HO-1 and ferritin induction by HbLDL. Dose-dependent induction of HO-1 by HbLDL in RAECs (A) and MPHs (B); time course of HO-1 induction in RAECs (C) and MPHs (D); ferritin (heavy chain) induction in MPHs (E). The diagrams represent corresponding optical densities normalized on β-actin levels, calculated as percent of nLDL and presented graphically. Cells grown in 12-well dishes were treated with increasing amounts of LDL and HbLDL for 24 hours, or in the case of time-course studies with 100 μg/mL LDL-protein, for indicated time intervals. HO-1, ferritin, and β-actin from lysates were visualized by immunoblotting after SDS-PAGE on 12% polyacrylamide gels. Experimental details are described in “Materials and methods.”