barrier destruction and statistical analysis after teer measurement in an in vitro blood-brain barrier model

Mesure de la résistance transendothéliale pour évaluer l’intégrité de la barrière cellulaire

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.

Pleins feux sur l’auteur : Applications de la détection TEER pour évaluer l’intégrité de la barrière cellulaire 

Enregistrement de l’intégrité fonctionnelle de la barrière sur les cellules endothéliales vasculaires bEnd.3 via la détection de résistance électrique transendothéliale

Current studies typically use permeability tests and associated protein expression to verify the accuracy of TEER detection. The BBB model of monolayer cells in virtue is less effective for drug screening, and the use of more cells makes it more difficult to construct the model. The protocol of this study is relatively simple, as the non-invasive procedure allows the cell samples to be used in other experiments after TEER detection.The detection of TEER to assess the permeability of cell models can accelerate the screening of drugs for treatment and prevention of the central nervous system to increase the success rate of new drug development. In the future, we will detect the expression of tight junction protein in upper compartment cells of chest wall to verify that TEER test results can effectively represent the integrity of BBB barrier function.

Watch this Scientific Journal Video about Barrier Destruction and Statistical Analysis After TEER Measurement in an In Vitro Blood-Brain Barrier Model at JoVE.com

Barrier Destruction and Statistical Analysis After TEER Measurement in an In Vitro Blood-Brain Barrier Model  

Destruction de la barrière et analyse statistique après mesure TEER dans un modèle in vitro de barrière hémato-encéphalique

Commencez par cultiver les cellules BEND3, puis divisez les puits en groupe témoin et en groupe chlorure de cobalt. Ajouter 200 microlitres de milieu de culture dans la chambre supérieure du groupe témoin et un milieu de culture contenant 300 micromolaires de chlorure de cobalt dans le groupe chlorure de cobalt. Incuber les plaques à 37 degrés Celsius et détecter les valeurs de résistance à 12 et 24 heures d’incubation à l’aide de la méthode TEER.Utilisez un logiciel commercial pour cartographier la tendance des valeurs TEER de la barrière cellulaire. Utilisez un logiciel d’analyse statistique pour analyser la différence de valeurs de résistance entre les cellules traitées au chlorure de cobalt et les cellules témoins. L’ajout de 300 micromolaires de chlorure de cobalt a entraîné une diminution significative des valeurs TEER par rapport au témoin aux points de temps de 12 heures et de 24 heures.Après 24 heures, la valeur TEER du groupe 300 micromolaires de chlorure de cobalt a diminué par rapport au groupe témoin, indiquant une rupture de la barrière cellulaire induite par des conditions hypoxiques dues au chlorure de cobalt.

barrier-destruction-statistical-analysis-after-teer-measurement-an

Research

JoVE Journal

Neuroscience

Barrier Destruction and Statistical Analysis After TEER Measurement in an In Vitro Blood-Brain Barrier Model

132 Views.  Chengdu University of Traditional Chinese Medicine. Begin by culturing the BEND3 cells, then divide the wells into the control group and cobalt chloride group. Add 200 microliters of culture medium into the upper chamber of the control group and culture medium containing 300 micromolar cobalt chloride into the cobalt chloride group. Incubate the plates at 37 degrees Celsius and detect the resistance values at 12 and 24 hours of incubation using TEER method.Use commercial software to map the trend of TEER values of the cell barrier. Use ...