FIG. 5.

Copper and pro-inflammatory cytokines down-regulate LRP1 in microvascular endothelial cells. Human primary microvascular endothelial cells (MVECs) were exposed to copper or human recombinant IL-1β, IL-6 or TNFα for 24 h, and the steady-state levels of LRP1 was quantitatively measured by immunoblot. A, Copper down-regulates LRP1 in MVECs in a concentration-dependent manner. B, Transferrin receptor (TfR) was not altered in MVEC exposed to copper. C, IL-1β, IL-6 or TNFα alone also significantly down-regulates LRP1 in MVECs in a concentration-dependent manner. Each graph represents mean ± S.E.M. of 3 separate experiments (n = 6–9). *P < 0.05 or **P < 0.01 compared to the control group.