We discovered that the hyperplastic to hypertrophic transition phase of mammalian heart development was altered in mice lacking MYBPC3 and this was the critical period for subsequent development of cardiomyopathy.
Mutations in troponin T (TNNT2) gene represent the important part of currently identified disease-causing mutations in hypertrophic (HCM) and dilated (DCM) cardiomyopathy.
Thus current research efforts into the elucidation of the molecular mechanisms underlying these genetic diseases are not only directed towards studying skeletal muscle necrosis but also investigate abnormalities of heart and brain dystrophin-glycoprotein complexes in cardiomyopathy and brain deficiencies associated with muscular dystrophy.
In contrast to heterozygous pathogenic mutations, homozygous or compound heterozygous truncating pathogenic MYBPC3 mutations cause severe neonatal cardiomyopathy with features of left ventricular noncompaction and septal defects in approximately 60% of patients.
Contrary to previous reports, which indicated the involvement of 5'-end mutations in cardiomyopathies as a result of dystrophin gene alterations, this study shows that despite the apparent concentration of deletions in two regions (5'-end and exons 47 through 49), no general conclusions can be drawn regarding the involvement of specific gene mutations in the development of cardiomyopathy.
Phospholambanp.Arg14delcardiomyopathy is characterized by a distinct molecular signature compared to desmosomal ACM, specifically a different desmosomal protein distribution.
These findings indicate that AAV-mediated cardiac transduction with microdystrophin might be a promising therapeutic strategy for the treatment of dystrophin-deficient cardiomyopathy.
Based on the score analysis, we detected three substitutions in the MYBPC3 and CASQ2 genes and six combinations between loci in the MYBPC3, MYH7 and CASQ2 genes that were responsible for cardiomyopathy risk in our cohorts.
Thus, by chronic suppression of sarcoplasmic reticulum Ca(2+)-ATPase activity, the nonreversible superinhibitory function of mutant PLN-R14Del may lead to inherited dilated cardiomyopathy and premature death in both humans and mice.
The unique interaction between phospholamban and increased adrenergic drive, elucidated herein, provides the first evidence that compensatory increases in catecholamine stimulation can, even in the absence of preexisting heart failure, be a primary causative factor in the development of cardiomyopathy and early mortality.
Heart failure invariably affects patients with various forms of Muscular Dystrophy (MD), but the onset and molecular sequelae of altered structure and function resulting from full-length dystrophin (Dp427) deficiency in MD heart tissue are poorly understood.To better understand the role of dystrophin in cardiomyocyte development and the earliest phase of DMD cardiomyopathy, we studied human cardiomyocytes differentiated from induced pluripotent stem cells (hiPSC-CMs) obtained from the urine of a Deuchenne Muscular Dystrophy (DMD) patient.