Ketone bodies are considered alternative fuels for the brain when glucose availability is limited. To determine the neuroregenerative potential of D,L-sodium-beta-hydroxybutyrate (D/L-BHB), Sprague Dawley rat primary cortical neurons were exposed to simulated central nervous system injury using a scratch assay. The neuronal cell migration, cell density and degree of regeneration in the damaged areas (gaps) in the absence (control) and presence of BHB (2 mM) were documented with automated live-cell imaging by the CytoSMART system over 24 h, which was followed by immunocytochemistry, labeling synapsin-I and β3-tubulin. The cell density was significantly higher in the gaps with BHB treatment after 24 h compared to the control. In the control, only 1.5% of the measured gap areas became narrower over 24 h, while in the BHB-treated samples 49.23% of the measured gap areas became narrower over 24 h. In the control, the gap expanded by 63.81% post-injury, while the gap size decreased by 10.83% in response to BHB treatment, compared to the baseline. The cell density increased by 97.27% and the gap size was reduced by 74.64% in response to BHB, compared to the control. The distance travelled and velocity of migrating cells were significantly higher with BHB treatment, while more synapsin-I and β3-tubulin were found in the BHB-treated samples after 24 h, compared to the control. The results demonstrate that D/L-BHB enhanced neuronal migration and molecular processes associated with neural regeneration and axonogenesis. These results may have clinical therapeutic applications in the future for nervous system injuries, such as for stroke, concussion and TBI patients.
Keywords: BHB; beta-hydroxybutyrate; cell migration; exogenous ketones; ketone salt; neural injury; neuroplasticity; scratch assay; synapsin; tubulin.