Effects on both of senescence and apoptosis of collagen complexes. A) Senescence-associated β-galactosidase staining (blue) in Y-, Ac-, and A-fibroblasts. Magnification, × 200. B) Cell proliferation assay. Data are means ± SEM of three experiments performed in triplicate with p values < 0.05. C) Senescence-associated β-galactosidase staining in A-fibroblasts according to collagen types. D) Determination of apoptotic Y-, Ac-, and A- fibroblasts by FACS analysis. (down) Data were obtained from three independent experiments (means ± SD; lower panel; P < 0.05). Groups marked with different letters (a–c) are significantly different from each other at P < 0.05.