Increased tissue stiffness triggers contractile dysfunction and telomere shortening in dystrophic cardiomyocytes

Stem Cell Reports. 2021 Sep 14;16(9):2169-2181. doi: 10.1016/j.stemcr.2021.04.018. Epub 2021 May 20.

Abstract

Duchenne muscular dystrophy (DMD) is a rare X-linked recessive disease that is associated with severe progressive muscle degeneration culminating in death due to cardiorespiratory failure. We previously observed an unexpected proliferation-independent telomere shortening in cardiomyocytes of a DMD mouse model. Here, we provide mechanistic insights using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Using traction force microscopy, we show that DMD hiPSC-CMs exhibit deficits in force generation on fibrotic-like bioengineered hydrogels, aberrant calcium handling, and increased reactive oxygen species levels. Furthermore, we observed a progressive post-mitotic telomere shortening in DMD hiPSC-CMs coincident with downregulation of shelterin complex, telomere capping proteins, and activation of the p53 DNA damage response. This telomere shortening is blocked by blebbistatin, which inhibits contraction in DMD cardiomyocytes. Our studies underscore the role of fibrotic stiffening in the etiology of DMD cardiomyopathy. In addition, our data indicate that telomere shortening is progressive, contraction dependent, and mechanosensitive, and suggest points of therapeutic intervention.

Keywords: DMD; dilated cardiomyopathy; fibrosis; hiPSC-CM; telomere.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Cardiomyopathies / etiology
  • Cardiomyopathies / pathology
  • Cardiomyopathies / physiopathology
  • Cell Differentiation
  • Cells, Cultured
  • Cellular Microenvironment / drug effects
  • Culture Media, Conditioned / metabolism
  • Culture Media, Conditioned / pharmacology
  • Fibrosis
  • Fluorescent Antibody Technique
  • Gene Expression
  • Humans
  • Immunophenotyping
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / metabolism
  • Mechanical Phenomena
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / pathology
  • Muscular Dystrophies / physiopathology*
  • Muscular Dystrophy, Duchenne / etiology
  • Muscular Dystrophy, Duchenne / pathology
  • Muscular Dystrophy, Duchenne / physiopathology
  • Myocardial Contraction / drug effects
  • Myocardial Contraction / genetics*
  • Myocytes, Cardiac / metabolism*
  • Telomere Shortening / genetics*

Substances

  • Biomarkers
  • Culture Media, Conditioned