PARP-1 inhibition reduced TLR4 expression and suppressed HMGB1 translocation and release.

<p>After PARP-1 was inhibited by siRNA, HUVECs were stimulated by LSS, then TLR4 expression was determined by western blot analysis, TNF-α and IL-1β secretion were assessed by ELISA, HMGB1 release and HMGB1 translocation were assessed by ELISA and immunofluorescence, respectively. <b>(A, B)</b> The protein expression of TLR4 was assessed by western blot analysis. <b>(C)</b> TNF-α secretion was assessed by ELISA. <b>(D)</b> IL-1β secretion was assessed by ELISA. <b>(E)</b> HMGB1 release was determined by ELISA. <b>(F)</b> Immunofluorescence of HMGB1 protein expression. Nuclei were labelled with 4′,6-diamidino-2-phenylindole (DAPI) (blue); HMGB1 was stained with rabbit anti- HMGB1 primary antibody and Alexa 488-conjugated goat anti-rabbit second antibody (green). * <i>P</i><0.05 vs. USS; # <i>P</i><0.05 vs. LSS; si-PARP-1: PARP-1 siRNA.