Figure 2

Beneficial actions of IGF-I under severe frataxin deficiency. A, Transfection of floxed-Fxn astrocytes with GFP-Cre decreased frataxin levels along time. Representative blot and quantification graphs of frataxin levels along time in culture are shown. B, Treatment of Cre-deleted astrocytes with 100nM IGF-I for 24 hours increased frataxin levels. Representative blots are shown. C, Increased levels of ROS in frataxin-deficient cultures were normalized by IGF-I. D, Disturbed mitochondrial activity due to Fxn deficiency was also corrected by IGF-I as determined by normalization of MTT levels. E, Astrocytes promote survival of frataxin-deficient neurons when 100nM of IGF-I is added to the co-cultures for 24 hours. GFP⁺ (frataxin-deleted)-neurons were counted (n=4-5, independent experiments), *p<0.05, **p<0.01 and ***p<0.001.