Figure 4: NDNF Transduction Rejuvenated Old hBM-MSCs by Increasing Proliferation and Suppressing the Senescence Phenomenon

(A) Representative micrographs of immunofluorescent staining for BrdU (red) with nuclei stained blue with DAPI. Arrows indicate BrdU+ cells. The percentage of BrdU+ cells was significantly higher in NDNF-transduced (NDNF+old) compared with empty vector–transduced (old) hBM-MSCs, n = 5/group. (B) Cell growth curves showed that the growth rate was significantly higher in NDNF-transduced cells, n = 5/group. (C) Representative images show the cell migration of hBM-MSCs from the wound-scratch assay. There was no significant difference in migration rate between the 2 groups, n = 6/group. (D) Western blot showed that the expression of the senescence-associated (SA) protein p16 significantly decreased and RGN significantly increased in NDNF-transduced cells 12 days after transduction, n = 5/group. (E) Representative micrographs of senescence-associated β-galactosidase (β-gal) staining and quantification of β-gal+ cells. The percentage of β-gal+ cells was significantly higher in empty vector–transduced (old) hBM-MSCs compared with NDNF-transduced (NDNF+old) hBM-MSCs, n = 5/group. Abbreviations as in Figures 1 and 2.