Name: barrier functional integrity recording on bend.3 vascular endothelial cells via transendothelial electrical resistance detection
Uploaded: 2023-09-29T13:40:00.000+00:00
Duration: 9 min 3 s
Description: Watch this Scientific Journal Video about Applications of TEER Detection to Assess Cell Barrier Integrity at JoVE.com

We appreciate the financial support from the National Natural Science Foundation of China (82274207 and 82104533), the Key Research and Development Program of Ningxia (2023BEG02012), and Xinglin Scholar Research Promotion Project of Chengdu University of TCM (XKTD2022013).

NOTE: Mouse brain-derived Endothelial cells.3 (bEnd.3) were inoculated into the chambers of a 24-well plate to construct a simple in vitro model of BBB under specific medium conditions. The TEER of normal cells and hypoxic cells were measured by TEER meter (Figure 1 and Figure 2).
1. Solution preparation
<ol>
	<li>Prepare the DMEM cell culture medium containing FBS (10%, v/v), 100 U/mL penicillin, and 10 mg/mL streptomycin (see Table of Materials).</li>
	<li>Prepare 100 mM CoCl2 stock solution by adding 1.30 mg CoCl2 to 100 &#181;L DMSO solution. 
	NOTE: All the above solutions were stored at 4 &#176;C condition, and the stock solution was diluted according to the desired concentration before use.</li>
	<li>Prepare 5% sodium hypochlorite solution (v/v) by adding 2 mL of sodium hypochlorite solution to 38 mL of double distilled water.</li>
</ol>
2. Cell culture and cell viability
<ol>
	<li>Seed 1 mL of bEnd.3 cells in culture dish (100 mm) containing DMEM medium at a density of 1 x 106 cells/mL and culture at 37 &#176;C in a humidified atmosphere of 5% CO2. Change the medium every 2 to 3 days and subculture the cells 2x a week.</li>
	<li>After bEnd.3 cells grow to 80 % confluence, digest the cells with 0.25% trypsin for 30 s.</li>
	<li>Make a suspension of bEnd.3 cells at density of 7 x 104 cells/mL using DMEM medium through a cell counter. Then, seed 100 &#181;L of bEnd.3 cell suspension in a 96-well plate.</li>
	<li>After cell adhesion, clean the cells with PBS and culture the cells with 100 &#181;L of culture medium or drug-containing medium (100 &#181;M, 200 &#181;M, 300 &#181;M, 400 &#181;M, 500 &#181;M CoCl2) for 24 h under the same conditions. After removing the medium inside the well plate and cleaning it with PBS, add 100 &#181;L of CCK-8 solution. 
	NOTE: Do not generate bubbles in the well, which will affect the values of optical density (OD).</li>
	<li>Put 96-well plates at 37 &#176;C environment and incubate for 1 h. Measure the absorbance of the 96-well plates at 450 nm using a microplate reader. 
	NOTE: To avoid intra-group differences, the well plates were cooled to room temperature before detection.</li>
	<li>Calculate the cell viability induced by different concentrations of CoCl2 according to the formula [ODDrug - ODBlank] / [ODControl-ODBlank] x 100%. Select the CoCl2 concentration with a significant difference in cell viability reduction compared with the control group for the next experiment.</li>
</ol>
3. Model assembly
<ol>
	<li>Rinse the upper chamber of the 24-well plates with PBS. 
	NOTE: Cells grew and fused at the bottom of the upper chamber of the 24-well plate, and tight junctions between cells gradually formed to play a barrier role. If the endothelial cells used in some studies are not able to form a complete barrier on PET membranes independently, coating the membranes with collagen IV solution is required prior to cell inoculation.</li>
	<li>Mix the bEnd.3 cells with DMEM medium to make a suspension at a density of 5 x 105 cells/mL using a vortex mixer. Then, seed 200 &#181;L of bEnd.3 cell suspension on the PET membrane in the upper chamber of a 24-well plate (0.33 cm2, 0.4 &#181;m membrane pore size). 
	NOTE: The pilot study of this protocol found no difference in results when using 5 to 10 passages of bEnd.3 cells for experiments. To ensure the probability of successful modeling, please refer to the cell number interval of this protocol.</li>
	<li>Add 1200 &#181;L of complete medium to the lower chamber of the plate to ensure that the osmotic pressure of the upper and lower chambers tends to stabilize. There are differences in the volume of medium added depending on the type; ensure that the liquid level of the upper and lower chambers is flush.</li>
	<li>Change the medium of the upper chamber and the lower chamber at a fixed time every day and monitor the resistance value at the same time.
	<ol>
		<li>When changing the medium, the integrity of the cell layer will be damaged by artificial touch or excessive movement. To avoid the above situation, slowly remove the old medium from one side with a negative pressure pipette and slowly add a new medium along the wall during fluid exchange.</li>
	</ol>
	</li>
</ol>
4. Measurement of TEER
<ol>
	<li>Before work begins, place the resistor, 5% sodium hypochlorite solution, 75% ethanol, and double distilled water solution in an ultra-clean table. Turn on the UV irradiation for 30 min to eliminate residual bacteria and pathogens.</li>
	<li>Place the electrodes in 5% sodium hypochlorite solution with slow shaking for 3 s to 5 s, and then immerse in 75% ethanol for 15 min. Finally, transfer to PBS or double distilled water solution until use.</li>
	<li>Turn ON the switch on the back of the cell resistor meter, click Select Plate according to the parameters in Table 1, and select 24-Well Plate.</li>
	<li>According to the operation needs, select the appropriate detection sequence. We selected A1 procedure in this study.</li>
	<li>Insert a k&#937; resistor into the right plug to calibrate the instrument. If the calibration result is 1000 &#177; 5 &#937;, consider the accuracy of the instrument to be normal.
	<ol>
		<li>If the calibration result is not 1000 &#937;, click on Mode Units on the main interface to select OHMS, and then click Calibrate on the main screen to re-calibrate the instrument.</li>
	</ol>
	</li>
	<li>Pull out the k&#937; resistor on the right side and replace the measuring electrode with a connecting wire.</li>
	<li>Place the electrode into the 24-well plate without seeding cells vertically and click Blank Handling on the main screen of the instrument. The background value of the plate resistance without seeded cells is about 134.4 &#937;.</li>
	<li>Insert the two electrodes into the upper and lower chambers of the seeded plate with cells so that the cell layer is between them, and then record the resistance value by gently stepping on the Pedal.
	<ol>
		<li>Make sure that the electrode does not touch the cells in the upper chamber and the bottom of the lower chamber. The soaking time of the electrode in the solution has no effect on the resistance value, and it is only necessary to make sure that the electrode is in the correct position.</li>
	</ol>
	</li>
	<li>Obtain TEER values (&#937;cm2) by multiplying electrical resistance values (ohms) with the bottom area (cm2) of the upper chamber, as in the equation: 
	TEER (&#937;cm2) = Resistance (&#937;) x Sinsert (cm2)</li>
	<li>Draw a line plot of TEER-Time (in days). When the resistance value does not increase further with time (measured over days), consider the cell formed a barrier. 
	NOTW: The monolayer BBB model of bEnd.3 cells will be successfully constructed by culturing bEND.3 cells with the parameters in this study for about 6 days. The TEER of bEnd.3 cell monolayer model ranged from 16.49 &#177; 2.12 &#937;cm2 to 27.59 &#177; 1.50 &#937;cm2 within 6 days (n=8, mean &#177; SD).</li>
</ol>
5. Barrier destruction and statistical analysis
<ol>
	<li>According to the TEER - time curve, select the wells with barrier function and divide them into the control group and CoCl2 group (n = 4).</li>
	<li>Add the culture medium and culture medium containing 300 &#181;M CoCl2 (200 &#181;L) into the control group and CoCl2 group upper chamber, respectively.</li>
	<li>Detect the resistance values of the control and CoCl2 groups at 12 h and 24 h of incubation at 37 &#176;C using the procedure described in step 4.</li>
	<li>Use commercial software to map the trend of TEER values of the barrier of cells cultured with or without 300 &#181;M CoCl2.</li>
	<li>Use statistical analysis software to analyze the difference in resistance values between CoCl2-treated cells and normal cells (n=4, *p&#60;0.05, **p&#60;0.01, ***p&#60;0.001).</li>
</ol>

