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Updated: May 10, 2026

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
Published on: September 28, 2017
New evidence for cross talk between melatonin and mitochondria mediated by a circadian-compatible interaction with
Paolo Sarti1, Maria Chiara Magnifico, Fabio Altieri
1Department of Biochemical Sciences, Sapienza University of Rome, Rome 00185, Italy. paolo.sarti@uniroma1.it.
Abstract:
Extending our previous observations, we have shown on HaCat cells that melatonin, at ~10-9 M concentration, transiently raises not only the expression of the neuronal nitric oxide synthase (nNOS) mRNA, but also the nNOS protein synthesis and the nitric oxide oxidation products, nitrite and nitrate. Interestingly, from the cell bioenergetic point of view, the activated NO-related chemistry induces a mild decrease of the oxidative phosphorylation (OXPHOS) efficiency, paralleled by a depression of the mitochondrial membrane potential. The OXPHOS depression is apparently balanced by glycolysis. The mitochondrial effects described have been detected only at nanomolar concentration of melatonin and within a time window of a few hours' incubation; both findings compatible with the melatonin circadian cycle.
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