Referenced in: none

Automatically associated channels: ClC1 , ClC4

Title: Functional repair of a mutant chloride channel using a trans-splicing ribozyme.

Authors: Christopher S Rogers, Carlos G Vanoye, Bruce A Sullenger, Alfred L George

Journal, date & volume: J. Clin. Invest., 2002 Dec , 110, 1783-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12488428

Abstract
RNA repair has been proposed as a novel gene-based therapeutic strategy. Modified Tetrahymena group I intron ribozymes have been used to mediate trans-splicing of therapeutically relevant RNA transcripts, but the efficiency of the ribozyme-mediated RNA repair process has not been determined precisely and subsequent restoration of protein function has been demonstrated only by indirect means. We engineered a ribozyme that targets the mRNA of a mutant canine skeletal muscle chloride channel (cClC-1) (mutation T268M in ClC-1 causing myotonia congenita) and replaces the mutant-containing 3' portion by trans-splicing the corresponding 4-kb wild-type sequence. Repair efficiency assessed by quantitative RT-PCR was 1.2% +/- 0.1% in a population of treated cells. However, when chloride channel function was examined in single cells, a wide range of electrophysiological activity was observed, with 18% of cells exhibiting significant functional restoration and some cells exhibiting complete rescue of the biophysical phenotype. These results indicate that RNA repair can restore wild-type protein activity and reveal considerable cell-to-cell variability in ribozyme-mediated trans-splicing reaction efficiency.