Mitochondrial protein kinase Cϵ (PKCϵ): emerging role in cardiac protection from ischaemic damage

Mitochondria mediate diverse cellular functions including energy generation and ROS (reactive oxygen species) production and contribute to signal transduction. Mitochondria are also key regulators of cell viability and play a central role in necrotic and apoptotic cell death pathways induced by cardiac ischaemia/reperfusion injury. PKC (protein kinase C) ϵ plays a critical role in cardioprotective signalling pathways that protect the heart from ischaemia/reperfusion. Emerging evidence suggests that the cardioprotective target of PKCϵ resides at the mitochondria. Proposed mitochondrial targets of PKCϵ include mitoK_ATP (mitochondrial ATP-sensitive K⁺ channel), components of the MPTP (mitochondrial permeability transition pore) and components of the electron transport chain. This review highlights mitochondrial targets of PKCϵ and their possible role in cardioprotective signalling in the setting of ischaemia/reperfusion injury.