Modes of Mitochondrial Reactive Oxygen Species Production in Inflammation.

Background: Inflammation is one of the most important pathways in innate immunity and its relationship with redox biology is becoming increasingly clear in the last decades. However, the specific redox modes and pathways by which inflammation is produced are not yet well defined. Significance: In this review, we provide a general explanation of the reactive oxygen species (ROS) production and quenching modes occurring in mammalian mitochondria, as well as a summary of the most recent advances in mitochondrial redox biology and bioenergetics regarding sodium (Na⁺) homeostasis. In addition, we provide a collection of examples in which several inflammatory pathways have been associated with specific modes of either mitochondrial ROS production or quenching. Innovation: The role of Na⁺ in mitochondrial biology is being developed. Since its discovery as a second messenger, the research of its role in the immune system has emerged. Now, the role of Na⁺ in mitochondrial bioenergetics has recently been identified, which owns unprecedented applications. The potential implication of Na⁺ in inflammatory mechanisms grows as its role does not only cover ROS production and respiration but also the control through the management of mitochondrial membrane potential. Future directions: Na⁺ is becoming relevant for mitochondrial biology. Thus, processes regarding mitochondrial bioenergetics, redox state, or metabolism may probably need to include the study of Na⁺ in their road map. Some of these pathways are involved in inflammation and more are possibly to come. This review is expected to serve as a bridge between both fields. Antioxid. Redox Signal. 00, 000-000.