Transient receptor potential channel 6 regulates abnormal cardiac S-nitrosylation in Duchenne muscular dystrophy

Proc Natl Acad Sci U S A. 2017 Dec 12;114(50):E10763-E10771. doi: 10.1073/pnas.1712623114. Epub 2017 Nov 29.

Abstract

Duchenne muscular dystrophy (DMD) is an X-linked disorder with dystrophin loss that results in skeletal and cardiac muscle weakening and early death. Loss of the dystrophin-sarcoglycan complex delocalizes nitric oxide synthase (NOS) to alter its signaling, and augments mechanosensitive intracellular Ca2+ influx. The latter has been coupled to hyperactivation of the nonselective cation channel, transient receptor potential canonical channel 6 (Trpc6), in isolated myocytes. As Ca2+ also activates NOS, we hypothesized that Trpc6 would help to mediate nitric oxide (NO) dysregulation and that this would be manifest in increased myocardial S-nitrosylation, a posttranslational modification increasingly implicated in neurodegenerative, inflammatory, and muscle disease. Using a recently developed dual-labeling proteomic strategy, we identified 1,276 S-nitrosylated cysteine residues [S-nitrosothiol (SNO)] on 491 proteins in resting hearts from a mouse model of DMD (dmdmdx:utrn+/-). These largely consisted of mitochondrial proteins, metabolic regulators, and sarcomeric proteins, with 80% of them also modified in wild type (WT). S-nitrosylation levels, however, were increased in DMD. Genetic deletion of Trpc6 in this model (dmdmdx:utrn+/-:trpc6-/-) reversed ∼70% of these changes. Trpc6 deletion also ameliorated left ventricular dilation, improved cardiac function, and tended to reduce fibrosis. Furthermore, under catecholamine stimulation, which also increases NO synthesis and intracellular Ca2+ along with cardiac workload, the hypernitrosylated state remained as it did at baseline. However, the impact of Trpc6 deletion on the SNO proteome became less marked. These findings reveal a role for Trpc6-mediated hypernitrosylation in dmdmdx:utrn+/- mice and support accumulating evidence that implicates nitrosative stress in cardiac and muscle disease.

Keywords: Duchenne muscular dystrophy; Trpc6; mass spectrometry; nitric oxide synthase signaling; protein S-nitrosylation.

Publication types

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

MeSH terms

  • Animals
  • Calcium Signaling
  • Cysteine / metabolism
  • Disease Models, Animal
  • Epinephrine / pharmacology
  • Gene Deletion
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Muscular Dystrophy, Duchenne / metabolism*
  • Muscular Dystrophy, Duchenne / pathology
  • Muscular Dystrophy, Duchenne / physiopathology
  • Myocardium / metabolism*
  • Nitrosation
  • S-Nitrosothiols / metabolism
  • Sympathomimetics / pharmacology
  • TRPC Cation Channels / genetics
  • TRPC Cation Channels / metabolism*
  • TRPC6 Cation Channel
  • Ventricular Remodeling

Substances

  • S-Nitrosothiols
  • Sympathomimetics
  • TRPC Cation Channels
  • TRPC6 Cation Channel
  • Trpc6 protein, mouse
  • Cysteine
  • Epinephrine