Figure 3.

Treatment of FRDA4078 Fibroblasts with plTALE_ST10Xs and plTALE_ST24Xs

(A) Scheme of pCR3.1-plTALE_ST expressing a plTALE fused with 10 or 24 SunTag (ST) epitopes, each recruiting an scFv-sfGFP-VP64. (B) Scheme of pCR3.1-scFV-sfGFP-VP64-GB1-NLS, which expresses an scFv binding with an ST to activate the expression of the FXN gene. (C) Induction of FXN gene expression in FRDA4087 cells by a plTALE_ST10X or a plTALE_ST24X normalized with GAPDH and HPRT mRNAs compared to FRDA4078 controls. The plTALE_ST24Xs slightly increased FXN gene expression in FRDA4078 cells. This increase reached about 2-fold for plTALE_ST24X-6-15 normalized by GAPDH or HPRT. The plTALE_ST10X-6-15 and plTALE_ST10X-8-15 induced FXN transcription normalized with GAPDH by 4- to 5-fold. (D and E) Frataxin protein in negative controls and in the cells treated with 1 or 2 plTALE_ST10X or with 1 plTALE_ST24X normalized with GAPDH protein. Western blots for frataxin protein (D) were quantified by densitometry and normalized with the GAPDH band (E). *p < 0.05, **p < 0.003, ***p < 0.0003, and ****p < 0.0001. (C and E) Results are the average ± SEM.