Aims: We identified an autosomal dominant non‐sense mutation (R225X) in exon 4 of the lamin A/C (LMNA) gene in a Chinese family spanning 3 generations with familial dilated cardiomyopathy (DCM). In present study, we aim to generate induced pluripotent stem cells derived cardiomyocytes (iPSC‐CMs) from an affected patient with R225X and another patient bearing LMNA frame‐shift mutation for drug screening.
Methods and results: Higher prevalence of nuclear bleb formation and micronucleation was present in LMNA(R225X/WT) and LMNA(Framshift/WT) iPSC‐CMs. Under field electrical stimulation, percentage of LMNA‐mutated iPSC‐CMs exhibiting nuclear senescence and cellular apoptosis markedly increased. shRNA knockdown of LMNA replicated those phenotypes of the mutated LMNA field electrical stress. Pharmacological blockade of ERK1/2 pathway with MEK1/2 inhibitors, U0126 and selumetinib (AZD6244) significantly attenuated the pro‐apoptotic effects of field electric stimulation on the mutated LMNA iPSC‐CMs.
Conclusion: LMNA‐related DCM was modeled in‐vitro using patient‐specific iPSC‐CMs. Our results demonstrated that haploinsufficiency due to R225X LMNA non‐sense mutation was associated with accelerated nuclear senescence and apoptosis of iPSC‐ CMs under electrical stimulation, which can be significantly attenuated by therapeutic blockade of stress‐related ERK1/2 pathway.