Figure 2. Expression of heat shock proteins during ARPE-19 senescence. (A) Immunoblot of HSP90α, HSP70, HSC70, BIP, HSPB1 (HSP27), HSPB5 (αB-crystallin) and β-actin in ARPE-19 cells treated with H2O2 in the same way as Figure 1B. (B) Densitometry quantitation of protein bands in A in image J. The data shown are mean ± SD. The two-tailed unpaired t-test was used for statistical analysis (n = 3). (C–G) Quantitative PCR to measure the expression of HSP90α, BIP, HSC70, HSPB1 and HSPB5 in the cells treated with H2O2 the same way as A. The data were from three independent experiments. The two-tailed unpaired t-test was used for statistical analysis (n = 3).