(A) Heat map representing the relative expression and fold change of genes known to regulate vascular permeability in PR vs. PR+P4 HUVECS at 4h. (B) qPCR of VE-cadherin (CDH5) and claudin-5 (CLDN5) expression following P4 treatment of non-infected (NI), GFP infected (GFP) and PR infected (hPR) HUVECs. n=3. GFP infected HUVECs were used as a control for infection. (C) Western blot analysis of total protein levels from GFP control or PR infected HUVECs following P4 treatment. GAPDH/β-actin=loading controls. Blots are representative of three independent experiments. (D) Densitometry of VE-cadherin, claudin-5, and PECAM-1 protein levels following P4 treatment. n=3. (E,F) Evaluation of HUVEC monolayer resistance following treatment with cycloheximide (CHX, 10μg/ml), actinomycin D (ACD, 10μg/ml), or P4 and vehicle as indicated. Error bars=+/− SEM. *p<0.05, **p<0.01, ***p<0.001. See also Figure S5.