Effect Of Oxidative Stress-induced Autophagy On Proliferation And Apoptosis Of Mscs

Objective: By investigating whether oxidative stress is able to induce autophagy in MSC, and exploring the effects of autopahgy on MSC survival and apoptosis under oxidative stress circumstance as well as the underlying mechanism, we sought to promote the therapeutic effects of transplanted MSC on diabetes mellitus erectile dysfunction（DMED）.Methods: Hydrogen peroxide（H₂O₂） was applied to simulate the oxidative stress circumstance. The effects of various concentration of H₂O₂（0, 50, 100, 200, 400 μmol/L） on the viability of MSC was tested by Trypan blue and MTT assay. A combination of methods of MTT assay, Western blotting, and transmission electron microscope（TEM） were used to explore the effects of H₂O₂ on MSC apoptosis and autophagy.Results: The proliferation of MSC was obviously inhibited by H₂O₂ in a dose-dependent manner（P<0.001） and the 50% inhibiting concentration（IC50） was 384.5751±16.8895 μmol/L. H₂O₂ induced apoptosis as well as autophay. The proliferation rate of MSC was suppressed by H₂O₂ significantly（P<0.05）, with a further decline by blockade of autophagy（P<0.05） whereas increased by blockade of apoptosis（P<0.05）. H₂O₂ induced MSC apoptosis obviously（P<0.05）, with an augment of apoptosis（P < 0.05） by blockade of autophagy accompanying by a decreased apoptosis（P<0.05） with blockade of apoptosis. Furthermore, Western blot indicated that H₂O₂ increased cleaved-Caspase3 expression and cleavage of poly ADP-ribose polymerase 1（PARP-1）, with the attenuated expression of cleaved-Caspase3 and cleavage of PARP-1 by apoptosis blockade whereas both of them were enhanced by blockade of autopahgy.Conclusion: Oxidative stress plays a dual role in MSC survival, which induces MSC apoptosis as well as protective autophagy. Moreover, Blockade of autophagy intensifies MSC apoptosis. Therefore, it is a promising method to ameliorate effects of stem-cell based therapy on DMED by enhancing protective autophagy to increase the survival rate of transplanted MSC against oxidative stress circumstance caused by diabetes mellitus.