Figure 6

Characterization of the eIF-5A2 transgenic MEF cells. (A) Senescence associated β-galactosidase staining in transgenic and wild-type MEFs. No difference was observed between these two MEFs. (B) Western blot analysis of lysates from transgenic and wild-type MEFs showed activation of eIF-5A2 repressed p19 level and therefore destabilized p53 and consequently repressed p21 in transgenic MEFs. (C) The replication capacity of both MEFs were measured by seeding 1 × 10⁴ cells into one well of 6-well plate and counted every 3 days. Both wild-type and transgenic MEFs proliferated normally until passage 4 and proliferation capability declined during later passages (p5 and p6). (D, E) The comparison of cell growth curves of transgenic and wild-type MEFs in 10% serum (D) and 1% serum (E). The cell growth rate was significantly higher in transgenic MEFs than in wild-type MEFs (p < 0.05). (F) Increased telomerase activity was detected in eIF-5A2 transgenic mice compared with their wild-type siblings. Protein extracted from HeLa cells was included as positive (+). A 36-bp internal standard was used as a control (IC) in the assay: the bands were weaker in samples with excessively high telomerase activity because amplification of the TRAP products and the IC bands were semicompetitive.