| First Author | Lebek S | Year | 2023 |
| Journal | Circulation | Volume | 148 |
| Issue | 19 | Pages | 1490-1504 |
| PubMed ID | 37712250 | Mgi Jnum | J:358926 |
| Mgi Id | MGI:7714835 | Doi | 10.1161/CIRCULATIONAHA.123.065117 |
| Citation | Lebek S, et al. (2023) Elimination of CaMKIIdelta Autophosphorylation by CRISPR-Cas9 Base Editing Improves Survival and Cardiac Function in Heart Failure in Mice. Circulation 148(19):1490-1504 |
| abstractText | BACKGROUND: Cardiovascular diseases are the main cause of worldwide morbidity and mortality, highlighting the need for new therapeutic strategies. Autophosphorylation and subsequent overactivation of the cardiac stress-responsive enzyme CaMKIIdelta (Ca(2+)/calmodulin-dependent protein kinase IIdelta) serves as a central driver of multiple cardiac disorders. METHODS: To develop a comprehensive therapy for heart failure, we used CRISPR-Cas9 adenine base editing to ablate the autophosphorylation site of CaMKIIdelta. We generated mice harboring a phospho-resistant CaMKIIdelta mutation in the germline and subjected these mice to severe transverse aortic constriction, a model for heart failure. Cardiac function, transcriptional changes, apoptosis, and fibrosis were assessed by echocardiography, RNA sequencing, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and standard histology, respectively. Specificity toward CaMKIIdelta gene editing was assessed using deep amplicon sequencing. Cellular Ca(2+) homeostasis was analyzed using epifluorescence microscopy in Fura-2-loaded cardiomyocytes. RESULTS: Within 2 weeks after severe transverse aortic constriction surgery, 65% of all wild-type mice died, and the surviving mice showed dramatically impaired cardiac function. In contrast to wild-type mice, CaMKIIdelta phospho-resistant gene-edited mice showed a mortality rate of only 11% and exhibited substantially improved cardiac function after severe transverse aortic constriction. Moreover, CaMKIIdelta phospho-resistant mice were protected from heart failure-related aberrant changes in cardiac gene expression, myocardial apoptosis, and subsequent fibrosis, which were observed in wild-type mice after severe transverse aortic constriction. On the basis of identical mouse and human genome sequences encoding the autophosphorylation site of CaMKIIdelta, we deployed the same editing strategy to modify this pathogenic site in human induced pluripotent stem cells. It is notable that we detected a >2000-fold increased specificity for editing of CaMKIIdelta compared with other CaMKII isoforms, which is an important safety feature. While wild-type cardiomyocytes showed impaired Ca(2+) transients and an increased frequency of arrhythmias after chronic beta-adrenergic stress, CaMKIIdelta-edited cardiomyocytes were protected from these adverse responses. CONCLUSIONS: Ablation of CaMKIIdelta autophosphorylation by adenine base editing may offer a potential broad-based therapeutic concept for human cardiac disease. |
