SNAP23 Regulates Endothelial Exocytosis of von Willebrand Factor
Fig 4
SNAP23 is important for endothelial exocytosis.
(A) siRNA against SNAP23 knocks down SNAP23 protein levels as measured by Western blot. The siRNA against SNAP23 has no effect on the expression of other SNARE proteins including STX4, VAMP3, and VAMP8. GAPDH was used as loading control. (B) SNAP23 knockdown does not affect VWF expression in HDMVEC or HUVEC. Total VWF content was measured in total cell lysate by an ELISA in control siRNA and siSNAP23 treated cells (n = 6; NS, non-significant). (C) SNAP23 knockdown decreases endothelial exocytosis. HDMVEC and HUVEC were treated with siControl or siSNAP23, stimulated with serum-free medium only (resting), or 10 μM histamine, or 1 U/ml thrombin, or 10 μM Ca2+ ionophore A23187 for 30 min; and then VWF released into the media was measured by an ELISA (n = 4–7; * P < 0.05 vs. siControl; NS, non-significant vs. siControl). Data are represented as mean ± SD.