Albumin clearance assay

HDMEC were seeded at confluence on 0.4 μm pore transwell chambers (Corning) and incubated 48–72 h prior to the experiments. Then, cells were infected and treated as indicated in the figures. After treatments, cells were incubated in medium devoid of phenol red and containing an excess (5 mg/ml) of non-labeled albumin in both chambers. Then, 0.5 mg/ml FITC-labeled albumin was added to the upper chamber. Sixty minutes later, fluorescence in the lower chamber was measured in a multiwell fluorometer (BioTek) and compared to a FITC-albumin standard curve (0.08–40 μg/ml).