CsA inhibits ERK, JNK, and p38 activation and NF-κB nuclear translocation. (A) CsA inhibits MAPK activation. Day 5 murine BMDCs were treated with CsA (1 μg/mL) for 12 hours or stimulated with LPS (100 ng/mL) for 30 minutes, at the indicated concentrations. Total cell lysates were prepared and analyzed for phospho-ERK1/2 (p-ERK), phospho-JNK (p-JNK), and phospho-p38 (p-p38) expression. Unphosphorylated proteins were also detected using specific antibodies. (B) CsA inhibits LPS-induced I-κBα activation. BMDCs were treated as in panel A. (C) CsA inhibits LPS-induced NF-κB nuclear translocation. Nuclear proteins were extracted from cells, treated as above, and Western blotted for NF-κBp65. (D) CsA inhibits the activation and degradation of I-κBα induced by pulsing with LPS. BMDCs were stimulated with LPS/CsA as indicated. (E) PGE₂ restores the activation of I-κBα and NF-κBp65. BMDCs were treated as in panel A.