1. Mechanisms of pathogenicity in the hypertrophic cardiomyopathy-associated TNNI3 c.235C > T variant.
- Author
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Zhang L, Ding F, Ren Z, Cheng W, Dai H, Liang Q, Kong F, Xu W, Wang M, Zhang Y, and Tao Q
- Subjects
- Humans, Male, Female, Adult, Middle Aged, Myocytes, Cardiac metabolism, Myocytes, Cardiac pathology, Troponin I, Cardiomyopathy, Hypertrophic genetics, Cardiomyopathy, Hypertrophic physiopathology, Mutation, Pedigree
- Abstract
Background: Hypertrophic cardiomyopathy (HCM) is typically manifested as a hereditary disorder, with 30 %-60 % of cases linked to cardiac sarcomere gene mutations. Despite numerous identified TNNI3 mutations associated with HCM, their severity, prevalence, and disease progression vary. The link between TNNI3 variants and phenotypes remains largely unexplored. This study aims to elucidate the impact of the TNNI3 c.235C > T mutation on HCM through clinical research and cell experiments and to explore its mechanism in HCM development., Methods: We screened an HCM family for pathogenic gene mutations using gene sequencing. The proband and family members were assessed through electrocardiography, echocardiography, and cardiac MRI, and a pedigree map was created for disease prediction analysis. Mutant plasmids were constructed with the TNNI3 c.235C > T mutation and transfected into the AC16 human cardiomyocyte cell line to investigate the mutation's effects., Results: The TNNI3 c.235C > T mutation was identified as the disease-causing variant in the family. This mutation led to the upregulation of hypertrophy-associated genes ANP, BNP, and MYH7, increased cardiomyocyte size, and activation of the ERK signaling pathway. Further investigations revealed that the TNNI3 c.235C > T mutation impaired mitochondrial function, disrupted cardiomyocyte metabolism, and increased cellular autophagy and apoptosis., Conclusions: The TNNI3 c.235C > T gene mutation may be a pathogenic factor for HCM, showing heterogeneous features and clinical phenotypes. This mutation induces myocardial hypertrophy, activates the ERK signaling pathway, and exacerbates mitochondrial dysfunction, apoptosis, and autophagy in cardiomyocytes. These findings provide insights into the mechanism of HCM caused by gene mutations and may inform HCM treatment strategies., Competing Interests: Declaration of competing interest The authors reported no conflict of interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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