Involvement of caspase-9 and gap junctions on ASC-dependent apoptosis at a high cell density.

<p>(A) Relative mRNA expressions of the NF-κB-regulated genes IL-1β and XIAP were evaluated by quantitative RT-PCR at both low and high cell densities (n = 4 for each). (B) Effects of caspase inhibitors on ASC-dependent apoptosis as evaluated by relative GFP-positive ratio at a high cell density. Z-VAD-fmk; pan-caspase inhibitor, z-YVAD-fmk; caspase-1 inhibitor, Z-LEHD-fmk; caspase-9 inhibitor (n = 4 for each). (C) Activation of caspase-9 induced by ASC introduction as detected by Western blotting at low and high cell densities. (D) Relative mRNA expression of connexin 43 evaluated by quantitative RT-PCR at both low and high cell densities (n = 3 for each). (E) Effect of the gap junction inhibitor CBX on relative GFP-positive ratio at a high cell density (n = 4). (F) Effects of CBX on the activation of caspase-9 at a high cell density by Western blotting. (G) Confirmation of connexin 43 (Cx 43) silencing performed by quantitative RT-PCR (n = 3). And effects of connexin 43 silencing on the activation of caspase-9 at high cell density by Western blotting. Representative results of triplicate experiments. **p<0.01.