Figure 3

The modulation of PLD expression has trophic effects in L6 myotubes. (A) Effects of siRNA-mediated PLD depletion on the area of differentiated myotubes. An irrelevant siRNA was used for control. Results shown are the means ± SE of 3 experiments, with 10 repeats. **: different from control siRNA, p < 0.01. The down-regulation of PLD isoforms was verified by RT-qPCR (right panel). Means ± SE of n = 3 or 4 are shown. ***: different from control siRNA, p < 0.0001; **: p < 0.01; *: p = 0.05. (B) Effects of siRNA-mediated PLD depletion on CK activity of differentiated myotubes. Means ± SE of n = 4 are shown. **: different from control siRNA-treated cells, p < 0.01. (C) Effects of adenovirus-mediated PLD overexpression on myotube area. An adenovirus encoding GFP was used for control. Shown are the means ± SE of 8 experiments with 10 replicates. ***: different from GFP-adenovirus infected cells, p < 0.0001. The overexpression of PLD isoforms was verified by immunoblotting of HA-tagged PLDs (right panel). (D) Effects of Adenovirus-mediated PLD overexpression on myotube CK activity. Means ± SE of n = 5. ***: different from GFP-adenovirus infected cells, p < 0.001. (E) Effect of PLD inhibition on the hypertrophic response of myotubes overexpressing PLD1. Myotubes were infected with GFP- or PLD1-adenovirus and simultaneously treated with PLD inhibitors as detailed in Figure 2 legend. Results are shown as means ± SE of 10 to 20 replicates. **: different from GFP-adenovirus infected cells, p = 0.002; ⁺⁺⁺: different from PLD1-adenovirus infected cells, p < 0.001; NS: not significantly different from PLD1-adenovirus infected cells.