Enhanced neuroprotective effect of mild-hypothermia with VPA against ethanol-mediated neuronal injury

Progress in understanding pathophysiological mechanisms and the development of targeted regenerative strategies have been hampered by the lack of predictive disease models, specifically for the conditions to which affected cell types are inaccessible. The present study has aimed to unearth the role of valproic acid (VPA) and mild hypothermia (MH) as promising strategy to enhance the neuroprotective mechanisms in undifferentiated and differentiated human neural precursor cells (hNPCs) against ethanol-induced damage.

5mM VPA alone or in combination with MH (33°C) was used to prevent the damage in proliferating and differentiating hNPCs. CD133+ve enriched hNPCs were cultured in vitro and exposed to 1M chronic ethanol concentration for 72h and followed by VPA and MH treatment for 24h. Morphometric analysis was performed to identify changes in neurospheres development and neuronal cell phenotypes. Flow cytometry and RT-qPCR analysis was performed to investigate alterations in key molecular pathways involved in cell survival and signaling.

Combination of VPA with MH displayed higher proportion of neuronal cell viability as compared to single treatment. Combination treatment was most effective in reducing apoptosis and reactive oxygen species levels in both the undifferentiated and differentiated hNPCs. VPA with MH significantly improved neuronal cell phenotype, active chromatin modeling, chaperon and multi-drug resistant pumps activity and expression of neuronal signaling molecules.

The study provided an efficient and disease specific in vitro model and demonstrated that combined treatment with VPA and MH activates several neuroprotective mechanisms and provides enhanced protection against ethanol-induced damage in cultured undifferentiated and differentiated hNPCs.