Creatine protects and improves the morpho-functional differentiation of neuroblasts in spinal cord primary cultures

Aim: Creatine (Cr) is an essential component of Cr/Cr-phosphate system. Recent papers on different cell lines showed that Cr supplementation protects from cell death following radical insult by improving cell energy balance and/or exerting an antioxidant action. Neurons are known to have a low capacity to synthesize Cr and the relevance of oxidative stress-related mechanisms in the pathogenesis of several neurodegenerative diseases (ALS, Ataxia, Parkinson) is known. We studied the effects of Cr supplementation on primary cell cultures obtained from chick spinal cord embryo following oxidative stress. Methods: Neuroblast cultures were evaluated for viability (MTT test), morphological differentiation by Neuron J software and functional differentiation by whole-cell patch-clamp, in control conditions and following a treatment with hydrogen peroxide. Results: Hydrogen peroxide (20 mM) caused a significant decrease of viability and neurite/neuroblast extension length. Both actions were fully reversed by preincubation with Cr 10 mM. Protective effect of Cr was absent if Cr membrane transporters were blocked by b-guanidine propionic acid, thus demonstrating a cytosolic action of Cr. Moreover, electrophysiological studies demonstrated that Cr supplementation increases Na+ e K+ currents with respect to controls. Conclusions: Our results suggest that Cr is able to protect neurons from oxidative stress. Moreover, the increase in Na+ e K+ currents recorded in neuroblasts leads to suppose a higher number of voltage-dependent ion channels in membrane, indicating a possible role of Cr in functional differentiation of neurons.