Figure 7.

Inhibition of ERK1/2 and p38 prevents phosphorylation of Ser-345 on p47^phox in cultured cardiomyocytes in response to simulated microgravity. Neonatal mouse cardiomyocytes were subjected to SMG in the presence of PD98059, SB203580, or vehicle for 24 h. A and B, top, a representative Western blot from three different cell cultures with each in duplicate for total and phosphorylated p47^phox (Ser-345); Bottom, quantitation for phosphorylated p47^phox relative to total p47^phox. C, effect of ERK1/2 inhibition on p38 phosphorylation in cardiomyocytes after SMG. Top, a representative Western blot from three different cell cultures with each in duplicate for total and phosphorylated p38; bottom, quantitation for phosphorylated p38 (p-p38) relative to total p38. Data are mean ± S.D. (error bars), n = 3 in each group. Two-way ANOVA followed by Newman–Keuls test was performed for statistical analysis. A, interaction, F = 5.958, p = 0.0311; row factor, F = 15.48, p = 0.002; column factor, F = 3.788, p = 0.0754. B, interaction, F = 8.13, p = 0.0145; row factor, F = 3.085, p = 0.1045; column factor, F = 2.035, p = 0.1792. C, interaction, F = 0.1223, p = 0.7356; row factor, F = 48.81, p = 0.0001; column factor, F = 0.29, p = 0.6049. *, p < 0.05 versus sham + vehicle; †, p < 0.05 versus SMG + vehicle.