Figure 1

IGF-I stimulates frataxin in a cell-context fashion. A, Treatment with IGF-I (100 nM, 24 hours) increased frataxin levels in frataxin-deficient (right) but not in normal neurons (left). B, IGF-I stimulated frataxin both in frataxin-deficient and normal astrocytes. C, IGF-I normalized levels of reactive oxygen species (ROS) in frataxin-deficient astrocytes (upper panel) and neurons (lower panel). D, IGF-I stimulated frataxin content in cardiomyocytes. E, Levels of SOD2 are increased by IGF-I in wild type astrocytes. F, IGF-I did not alter aconitase levels in astrocytes. Western blots were performed to measure the levels of frataxin, SOD2 and aconitase, and protein load normalized against β-actin. Representative blots are shown; the upper blots correspond to frataxin (A, B, D), SOD2 (E) or aconitase (F) and the lower blots to β-actin (n=3-6, independent experiments); *p<0.05; **p<0.01; ***p<0.001.