Transendothelial Resistance Measurement to Assess Cell Barrier Integrity

<ol>
	<li>Kim, 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=CLEC14A+deficiency+exacerbates+neuronal+loss+by+increasing+blood-brain+barrier+permeability+and+inflammation.">CLEC14A deficiency exacerbates neuronal loss by increasing blood-brain barrier permeability and inflammation.</a> J Neuroinflammation. 17 (1), 48 (2020).</li><li>Bagchi, S., 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=In-vitro+blood-brain+barrier+models+for+drug+screening+and+permeation+studies:+an+overview.">In-vitro blood-brain barrier models for drug screening and permeation studies: an overview.</a> Drug Des Devel Ther. 13, 3591-3605 (2019).</li><li>Daneman, R., Prat, 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+blood-brain+barrier.">The blood-brain barrier.</a> Cold Spring Harb perspect Biol. 7 (1), 020412 (2015).</li><li>Profaci, C. P., Munji, R. N., Pulido, R. S., Daneman, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+blood-brain+barrier+in+health+and+disease:+Important+unanswered+questions.">The blood-brain barrier in health and disease: Important unanswered questions.</a> J Exp Med. 217 (4), 20190062 (2020).</li><li>Pardridge, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+delivery.">Blood-brain barrier delivery.</a> Drug Discov Today. 12 (1-2), 54-56 (2007).</li><li>Eigenmann, D. E., 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=Comparative+study+of+four+immortalized+human+brain+capillary+endothelial+cell+lines,+hCMEC/D3,+hBMEC,+TY10,+and+BB19,+and+optimization+of+culture+conditions,+for+an+in+vitro+blood-brain+barrier+model+for+drug+permeability+studies.">Comparative study of four immortalized human brain capillary endothelial cell lines, hCMEC/D3, hBMEC, TY10, and BB19, and optimization of culture conditions, for an in vitro blood-brain barrier model for drug permeability studies.</a> Fluids Barriers CNS. 10 (1), 33 (2013).</li><li>Gajd&#225;cs, 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+concept+of+an+ideal+antibiotic:+Implications+for+drug+design.">The concept of an ideal antibiotic: Implications for drug design.</a> Molecule. 24 (5), 892 (2019).</li><li>Stanimirovic, D. B., Bani-Yaghoub, M., Perkins, M., Haqqani, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+models:+in+vitro+to+in+vivo+translation+in+preclinical+development+of+CNS-targeting+biotherapeutics.">Blood-brain barrier models: in vitro to in vivo translation in preclinical development of CNS-targeting biotherapeutics.</a> Expert Opin Drug Discov. 10 (2), 141-155 (2015).</li><li>Helms, H. C., 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=In+vitro+models+of+the+blood-brain+barrier:+An+overview+of+commonly+used+brain+endothelial+cell+culture+models+and+guidelines+for+their+use.">In vitro models of the blood-brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use.</a> J Cereb Blood Flow Metab. 36 (5), 862-890 (2016).</li><li>&#214;zyurt, M. G., Bayir, E., Do&#286;an, &. #. 3. 5. 0. ;., &#214;zt&#220;rk, &. #. 3. 5. 0. ;., &#350;endem&#304;r, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coculture+model+of+blood-brain+barrier+on+electrospun+nanofibers.">Coculture model of blood-brain barrier on electrospun nanofibers.</a> Turk J Biol. 44 (4), 121-132 (2020).</li><li>Kim, W., 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=Functional+validation+of+the+simplified+in+vitro+3D+Co-culture+based+BBB+model.">Functional validation of the simplified in vitro 3D Co-culture based BBB model.</a> Biochem Biophys Res Commun. 625, 128-133 (2022).</li><li>Aazmi, 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=Vascularizing+the+brain+in+vitro.">Vascularizing the brain in vitro.</a> iScience. 25 (4), 104110 (2022).</li><li>Burkhart, 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=Transfection+of+brain+capillary+endothelial+cells+in+primary+culture+with+defined+blood-brain+barrier+properties.">Transfection of brain capillary endothelial cells in primary culture with defined blood-brain barrier properties.</a> Fluids Barriers CNS. 12, 19 (2015).</li><li>Campisi, M., 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=3D+self-organized+microvascular+model+of+the+human+blood-brain+barrier+with+endothelial+cells,+pericytes+and+astrocytes.">3D self-organized microvascular model of the human blood-brain barrier with endothelial cells, pericytes and astrocytes.</a> Biomaterials. 180, 117-129 (2018).</li><li>Peng, 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=Neuroinflammatory+in+vitro+cell+culture+models+and+the+potential+applications+for+neurological+disorders.">Neuroinflammatory in vitro cell culture models and the potential applications for neurological disorders.</a> Front Pharmacol. 12, 671734 (2021).</li><li>Secker, P. F., Schlichenmaier, N., Beilmann, M., Deschl, U., Dietrich, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+transepithelial+transport+measurements+to+detect+nephrotoxicity+in+vitro+using+the+RPTEC/TERT1+cell+line.">Functional transepithelial transport measurements to detect nephrotoxicity in vitro using the RPTEC/TERT1 cell line.</a> Arch Toxicol. 93 (7), 1965-1978 (2019).</li><li>Nazari, H., 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=Advances+in+TEER+measurements+of+biological+barriers+in+microphysiological+systems.">Advances in TEER measurements of biological barriers in microphysiological systems.</a> Biosens Bioelectron. 234, 115355 (2023).</li><li>Nicolas, 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=High+throughput+transepithelial+electrical+resistance+(TEER)+measurements+on+perfused+membrane-free+epithelia.">High throughput transepithelial electrical resistance (TEER) measurements on perfused membrane-free epithelia.</a> Lab Chip. 21 (9), 1676-1685 (2021).</li><li>Yang, Z., 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=Autophagy+alleviates+hypoxia-induced+blood-brain+barrier+injury+via+regulation+of+CLDN5+(claudin+5).">Autophagy alleviates hypoxia-induced blood-brain barrier injury via regulation of CLDN5 (claudin 5).</a> Autophagy. 17 (10), 3048-3067 (2021).</li><li>Feng, S., 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=RhoA/ROCK-2+pathway+inhibition+and+tight+junction+protein+upregulation+by+catalpol+suppresses+lipopolysaccaride-induced+disruption+of+blood-brain+barrier+permeability.">RhoA/ROCK-2 pathway inhibition and tight junction protein upregulation by catalpol suppresses lipopolysaccaride-induced disruption of blood-brain barrier permeability.