Figure 3
Addition of exogenous TGFβ3 recapitulates the effects of MBNL1 knockdown. Stage 14 AVC explants were treated with M199 supplemented with 0 to 200 ng/ml recombinant TGFβ3 at 6 hours. (A) The number of invaded cells was counted at 38 hrs. The mean number of invaded cells per explant + the standard error of the mean is shown. Addition of rTGFβ3 induced an increase in cell invasion, comparable at the highest dose tested to that seen following MBNL1 siRNA treatment. (B) The myocardium was removed and total RNA was harvested at 38 hrs. Expression of the mesenchymal markers ACTA2 and FBN2 were measured by real-time RT-PCR. Error bars denote 95% confidence intervals. Although the extent of ACTA2 and FBN2 up-regulation was somewhat variable, both markers were elevated in each of the pooled samples for all three doses (individual data not shown). An asterisk indicates a significant difference from 0 ng/ml rTGFβ3 (P ≤ 0.05).