Figure 2: hBM-MSC Proliferation and Migration Decreased and the Senescence Phenomenon Increased With Age

(A) Representative micrographs of immunofluorescent staining for bromodeoxyuridine (BrdU) (red) with nuclei stained blue with DAPI. Arrows indicate BrdU+ cells. (B) The percentage of BrdU+ cells significantly decreased with age, n = 5/group. The rate of cell growth was significantly higher in young hBM-MSCs compared with old cells, n = 5/group. (C) Representative images show the cell migration of hBM-MSCs from the wound-scratch assay. Migration rates were significantly higher in infant and young cells compared with old cells, n = 3/group. (D) Western blot analyses of protein cyclin-dependent kinase inhibitor 2A (p16) and regucalcin (RGN) protein levels in hBM-MSCs revealed an obvious senescence phenomenon with significantly increased p16 and significantly decreased RGN expression in old compared with infant and young cells, n = 3/group. (E) The RGN protein level negatively correlated with age. The list of x (age) and y (RGN [regucalcin] protein level) was analyzed using a correlation regression analysis. Abbreviations as in Figure 1.