Figure 7
Sodium influx does not occur in the course of apoptosis, and potassium and calcium influx are not detected during necroptosis of L929 cells. (A) Representative time-lapse images of RIP1 KO L929 cells undergoing apoptosis induced by TNF (10 ng/ml). The intracellular sodium concentration was measured by fluorescence sodium indicator CoroNa Green and cell membrane integrity was monitored by PI uptake. Elapsed time is indicated on the left side of each frame and each scale bar represents 15 μm. (B) Relative changes in CoroNa Green and PI fluorescence over time in one representative cell shown in A were graphed. The stages of apoptosis and secondary necrosis of the selected single cell from A were indicated above dotted lines. (C) L929 cells loaded with calcium indicator Fluo-4, as described in Materials and Methods, were treated with TNF + zVAD (10 ng/ml + 20 μM). Relative changes in calcium indicator Fluo-4 and PI fluorescence over time in one representative cell were graphed. (D) Relative changes in potassium indicator PBFI and PI fluorescence over time in one representative L929 cell were graphed.
