RT Journal Article
SR Electronic
T1 Gene augmentation and read-through rescue channelopathy in an iPSC-RPE model of congenital blindness
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 485847
DO 10.1101/485847
A1 Pawan K. Shahi
A1 Dalton Hermans
A1 Divya Sinha
A1 Simran Brar
A1 Hannah Moulton
A1 Sabrina Stulo
A1 Katarzyna D. Borys
A1 Elizabeth Capowski
A1 De-Ann M. Pillers
A1 David M. Gamm
A1 Bikash. R. Pattnaik
YR 2018
UL http://biorxiv.org/content/early/2018/12/04/485847.abstract
AB Purpose Mutations in the KCNJ13 gene are known to cause Leber’s Congenital Amaurosis (LCA16), an inherited pediatric blindness. KCNJ13 gene encodes the Kir7.1 subunit protein which acts as a tetrameric inwardly rectifying potassium ion channel in the retinal pigment epithelium to maintain ionic homeostasis thereby allowing photoreceptors to encode visual information. We sought to determine if genetic approaches might be effective in treating blindness due to mutations in KCNJ13.Methods We developed patient-derived hiPSC-RPE carrying an autosomal recessive nonsense mutation in the KCNJ13 gene (c.158G>A, p.Trp53*). We performed biochemical and electrophysiology assays of Kir7.1 function. Both small molecule read-through drug and gene-therapy approaches were tested using this disease-in-a-dish approach.Results We found that the LCA16 hiPSC-RPE had normal morphology but did not express a functional Kir7.1 channel and was unable to demonstrate normal physiology. Following read-through drug treatment, the LCA16 hiPSC cells were hyperpolarized by 30 mV and Kir7.1 current was restored. Similarly, loss-of-function of Kir7.1 channel was circumvented by lentiviral gene delivery to the hiPSC-RPE cells. In either approach, Kir7.1 protein was expressing normally with restoration of membrane potential and Kir7.1 current.Conclusion Loss-of-function mutation in Kir7.1 is a cause of LCA. Using either read-through therapy or gene augmentation, we rescued Kir7.1 channel function in patient-derived iPSC-RPE cells via a precision medicine approach.