Fig. 4

Proliferation of human dermal fibroblasts cultured in the AF-MSC-CMs. a Optical images and relative growth rates of dermal fibroblasts after 3 days of culture in AF-MSC-CM (b/−), CM (−/s), and CM (b/s) obtained from AF-MSCs cultured with bFGF, selenium, or both, respectively. Scale bars, 1 mm. b Fluorescence images and relative quantification of BrdU-labeled AF-MSCs after 3 days of culture in AF-MSC-CM (b/−), CM (−/s), and CM (b/s). Scale bars, 1 mm. c Cell cycle progression of human dermal fibroblasts induced by AF-MSC-CM. d Senescence-associated mRNA expression level of human dermal fibroblasts induced by AF-MSC-CM. Error bars represent the mean ± SD of three independent experiments performed in triplicate. *p < 0.05, **p < 0.01