Study On The Repair And Mechanism Of MiPS On Radiation Injury In Mice

Objective:The aim of this study was to establish a stable mouse pluripotent stem cell(miPS)culture system and to explore the repair effect of miPS in the treatment of radiation-induced diseases in mice,so as to provide a theoretical basis for the treatment of radiation diseases.Methods:The experiment is divided into two parts,the first part is the cultivation of pluripotent stem cells.Firstly,the isolation,culture and detection of primary MEF in ICR male mice were determined to be non-mycoplasmic contamination and could be used as a trophoblast for miPS.The miPS was then inoculated on mitomycin C-treated MEF for subculture,and a stable miPS culture system was established by biological characteristics and undifferentiated characteristics.The second part of 100 ICR mice were randomly divided into four groups:Control group,NaCl group,NaCl+iPS group and iPS+iPS group.Control group:No radiation,only saline injection.The latter three groups received6 MeV electron radiation source for 8 Gy single whole body irradiation(radiation dose rate 1.0 Gy/min).NaCl group:normal saline was injected into tail vein 12 hours and 24hours after irradiation;NaCl+iPS group:miPS cell suspension(3*10~6/time/200 ul)and saline of equal volume were injected into tail vein 12 hours and 24 hours after irradiation;iPS+iPS group:miPS cell suspension was injected into tail vein 12 hours and 24 hours after irradiation,respectively.One day,three days,seven days and fourteen days after injection,the living condition of mice was observed,the survival rate was recorded,and the hemographic indexes were detected;the intestinal pathological morphological changes,intestinal recess and apoptosis were observed;the pathological changes of spleen and splenic index,splenic nodule analysis were performed to determine the expression of apoptotic genes and inflammatory genes;the liver pathological morphological changes were observed,and the antioxidant index of liver was determined.Malondialdehyde(MDA)content,superoxide dismutase activity(SOD)and fibrosis gene expression.Results:A stable culture system of miPS cells was established to provide high quality cell sources for future research and application of miPS cells.The mortality rate of mice in NaCl group was significantly higher than it in the control group,and the ratio of white blood cells,red blood cells,platelets,hemoglobin and lymphocyte was in a declining state,while the ratio of neutrophils was increased.Compared with NaCl group,the pathological changes of spleen,liver and intestine were observed in NaCl group,NaCl+iPS group and NaCl group,while those in iPS+iPS group improved significantly with time.In terms of oxidation,apoptosis and inflammation,the NaCl group suffered severe injury compared with the Control group.Compared with the NaCl group,the iPS group had regenerative repair effect in these aspects.Conclusion:This study shows that the radiation repair effect of miPS on the blood system and immune system is attributed to its ability of regenerative therapy.The damage of oxidative stress,apoptosis,inflammation and inflammation-induced fibrosis induced by ionizing radiation were all improved.