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Cardiac myosin binding protein-C plays no regulatory role in skeletal muscle structure and function

Brian Lin1, Suresh Govindan, Kyounghwan Lee

  • 1Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.

Plos One
|August 13, 2013
PubMed

Insights

Cardiac myosin binding protein-C (cMyBP-C) is not essential for adult skeletal muscle development or function. Skeletal muscle isoforms can compensate in the heart, but cMyBP-C absence doesn't prevent cardiac dysfunction.

Area of Science:

  • Muscle physiology and molecular biology.
  • Cardiac and skeletal muscle development.
  • Myosin binding protein-C isoform regulation.

Background:

  • Myosin binding protein-C (MyBP-C) has three isoforms: slow skeletal, fast skeletal, and cardiac (cMyBP-C).
  • cMyBP-C is primarily cardiac but transiently expressed in neonatal skeletal muscle.
  • The necessity of cMyBP-C for skeletal muscle development is unknown.

Purpose of the Study:

  • To investigate the role of cMyBP-C in adult skeletal muscle structure and function.
  • To determine if cMyBP-C absence affects MyBP-C isoform expression in skeletal muscle.
  • To assess skeletal muscle compensation in cMyBP-C null mice.

Main Methods:

  • Utilized a cMyBP-C null mouse model (cMyBP-C((t/t))).
  • Analyzed MyBP-C isoform expression in skeletal and cardiac tissues.
  • Performed histological, ultrastructural, and functional assessments of skeletal muscles.
  • Examined cardiac function in the context of dilated cardiomyopathy.

Main Results:

  • Skeletal MyBP-C isoform expression was unaffected in cMyBP-C((t/t)) mice.
  • Skeletal muscles showed no structural or functional deficits compared to wild-type.
  • Fast MyBP-C expression increased in failing hearts of cMyBP-C((t/t)) mice.
  • Skeletal isoforms increased in myopathic skeletal muscles.

Conclusions:

  • cMyBP-C is dispensable for adult skeletal muscle development and function.
  • Skeletal MyBP-C isoforms can transcomplement in the heart lacking cMyBP-C.
  • MyBP-C isoforms are differentially regulated across muscle types and in disease states.

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