The TTN p. Tyr4418Ter mutation causes cardiomyopathy in human and mice

PLoS One. 2024 Feb 21;19(2):e0296802. doi: 10.1371/journal.pone.0296802. eCollection 2024.

Abstract

Objective: To generate a mouse model carrying TTNtv Y4370* simulating the newly discovered human heterozygous nonsense TTNtv c.13254T>G (p.Tyr4418Ter) to supplement and improve the functional evidence of pathogenic mutation TTNtv c.13254T>G on the pathogenic type of dilated cardiomyopathy.

Methods: We generated 4 mice carrying TTNtv p. Y4370* through CRISPR/Cas-mediated genome engineering. Monthly serological detection, bimonthly echocardiography, and histology evaluation were carried out to observe and compare alterations of cardiac structure and function between 4 TTN+/- mice and 4 wild-type (WT) mice.

Results: For the two-month-old TTN+/- mice, serum glutamic-oxalacetic transaminase (AST), lactic dehydrogenase (LDH), and creatine kinase (CK) were significantly increased, the diastolic Left Ventricular Systolic Anterior Wall (LVAW), and the LV mass markedly rose, with the left ventricular volume displaying an increasing trend and Ejection Fraction (EF) and Fractional Shortening (FS) showing a decreasing trend. Besides, the histological evaluation showed that cardiac fibrosis level and positive rate of cardiac mast cell of TTN+/- mice were obviously increased compared with WT mice.

Conclusions: TTNtv Y4370* could lead to cardiac structure and function alterations in mice, supplementing the evidence of TTNtv c.13254T>G pathogenicity in human.

MeSH terms

  • Animals
  • Cardiomyopathies* / genetics
  • Cardiomyopathy, Dilated*
  • Connectin / genetics
  • Heart
  • Humans
  • Infant
  • Mice
  • Mutation

Substances

  • Connectin
  • TTN protein, human
  • titin protein, mouse

Grants and funding

This study is supported by Hubei Provincial Natural Science Foundation of China(2022CFB841) and Scientific Research Program of Wuhan Municipal Health Commission (WX20D15). There was no other additional external funding received for this study. The author Wenqiang Sun received both grants. Dr Wenqiang Sun investigated and analyzed the data of this study, and wrote the original manuscript and reviewed the logic of the manuscript. In addition, Dr Wenqiang Sun supervised and reviewed the whole research process.