthy volunteer and collect it in a nine milliliter neutral polypropylene tube, with no anticoagulant.Slowly transfer eight milliliters of blood into each of the polypropylene tubes containing two milliliters of cell coated beads, to make a total volume of 10 milliliters. Be sure to carefully handle the blood and the beads to avoid premature EC activation. Carefully tilt the blood bead mixture to ensure equal mixing and seal the cap with paraffin film.Place the tubes on a horizontal tilting table with gentle settings, inside a 37 degree celsius incubator and record the clotting times. At set time intervals, remove at least 1.5 to two milliliters of the blood bead mixture for serum or plasma analysis. For serum collection, leave the blood to coagulate.Finally, centrifuge the tubes at 2, 500 G for 10 minutes at four degree celsius. Store the serum or plasma at 80 degree celsius until use. Microcarrier beads stained for CD31 and nuclei clearly show confluency.Visual observation determined that prolongation of the clotting time could be observed if a monolayer of EC was present on the surface of the microcarrier beads. A significant increase in clotting time was observed when porcine aortic endothelial cells, PAEC GalTKO/hCD46/hTBM were present on microcarrier beads, suggesting a successful modulation of both the complement and coagulation systems. Once mastered, the incubation of endothelial cell coated beads with non-anticoagulated human blood can be done in about six hours.The actual duration of the experiment depends mainly on the clotting time, which is seen in the experiment. While attempting this procedure, it's important to remember to ensure complete coverage of the micro beads with endothelial cells and prevent pre-mature activation of human blood.

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Medicine

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&beta; using a Whole Blood Stimulation Assay

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues as well as altered cytokine homeostasis. The innate immune system plays a crucial role in recognizing pathogens and other endogenous danger stimuli. One of the major cytokines released by innate immune cells is Interleukin (IL)-1. Therefore, we utilize a whole blood stimulation assay in order to measure the secretion of inflammatory cytokines and specifically of the pro-inflammatory cytokine IL-1&beta; 1, 2, 3.
Patients with genetic dysfunctions of the innate immune system causing autoinflammatory syndromes show an exaggerated release of mature IL-1&beta; upon stimulation with LPS alone. In order to evaluate the innate immune component of patients who present with inflammatory-associated pathologies, we use a specific immunoassay to detect cellular immune responses to pathogen-associated molecular patterns (PAMPs), such as the gram-negative bacterial endotoxin, lipopolysaccharide (LPS). These PAMPs are recognized by pathogen recognition receptors (PRRs), which are found on the cells of the innate immune system 4, 5, 6, 7. A primary signal, LPS, in conjunction with a secondary signal, ATP, is necessary for the activation of the inflammasome, a multiprotein complex that processes pro-IL-1&beta; to its mature, bioactive form 4, 5, 6, 8, 9, 10.
The whole blood assay requires minimal sample manipulation to assess cytokine production when compared to other methods that require labor intensive isolation and culturing of specific cell populations. This method differs from other whole blood stimulation assays; rather than diluting samples with a ratio of RPMI media, we perform a white blood cell count directly from diluted whole blood and therefore, stimulate a known number of white blood cells in culture 2. The results of this particular whole blood assay demonstrate a novel technique useful in elucidating patient cohorts presenting with autoinflammatory pathophysiologies.

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&#946; using a Whole Blood Stimulation Assay

We describe a simple immunoassay to measure the production of pro-inflammatory cytokines, such as IL-1 beta production, in patients presenting with autoinflammatory phenotypes. By activating cells in whole blood cultures with pathogen-associated molecular patterns, specifically with lipopolysaccharide, cytokine secretion can be conveniently evaluated in whole blood supernatants.

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues ...

