Modeling of lamin A/C mutation premature cardiac aging using patient-specific induced pluripotent stem cells

Abstract

AIMSWe 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 RESULTSHigher prevalence of nuclear bleb formation and micronucleation was present in LMNAR225X/WT and LMNAFramshift/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.CONCLUSIONLMNA-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.

Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective

“…Reduced levels of lamin A are associated with increased expression of pluripotent genes Oct4 and Nanog, and of telomerase genes Tert and Terc [464]. As progeroid syndromes affected mainly cells from mesenchymal lineage, HGPS iPSC have been differentiated into several derivates from mesenchymal stem cells [465], cardiomyocytes [466] and adipocytes, whose differentiation is impaired through the inhibition by progerin of two transcription factors, PPAR␥2 and C/EBP␣ active at late stage [467]. HGPS iPSC were also differentiated into neural cells [465], where miR-9 negatively controls lamin A and progerin expression [287].…”

Deleterious assembly of the lamin A/C mutant p.S143P causes ER stress in familial dilated cardiomyopathy

“…Interestingly, drugs inhibiting the MAPK pathway (MEK1 and MEK2) improve cardiac function and prolong survival of LMNA H222P/H222P mice (Wu et al, 2011). In support for this, MAPK inhibitors protect induced pluripotent stem cell (iPSC)-derived cultured LMNA R225X/WT cardiomyocytes from apoptosis after electrical stimulation (Siu et al, 2012). Furthermore, LMNA N195K/N195K mice develop DCM and show alterations in cytoskeletal protein structure and focal adhesions as well as impairment of nuclear translocation and signaling downstream of the mechanosensitive transcription factor megakaryoblastic leukaemia 1 (MKL1) (Ho et al, 2013).…”

Induced pluripotent stem cells: at the heart of cardiovascular precision medicine

“…80, 81 Most recently, DCMs due to mutations that truncate the massive sarcomere protein titin (TTNtvs) were modeled using hiPSC-derived 3-dimensional cardiac microtissues (CMTs), which had the advantage of yielding more mature cardiac phenotypes than a monolayer of hiPSC-CMs. 105 In this study, patient-derived CMTs with TTNtvs developed sarcomere insufficiency, impaired contractile response to mechanical or beta-adrenergic stress, as well as attenuated growth factor signaling activation.…”