| Popis: |
In brain, ATP regeneration from ADP is mainly based on the anaerobic glycolysis in astrocytes and the aerobic oxidation of astrocytic lactate by mitochondria in neurons. In contrast to other high energy- demanding tissues, such as heart, kidney or liver, for the cerebral energy metabolism fatty acids are a negligible source of input. Despite not being a fuel, polyunsaturated docosahexaenoic acid (DHA) is required for multiple cellular functions. Ca2 +-independent phospholipase A2 (iPLA2), which belongs to the enzyme family with highly tuned hydrolytic activity, is crucial for liberation of DHA from membrane phospholipids. Depending on the metabolic conditions, DHA can contribute by mild-uncoupling of mitochondria or by triggering the transcription of certain enzymes involved in the cellular antioxidative defense. Alternatively, DHA is able to enhance the production of reactive oxygen species, for example, by partially impairing the functionality of the mitochondrial electron transport chain. A growing number of reports uncover a combined role of iPLA2 and DHA for maintaining bioenergetic functions of mitochondria, the cellular power plants. |
