Preincubation with low dose of hydrogen peroxide enhances anti-oxidative stress potential of mouse BMSCs / 基础医学与临床

ABSTRACT

Objective To investigate the effects of preconditioning with low-concentration hydrogen peroxide ( H2O2 ) on oxidative stress-induced bone marrow mesenchymal stem cells ( BMSCs ) apoptosis and its mecha-nism.Methods Mouse bone marrow mesenchymal stem cells ( BMSCs) were isolated and purified by differential centrifugation, and were treated with 0,200,250,300, 500 μmol/L H2O2 after preincubation with 50 μmol/L H2O2 or control medium.Apoptosis of these cells was measured by flow cytometry, and the expression of phos-phorylated PI3K, Akt and mTOR was analyzed by Western blot; BMSCs were also primed with PI3K inhibitor LY294002 for 30 min, then preincubated with 50 μmol/L H2O2 or control medium for 12 h before treatment with 300 μmol/L H2O2.Expression of apoptosis proteins Bcl-2, Bax, caspaase-3, cleaved-caspase-3 and the key pro-teins of the PI3K/Akt/mTOR pathway were detected by Western blot .Results H2O2 induced BMSCs apoptosis in a dose-dependent manner ,and pretreatment of BMSCs with low concentration of H2O2 significantly decreased H2O2-induced apoptosis of the BMSCs .Western blot results revealed that preconditioning with low-concentration H2O2 re-markably reversed the decrease in Bcl-2, total and phosphorylated PI3K, Akt and mTOR levels, and increased in Bax, cleaved-caspase-3 expression after high-dose H2O2 treatment.Such effects were antagonized by PI3K inhibitor LY294002 .Conclusions Preincubation with low-concentration H2O2 may indnce resistance of BMSC to oxidative stress, and such effect may be mediated by inhibition of pro-apoptotic proteins and activation of the PI 3K/Akt/mTOR pathway .