[HTML][HTML] Precision medicine: genetic repair of retinitis pigmentosa in patient-derived stem cells

AG Bassuk, A Zheng, Y Li, SH Tsang, VB Mahajan - Scientific reports, 2016 - nature.com
Scientific reports, 2016nature.com
Induced pluripotent stem cells (iPSCs) generated from patient fibroblasts could potentially
be used as a source of autologous cells for transplantation in retinal disease. Patient-
derived iPSCs, however, would still harbor disease-causing mutations. To generate healthy
patient-derived cells, mutations might be repaired with new gene-editing technology based
on the bacterial system of clustered regularly interspersed short palindromic repeats
(CRISPR)/Cas9, thereby yielding grafts that require no patient immunosuppression. We …
Abstract
Induced pluripotent stem cells (iPSCs) generated from patient fibroblasts could potentially be used as a source of autologous cells for transplantation in retinal disease. Patient-derived iPSCs, however, would still harbor disease-causing mutations. To generate healthy patient-derived cells, mutations might be repaired with new gene-editing technology based on the bacterial system of clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9, thereby yielding grafts that require no patient immunosuppression. We tested whether CRISPR/Cas9 could be used in patient-specific iPSCs to precisely repair an RPGR point mutation that causes X-linked retinitis pigmentosa (XLRP). Fibroblasts cultured from a skin-punch biopsy of an XLRP patient were transduced to produce iPSCs carrying the patient’s c.3070G > T mutation. The iPSCs were transduced with CRISPR guide RNAs, Cas9 endonuclease and a donor homology template. Despite the gene’s repetitive and GC-rich sequences, 13% of RPGR gene copies showed mutation correction and conversion to the wild-type allele. This is the first report using CRISPR to correct a pathogenic mutation in iPSCs derived from a patient with photoreceptor degeneration. This important proof-of-concept finding supports the development of personalized iPSC-based transplantation therapies for retinal disease.
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