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood

There is the need for a clinical assay to determine the extent to which a patient's blood is effectively anticoagulated by the low-molecular-weight-heparin (LMWH), enoxaparin. There are also urgent clinical situations where it would be important if this could be determined rapidly. The present assay is designed to accomplish this. We only assayed human blood samples that were spiked with known concentrations of enoxaparin. The essential feature of the present assay is the quantification of the efficacy of enoxaparin in a patient's blood sample by degrading it to complete inactivity with heparinase. Two blood samples were drawn into Vacutainer tubes (Becton-Dickenson; Franklin Lakes, NJ) that were spiked with enoxaparin; one sample was digested with heparinase for 5 min at 37 &deg;C, the other sample represented the patient's baseline anticoagulated status. The percent shortening of clotting time in the heparinase-treated sample, as compared to the baseline state, yielded the anticoagulant contribution of enoxaparin. We used the portable, battery operated Hemochron 801 apparatus for measurements of clotting times (International Technidyne Corp., Edison, NJ). The apparatus has 2 thermostatically controlled (37 &deg;C) assay tube wells. We conducted the assays in two types of assay cartridges that are available from the manufacturer of the instrument. One cartridge was modified to increase its sensitivity. We removed the kaolin from the FTK-ACT cartridge by extensive rinsing with distilled water, leaving only the glass surface of the tube, and perhaps the detection magnet, as activators. We called this our minimally activated assay (MAA). The use of a minimally activated assay has been studied by us and others. 2-4 The second cartridge that was studied was an activated partial thromboplastin time (aPTT) assay (A104). This was used as supplied from the manufacturer. The thermostated wells of the instrument were used for both the heparinase digestion and coagulation assays. The assay can be completed within 10 min. The MAA assay showed robust changes in clotting time after heparinase digestion of enoxaparin over a typical clinical concentration range. At 0.2 anti-Xa I.U. of enoxaparin per ml of blood sample, heparinase digestion caused an average decrease of 9.8% (20.4 sec) in clotting time; at 1.0 I.U. per ml of enoxaparin there was a 41.4% decrease (148.8 sec). This report only presents the experimental application of the assay; its value in a clinical setting must still be established.

Demonstration of a rapid quantitative assay of the inhibition of blood coagulation by the low-molecular-weight-heparin, enoxaparin. The contribution of enoxaparin is assessed by removing its influence through digestion with heparinase. A fuller description of the assay is detailed in our published paper.1 The assay still requires clinical confirmation.

There is the need for a clinical assay to determine the extent to which a patient's blood is effectively anticoagulated by the ...

Isolation, Characterization and Comparative Differentiation of Human Dental Pulp Stem Cells Derived from Permanent Teeth by Using Two Different Methods

Developing wisdom teeth are easy-accessible source of stem cells during the adulthood which could be obtained by routine orthodontic treatments. Human pulp-derived stem cells (hDPSCs) possess high proliferation potential with multi-lineage differentiation capacity compare to the ordinary source of adult stem cells1-8; therefore, hDPSCs could be the good candidates for autologous transplantation in tissue engineering and regenerative medicine. Along with these benefits, possessing the mesenchymal stem cells (MSC) features, such as immunolodulatory effect, make hDPSCs more valuable, even in the case of allograft transplantation6,9,10. Therefore, the primary step for using this source of stem cells is to select the best protocol for isolating hDPSCs from pulp tissue. In order to achieve this goal, it is crucial to investigate the effect of various isolation conditions on different cellular behaviors, such as their common surface markers &amp; also their differentiation capacity.
Thus, here we separate human pulp tissue from impacted third molar teeth, and then used both existing protocols based on literature, for isolating hDPSCs,11-13 i.e. enzymatic dissociation of pulp tissue (DPSC-ED) or outgrowth from tissue explants (DPSC-OG). In this regards, we tried to facilitate the isolation methods by using dental diamond disk. Then, these cells characterized in terms of stromal-associated Markers (CD73, CD90, CD105 &amp; CD44), hematopoietic/endothelial Markers (CD34, CD45 &amp; CD11b), perivascular marker, like CD146 and also STRO-1. Afterwards, these two protocols were compared based on the differentiation potency into odontoblasts by both quantitative polymerase chain reaction (QPCR) &amp; Alizarin Red Staining. QPCR were used for the assessment of the expression of the mineralization-related genes (alkaline phosphatase; ALP, matrix extracellular phosphoglycoprotein; MEPE &amp; dentin sialophosphoprotein; DSPP).14

The method described isolation and characterization of human Dental Pulp Stem Cells (hDPSCs) by using either enzymatic dissociation of pulp (DPSC-ED) or direct outgrowth of stem cells from pulp tissue explants (DPSC-OG). Then followed by in vitro comparative differentiation of both types of hDPSCs into odontoblasts.

Developing wisdom teeth are easy-accessible source of stem cells during the adulthood which could be obtained by routine orthodontic treatments. Human ...

Non-invasive Assessment of Microvascular and Endothelial Function

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of cardiovascular disease. Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. Percent capillary recruitment is assessed by dividing the increase in capillary density induced by postocclusive reactive hyperemia (postocclusive reactive hyperemia capillary density minus baseline capillary density), by the maximal capillary density (observed during passive venous occlusion). Percent perfused capillaries represents the proportion of all capillaries present that are perfused (functionally active), and is calculated by dividing postocclusive reactive hyperemia capillary density by the maximal capillary density. Both percent capillary recruitment and percent perfused capillaries reflect the number of functional capillaries. The forearm blood flow (FBF) technique provides accepted non-invasive measures of endothelial function: The ratio FBFmax/FBFbase is computed as an estimate of vasodilation, by dividing the mean of the four FBFmax values by the mean of the four FBFbase values. Forearm vascular resistance at maximal vasodilation (FVRmax) is calculated as the mean arterial pressure (MAP) divided by FBFmax. Both the capillaroscopy and forearm techniques are readily acceptable to patients and can be learned quickly.
The microvascular and endothelial function measures obtained using the methodologies described in this paper may have future utility in clinical patient cardiovascular risk-reduction strategies. As we have published reports demonstrating that microvascular and endothelial dysfunction are found in initial stages of hypertension including prehypertension, microvascular and endothelial function measures may eventually aid in early identification, risk-stratification and prevention of end-stage vascular pathology, with its potentially fatal consequences.

Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. The forearm blood flow technique provides accepted non-invasive measures of endothelial function.

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of ...

Evaluation of Stem Cell Properties in Human Ovarian Carcinoma Cells Using Multi and Single Cell-based Spheres Assays

Years of research indicates that ovarian cancers harbor a heterogeneous mixture of cells including a subpopulation of so-called &#8220;cancer stem cells&#8221; (CSCs) responsible for tumor initiation, maintenance and relapse following conventional chemotherapies. Identification of ovarian CSCs is therefore an important goal. A commonly used method to assess CSC potential in vitro is the spheres assay in which cells are plated under non-adherent culture conditions in serum-free medium supplemented with growth factors and sphere formation is scored after a few days. Here, we review currently available protocols for human ovarian cancer spheres assays and perform a side-by-side analysis between commonly used multi cell-based assays and a more accurate system based on single cell plating. Our results indicate that both multi cell-based as well as single cell-based spheres assays can be used to investigate sphere formation in vitro. The more laborious and expensive single cell-based assays are more suitable for functional assessment of individual cells and lead to overall more accurate results while multi cell-based assays can be strongly influenced by the density of plated cells and require titration experiments upfront. Methylcellulose supplementation to multi cell-based assays can be effectively used to reduce mechanical artifacts.

In vitro spheres assays are commonly used to identify cancer stem cells. Here we compare single with multi cell-based spheres assays. The more laborious single cell-based assays or methylcellulose supplementation give more accurate results while multi cell-based assays performed in liquid medium can be highly influenced by cell density.

Years of research indicates that ovarian cancers harbor a heterogeneous mixture of cells including a subpopulation of so-called &#8220;cancer stem ...

Isolation of Human Lymphatic Endothelial Cells by Multi-parameter Fluorescence-activated Cell Sorting

Lymphatic system disorders such as primary lymphedema, lymphatic malformations and lymphatic tumors are rare conditions that cause significant morbidity but little is known about their biology. Isolating highly pure human lymphatic endothelial cells (LECs) from diseased and healthy tissue would facilitate studies of the lymphatic endothelium at genetic, molecular and cellular levels. It is anticipated that these investigations may reveal targets for new therapies that may change the clinical management of these conditions. A protocol describing the isolation of human foreskin LECs and lymphatic malformation lymphatic endothelial cells (LM LECs) is presented. To obtain a single cell suspension tissue was minced and enzymatically treated using dispase II and collagenase II. The resulting single cell suspension was then labelled with antibodies to cluster of differentiation (CD) markers CD34, CD31, Vascular Endothelial Growth Factor-3 (VEGFR-3) and PODOPLANIN. Stained viable cells were sorted on a fluorescently activated cell sorter (FACS) to separate the CD34LowCD31PosVEGFR-3PosPODOPLANINPos LM LEC population from other endothelial and non-endothelial cells. The sorted LM LECs were cultured and expanded on fibronectin-coated flasks for further experimental use.

The goal of this protocol is to isolate lymphatic endothelial cells lining human lymphatic malformation cyst-like vessels and foreskins using fluorescence-activated cell sorting (FACS). Subsequent cell culturing and expansion of these cells permits a new level of experimental sophistication for genetic, proteomic, functional and cell differentiation studies.

Lymphatic system disorders such as primary lymphedema, lymphatic malformations and lymphatic tumors are rare conditions that cause significant morbidity ...

Isolation and Culture Expansion of Tumor-specific Endothelial Cells

Freshly isolated tumor-specific endothelial cells (TEC) can be used to explore molecular mechanisms of tumor angiogenesis and serve as an in vitro model for developing new angiogenesis inhibitors for cancer. However, long-term in vitro expansion of murine endothelial cells (EC) is challenging due to phenotypic drift in culture (endothelial-to-mesenchymal transition) and contamination with non-EC. This is especially true for TEC which are readily outcompeted by co-purified fibroblasts or tumor cells in culture. Here, a high fidelity isolation method that takes advantage of immunomagnetic enrichment coupled with colony selection and in vitro expansion is described. This approach generates pure EC fractions that are entirely free of contaminating stromal or tumor cells. It is also shown that lineage-traced Cdh5cre:ZsGreenl/s/l reporter mice, used with the protocol described herein, are a valuable tool to verify cell purity as the isolated EC colonies from these mice show durable and brilliant ZsGreen fluorescence in culture.