</a> Molecules. 23 (9), (2018).</li><li>Sulhan, S., Lyon, K. A., Shapiro, L. A., Huang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroinflammation+and+blood-brain+barrier+disruption+following+traumatic+brain+injury:+Pathophysiology+and+potential+therapeutic+targets.">Neuroinflammation and blood-brain barrier disruption following traumatic brain injury: Pathophysiology and potential therapeutic targets.</a> J Neurosci Res. 98 (1), 19-28 (2020).</li><li>Liu, B., 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=Notoginsenoside+R1+intervenes+degradation+and+redistribution+of+tight+junctions+to+ameliorate+blood-brain+barrier+permeability+by+Caveolin-1/MMP2/9+pathway+after+acute+ischemic+stroke.">Notoginsenoside R1 intervenes degradation and redistribution of tight junctions to ameliorate blood-brain barrier permeability by Caveolin-1/MMP2/9 pathway after acute ischemic stroke.</a> Phytomedicine. 90, 153660 (2021).</li><li>Hou, 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=Salidroside+intensifies+mitochondrial+function+of+CoCl2-damaged+HT22+cells+by+stimulating+PI3K-AKT-MAPK+signaling+pathway.">Salidroside intensifies mitochondrial function of CoCl2-damaged HT22 cells by stimulating PI3K-AKT-MAPK signaling pathway.</a> Phytomedicine. 109, 154568 (2023).</li><li>Mu&#241;oz-S&#225;nchez, J., Ch&#225;nez-C&#225;rdenas, M. E. <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+cobalt+chloride+as+a+chemical+hypoxia+model.">The use of cobalt chloride as a chemical hypoxia model.</a> J Appl Toxicol. 39 (4), 556-570 (2019).</li><li>Jiang, S., 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=Salidroside+attenuates+high+altitude+hypobaric+hypoxia-induced+brain+injury+in+mice+via+inhibiting+NF-&#954;B/NLRP3+pathway.">Salidroside attenuates high altitude hypobaric hypoxia-induced brain injury in mice via inhibiting NF-&#954;B/NLRP3 pathway.</a> Eur J Pharmacol. 925, 175015 (2022).</li><li>Xie, N., 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=Rhodiola+crenulate+alleviates+hypobaric+hypoxia-induced+brain+injury+via+adjusting+NF-&#954;B/NLRP3-mediated+inflammation.">Rhodiola crenulate alleviates hypobaric hypoxia-induced brain injury via adjusting NF-&#954;B/NLRP3-mediated inflammation.</a> Phytomedicine. 103, 154240 (2022).</li><li>Thiebaut de Schotten, M., Forkel, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+emergent+properties+of+the+connected+brain.">The emergent properties of the connected brain.</a> Science. 378 (6619), 505-510 (2022).</li><li>Tu, W. J., 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=Estimated+burden+of+stroke+in+China+in+2020.">Estimated burden of stroke in China in 2020.</a> JAMA Netw Open. 6 (3), 231455 (2023).</li><li>Alzheimers Dement. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alzheimer's+disease+facts+and+figures.">Alzheimer's disease facts and figures.</a> Alzheimers Dement. 17 (3), 327-406 (2021).</li><li>Wang, R., 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=Neutrophil+extracellular+traps+promote+tPA-induced+brain+hemorrhage+via+cGAS+in+mice+with+stroke.">Neutrophil extracellular traps promote tPA-induced brain hemorrhage via cGAS in mice with stroke.</a> Blood. 138 (1), 91-103 (2021).</li><li>Liu, X. X., 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=Endothelial+Cdk5+deficit+leads+to+the+development+of+spontaneous+epilepsy+through+CXCL1/CXCR2-mediated+reactive+astrogliosis.">Endothelial Cdk5 deficit leads to the development of spontaneous epilepsy through CXCL1/CXCR2-mediated reactive astrogliosis.</a> J Exp Med. 217 (1), 20180992 (2020).</li><li>Chen, X., 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=Modeling+Sporadic+Alzheimer's+Disease+in+Human+Brain+Organoids+under+Serum+Exposure.">Modeling Sporadic Alzheimer's Disease in Human Brain Organoids under Serum Exposure.</a> Adv Sci (Weinh). 8 (18), 2101462 (2021).</li><li>Qi, D., Lin, H., Hu, B., Wei, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+in+vitro+model+of+the+blood-brain+barrier+(BBB)+based+on+hCMEC/D3+cells.">A review on in vitro model of the blood-brain barrier (BBB) based on hCMEC/D3 cells.</a> J Control Release. 358, 78-97 (2023).</li><li>Artus, C., 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+Wnt/planar+cell+polarity+signaling+pathway+contributes+to+the+integrity+of+tight+junctions+in+brain+endothelial+cells.">The Wnt/planar cell polarity signaling pathway contributes to the integrity of tight junctions in brain endothelial cells.</a> J Cereb Blood Flow Metab. 34 (3), 433-440 (2014).</li><li>Sivandzade, F., Cucullo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-vitro+blood-brain+barrier+modeling:+A+review+of+modern+and+fast-advancing+technologies.">In-vitro blood-brain barrier modeling: A review of modern and fast-advancing technologies.</a> J Cereb Blood Flow Metab. 38 (10), 1667-1681 (2018).</li><li>Galla, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monocultures+of+primary+porcine+brain+capillary+endothelial+cells:+Still+a+functional+in+vitro+model+for+the+blood-brain-barrier.">Monocultures of primary porcine brain capillary endothelial cells: Still a functional in vitro model for the blood-brain-barrier.</a> J Control Release. 285, 172-177 (2018).</li><li>Srinivasan, B., Kolli, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transepithelial/transendothelial+electrical+resistance+(TEER)+to+measure+the+integrity+of+blood-brain+barrier.">Transepithelial/transendothelial electrical resistance (TEER) to measure the integrity of blood-brain barrier.</a> Blood-Brain Barrier. 142, 99-114 (2019).</li><li>Liang, Y., Yoon, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+sensors+for+blood-brain+barrier+(BBB)+on+a+chip.">In situ sensors for blood-brain barrier (BBB) on a chip.</a> Sens Actuators Rep. 3, 100031 (2021).</li><li>Ozg&#252;r, B., Helms, H. C. C., Tornabene, E., Brodin, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+increases+expression+of+selected+blood-brain+barrier+transporters+GLUT-1,+P-gp,+SLC7A5+and+TFRC,+while+maintaining+barrier+integrity,+in+brain+capillary+endothelial+monolayers.">Hypoxia increases expression of selected blood-brain barrier transporters GLUT-1, P-gp, SLC7A5 and TFRC, while maintaining barrier integrity, in brain capillary endothelial monolayers.</a> Fluids Barriers CNS. 19 (1), (2022).</li></ol>

