• Anne Katrine Johansen, Bas Molenaar, Danielle Versteeg, Ana Rita Leitoguinho, Charlotte Demkes, Bastiaan Spanjaard, Hesther de Ruiter, Farhad Akbari Moqadam, Lieneke Kooijman, Lorena Zentilin, Mauro Giacca, and Eva van Rooij.
• From the Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (A.K.J., B.M., D.V., A.R.L., C.D., B.S., H.d.R., F.A.M., L.K., E.v.R.) and Department of Cardiology (D.V., C.D., E.v.R.), University Medical Center Utrecht, The Netherlands; and International Centre for Genetic Engineering and Biotechnology, Trieste, Italy (L.Z., M.G.).
• Circ. Res. 2017 Oct 27; 121 (10): 1168-1181.

RationaleCRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated protein 9)-based DNA editing has rapidly evolved as an attractive tool to modify the genome. Although CRISPR/Cas9 has been extensively used to manipulate the germline in zygotes, its application in postnatal gene editing remains incompletely characterized.ObjectiveTo evaluate the feasibility of CRISPR/Cas9-based cardiac genome editing in vivo in postnatal mice.Methods And ResultsWe generated cardiomyocyte-specific Cas9 mice and demonstrated that Cas9 expression does not affect cardiac function or gene expression. As a proof-of-concept, we delivered short guide RNAs targeting 3 genes critical for cardiac physiology, Myh6, Sav1, and Tbx20, using a cardiotropic adeno-associated viral vector 9. Despite a similar degree of DNA disruption and subsequent mRNA downregulation, only disruption of Myh6 was sufficient to induce a cardiac phenotype, irrespective of short guide RNA exposure or the level of Cas9 expression. DNA sequencing analysis revealed target-dependent mutations that were highly reproducible across mice resulting in differential rates of in- and out-of-frame mutations. Finally, we applied a dual short guide RNA approach to effectively delete an important coding region of Sav1, which increased the editing efficiency.ConclusionsOur results indicate that the effect of postnatal CRISPR/Cas9-based cardiac gene editing using adeno-associated virus serotype 9 to deliver a single short guide RNA is target dependent. We demonstrate a mosaic pattern of gene disruption, which hinders the application of the technology to study gene function. Further studies are required to expand the versatility of CRISPR/Cas9 as a robust tool to study novel cardiac gene functions in vivo.© 2017 American Heart Association, Inc.

26 keywords...

hide…