Cas13b-mediated RNA targeted therapy alleviates genetic dilated cardiomyopathy in mice

Abstract Background Recent advances in gene editing technology have opened up new avenues for in vivo gene therapy, which holds great promise as a potential treatment method for dilated cardiomyopathy (DCM). The CRISPR-Cas13 system has been shown to be an effective tool for knocking down RNA expression in mammalian cells. PspCas13b, a type VI-B effector that can be packed into adeno-associated viruses and improve RNA knockdown efficiency, is a potential treatment for diseases characterized by abnormal gene expression. Results Using PspCas13b, we were able to efficiently and specifically knockdown the mutant transcripts in the AC16 cell line carrying the heterozygous human TNNT2 R141W (hTNNT2 R141W ) mutation. We used adeno-associated virus vector serotype 9 to deliver PspCas13b with specific single guide RNA into the hTNNT2 R141W transgenic DCM mouse model, effectively knocking down hTNNT2 R141W transcript expression. PspCas13b-mediated knockdown significantly increased myofilament sensitivity to Ca2+, improved cardiac function, and reduced myocardial fibrosis in hTNNT2 R141W DCM mice. Conclusions These findings suggest that targeting genes through Cas13b is a promising approach for in vivo gene therapy for genetic diseases caused by aberrant gene expression. Our study provides further evidence of Cas13b’s application in genetic disease therapy and paves the way for future applicability of genetic therapies for cardiomyopathy.