The authors have nothing to disclose.

One of the most developed bodily organs, the brain controls a wide range of intricate physiological processes, including memory, cognition, hearing, smell, and movement27. The brain is one of the human body&#39;s most complicated and diseased organs at the same time. The occurrence of many central nervous system disorders shows a growing tendency year over year due to factors including air pollution, irregular eating patterns, and other factors27,<sup class="xref...

BBB is a unique biological interface between blood circulation and nerve tissue, which is composed of vascular endothelial cells, pericytes, astrocytes, neurons, and other cellular structures1. The flow of ions, chemicals, and cells between the blood and the brain is strictly regulated by this barrier. This homeostasis safeguards the nervous tissues against toxins and pathogens while also enabling the appropriate operation of the brain&#39;s nerves2,3. Maintaining the integrity of the BBB can effectively prevent the development and progression of disorders affecting the central nervous system, such as neuronal dysfunction, edema, and neuroinflammation4. However, the unique physiological properties of the BBB prevent more than 98% of small molecule medications and 100% of macromolecular pharmaceuticals from entering the central nervous system5. Therefore, increasing the penetration of medications through the BBB during the development of drugs for the central nervous system is essential for achieving therapeutic efficacy6,7. Even though computer simulation screening of substrates has significantly raised the probability of drug candidates crossing the BBB, reliable and affordable in vitro/in vivo BBB models are still needed to meet the needs of scientific research8.
A quick and affordable technique for high-throughput drug screening is the in vitro model9. To shed light on the fundamental processes of medicines&#39; effects on BBB function and their part in the development and progression of disease, a series of simplified in vitro BBB models has been created. At present, the common in vitro BBB models are the monolayer, co-culture, dynamic, and microfluidic models10,11,12, constructed by vascular endothelial cells and astrocytes, pericytes, or microglia13,14. Although 3D cell cultures are morein line with the physiological structure of BBB15, their application as a means of drug screening for BBB is still constrained by their intricate design and subpar reproducibility. In contrast, the monolayer in vitro model is the one most frequently used to research the BBB and is applicable for determining the expression of membrane transporters and tight junction proteins in particular cells.
Transmembrane electrical resistance (TEER) measurement is a technique to evaluate and monitor the layer of cells across the resistance and evaluate the cell integrity and permeability of the barrier. By simultaneously inserting two electrodes into the growth medium or buffer solution on either side of the monolayer, it is possible to measure the alternating current or electrical impedance through the cell&#39;s compact layer16,17. In order to determine whether the in vitro BBB model has been properly created, the measurement of TEER will usually be employed as the gold standard18. On the other hand, the trend of medication action on BBB permeability can be accurately predicted by measuring the change in electrical resistance of the cell layer after drug involvement19. For example, Feng et al. discovered that catalpol (the primary active monomer of rehmanniae) could effectively reverse the lipopolysaccharide-induced down-regulation of tight junction proteins in the BBB and raise the TEER value of the mouse brain endothelial cell layer20.
The neuroinflammatory response is usually the main cause of BBB homeostasis imbalance21. Hypoxic treatment to induce neuroinflammatory injury is the main method to destroy the blood-brain barrier, mainly including physical methods and chemical reagent methods. The former primarily utilizes a three-gas incubator to vary the oxygen content in the cell growth environment to simulate hypoxic conditions22,while the latter is achieved by artificially introducing deoxy reagents such as CoCl2 to the cell culture medium23. The cells will remain in a deoxygenated condition if Fe2+ is substituted for Co2+ in the heme. If Fe2+ is substituted for Co2+ in the catalytic group, proline hydroxylase and aspartate hydroxylase activity will be inhibited, resulting in an accumulation of hypoxia-inducible factor-1&#945; (HIF-1&#945;)24. Under persistent hypoxia, the dephosphorylation of HIF-1&#945; in the cytoplasm triggers cell death and activates vascular endothelial growth factor, which ultimately raises vascular permeability. In previous studies25,26, it has been well demonstrated that hypoxia can significantly reduce the expression of endothelial tight junction proteins to increase the permeability of BBB. In this study, the time-resistance curve of bEnd.3 cells seeded in 24-well plates were measured in order to create a straightforward BBB model. Using this model, we characterized the changes in cell TEER after CoCl2 intervention in order to construct a cell model that can be used to screen drugs for BBB protection.

