mTOR Inhibition Rejuvenates the Aging Gingival Fibroblasts through Alleviating Oxidative Stress

Figure 2

mTOR inhibition protects human gingival fibroblasts from loss of proliferative capacity. (a) Cumulative population doubling from a representative culture of primary hGFs in control conditions or in the continuous presence of rapamycin. Each dot represents a passage. (b, c) Continuous presence of rapamycin doubles the average of the days before replicative senescence and the maximum cumulative population doublings from three different cultures of hGFs. (d) Representative pictures and quantification of the nuclei (blue), the proliferation marker Ki-67 (red), and cytoskeletal protein actin (green). Staining was performed in low passage of hGFs (LP), high passage of hGFs (HP), and high passage of hGFs treated with rapamycin for 30 d (HP + 30 d RAPA). Graphs show the percentage of the Ki-67+ cells (percentage of Ki-67+ cells/total cells) ( means , means , and means , compared with the high-passage group).

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