An engineered tale-transcription factor rescues transcription of factor VII impaired by promoter mutations and enhances its endogenous expression in hepatocytes

作者：Barbon Elena; Pignani Silvia; Branchini Alessio; Bernardi Francesco; Pinotti Mirko^*; Bovolenta Matteo^*

来源：Scientific Reports, 2016, 6(1): 28304.

DOI：10.1038/srep28304

Tailored approaches to restore defective transcription responsible for severe diseases have been poorly explored. We tested transcription activator-like effectors fused to an activation domain (TALE-TFs) in a coagulation factor VII (FVII) deficiency model. In this model, the deficiency is caused by the -94C > G or -61T > G mutation, which abrogate the binding of Sp1 or HNF-4 transcription factors. Reporter assays in hepatoma HepG2 cells naturally expressing FVII identified a single TALE-TF (TF4) that, by targeting the region between mutations, specifically trans-activated both the variant (> 100-fold) and wild-type (20-40-fold) F7 promoters. Importantly, in the genomic context of transfected HepG2 and transduced primary hepatocytes, TF4 increased F7 mRNA and protein levels (2- to 3-fold) without detectable off-target effects, even for the homologous F10 gene. The ectopic F7 expression in renal HEK293 cells was modestly affected by TF4 or by TALE-TF combinations. These results provide experimental evidence for TALE-TFs as gene-specific tools useful to counteract disease-causing promoter mutations.

• 出版日期2016-6-24