Fig. 4.

Calpain inhibition prevents IL-1α nuclear localization. (A) IL-1α localization determined by confocal microscopy of HT1080 fibrosarcomas with indicated treatments. The calpain inhibitor (MDL28170) was used at a concentration of 40 µM and was added to media 3 h post transfection. H₂O₂ was used at a concentration of 50 μM for 1 h prior to fixing. (B) Ratiometric Ca²⁺ imaging of HT1080 fibrosarcomas treated as indicated. H₂O₂ was used at a concentration of 50 μM and extracellular Ca²⁺ at a concentration of 2 mM. Ionomycin was used at a concentration of 10 μM and was added at the end of the time course as a control to show effective Fura2 loading. (C) Quantification of peaks in (B). Data represents n≥3±SEM. * p≤0.05, ** p≤0.01, *** p≤0.001.