Optimization of oxidative preconditioning of hWJ-MSCs to overcome oxidative stress

Aim. It has been shown that biological properties of MSCs can be modulated by preconditioning of MSCs under specific culture conditions. Our study aimed to evaluate the effects of different H2O2 concentrations during oxidative preconditioning of hWJ-MSCs to overcome subsequent severe oxidative stress and reduce cytotoxic effects. Methods. MSCs were derived from human umbilical cord, cultured as monolayers according to standard methods. Oxidative stress was induced by hydrogen peroxide (H2O2). Treated WJ-MSCs were analyzed for metabolic activity and survival by MTT assay. Results. Our findings indicated that preconditioning of WJ-MSCs with 10, 20, 30 and 40 μM H2O2 for 24 h enhanced their survival under toxic H2O2-doses and survival rates varied between different modes of preconditioning and levels of severe stress. The maximum protective effect was observed at 10 μM H2O2 preconditioning for 300 μM H2O2 severe stress. Simultaneouly, the maximum adaptive response to a stress level of 500 μM was detected only after preconditioning with 30 μM H2O2. Conclusions. Our results demonstrate that the H2O2 preconditioning of WJ-MSCs could induce the cell-survival adaptive response to subsequent severe oxidative stress. However, benefit of preconditioning depends on the H2O2 concentration under preconditioning, the level of oxidative stress, and the characteristics of MSCs from a particular cell donor.