FIGURE 8.

FGF12 internalization is responsible for its anti-apoptotic effects. A, TAT peptide coding sequence was fused to the coding sequence for the C-terminal end of Δ140–181 (Δ140–181/TAT). FGF12B and protein Δ140–181 were produced without fusion to a Nus Tag, whereas protein Δ140–181/TAT was fused to a Nus tag. B, IEC6 cells were incubated in complete medium with 1 μg/ml of Alexa Fluor 568-labeled FGF12B, Δ140–181, or Δ140–181/TAT. They were analyzed in a time course up to 48 h by flow cytometry to estimate fluorescence intensity. C, 10 μg of FGF12B, Δ140–181, or Δ140–181/TAT was administered intraperitoneally without heparin to BALB/c mice 24 h before TBI at 12 Gy, and apoptosis in the crypts of the jejunum was evaluated by TUNEL assay 24 h after TBI. All values are means ± S.D. (n = 6). Similar findings were observed in two independents experiments. *, p < 0.05; **, p < 0.01; ***, p < 0.001.