Effect of oxidative stress-induced autophagy on proliferation and apopto-sis of MSCs / 中国病理生理杂志

AIM:To investigate whether oxidative stress is able to induce autophagy in mesenchymal stem cells (MSCs), and to explore the effects of autophagy on MSC proliferation and apoptosis under oxidative stress circumstance as well as the underlying mechanism for promoting the therapeutic effects of transplanted MSCs on treating diabetes mellitus e -rectile dysfunction ( DMED) .METHODS: Hydrogen peroxide ( H2 O2 ) was applied to simulate the oxidative stress cir-cumstance.The effects of H2 O2 at concentration of 0, 50, 100, 200, 400μmol/L on the viability of MSCs were tested by the method of Trypan blue exclusion and MTT assay respectively .The methods of MTT assay , Western blot and transmis-sion electron microscope ( TEM) were used to explore the effects of H 2 O2 on MSC apoptosis and autophagy .RESULTS:The proliferation of MSCs was obviously inhibited by H 2 O2 in a dose-dependent manner ( P<0.01) and the 50%inhibiting concentration (IC50) was (384.58 ±16.89) μmol/L.H2O2 induced apoptosis and autophay of MSCs .The proliferation rate of MSCs was suppressed by H 2 O2 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 MSCs apoptosis obviously (P<0.05), with an augment of apoptosis ( P<0.05) by blockade of autophagy .Furthermore, the H2 O2 increased expression of cleaved caspase-3 and cleavage of poly ADP-ribose polymerase 1 (PARP1), Which were decreased by apoptosis blockade whereas were enhanced by blockade of autopahgy .CONCLUSION:Oxidative stress plays a dual role in MSC survival , which in-duces MSC apoptosis and autophagy .Moreover , blockade of autophagy intensifies MSC apoptosis .Therefore , it is a promis-ing method to ameliorate the effects of stem-cell based therapy on DMED by enhancing protective autophagy to increase the survival rate of transplanted MSCs against oxidative stress circumstance caused by diabetes mellitus .

Sexual and reproductive health issues and their causes of adolescents in developing countries / 中华医学教育探索杂志

Developing countries are facing a big challenge of how to promote sexual and reproductive healthe Poverty erasion.reproductive health service promotion,schools and communities intervention,discussion between children and their parents encouragment are helpful to solve the sexual and reproductive problems with the adolescents