<table><tbody><tr><td>24-well transwell plate</td><td>Corning (Corning 3470, 0.33 cm&lt;sup&gt;2&lt;/sup&gt;, 0.4 &amp;micro;m)</td><td>10522023</td><td></td></tr><tr><td>75 % ethanol</td><td>ChengDu Chron Chemicals Co,.Ltd</td><td>2023052901</td><td></td></tr><tr><td>96-well plate</td><td>Guangzhou Jet Bio-Filtration Co., Ltd</td><td>220412-078-B</td><td></td></tr><tr><td>bEnd.3 cells</td><td>Hunan Fenghui Biotechnology Co., Ltd</td><td>CL0049</td><td></td></tr><tr><td>Cell counting kit-8 (CCK-8)</td><td>Boster Biological Technology Co., Ltd</td><td>BG0025</td><td></td></tr><tr><td>Cell culture dish (100mm)</td><td>Zhejiang Sorfa Life Science Research Co., Ltd</td><td>1192022</td><td></td></tr><tr><td>Cobalt Chloride (CoCl&lt;sub&gt;2&lt;/sub&gt;)</td><td>Sigma</td><td>15862</td><td></td></tr><tr><td>DMSO</td><td>Boster Biological Technology Co., Ltd</td><td>PYG0040</td><td></td></tr><tr><td>Dulbecco&#039;s modified eagle medium (1x)</td><td>Gibco ThermoFisher Scientific</td><td>8121587</td><td></td></tr><tr><td>Fetal bovine serum</td><td>Gibco ThermoFisher Scientific</td><td>2166090RP</td><td></td></tr><tr><td>GraphPad Prism software</td><td>GraphPad Software</td><td>9.0.0(121)</td><td></td></tr><tr><td>Matrigel (Contains collagen IV)</td><td>MedChemexpress</td><td>HY-K6002</td><td></td></tr><tr><td>Microplate reader</td><td>Molecular Devices</td><td>SpectraMax iD5</td><td></td></tr><tr><td>OriginPro 8 software</td><td>OriginLab Corporation</td><td>v8.0724(B724)</td><td></td></tr><tr><td>Penicillin-Streptomycin (100x)</td><td>Boster Biological Technology Co., Ltd</td><td>17C18B16</td><td></td></tr><tr><td>Phosphate buffered saline (PBS, 1x)</td><td>Gibco ThermoFisher Scientific</td><td>8120485</td><td></td></tr><tr><td>Sodium hypochlorite</td><td>ChengDu Chron Chemicals Co,.Ltd</td><td>2022091501</td><td></td></tr><tr><td>Transmembrane resistance meter</td><td>World Precision Instruments LLC</td><td>VOM3 (verison 1.6)</td><td></td></tr></tbody></table>

barrier functional integrity recording on bend.3 vascular endothelial cells via transendothelial electrical resistance detection

The blood-brain barrier (BBB) is a dynamic physiological structure composed of microvascular endothelial cells, astrocytes, and pericytes. By coordinating the interaction between restricted transit of harmful substances, nutrient absorption, and metabolite clearance in the brain, the BBB is essential in preserving central nervous system homeostasis. Building in vitro models of the BBB is a valuable tool for exploring the pathophysiology of neurological disorders and creating pharmacological treatments. This study describes a procedure for creating an in vitro monolayer BBB cell model by seeding bEnd.3 cells into the upper chamber of a 24-well plate. To assess the integrity of cell barrier function, the conventional epithelial cell voltmeter was used to record the transmembrane electrical resistance of normal cells and CoCl2-induced hypoxic cells in real-time. We anticipate that the above experiments will provide effective ideas for the creation of in vitro models of BBB and drugs to treat disorders of central nervous system diseases.

This protocol allowed the recording of changes in the resistance values of cells according to the parameters set in the transendothelial resistor meter. The viability of bEnd.3 cells (number of live cells) treated with different concentrations of CoCl2 were screened by CCK-8 assay. Greater cell damage produced by CoCl2 was represented by lower cell viability. We found that 300 &#181;M of CoCl2 was significantly cytotoxic in vitro, and this concentration was used for the next expe...

Watch this Scientific Journal Video about Applications of TEER Detection to Assess Cell Barrier Integrity at JoVE.com

Author Spotlight: Applications of TEER Detection to Assess Cell Barrier Integrity 

This protocol describes a dependable and efficient in vitro model of the brain blood barrier. The method uses mouse cerebral vascular endothelial cells bEnd.3 and measures transmembrane electrical resistance.

Barrier Functional Integrity Recording on bEnd.3 Vascular Endothelial Cells via Transendothelial Electrical Resistance Detection

The blood-brain barrier (BBB) is a dynamic physiological structure composed of microvascular endothelial cells, astrocytes, and pericytes. By coordinating ...

barrier-functional-integrity-recording-on-bend3-vascular-endothelial

Research

JoVE Journal

Neuroscience

2.8K Views.  Chengdu University of Traditional Chinese Medicine. Huidige studies maken doorgaans gebruik van permeabiliteitstests en bijbehorende eiwitexpressie om de nauwkeurigheid van TEER-detectie te verifiëren. Het BBB-model van monolaagcellen is minder effectief voor het screenen van geneesmiddelen, en het gebruik van meer cellen maakt het moeilijker om het model te construeren. Het protocol van deze studie is relatief eenvoudig, omdat de niet-invasieve procedure het mogelijk maakt om de celmonsters na TEER-detectie in andere experimenten te gebruike...

Video: Auteur in de schijnwerpers: Toepassingen van TEER-detectie om de integriteit van de celbarrière te beoordelen 

Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor

The gastrointestinal tract is an example of barrier tissue that provides a physical barrier against entry of pathogens and toxins, while allowing the passage of necessary ions and molecules. A breach in this barrier can be caused by a reduction in the extracellular calcium concentration. This reduction in calcium concentration causes a conformational change in proteins involved in the sealing of the barrier, leading to an increase of the paracellular flux. To mimic this effect the calcium chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N&#39;,N&#39;-tetra acetic acid (EGTA) was used on a monolayer of cells known to be representative of the gastrointestinal tract. Different methods to detect the disruption of the barrier tissue already exist, such as immunofluorescence and&#160;permeability assays. However, these methods are time-consuming and costly and not suited to dynamic or high-throughput measurements. Electronic methods for measuring barrier tissue integrity also exist for measurement of the transepithelial resistance (TER), however these are often costly and complex. The development of rapid, cheap, and sensitive methods is urgently needed as the integrity of barrier tissue is a key parameter in drug discovery and pathogen/toxin diagnostics. The organic electrochemical transistor (OECT) integrated with barrier tissue forming cells has been shown as a new device capable of dynamically monitoring barrier tissue integrity. The device is able to measure minute variations in ionic flux with unprecedented temporal resolution and sensitivity, in real time, as an indicator of barrier tissue integrity. This new method is based on a simple device that can be compatible with high throughput screening applications and fabricated at low cost.

The Organic Electrochemical Transistor is integrated with live cells and used to monitor ion flux across the gastrointestinal epithelial barrier. In this study, an increase in ion flux, related to disruption of tight junctions, induced by the presence of the calcium chelator EGTA (ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetra acetic acid), is measured.

The gastrointestinal tract is an example of barrier tissue that provides a physical barrier against entry of pathogens and toxins, while allowing the ...

