Journal: Alzheimer's & Dementia

Article Title: Fibrillar tau alters cerebral endothelial cell metabolism, vascular inflammatory activation, and barrier function in vitro and in vivo

doi: 10.1002/alz.70077

Figure Lengend Snippet: Protofibrillar tau induces loss of barrier resistance independently of cell death. A, Transmission electron microscope analysis of tau aggregates after negative staining with 1% uranyl acetate, reveals primarily protofibrillar species (scale bars 600 nm). B, One hour of treatment with AcidSensor‐labeled protofibrillar tau demonstrates early internalization in hCMECs. C, Left panel TEER (at 4000 Hz) measurement of hCMECs with the ECIS Zθ system illustrates barrier formation at about 48 hours after plating. Middle panel: TEER of hCMECs monolayers treated with 5 or 25 nM fibrillar tau, measured over time for 48 hours, indicates progressive loss of barrier resistance induced by protofibrillar tau species. Right panel: TEER of hCMECs treated with fibrillization vehicle, protofibrillar or monomeric tau (25 nM) for 48 hours (right). Data are represented as change in resistance normalized to the untreated control, n = 3 experiments with two replicates per condition. D, Apoptosis, measured as DNA fragmentation, of hCMECs treated for 24 hours with 5 or 25 nM tau. E, LDH release for hCMECs treated for 24 hours with 5 or 25 nM tau. F, Caspase 3/7 fluorescence in hCMECs treated with aggregated tau for 24 hours, or H 2 O 2 as a positive control (left), with quantification of caspase positive cells (right). **Statistical significance established by one‐way ANOVA (Cell Death ELISA, LDH); Tukey post test. Two‐way ANOVA (ECIS). Significant P values are reported in the graphs. ANOVA, analysis of variance; hCMEC, human cerebral microvascular endothelial cell; LDH, lactate dehydrogenase; TEER, trans‐endothelial electrical resistance.

Article Snippet: Samples of the 2 μM protofibrillar stock were fluorescently tagged using the AcidSensor Labeling Kit (Dojindo A558), according to manufacturer's instructions.

Techniques: Transmission Assay, Microscopy, Negative Staining, Labeling, Control, Fluorescence, Positive Control, Enzyme-linked Immunosorbent Assay