RÉSUMÉ
BACKGROUND:Autoimmune regulator gene(Aire)and Wnt signaling pathway play an important role in the maintenance and differentiation of mouse embryonic stem cell pluripotency.However,whether the Wnt signal and Aire are involved in the differentiation of embryonic stem cells to thymic epithelial progenitor cells remains poorly understood. OBJECTIVE:To investigate the relationship of the Wnt signaling pathway and Aire with the differentiation of embryonic stem cells. METHODS:A two-step differentiation method was used to induce mouse embryonic stem cells to differentiate into endoderm and then into thymic epithelial progenitor cells.Mouse embryonic stem cells were infected with Aire shRNA lentivirus,and monoclonal stable strains were screened by puromycin.Mouse embryonic stem cells were collected on days 0,3 and 10 of the directed induction of differentiation after the induced differentiation by the two-step differentiation method.Cellular immunofluorescence,flow cytometry,western blot assay,and real-time qPCR were used to detect the expression changes of related genes and proteins. RESULTS AND CONCLUSION:(1)Immunofluorescence staining showed positive expression of SSEA1 and OCT4 on day 0 of targeted induction of differentiation.(2)Immunofluorescence staining showed double-positive expression of SOX17 and FOXA2 on day 3 of targeted induction of differentiation.(3)Flow cytometry results showed positive expression of EPCAM1,K5 and K8 on day 10 of targeted induction of differentiation.(4)Compared with undifferentiated mouse embryonic stem cells,the expressions of Wnt7a,β-catenin,and Gsk-3β proteins were elevated,and the expression level of Aire protein was decreased in induced differentiated thymic epithelial progenitor cells.(5)Compared with undifferentiated mouse embryonic stem cells,the expressions of Wnt7a,β-catenin,Gsk-3β and Aire mRNA were elevated in thymic epithelial progenitor cells.(6)Compared with normal cultured mouse embryonic stem cells and their ultimately differentiated thymic epithelial progenitor cells,the expression levels of Wnt7a,β-catenin and Gsk-3β proteins were reduced in mouse embryonic stem cells with knockdown of Aire genes and their final differentiated thymic epithelial progenitor cells.In conclusion,the Wnt signaling pathway and Aire are jointly involved in the process of targeted induction of differentiation of mouse embryonic stem cells into mouse thymic epithelial progenitor cells.
RÉSUMÉ
BACKGROUND:The occurrence and development of various ophthalmic diseases are closely related to excessive oxidative stress,and the inhibition of oxidative stress response may produce preventive and therapeutic effects. OBJECTIVE:To explore the role of Pax6 gene expression on hydrogen peroxide-induced aging of mouse bone marrow mesenchymal stem cells(BM-MSCs). METHODS:Resuscitated BM-MSCs,Pax6/BM-MSCs,and shPax6/BM-MSCs were treated with hydrogen peroxide for 24 hours,and then β-galactosidase staining was performed.The proliferation index Ki67 expression and apoptosis were detected by flow cytometry.The expression of senescence-associated molecules(Wnt7a,p21,and p53)was detected by RT-PCR. RESULTS AND CONCLUSION:(1)After hydrogen peroxide treatment,the cells of the three groups showed senescence phenotype and β-galactosidase staining was positive.Compared with BM-MSCs group,the expression of positive cells in Pax6/BM-MSCs group was less and that in the shPax6/BM-MSCs group was more,and the difference was statistically significant(P<0.05).(2)The results of flow cytometry showed that compared with BM-MSCs group,the positive expression of Ki67 in the Pax6/BM-MSCs group increased and the level of apoptosis decreased,while the positive expression of Ki67 decreased and the level of apoptosis increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(3)RT-PCR showed that compared with the BM-MSCs group,the expression of Wnt7a,p53,and p21 decreased in the Pax6/BM-MSCs group,while the expression of Wnt7a,p53,and p21 increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(4)These findings indicate that overexpression of Pax6 can antagonize the aging progression of BM-MSCs induced by hydrogen peroxide,which may be related to Wnt signaling pathway.