Fig. 4.

A: enhanced expression of ER stress-responsive proteins in primary LECs obtained from aging human subjects. Western analysis is a representative of 24- and 64-yr-old subjects. Cell lysate was prepared from LECs isolated from lenses of young (18 or 24 yr old) and aging (63, 64, or 74 yr old) human subjects and analyzed by Western analysis. Protein blots were quantified using a densitometer, and levels were normalized to corresponding β-actin levels; histograms are shown beside the protein bands. B: ROS expression in aging and younger cells. Data represent means ± SD of three independent experiments. hLECs, human LECs. C: increased expression of Bip in cells after H₂O₂ exposure. Cells were treated with 50 μM H₂O₂ for 24 h, and cell lysate was prepared. A marked increase in the expression of Bip was observed in aged cells after H₂O₂ exposure (top). Results are derived from three independent experiments. *P <0.05, **P < 0.001.