Genetic ablation of endothelial sAC inhibits leukocyte transmigration. (a) Quantitative PBMC TEM assays were performed on HUVECs expressing either scrambled (SCR) or sAC shRNA. Where indicated, the rescue construct (sACt) was also expressed. (b) Immunoblot analysis for sAC and β-actin was performed on samples treated in parallel. (c) Quantification of immunoblots. Total sAC expression was normalized to β-actin for each sample and then normalized to SCR control. (d and e) TEM-IF assays were performed on HUVECs expressing SCR, sAC, or CD99 shRNA. (f) Immunoblot analysis for CD99, sAC, and β-actin was performed on samples treated in parallel. (g) Quantification of immunoblots. Total sAC or CD99 expression was normalized to β-actin for each sample and then normalized to SCR control. (h) Quantitative PMN TEM-IF assays were performed on TNF-activated (4 h) HUVECs expressing SCR, sAC, or CD99 shRNA. (i) Quantitative PMBC TEM-IF assays were performed on TNF-activated (4 h) HUVECs expressing SCR, sAC, or CD99 shRNA. (j) Immunoblot analysis of samples treated in parallel were performed for sAC, ICAM-1, PECAM, JAM-A, and CD99 expression. Bars, 10 µm. Images are representative of three (b, e, and j) independent experiments. Numerical values are the mean of two (h and i) or three (a, c, d, and g) independent experiments. Error bars represent SD (c and g) or SEM (a, d, h, and i; *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; Student’s t test [a and c] and ANOVA [d, g, h, and i]).