Fig. 4.

Alterations in calpain activity and expression of MHC-I, p-ERK 1/2, NF-κB, and I-κB by the calpain inhibitor. Cells were treated with IFN-γ (500 units/ml) for 24 hr. Calpeptin (1 and 5μM) was added 5 min after the IFN-γ addition. (A) Determination of percent changes in calpain activity (n = 3). (B) Representative Western blots to show levels of 41 kD MHC-I, 44/42 kD p-ERK 1/2, 65 kD NF-κB, 37 kD I-κB, and 42 kD β-actin. (C) Determination of percent changes in 41 kD MHC-I (n = 4) and 44/42 kD p-ERK 1/2 (n = 5) expression based on Western blotting. (D) Determination of NF-κB:I-κB ratio based on Western blotting (n = 3).