Abstract 12431: Analysis of Cardiomyocytes Differentiated from Disease-Specific Induced Pluripotent Stem Cells in Lamin A/C-related Cardiomyopathy
Mutations in the lamin A/C gene, encoding the nuclear membrane proteins, lamin A and C, have been linked to familial dilated cardiomyopathy (DCM) combined with conduction disease. We previously reported a heterozygous frame-shift mutation in the lamin A/C gene (p.S303fsX25) in a patient with a significant history of DCM and pacemaker implants. In this study, we obtained dermal fibroblasts from the proband and successfully generated induced pluripotent stem (iPS) cells using a combination of 4 transcription factors (Oct3/4, Sox2, Klf4, and c-Myc) by retrovirus systems. Cardiomyocyte differentiation of the iPS cells was induced with the embryoid body (EB) differentiation system. We used beating EBs (4-6 weeks of differentiation) for real-time PCR, immunostaining and electron microscopic analysis. Real-time PCR analysis with iPS cells exhibited the restoration of mutant lamin A/C mRNA to levels comparable to that of control human iPS cells. However, both of the control and mutant iPS cells failed to be stained with anti-lamin A/C antibody, suggesting low level expression of lamin A/C in iPS cells. On the other hand, both of the differentiated cardiomyocytes were stained positively for lamin A/C. The total mRNA levels of mutant EBs were decreased to 48% compared to control EBs, indicating that nonsense-mediated mRNA decay occurred in differentiated cardiomyocytes with the lamin A/C frame-shift mutation. In addition, electron microscopic analysis showed a damaged nuclear membrane structure in the cardiomyocytes derived from the patient. Thus, we first report disease-specific iPS cells of lamin A/C-related cardiomyopathy. The differentiated cardiomyocytes could be a useful model of lamin A/C-related cardiomyopathy and further studies will provide us the disease causing mechanisms.
- © 2011 by American Heart Association, Inc.