Stable truncating mutations in plakophilin-2 induce arrhythmogenic cardiomyopathy-like phenotypes in adult zebrafish

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disorder characterized by arrhythmias and fibrofatty myocardial remodeling, often leading to heart failure and sudden cardiac death. Mutations in plakophilin-2 ( PKP2 ) represent the most prevalent genetic cause of ACM. Here, we establish zebrafish ( Danio rerio ) as a complementary vertebrate model for PKP2 mutation-based ACM. Comparative single-cell RNA-seq analyses revealed distinct cardiac expression patterns of PKP2 and its homologs across species. Using CRISPR-Cas9, we generated two truncating mutations in zebrafish pkp2 , resulting in frameshifts and premature terminations (p.Glu250Glyfs∗17 and p.Glu31Glyfs∗72, respectively). Mutant zebrafish exhibited impaired cardiac contractility, arrhythmias, lipid accumulation on the ventricular surface, ultrastructural abnormalities of intercalated discs, and increased susceptibility to swimming exercise-induced sudden death. Transcriptomic analyses identified transcriptional alterations in genes involved in muscle contraction and lipid metabolism. Together, these data establish zebrafish as a useful complementary vertebrate model for studying PKP2 -based ACM and gene-environment interactions underlying disease progression.