Background: Left ventricular noncompaction (LVNC) is a primary cardiomyopathy with heterogeneous genetic origins. The aim of this study was to elucidate the role of sarcomere gene variants in the pathogenesis and prognosis of LVNC.
Methods And Results: We screened 82 Japanese patients (0-35 years old), with a diagnosis of LVNC, for mutations in seven genes encoding sarcomere proteins, by direct DNA sequencing. We identified variants in a significant proportion of cases (27%), which were associated with poor prognosis (p = 0.012), particularly variants in TPM1, TNNC1, and ACTC1 (p = 0.012). To elucidate the pathological role, we developed and studied human-induced pluripotent stem cells (hiPSCs) from a patient carrying a TPM1 p.Arg178His mutation, who underwent heart transplantation. These cells displayed pathological changes, with mislocalization of tropomyosin 1, causing disruption of the sarcomere structure in cardiomyocytes, and impaired calcium handling. Microarray analysis indicated that the TPM1 mutation resulted in the down-regulation of the expression of numerous genes involved in heart development, and positive regulation of cellular process, especially the calcium signaling pathway.
Conclusions: Sarcomere genes are implicated as genetic triggers in the development of LVNC, regulating the expression of numerous genes involved in heart development, or modifying the severity of disease.
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http://dx.doi.org/10.1038/s41390-018-0162-1 | DOI Listing |
Am J Pathol
January 2025
Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands. Electronic address:
The tongue facilitates vital activities such as swallowing. Swallowing difficulties (dysphagia) are common in the elderly and in many adult-onset neuromuscular diseases. In oculopharyngeal muscular dystrophy (OPMD), dysphagia is often the first symptom.
View Article and Find Full Text PDFJ Mol Cell Cardiol
January 2025
Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Institute of Engineering Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92093, USA. Electronic address:
Vinculin (VCL) is a key adapter protein located in force-bearing costamere complexes, which mechanically couples the sarcomere to the ECM. Heterozygous vinculin frameshift genetic variants can contribute to cardiomyopathy when external stress is applied, but the mechanosensitive pathways underpinning VCL haploinsufficiency remain elusive. Here, we show that in response to extracellular matrix stiffening, heterozygous loss of VCL disrupts force-mediated costamere protein recruitment, thereby impairing cardiomyocyte contractility and sarcomere organization.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
Life and Environmental Science College, Wenzhou University, Wenzhou 325003, China; Zhejiang Provincial Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325003, China. Electronic address:
Methimazole (MMI) is an emerging endocrine disrupting chemical (EDC) due to its increasing use in the treatment of thyrotoxicosis (hyperthyroidism), but its potential impact on amphibian development remains largely unexplored. In the present study, the effects of 8 mg/L MMI and 1 μg/L thyroxine (T4) exposure on skeletal ossification and muscle development in Bufo gargarizans tadpoles were comprehensively investigated by double skeletal staining, histological analysis and RNA sequencing. Our results indicated that MMI treatment down-regulated the expression levels of ossification-related genes (e.
View Article and Find Full Text PDFEgypt Heart J
January 2025
Department of Physiology, Faculty of Basic Medical Sciences, Obafemi Awolowo College of Health Sciences, Olabisi Onabanjo University, Sagamu Campus, Sagamu, Ogun State, Nigeria.
Background: Hypertrophic cardiomyopathy (HCM) is a frequently encountered cardiac condition worldwide, often inherited, and characterized by intricate phenotypic and genetic manifestations. The natural progression of HCM is diverse, largely due to mutations in the contractile and relaxation proteins of the heart. These mutations disrupt the normal structure and functioning of the heart muscle, particularly affecting genes that encode proteins involved in the contraction and relaxation of cardiac muscle.
View Article and Find Full Text PDFFront Transplant
December 2024
Pediatric Cardiology and Adult with Congenital Heart Disease Unit, Instituto do Coração (InCor) do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Background: Cardiomyopathy is a disease that affects the myocardium and can be classified as dilated, restrictive, or hypertrophic cardiomyopathy. Among the subtypes, restrictive cardiomyopathy is characterized by restriction of ventricular filling and its uncommon cause is a disease due to mutation on Filamin C (FLNC) gene. Filamin C is an actin-binding protein encoded by FLNC gene and participates in sarcomere stability maintenance, which is expressed on the striated muscle.
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