Fig. 7.
Quantitation of the effect of myotube culture with NG108-15 cell conditioned medium, NG108-15 cell subcellular membrane fraction, or NG108-15 cells on nPKC θ expression. Primary myoblast cultures were established and cultured for 7–8 d as described in the legend to Figure 2. Myotubes were cultured in parallel for 2.5 d alone (CTL) or with conditioned medium (CM) from, or the subcellular membrane fraction (MF) from, 5 × 105 NG108-15 cells. Alternatively, myotubes were indirectly cocultured with 5 × 105 NG108-15 cells separated from the myotubes by a semipermeable membrane of the indicated pore size. Myotubes were homogenized, and equal protein (120 μg) was analyzed as described in the legend to Figure 1. Data are expressed as percent increase in nPKC θ expression in cytosolic plus membrane fractions of experimental compared with control cultures. Each experiment was performed in triplicate except for control (CTL) and 0.3 μm filters where n = 15 for each. Error bars represent SEM.