Figure 4.

Inhibition of calpain prevents reporter gene expression mediated by the C/EBPα gene promoter. Two-day postconfluent preadipocytes were transiently cotransfected with a C/EBPα-luciferase expression vector and with or without a CMV-human calpastatin expression vector. Twenty-four hours later, transfected cells were induced to differentiate with medium containing MDI or MDI and 26 μM ALLN (as indicated) for an additional 24 h. Cell lysates were analyzed for total cellular protein and luciferase activity was normalized to values from MDI-treated cells.