Figure 5. Lamin C/prelamin A splicing in mouse cells and tissues depends on SRSF2 expression.

(A) Inactivating Srsf2 in mouse fibroblasts reduces prelamin A transcript levels and increases lamin C transcript levels without affecting total Lmna transcripts. A Srsf2^fl/fl mouse fibroblast cell line was treated with adeno-Cre or adeno-LacZ. After 3 or 6 days, prelamin A and lamin C transcript levels were measured by qRT-PCR (mean ± SD). Srsf2 mRNA levels were reduced by >95% in the adeno-Cre–treated cells. (B) Western blots showing that Srsf2 inactivation in fibroblasts leads to reduced lamin A protein levels. Two Srsf2^fl/fl fibroblast cell lines (cell lines 1 and 2) were treated with either adeno-Cre or adeno-LacZ. After 6 days, lamin A and lamin C levels were assessed by Western blotting. The bar graph shows changes in lamin expression (mean ± SEM) for 4 independent experiments. **P < 0.01, t test. (C) Western blots showing that an Srsf2 inactivation in the liver decreases lamin A levels and increases lamin C levels. Lamin A and lamin C protein levels were measured in isolated hepatocytes from Srsf2^fl/fl mice (P23) expressing Cre in the liver (Srsf2^fl/flAlb-Cre⁺). Actin levels were measured as a loading control. The bar graph shows the mean ± SEM for 3 mice per group. *P < 0.05.