The IKK-NF-κB pathway is activated in LRP-1-deficient cells. (A) PEA-10 and MEF-2 cells were treated with TNF-α (50 ng/mL) or with vehicle for 10 minutes. Equal amounts of cell extract were subjected to immunoblot analysis for phosphorylated IKK, total IKK, phosphorylated IκB, total IκB, phosphorylated NF-κB, total NF-κB, and tubulin. (B) PEA-10 and MEF-2 cells were transfected with pNF-κB-Luc to measure NF-κB activity. Cells were treated with TNF-α (50 ng/mL) or vehicle. Luciferase activity was measured 6 hours later. Error bars represent SD. (C) CL-16 and shLRP-1 cells were treated with TNF-α (50 ng/mL) or with vehicle for 10 minutes. Equal amounts of cell extract were subjected to immunoblot analysis for total IKK, phosphorylated IκB, and total IκB.