Fig. 2

Effect of MβCD on tau transcytosis across an in vitro model of the BBB. A Freshly isolated cerebrovessels from naïve wild-type mice (9 months old) were pretreated with various concentrations of the caveolin inhibitor MβCD (0, 1 mM, 10 mM) for 30 min at 37 °C, before being exposed to recombinant human tau (5 ng/ml) for 1 h at 37 °C. Lysates were analyzed for tau content using an ELISA and normalized total protein using the BCA assay. Values represent mean ± SD (n = 5) and are expressed as pg of tau per mg of total protein. ****P < 0.0001 compared to vehicle as determined by one-way ANOVA and Bonferroni post-hoc test. B MβCD (10 mM) was exposed to the basolateral compartment of the in vitro BBB model for 30 min at 37 °C. Following the pretreatment with MβCD, biotin-labeled monomeric or aggregate enriched biotin-labeled tau was added alongside the known paracellular marker 10 kDa LyD to the basolateral compartment of the in vitro BBB model. Samples were collected from the apical compartment at 0, 30, and 60 min to determine the permeability of biotin-labeled tau and LyD across the BBB model. Values represent mean ± SD (n = 3) and are expressed as the apparent permeability coefficient (Papp). *P < 0.05, **P < 0.01 compared to each respective tau species with vehicle as determined by unpaired t-Test