[OXIDATIVE STRESS-PROMOTED RESPONSES IN HUMAN ENDOMETRIAL STEM CELLS AND LUNG EMBRYONIC FIBROBLASTS]

Human mesenchymal stem cells are an attractive cell source for tissue engineering. During transplantation they may be subjected to oxidative stress due to unfavorable cellular microenvironment, which is characterized by increased levels of reactive oxygen species. Recently, we have demonstrated that oxidative stress responses of human mesenchymal stem cells derived from endometrium (hMESCs) depend upon the oxidizer concentration. Besides, the duration of the H2O2-treatment duration. The effects of the high H2O2 doses on hMESCs and human lung embryonic fibroblasts were compared. In both cell types, H2O2-treatment for 60 min was shown to promote the multiphase cell cycle arrest, as well as to the dose-dependent cell death that occurred equally from all phases of cell cycle. However, the cell death dynamics in hMESCs and fibroblasts were different. Interestingly, in both cell types, shortening of H2O2-treatment duration from 60 to 10 min induced growth retardation, G1-phase accumulation and the cell size increase. Together, these findings allow us to suggest an induction of the premature senescence as a result of the short cell exposure to the high H2O2 doses. Thus, regarding both human endometrial stem cells and human embryonic fibroblasts, shortening of oxidative stress duration induced by high H2O2 doses enables to avoid the cell death and to produce the features of the premature senescence.