In Vitro Assays to Assess Blood-brain Barrier Mesh-like Vessel Formation and Disruption

The goals of this assay are to dissect the role of disease-relevant processes in blood brain-barrier coverage disruption, identify the underlying mechanisms, and test potential treatments in vitro.This method can answer key basic and applied research questions in the blood-brain barrier and neuro-degeneration fields.For example, by addressing whether disease-relevant stresses disrupt preformed network structures and identifying the underlying pathways.Through further screening, treatments can be identified that prevent stress-induced blood-brain barrier disruption for future in vivo testing.The implications of this technique extend towards mechanistic understanding of and treatment for Alzheimer's disease, because of the importance of the homeostatic functions of the blood-brain barrier on cognition.Though this method can provide insight into the blood-brain barrier dysfunction in Alzheimer's disease, it can also be applied to other neurodegenerative disorders with blood-brain barrier dysfunction, such as stroke.Begin by passaging hCMEC/D3 immortal endothelial cells at a ratio of one to five by incubating the cell sheet with calcium and magnesium-free HBSS for three minutes.Then detach the cells using five milliliters of 0.25%trypsin EDTA for five minutes.Neutralize the trypsin by adding five milliliters of EBM-2 complete medium.Collect the cells, and centrifuge at 290 times g for five minutes at four degrees Celsius.Following centrifugation, discard the supernatant, and resuspend the pellet in EBM-2 complete medium.Then, replate the cells at a one to five ratio.To prepare endothelial cells from the mouse brain, remove the brain stems and cerebella from seven euthanized mice with forceps.Then, detach the meninges by carefully rolling the brains on gauss.Then, place the brain tissue into a petri dish containing minimal essential medium with HEPES, and use a sterile razor blade to mince the remaining brain tissue.Then transfer the minced brain tissue to a 15 milliliter conical tube.And centrifuge at 290 times g for five minutes at four degrees Celsius.After removing the supernatant, add papain and DNase solution, and incubate in a 37 degree Celsius water bath for one hour to digest the tissue.Following the incubation, triturate the homogenate using a 19-gauge needle, and then a 21-gauge needle.Once triturated, add one volume of 22%bovine serum albumin solution.Then centrifuge at 1, 360 times g for 10 minutes at four degrees Celsius.Resuspend the resulting pellet in one milliliter of EBM-2 complete, and then centrifuge at 290 times g for five minutes at four degrees Celsius.After the centrifugation, again use one milliliter of EBM-2 complete medium to resuspend the cells, and plate the cells at one milliliter per well in collagen-coated, six-well plates.24 hours later, replace the medium with EBM-2 complete medium containing four micrograms per milliliter of puromycin hydrochloride, and continue to culture the cells until they reach full confluence at one times 10 to the fifth cells per square centimeter.Lastly, 24 hours prior to the assay, incubate the fully confluent brain endothelial cells in EBM-2 basal medium.On the day of the assay, pipette 10 microliters of basement membrane matrix into each well of a 96-well plate, and allow to set for one hour at 37 degrees Celsius.Suspend the lyophilized green cell tracking dye in 10 microliters of DMSO to generate a 10-millimolar stock solution.Dilute this solution to 10-micromolar in EBM-2 basal medium.Remove the medium from the six-well plate containing brain endothelial cells, and replace with EBM-2 basal containing the green cell tracking dye.Incubate the cells for 20 to 30 minutes at 37 degrees Celsius.Following the incubation, remove the medium with cell tracking dye, wash the cell sheet, and attach the cells with trypsin.Neutralize the trypsin with EBM-2 containing 10%FBS, and transfer the cells to centrifuge tubes.Centrifuge at 240 time g for five minutes at four degrees Celsius.Following centrifugation, resuspend the cell pellets in one milliliter of EBM-2 basal medium, plate the labeled cells in multiple 96-well plates at 10, 000 cells per well, and return the cells to the incubator until oligomeric oa