Assessment of FITC-labeled albumin leakage across HPAEC monolayers transfected with siRNA-targeting BMPR-II, nontargeting control siRNA, or mock-transfected HPAEC. Mock-transfected HPAECs or HPAECs transfected with BMPR-IIsi or NTC siRNA were seeded onto Transwell filters. FITC-labeled albumin was added to the upper chamber, and leakage into the lower chamber was measured after 0.5, 1, and 2 hours and normalized to FITC-albumin leakage through mock-transfected HPAECs. Data are the mean ± SEM for 4 independent experiments. *P < .05, compared with NTCsi-transfected HPAECs by Student t test.