Bioengineering

Electric Cell-substrate Impedance Sensing for the Quantification of Endothelial Proliferation, Barrier Function, and Motility

Electric Cell-substrate Impedance Sensing (ECIS) is an in vitro impedance measuring system to quantify the behavior of cells within adherent cell layers. To this end, cells are grown in special culture chambers on top of opposing, circular gold electrodes. A constant small alternating current is applied between the electrodes and the potential across is measured. The insulating properties of the cell membrane create a resistance towards the electrical current flow resulting in an increased electrical potential between the electrodes. Measuring cellular impedance in this manner allows the automated study of cell attachment, growth, morphology, function, and motility. Although the ECIS measurement itself is straightforward and easy to learn, the underlying theory is complex and selection of the right settings and correct analysis and interpretation of the data is not self-evident. Yet, a clear protocol describing the individual steps from the experimental design to preparation, realization, and analysis of the experiment is not available. In this article the basic measurement principle as well as possible applications, experimental considerations, advantages and limitations of the ECIS system are discussed. A guide is provided for the study of cell attachment, spreading and proliferation; quantification of cell behavior in a confluent layer, with regard to barrier function, cell motility, quality of cell-cell and cell-substrate adhesions; and quantification of wound healing and cellular responses to vasoactive stimuli. Representative results are discussed based on human microvascular (MVEC) and human umbilical vein endothelial cells (HUVEC), but are applicable to all adherent growing cells.

This protocol reviews Electric Cell-substrate Impedance Sensing, a method to record and analyze the impedance spectrum of adherent cells for the quantification of cell attachment, proliferation, motility, and cellular responses to pharmacological and toxic stimuli. Detection of endothelial permeability and assessment of cell-cell and cell-substrate contacts are emphasized.

Electric Cell-substrate Impedance Sensing (ECIS) is an in vitro impedance measuring system to quantify the behavior of cells within adherent cell layers. ...

Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), magnetoencephalography or functional magnetic-resonance imaging. These techniques have either inherently low temporal or low spatial resolution, and suffer from low signal-to-noise ratio and/or poor high-frequency sensitivity. Thus, they are suboptimal for exploring the short-lived spatio-temporal dynamics of many of the underlying brain processes. In contrast, the invasive technique of electrocorticography (ECoG) provides brain signals that have an exceptionally high signal-to-noise ratio, less susceptibility to artifacts than EEG, and a high spatial and temporal resolution (i.e., &lt;1 cm/&lt;1 millisecond, respectively). ECoG involves measurement of electrical brain signals using electrodes that are implanted subdurally on the surface of the brain. Recent studies have shown that ECoG amplitudes in certain frequency bands carry substantial information about task-related activity, such as motor execution and planning1, auditory processing2 and visual-spatial attention3. Most of this information is captured in the high gamma range (around 70-110 Hz). Thus, gamma activity has been proposed as a robust and general indicator of local cortical function1-5. ECoG can also reveal functional connectivity and resolve finer task-related spatial-temporal dynamics, thereby advancing our understanding of large-scale cortical processes. It has especially proven useful for advancing brain-computer interfacing (BCI) technology for decoding a user's intentions to enhance or improve communication6 and control7. Nevertheless, human ECoG data are often hard to obtain because of the risks and limitations of the invasive procedures involved, and the need to record within the constraints of clinical settings. Still, clinical monitoring to localize epileptic foci offers a unique and valuable opportunity to collect human ECoG data. We describe our methods for collecting recording ECoG, and demonstrate how to use these signals for important real-time applications such as clinical mapping and brain-computer interfacing. Our example uses the BCI2000 software platform8,9 and the SIGFRIED10 method, an application for real-time mapping of brain functions. This procedure yields information that clinicians can subsequently use to guide the complex and laborious process of functional mapping by electrical stimulation.
Prerequisites and Planning:
Patients with drug-resistant partial epilepsy may be candidates for resective surgery of an epileptic focus to minimize the frequency of seizures. Prior to resection, the patients undergo monitoring using subdural electrodes for two purposes: first, to localize the epileptic focus, and second, to identify nearby critical brain areas (i.e., eloquent cortex) where resection could result in long-term functional deficits. To implant electrodes, a craniotomy is performed to open the skull. Then, electrode grids and/or strips are placed on the cortex, usually beneath the dura. A typical grid has a set of 8 x 8 platinum-iridium electrodes of 4 mm diameter (2.3 mm exposed surface) embedded in silicon with an inter-electrode distance of 1cm. A strip typically contains 4 or 6 such electrodes in a single line. The locations for these grids/strips are planned by a team of neurologists and neurosurgeons, and are based on previous EEG monitoring, on a structural MRI of the patient's brain, and on relevant factors of the patient's history. Continuous recording over a period of 5-12 days serves to localize epileptic foci, and electrical stimulation via the implanted electrodes allows clinicians to map eloquent cortex. At the end of the monitoring period, explantation of the electrodes and therapeutic resection are performed together in one procedure.
In addition to its primary clinical purpose, invasive monitoring also provides a unique opportunity to acquire human ECoG data for neuroscientific research. The decision to include a prospective patient in the research is based on the planned location of their electrodes, on the patient's performance scores on neuropsychological assessments, and on their informed consent, which is predicated on their understanding that participation in research is optional and is not related to their treatment. As with all research involving human subjects, the research protocol must be approved by the hospital's institutional review board. The decision to perform individual experimental tasks is made day-by-day, and is contingent on the patient's endurance and willingness to participate. Some or all of the experiments may be prevented by problems with the clinical state of the patient, such as post-operative facial swelling, temporary aphasia, frequent seizures, post-ictal fatigue and confusion, and more general pain or discomfort.
At the Epilepsy Monitoring Unit at Albany Medical Center in Albany, New York, clinical monitoring is implemented around the clock using a 192-channel Nihon-Kohden Neurofax monitoring system. Research recordings are made in collaboration with the Wadsworth Center of the New York State Department of Health in Albany. Signals from the ECoG electrodes are fed simultaneously to the research and the clinical systems via splitter connectors. To ensure that the clinical and research systems do not interfere with each other, the two systems typically use separate grounds. In fact, an epidural strip of electrodes is sometimes implanted to provide a ground for the clinical system. Whether research or clinical recording system, the grounding electrode is chosen to be distant from the predicted epileptic focus and from cortical areas of interest for the research. Our research system consists of eight synchronized 16-channel g.USBamp amplifier/digitizer units (g.tec, Graz, Austria). These were chosen because they are safety-rated and FDA-approved for invasive recordings, they have a very low noise-floor in the high-frequency range in which the signals of interest are found, and they come with an SDK that allows them to be integrated with custom-written research software. In order to capture the high-gamma signal accurately, we acquire signals at 1200Hz sampling rate-considerably higher than that of the typical EEG experiment or that of many clinical monitoring systems. A built-in low-pass filter automatically prevents aliasing of signals higher than the digitizer can capture. The patient's eye gaze is tracked using a monitor with a built-in Tobii T-60 eye-tracking system (Tobii Tech., Stockholm, Sweden). Additional accessories such as joystick, bluetooth Wiimote (Nintendo Co.), data-glove (5th Dimension Technologies), keyboard, microphone, headphones, or video camera are connected depending on the requirements of the particular experiment.
Data collection, stimulus presentation, synchronization with the different input/output accessories, and real-time analysis and visualization are accomplished using our BCI2000 software8,9. BCI2000 is a freely available general-purpose software system for real-time biosignal data acquisition, processing and feedback. It includes an array of pre-built modules that can be flexibly configured for many different purposes, and that can be extended by researchers' own code in C++, MATLAB or Python. BCI2000 consists of four modules that communicate with each other via a network-capable protocol: a Source module that handles the acquisition of brain signals from one of 19 different hardware systems from different manufacturers; a Signal Processing module that extracts relevant ECoG features and translates them into output signals; an Application module that delivers stimuli and feedback to the subject; and the Operator module that provides a graphical interface to the investigator.
A number of different experiments may be conducted with any given patient. The priority of experiments will be determined by the location of the particular patient's electrodes. However, we usually begin our experimentation using the SIGFRIED (SIGnal modeling For Realtime Identification and Event Detection) mapping method, which detects and displays significant task-related activity in real time. The resulting functional map allows us to further tailor subsequent experimental protocols and may also prove as a useful starting point for traditional mapping by electrocortical stimulation (ECS).
Although ECS mapping remains the gold standard for predicting the clinical outcome of resection, the process of ECS mapping is time consuming and also has other problems, such as after-discharges or seizures. Thus, a passive functional mapping technique may prove valuable in providing an initial estimate of the locus of eloquent cortex, which may then be confirmed and refined by ECS. The results from our passive SIGFRIED mapping technique have been shown to exhibit substantial concurrence with the results derived using ECS mapping10.
The protocol described in this paper establishes a general methodology for gathering human ECoG data, before proceeding to illustrate how experiments can be initiated using the BCI2000 software platform. Finally, as a specific example, we describe how to perform passive functional mapping using the BCI2000-based SIGFRIED system.

Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), ...

Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model

Epithelial and endothelial cells (EC) are building paracellular barriers which protect the tissue from the external and internal environment. The blood-brain barrier (BBB) consisting of EC, astrocyte end-feet, pericytes and the basal membrane is responsible for the protection and homeostasis of the brain parenchyma. In vitro BBB models are common tools to study the structure and function of the BBB at the cellular level. A considerable number of different in vitro BBB models have been established for research in different laboratories to date. Usually, the cells are obtained from bovine, porcine, rat or mouse brain tissue (discussed in detail in the review by Wilhelm et al. 1). Human tissue samples are available only in a restricted number of laboratories or companies 2,3. While primary cell preparations are time consuming and the EC cultures can differ from batch to batch, the establishment of immortalized EC lines is the focus of scientific interest.
Here, we present a method for establishing an immortalized brain microvascular EC line from neonatal mouse brain. We describe the procedure step-by-step listing the reagents and solutions used. The method established by our lab allows the isolation of a homogenous immortalized endothelial cell line within four to five weeks. The brain microvascular endothelial cell lines termed cEND 4 (from cerebral cortex) and cerebEND 5 (from cerebellar cortex), were isolated according to this procedure in the F&ouml;rster laboratory and have been effectively used for explanation of different physiological and pathological processes at the BBB. Using cEND and cerebEND we have demonstrated that these cells respond to glucocorticoid- 4,6-9 and estrogen-treatment 10 as well as to pro-infammatory mediators, such as TNFalpha 5,8. Moreover, we have studied the pathology of multiple sclerosis 11 and hypoxia 12,13 on the EC-level. The cEND and cerebEND lines can be considered as a good tool for studying the structure and function of the BBB, cellular responses of ECs to different stimuli or interaction of the EC with lymphocytes or cancer cells.

Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model

This method describes how to isolate and immortalize microvascular endothelial cells from mouse brain. We describe a step-by-step protocol starting from the homogenization of brain tissue, digestion steps, seeding and immortalization of the cells. Usually, it takes about five weeks to obtain a homogenous, immortalized microvascular endothelial cell line.

Epithelial and endothelial cells (EC) are building paracellular barriers which protect the tissue from the external and internal environment. The ...

An In Vitro Model of the Blood-brain Barrier Using Impedance Spectroscopy: A Focus on T Cell-endothelial Cell Interaction

Breakdown of the blood-brain barrier (BBB) is a critical step in the development of autoimmune diseases such as multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). This process is characterized by the transmigration of activated T cells across brain endothelial cells (ECs), the main constituents of the BBB. However, the consequences on brain EC function upon interaction with such T cells are largely unknown. Here we describe an assay that allows for the evaluation of primary mouse brain microvascular EC (MBMEC) function and barrier integrity during the interaction with T cells over time. The assay makes use of impedance cell spectroscopy, a powerful tool for studying EC monolayer integrity and permeability, by measuring changes in transendothelial electrical resistance (TEER) and cell layer capacitance (Ccl). In direct contact with ECs, stimulated but not na&#239;ve T cells are capable of inducing EC monolayer dysfunction, as visualized by a decrease in TEER and an increase in Ccl. The assay records changes in EC monolayer integrity in a continuous and automated fashion. It is sensitive enough to distinguish between different strengths of stimuli and levels of T cell activation and it enables the investigation of the consequences of a targeted modulation of T cell-EC interaction using a wide range of substances such as antibodies, pharmacological reagents and cytokines. The technique can also be used as a quality control for EC integrity in in vitro T-cell transmigration assays. These applications make it a versatile tool for studying BBB properties under physiological and pathophysiological conditions.

An In Vitro Model of the Blood-brain Barrier Using Impedance Spectroscopy: A Focus on T Cell-endothelial Cell Interaction

Here, we describe an in vitro murine model of the blood-brain barrier that makes use of impedance cell spectroscopy, with a focus on the consequences on endothelial cell integrity and permeability upon interaction with activated T cells.

Breakdown of the blood-brain barrier (BBB) is a critical step in the development of autoimmune diseases such as multiple sclerosis (MS) and its animal ...

Immunology and Infection

Fabrication and Validation of an Organ-on-chip System with Integrated Electrodes to Directly Quantify Transendothelial Electrical Resistance

Organs-on-chips, in vitro models involving the culture of (human) tissues inside microfluidic devices, are rapidly emerging and promise to provide useful research tools for studying human health and disease. To characterize the barrier function of cell layers cultured inside organ-on-chip devices, often transendothelial or transepithelial electrical resistance (TEER) is measured. To this end, electrodes are usually integrated into the chip by micromachining methods to provide more stable measurements than is achieved with manual insertion of electrodes into the inlets of the chip. However, these electrodes frequently hamper visual inspection of the studied cell layer or require expensive cleanroom processes for fabrication. To overcome these limitations, the device described here contains four easily integrated electrodes that are placed and fixed outside of the culture area, making visual inspection possible. Using these four electrodes the resistance of six measurement paths can be quantified, from which the TEER can be directly isolated, independent of the resistance of culture medium-filled microchannels. The blood-brain barrier was replicated in this device and its TEER was monitored to show the device applicability. This chip, the integrated electrodes and the TEER determination method are generally applicable in organs-on-chips, both to mimic other organs or to be incorporated into existing organ-on-chip systems.

