FIGURE 5. Apoptosis induced by incubating wild-type and iPLA₂β-null mouse peritoneal macrophages with thapsigargin and fucoidan and effects of restoring iPLA₂β expression to iPLA₂β-null macrophages with a recombinant adenovirus.

A, wild-type (WT) and iPLA₂β-knock-out (KO) macrophages were incubated without (Control) or with thapsigargin (thap) alone, fucoidan (Fuc) alone, or both (thap + Fuc), and percent apoptotic cells was determined as in Fig. 2. B, WT or KO macrophages were incubated (24 h) without stimuli (lightly cross-hatched bars) or were subjected to FCL (solid black bars) with Ac-LDL and ACAT inhibitor 58035, and percent apoptotic cells was determined. Checkered bar represents experiments in which iPLA₂β expression was restored recombinant adenovirus encoding iPLA₂β (PLA₂). Other cells were infected with control (C) virus without iPLA₂β coding sequence. Immunoblots for iPLA₂β and tubulin (C) illustrate iPLA₂β expression in macrophages infected with virus (V) versus control (C), wild-type (W), or iPLA₂β-knock-out (K) cells. Mean values ± S.E. are displayed (n = 6). Asterisk denotes p < 0.05 for WT versus KO.