We report a reliable method to isolate and culture primary tumor-specific endothelial cells from genetically engineered mouse models.

Freshly isolated tumor-specific endothelial cells (TEC) can be used to explore molecular mechanisms of tumor angiogenesis and serve as an in vitro model ...

Imaging- and Flow Cytometry-based Analysis of Cell Position and the Cell Cycle in 3D Melanoma Spheroids

Three-dimensional (3D) tumor spheroids are utilized in cancer research as a more accurate model of the in vivo tumor microenvironment, compared to traditional two-dimensional (2D) cell culture. The spheroid model is able to mimic the effects of cell-cell interaction, hypoxia and nutrient deprivation, and drug penetration. One characteristic of this model is the development of a necrotic core, surrounded by a ring of G1 arrested cells, with proliferating cells on the outer layers of the spheroid. Of interest in the cancer field is how different regions of the spheroid respond to drug therapies as well as genetic or environmental manipulation. We describe here the use of the fluorescence ubiquitination cell cycle indicator (FUCCI) system along with cytometry and image analysis using commercial software to characterize the cell cycle status of cells with respect to their position inside melanoma spheroids. These methods may be used to track changes in cell cycle status, gene/protein expression or cell viability in different sub-regions of tumor spheroids over time and under different conditions.

We describe two complementary methods using the fluorescence ubiquitination cell cycle indicator (FUCCI) and image analysis or flow cytometry to identify and isolate cells in the inner G1 arrested and outer proliferating regions of 3D spheroids.

Three-dimensional (3D) tumor spheroids are utilized in cancer research as a more accurate model of the in vivo tumor microenvironment, compared to ...

Ultrasound Assessment of Endothelial Function: A Technical Guideline of the Flow-mediated Dilation Test

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a pathological condition characterized mainly by a disruption in the balance between vasodilator and vasoconstrictor substances and is proposed to play an important role in the development of atherosclerotic cardiovascular disease. Therefore, a precise evaluation of endothelial function in humans represents an important tool that could help better understand the etiology of multiple cardio-centric pathologies.
Over the past twenty-five years, many methodological approaches have been developed to provide an assessment of endothelial function in humans. Introduced in 1989, the FMD test incorporates a forearm occlusion and subsequent reactive hyperemia that promotes nitric oxide production and vasodilation of the brachial artery. The FMD test is now the most widely utilized, non-invasive, ultrasonic assessment of endothelial function in humans and has been associated with future cardiovascular events.
Although the FMD test could have clinical utility, it is a physiological assessment that has inherited several confounding factors that need to be considered. This article describes a standardized protocol for determining FMD including the recommended methodology to help minimize the physiological and technical issues and improve the precision and reproducibility of the assessment.

The flow mediated dilation (FMD) test is the most commonly utilized, non-invasive, ultrasound assessment of endothelial function in humans. Although the FMD test has been related with the prediction of future cardiovascular disease and events, it is a physiological assessment with many inherent confounding factors that need to be considered.

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a ...

Isolation and Culture of Primary Endothelial Cells from Canine Arteries and Veins

Cardiovascular disease is studied in both human and veterinary medicine. Endothelial cells have been used extensively as an in vitro model to study vasculogenesis, (tumor) angiogenesis, and atherosclerosis. The current standard for in vitro research on human endothelial cells (ECs) is the use of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Umbilical Artery Endothelial Cells (HUAECs). For canine endothelial research, only one cell line (CnAOEC) is available, which is derived from canine aortic endothelium. Although currently not completely understood, there is a difference between ECs originating from either arteries or veins. For a more direct approach to in vitro functionality studies on ECs, we describe a new method for isolating Canine Primary Endothelial Cells (CaPECs) from a variety of vessels. This technique reduces the chance of contamination with fast-growing cells such as fibroblasts and smooth muscle cells, a problem that is common in standard isolation methods such as flushing the vessel with enzymatic solutions or mincing the vessel prior to digestion of the tissue containing all cells. The technique we describe was optimized for the canine model, but can easily be utilized in other species such as human.

Novel isolation methods of primary endothelial cells from blood vessels are needed. This protocol describes a new technique that completely inverts blood vessels of interest, exposing only the endothelial side to enzymatic digestion. The resulting pure endothelial cell culture can be used to study cardiovascular diseases, disease modelling, and angiogenesis.

Cardiovascular disease is studied in both human and veterinary medicine. Endothelial cells have been used extensively as an in vitro model to study ...