Fig. 5. Active role of mitochondria in lipotoxic cell death of S. pombe. (A) Effects of mitochondrial inhibitors and other pharmacological agents on the nuclear morphology of DKO cells in conditioned rich medium (2 hours). Scale bar: 5 µm. (B) Viability of DKO cells in conditioned rich medium in the presence of various pharmacological agents (2 hours). Addition of DMSO or ethanol (used to dissolve drugs) into the control (conditioned rich medium only) did not produce any observable difference. (C) Effects of potassium cyanide (KCN) on log-phase DKO cells in rich medium and in treatments with DAG and ceramide. (D) Rh123 staining for mitochondrial membrane potentials at various growth phases in rich medium. (E) Oxygraphs showing the oxygen consumption of early stationary-phase wild-type and DKO cells in rich medium (from two independent experiments). Oxygen-consumption rates were determined from the slopes of the oxygraphs of signal (nmol oxygen/ml liquid phase, y-axis) versus time (x-axis). Red arrows mark the addition of KCN to ensure the drop of liquid-phase oxygen concentration was specific to mitochondrial respiration. (F) Oxygen-consumption rates of wild-type and DKO cells at various growth phases in rich medium. Values shown are means with s.e.m. from independent experiments (n3).