Cell culture

Human lung fibroblasts (HFL-1 cells), provided by Stem Cell Bank, Chinese Academy of Sciences (Shanghai, China), were cultured in high glucose DMEM, containing a 1% penicillin and streptomycin mixture and 10% FBS, and specifically used between passages 3 and 5. The medium was changed daily. To establish the CSE-induced senescent cell model, HFL-1 cells were cultured with 2.5% concentration of CSE for 7 consecutive days. The senescent cell model was identified by SA-β-GAL staining, western blot, quantitative real-time PCR (qPCR) and SASP detection.