Fig. 4

Compound identified in high-throughput screen increases sarcospan transcript and protein levels in both wild-type and dystrophin-deficient mdx myotubes. Felodipine increases sarcospan gene expression in a C2C12 wild-type and b mdx myotubes (n = 3–8) after 48 h of treatment. Gene expression was calculated using the ddCt method and normalized to β-actin with vehicle-treated cells serving as the calibrator sample. Using immunoblot analysis, total cell lysate from cells treated with felodipine was probed with anti-SSPN antibodies. GAPDH is shown as a loading control. Felodipine increases sarcospan protein levels in both c C2C12 wild-type and d and mdx myotubes (n = 3). e, f Quantification of SSPN protein levels are normalized to GAPDH. R.U., relative units. All data was obtained from murine myotubes treated for 48 h and assayed or harvested at day 4 of differentiation. *p < 0.05, **p < 0.01, ****p < 0.0001