Fig. 4.

Expression patterns of conserved irradiation response genes in BMSCs. Venn diagrams for up- (a) and downregulated (b) genes shared by the P6 and P10 BMSCs according to the DEG analysis. c The expression pattern of the upregulated genes: each cluster of genes was distinguished accordingly by colour. d Expression patterns of the downregulated genes: each cluster of genes was distinguished accordingly by colour. e Expression pattern of genes that were either upregulated or downregulated at both 8 h and 2 h after irradiation relative to 0 h. f Relative expression levels of GDF15, CDKN1A and MDM2 measured by RNA-seq (FPKM) (up) and qRT-PCR (down). For qPCR, actin was used as the reference gene, and non-irradiated P6 BMSCs were used as the control groups. g Western blotting to evaluate CDKN1A, GDF15, HUJRP and p53 expression. All western blots are representative of three independent experiments. h Representative immunofluorescence staining in BMSCs. DAPI (blue), HJURP (red), merged images and quantification of immunofluorescence intensity (right) were shown. The photos were selected randomly. Scale bar 50 μm. Data are represented as the mean ± SEM. Student’s t test was performed to compare P6 and P10 BMSCs with significance set at a P value of less than 0.05. *P < 0.05, **P < 0.01. The same letter (lowercase for P10 and uppercase for P6, respectively) indicates no significant difference among different post-irradiation time (Tukey HSD, P < 0.05)