Fig 4. Exogenous effect of SPARC on myogenin expression in differentiating myoblasts.
Confluent C2C12 myoblasts were trypsinized and plated in 12-well at 4×105 cells/well with GM. The myogenic differentiation was induced in DM with/without the induction/inhibition of SPARC for 5 days, and the mediums were replaced every 2 days. Proteins extraction was performed and five μg from total cell extracts were analyzed by western blot using anti-myogenin antibody. The experiments were repeated three times (three different passages of C2C12 cells) and a representative western blot image was shown. Data were expressed as a ratio to the positive control (pooled samples). One-way ANOVA with repeated measurements was used to adjust the validations of the different passages and a contrast analysis was performed. P value was set at < 0.05 after the Bonfferoni adjustments. The SPARC induction increased myogenin expression and SPARC inhibition decreased it. Abbreviations: PBS: phosphate buffered saline, rSPARC: recombinant SPARC protein, and anti-SPARC: anti-SPARC antibody. *Significant differences between experimental conditions.