The effect of Nr1d1 overexpression on cell senescence. (A) Cell proliferation of young Sca-1+CD31− cells transduced with Nr1d1-cDNA lentiviral as indicated by the embedding of EdU. The left panel shows a flow cytometric analysis of a representative Edu embedding, and the right panel shows a statistical plot of Edu embedding. The data were from three independent experiments (n = 3). A two-tail unpaired t-test was applied for statistical analysis. p < 0.05 was considered significant. (B) MTT analysis of cell proliferation of MCM transduced with lentiviral Nr1d1-cDNA was detected. The data were from three independent experiments, and each experiment had three replicates (n = 9). A two-tail unpaired t-test was used for statistical analysis, and p < 0.05 was considered significant. (C,D) Apoptosis rate of young Sca-1+CD31− cells (C) and MCM (D) transduced with lentiviral Nr1d1-cDNA analyzed by FCM with annexin V-PE/7-AAD staining. The left panel is a representative flow cytometric scatter plot, and the right panel is quantification of apoptosis. The data were from three independent experiments (n = 3). A two-tail unpaired t-test was applied for statistical analysis, and p < 0.05 was considered significant; (E) senescence-associated beta-galactosidase staining of MCM transduced with lentiviral Nr1d1-cDNA. Control was transduced with an empty lentivector. The image on the left panel is a representative field of view. The scale bars: 50 μm. The bar graph on the right panel shows the number of cells that were stained blue in each random field of view. Each experiment was repeated three times, and 10 random fields of view were counted (n = 10). A two-tail unpaired t-test was used for statistical analysis, and p < 0.05 was considered significant; (F,G) cell cycle analysis by FCM for young Sca-1+CD31− cells (F) and MCM (G) cells transduced with lentiviral Nr1d1-cDNA. The data were collected from three independent experiments (n = 3), two-way ANOVA was applied for statistical analysis, and p < 0.05 was considered significant. All data in bar graph presented as mean ± SD. Ctrl: control, OE: overexpression.