Nanomolar melatonin enhances nNOS expression and controls HaCaT‐cells bioenergetics

• Published in: IUBMB life 2012-03, Vol.64 (3), p.251-258
• Main Authors: Arese, Marzia, Magnifico, Maria Chiara, Mastronicola, Daniela, Altieri, Fabio, Grillo, Caterina, Blanck, Thomas J. J., Sarti, Paolo
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Antioxidants - pharmacology; Blotting, Western; Cells, Cultured; Energy Metabolism - drug effects; free radicals; general bioenergetics; Humans; Keratinocytes - cytology; Keratinocytes - drug effects; Keratinocytes - enzymology; Lactic Acid - metabolism; Melatonin - pharmacology; Membrane Potential, Mitochondrial - drug effects; mitochondria; Mitochondria - metabolism; nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase Type I - genetics; Nitric Oxide Synthase Type I - metabolism; Nitrites - metabolism; Oxidation-Reduction; Oxidative Phosphorylation; oxygen metabolism; reactive oxygen species; Real-Time Polymerase Chain Reaction; RNA, Messenger - genetics
• ISSN: 1521-6543; 1521-6551
• DOI: 10.1002/iub.603

A novel role of melatonin was unveiled, using immortalized human keratinocyte cells (HaCaT) as a model system. Within a time window compatible with its circadian rhythm, melatonin at nanomolar concentration raised both the expression level of the neuronal nitric oxide synthase mRNA and the nitric oxide oxidation products, nitrite and nitrate. On the same time scale, a depression of the mitochondrial membrane potential was detected together with a decrease of the oxidative phosphorylation efficiency, compensated by glycolysis as testified by an increased production of lactate. The melatonin concentration, ∼ nmolar, inducing the bioenergetic effects and their time dependence, both suggest that the observed nitric oxide‐induced mitochondrial changes might play a role in the metabolic pathways characterizing the circadian melatonin chemistry. © 2012 IUBMB IUBMB Life, 2012