Figure 6.

Lithium increases miR-124 expression, reduces REST abundance, and decreases protein deubiquitination in cortical neurons exposed to oxygen–glucose deprivation (OGD). Cultivated cortical neurons were exposed to OGD for 45 min and subsequently recultivated under standard cell culture conditions for 24 h. Cells were exposed to normal saline (control) or lithium (1 mM dissolved in normal saline) starting 24 h before OGD, while the GSK3β inhibitor SB216763 (1 µM dissolved in DMSO) was added at the end of OGD. (a) Cell death, evaluated using a Live/Dead Viability/Cytotoxicity kit, (b) miR-124 expression, assessed by RT-PCR, (c) REST abundance, analyzed by Western blots (using actin as housekeeping protein for controlling protein loading), and (d) protein deubiquitination, measured by ubiquitin-AMC (always n = 4 independent experiments or samples). Note that the GSK3β inhibitor SB216763 similar to its solvent DMSO did not affect miR-124 expression in (b), indicating that miR-124 induction by lithium was independent of lithium’s GSK3β inhibitory activity. *Significantly different from controls with p:0.047 (a), p:0.034 (b), p:0.036 (c), and p:0.002–0.027 (d).