Modulation of the matrix redox signaling by mitochondrial Ca2+

Figure 3 Proposed model for the modulation of the matrix redox signaling by mitochondrial Ca²⁺. After cell stimulation, Ca²⁺ released from the endoplasmic reticulum (ER) enters in mitochondria by the mitochondrial uniplex (left), stimulating matrix Ca²⁺-dependent dehydrogenases, which increase NADH levels and promoting a reduction of the mitochondrial glutathione pool. In cells over-expressing the mitochondrial Na⁺/Ca²⁺ exchanger (NCLX, right) Ca²⁺ extrusion is more efficient and therefore Ca²⁺-dependent dehydrogenases less activated. Such lowering the mitochondrial Ca²⁺ response blunts NADH formation and prevents matrix redox changes of the mitochondrial glutathione pool. NADH: Reduced form of nicotinamide-adenine dinucleotide; NCLX: Mitochondrial Na⁺/Ca²⁺ exchanger.