Testing therapeutic approaches in advanced hiPSC-cardiac models to rescue LMNA-related cardiomyopathy

Cardiac laminopathy is a late-onset genetic heart disease caused by mutations in the LMNA gene, encoding the nuclear envelope proteins Lamin A/C. It manifests as a severe and progressive dilated cardiomyopathy associated with ventricular arrhythmia, leading to heart failure and sudden cardiac death. Disease-specific therapies are currently lacking and clinical management is largely palliative, with heart transplantation as ultimate treatment option. In this study, we investigated different therapeutic strategies aimed at rescuing pathological phenotypes related to two clinically relevant LMNA mutations: LMNA c.665A>C (p.H222P) and LMNA c.147C>T (p.Q493X). Human induced pluripotent stem cell-derived cardiomyocytes were analyzed in both two-dimensional cultures and three-dimensional cardiac microtissue (cMT). Two independent approaches were tested: pharmacological treatment with small molecule EpoY and a mutation-specific shRNA interference strategy, targeting p.Q493X mutation. EpoY treatment was evaluated not only for its primary effect on reducing microtubule detyrosination, but also for its ability to rescue morphological and functional alterations previously observed in LMNA-mutated cardiomyocytes. Particularly, EpoY 72 hour-treatment markedly improved nuclear morphology, reduced DNA damage and restored contractile function in LMNA-mutant cMTs. Contraction abnormalities were also successfully rescued in p.Q493X-mutated cMTs by shRNA-based approach, highlighting the therapeutic potential of both pharmacological and gene-targeted strategies.