Table 3 Studies utilising FRDA iPSCs and their derived models to develop gene therapy approaches for FRDA
Technique | Study | Year | Cell type(s) utilised | Study outcome |
|---|---|---|---|---|
Zinc finger nuclease (ZFN)-mediated excision | Li et al. [80] | 2015 | FRDA iPSC-derived neurons | FRDA fibroblasts are corrected by ZFN-mediated excision of the GAA expansion. This correction persists during iPSC reprogramming, with disease phenotypes being reversed in ZFN-corrected FRDA iPSC-derived neuronal cells |
Li et al. [69] | 2019 | FRDA iPSC-derived cardiomyocytes | FRDA iPSC-derived cardiomyocytes exhibit pathological lipid accumulation and cardiac hypertrophy expression signatures which are reversed upon correction of the FXN gene via ZFN-mediated excision | |
Electroporation of gene silencing nucleic acids (antisense oligonucleotide activators and duplex RNA) | Shen et al. [67] | 2019 | FRDA iPSC-derived neuronal progenitor cells | Electroporation of duplex RNA and antisense oligonucleotide activators into FRDA iPSC-derived neural progenitor cells activates FXN expression |
CRISPR Cas9 gRNA-mediated knockdown | Mazzara et al. [12] | 2020 | FRDA iPSC-derived dorsal root ganglia organoid sensory neurons | Reversal of FRDA molecular and cellular phenotypes upon excision of the FXN intron 1 in a 3D-DRG iPSC-derived organoid model of FRDA |
LbL particle-mediated FXN expression plasmid delivery system | Czuba-Wojnilowicz et al. [68] | 2020 | FRDA iPSC-derived sensory neurons | Treatment of an FRDA iPSC-derived neuronal model with multi-layered nano-particles delivering FXN-expressing plasmids, results in a 27,000-fold increase in FXN expression |
Transfection of miniFXN plasmids containing endogenous FXN sequence | Li et al. [81] | 2020 | FRDA iPSC-derived neurons FRDA iPSC-derived cardiomyocytes | Establishment of minimal endogenous promotor sequence required for FXN expression. Constructs containing this FXN expression control region resulted in successful FXN expression in FRDA iPSCs, which persisted during subsequent differentiation to FRDA iPSC-derived cardiomyocytes and neurons |