Correction: Corrigendum: Muscle-specific CRISPR/Cas9 dystrophin gene editing ameliorates pathophysiology in a mouse model for Duchenne muscular dystrophy

Abstract

Nature Communications 8: Article number: 14454 (2017); Published: 14 February 2017; Updated: 23 June 2017 This Article contains an error in Fig. 4, for which we apologize. In panel a, the image reporting dystrophin labelling following SaCas9Δ5253 treatment was inadvertently duplicated from the corresponding image following SpCas9/Δ5253 treatment.

Challenges associated with homologous directed repair using CRISPR-Cas9 and TALEN to edit the DMD genetic mutation in canine Duchenne muscular dystrophy

“…Starting with myoblasts in culture, the efficiency of donor clone insertion varied, with CRISPR sgRNA B being the most effective of its group at 16%, and TALEN at 25%. The other treatments had an efficiency of less than 10% in line with previously published HDR in vivo results from mdx mice [8,10]. Somewhat unexpectedly, mRNA levels in GRMD myoblasts were higher than those of normal cells.…”

“…Dystrophin was only modestly increased, if at all, on Western analysis in other muscles from her and those of Friendly and Miercoles. Importantly, these modest levels of dystrophin expression are in keeping with the HDR gene-editing results in mdx mice [8,10]. In another recently published canine CRISPR study, dystrophin expression was as high as 67% when compared to normal levels after AAV intramuscular CT injection using NHEJ [11].…”

“…PCR bands of interest were cloned and Sanger sequencing confirmed inclusion of the corrected basepair (bp) in the splice site area of intron 6 ( Fig 2B, 2C and 2D). TA cloning was performed to determine the efficiency of donor clone insertion into various clones: TALEN showed around 25% insertion efficiency and sgRNA B was approximately 16% effective, while other treatments did not yield positive colonies, presumably due to less than 10% efficacy, in line with levels seen in mdx mice treated in vivo [8,10].…”

“…While there is currently no cure for DMD, recent treatment strategies have sought to restore the missing dystrophin protein by delivering part of the DMD gene [3] or by skipping the mutated area to restore the reading frame [4]. Successful DMD gene editing also has been achieved using clustered regularly interspaced short palindromic repeats (CRISPR) coupled with an enzyme, typically caspase (Cas)-9, in cell culture, the DMD murine model (mdx) [5][6][7][8][9][10], and, most recently, in the deltaE50-MD dog model for DMD [11]. Transcription activator-like effector nucleases (TALEN) has also been tested in vitro [7,12,13].…”

The progress of AAV-mediated gene therapy in neuromuscular disorders

“…expression was restricted to skeletal and cardiac muscles under a CK8 promoter to reduce possible off-target events in non-muscle cells. Widespread dystrophin expression, observed after both local and systemic deliveries, led to an improvement of dystrophic histopathology [49].…”