Alpha B-Crystallin Overexpression Protects Oligodendrocyte Precursor Cells Against Oxidative Stress-Induced Apoptosis Through the Akt Pathway.

Alpha B-crystallin (aBC), a member of the small heat shock protein family, is expressed in mature oligodendrocytes (mOLs), but not in oligodendrocyte precursor cells (OPCs). Our previous study found that the survival rate of OPCs was lower than that of mOLs under oxidative stress, suggesting that aBC may play a protective role in mOLs. In the present study, we investigated the effects of aBC overexpression on oxidative stress-induced cell injury in OPCs and examined the underlying mechanisms. We observed that the survival rates of aBC-overexpressed OPCs were significantly higher than those of control cells under oxidative stress induced by hydrogen peroxide. Akt activities were significantly suppressed by oxidative stress in control OPCs, but not in aBC-overexpressed OPCs. The expressions of Bax and cleaved caspase-3 were decreased, whereas Bcl-2 expression was increased in aBC-overexpressed OPCs under oxidative stress. These findings suggest that low Akt activity in OPCs due to aBC deficiency may cause high susceptibility of OPCs to oxidative stress. The findings may provide new insights into the implication of OPCs in demyelinating diseases.