Sarti Paolo, Magnifico Maria Chiara, Altieri Fabio, Mastronicola Daniela, Arese Marzia
Department of Biochemical Sciences, Sapienza University of Rome, Rome 00185, Italy.
Int J Mol Sci. 2013 May 28;14(6):11259-76. doi: 10.3390/ijms140611259.
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.
扩展我们之前的观察结果，我们在HaCaT细胞上发现，褪黑素在~10-9 M浓度时，不仅能短暂提高神经元型一氧化氮合酶（nNOS）mRNA的表达，还能促进nNOS蛋白的合成以及一氧化氮氧化产物亚硝酸盐和硝酸盐的生成。有趣的是，从细胞生物能量学的角度来看，激活的与NO相关的化学反应会导致氧化磷酸化（OXPHOS）效率轻度降低，同时线粒体膜电位也会下降。OXPHOS的降低显然由糖酵解来平衡。所描述的线粒体效应仅在纳摩尔浓度的褪黑素下以及数小时的孵育时间窗口内检测到；这两个发现都与褪黑素的昼夜节律周期相符。
