Figure 2.

Effect of knockdown of PTPμ through siRNA transfection on endothelial barrier function. A: Postconfluent human lung microvascular ECs were transfected with PTPμ-targeting (lanes 3, 5, 7, 9, 11, and 13) or control (lanes 2, 4, 6, 8, 10, and 12) siRNA and after increasing times (days 1 to 6), were lysed and the lysates resolved by SDS-PAGE, transferred to PVDF membrane, and immunoblotted for PTPμ. To confirm equivalent loading, each blot was stripped and reprobed with anti-β-tubulin antibody. B: Human lung microvascular ECs were cultured to confluence in barrier function assay chambers when baseline barrier function was established (day 0). The postconfluent ECs were cultured in media alone or were transfected with PTPμ-targeting or control siRNAs after which transendothelial ¹⁴C-BSA flux was assayed every 24 hours. Vertical bars represent mean (±SE) ¹⁴C-BSA flux in pmol/hour across media control EC monolayers or monolayers transfected with either PTPμ or control siRNA. *, Significantly increased compared to the simultaneous media control monolayers at P < 0.02. **, Significantly increased compared to the simultaneous siRNA control at P < 0.006.