This publication describes the fabrication of an organ-on-chip device with integrated electrodes for direct quantification of transendothelial electrical resistance (TEER). For validation, the blood-brain barrier was mimicked inside this microfluidic device and its barrier function was monitored. The presented methods for electrode integration and direct TEER quantification are generally applicable.

Organs-on-chips, in vitro models involving the culture of (human) tissues inside microfluidic devices, are rapidly emerging and promise to provide useful ...

Endothelial Cell Transcytosis Assay as an In Vitro Model to Evaluate Inner Blood-Retinal Barrier Permeability

Dysfunction of the blood-retinal barrier (BRB) contributes to the pathophysiology of several vascular eye diseases, often resulting in retinal edema and subsequent vision loss. The inner blood-retinal barrier (iBRB) is mainly composed of retinal vascular endothelium with low permeability under physiological conditions. This feature of low permeability is tightly regulated and maintained by low rates of paracellular transport between adjacent retinal microvascular endothelial cells, as well as transcellular transport (transcytosis) through them. The assessment of retinal transcellular barrier permeability may provide fundamental insights into iBRB integrity in health and disease. In this study, we describe an endothelial cell (EC) transcytosis assay, as an in vitro model for evaluating iBRB permeability, using human retinal microvascular endothelial cells (HRMECs). This assay assesses the ability of HRMECs to transport transferrin and horseradish peroxidase (HRP) in receptor- and caveolae-mediated transcellular transport processes, respectively. Fully confluent HRMECs cultured on porous membrane were incubated with fluorescent-tagged transferrin (clathrin-dependent transcytosis) or HRP (caveolae-mediated transcytosis) to measure the levels of transferrin or HRP transferred to the bottom chamber, indicative of transcytosis levels across the EC monolayer. Wnt signaling, a known pathway regulating iBRB, was modulated to demonstrate the caveolae-mediated HRP-based transcytosis assay method. The EC transcytosis assay described here may provide a useful tool for investigating the molecular regulators of EC permeability and iBRB integrity in vascular pathologies and for screening drug delivery systems.

Endothelial Cell Transcytosis Assay as an In Vitro Model to Evaluate Inner Blood-Retinal Barrier Permeability

This protocol illustrates an in vitro endothelial cell transcytosis assay as a model to evaluate inner blood-retinal barrier permeability by measuring the ability of human retinal microvascular endothelial cells to transport horseradish peroxidase across cells in caveolae-mediated transcellular transport processes.

Dysfunction of the blood-retinal barrier (BRB) contributes to the pathophysiology of several vascular eye diseases, often resulting in retinal edema and ...

Medicine

A Simple Approach to Perform TEER Measurements Using a Self-Made Volt-Amperemeter with Programmable Output Frequency

Transepithelial/endothelial electrical resistance (TEER) has been used since the 1980s to determine confluency and permeability of in vitro barrier model systems. In most cases, chopstick electrodes are used to determine the electric impedance between the upper and lower compartment of a cell culture filter insert system containing cellular monolayers. The filter membrane allows the cells to adhere, polarize, and interact by building tight junctions. This technique has been described with a variety of different cell lines (e.g., cells of the blood-brain barrier, blood-cerebrospinal fluid barrier, or gastrointestinal and pulmonary tract). TEER measurement devices can be readily obtained from different laboratory equipment suppliers. However, there are more cost-effective and customizable solutions imaginable if an appropriate voltammeter is self-assembled. The overall aim of this publication is to set up a reliable device with programmable output frequency that can be used with commercially available chopstick electrodes for TEER measurement.

Here, we demonstrate how to set up an inexpensive volt-amperemeter with programmable output frequency that can be used with commercially available chopstick electrodes for transepithelial/endothelial electrical resistance measurements.

Transepithelial/endothelial electrical resistance (TEER) has been used since the 1980s to determine confluency and permeability of in vitro barrier model ...

Biology

Impedance-Based Biosensors in Investigating Brain Endothelial Barrier Strength

Measuring Changes in Brain Endothelial Barrier Integrity with Two Impedance-based Biosensors in Response to Cancer Cells and Cytokines

The blood-brain barrier (BBB) protects the brain parenchyma against harmful pathogens in the blood. The BBB consists of the neurovascular unit, comprising pericytes, astrocytic foot processes, and tightly adhered endothelial cells. Here, the brain endothelial cells form the first line of barrier against blood-borne pathogens. In conditions like cancer and neuroinflammation, circulating factors in the blood can disrupt this barrier. Disease progression significantly worsens post barrier disruption, which permits access to or impairment of regions of the brain. This significantly worsens the prognoses, particularly due to limited treatment options available at the level of the brain. Hence, emerging studies aim to investigate potential therapeutics that can prevent these detrimental factors in the blood from interacting with the brain endothelial cells.
The commercially available Electric Cell-Substrate Impedance Sensing (ECIS) and cellZscope instruments measure the impedance across cellular monolayers, such as the BBB endothelium, to determine their barrier strength. Here we detail the use of both biosensors in assessing brain endothelial barrier integrity upon the addition of various stimuli. Crucially, we highlight the importance of their high-throughput capability for concurrent investigation of multiple variables and biological treatments.

Author Spotlight: Studying Brain Endothelial Barrier in Metastatic Cancer Using Impedance-Based Biosensors

Here we demonstrate the technique of using impedance-based biosensors: ECIS and cellZscope, for measuring brain endothelial barrier strength. We detail the preparation and technique of adding various stimuli to an in vitro model of the brain endothelium. We measure, record, and give a representative analysis of the findings.

The blood-brain barrier (BBB) protects the brain parenchyma against harmful pathogens in the blood. The BBB consists of the neurovascular unit, comprising ...

Assessing Transendothelial Electrical Resistance in an In Vitro Blood-Brain Barrier Model

Source: Kuzmanov, I., et al. <a href="https://app.jove.com/v/54592">An In Vitro Model of the Blood-brain Barrier Using Impedance Spectroscopy: A Focus on T Cell-endothelial Cell Interaction.</a> J. Vis. Exp. (2016)
This video demonstrates a method for assessing transendothelial electrical resistance (TEER) in mouse brain microvascular endothelial cells in vitro. A high TEER value indicates intact endothelial cell junctions, while the addition of activated T cells lowers the TEER value, reflecting disruption of the junctional barrier.

Source: Kuzmanov, I., et al. An In Vitro Model of the Blood-brain Barrier Using Impedance Spectroscopy: A Focus on T Cell-endothelial Cell Interaction. J. ...

Barrier Functional Integrity Recording on bEnd.3 Vascular Endothelial Cells via Transendothelial Electrical Resistance Detection

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