Cytokine Effects on BBB Permeability

Permeability tests using the small molecular marker sodium fluorescein (SF, MW = 376 Da) were carried out on an in-contact type double co-culture BBB model with primary astroglia when high TEER values were recorded. After applying IL-6, IL-10 and IL-6 + IL-10 in combination (both cytokines at 50 ng/ml concentration) for 24 h in the luminal compartment, the test was conducted as described previously [37 (link)]. The concentration of the SF marker molecule in samples from the upper and lower compartments was determined with a microplate reader (excitation at 440 nm, emission at 525 nm; BMG Fluostar Optima; BMG Labtech, Ortenberg, Germany). Flux across coated, cell-free inserts was also measured. Endothelial permeability coefficients (P_e) were calculated from clearance values of tracers as described in detail in our previous publication [32 (link)].