Proliferation and senescence of HC-MSCs and KD-MSCs.

<p>(A) Representative images of HC-MSCs and KD-MSCs (magnification, ×40). Left columns show assessment of senescence using the senescence biomarker SA-β-gal (green) in HC-MSCs and KD-MSCs. Black scale bars represent 50 µm. Right columns show DAPI staining of senescence-associated heterochromatic foci (SAHF) in MSC DNA foci. White scale bars represent 10 µm. Insets show an enlargement of DAPI staining (white scale bars represent 5 µm). Early passage: P5; late passage: P10. (B) Quantitative assessment of SA-β-gal positive cells. Data are the mean ± SE (<i>n</i> = 4). ^*<i>P</i><0.05. (C) Cumulative population doublings (PDs) of HC-MSCs (<i>n</i> = 5) and KD-MSCs (<i>n</i> = 5) from passage 5–10. Data are expressed as the mean ± SE. ^*<i>P</i><0.05. Experiments were performed in triplicate.