Arrhythmias & electrophysiology
Cardiac dysfunction related to cardiac mRNA and protein traffic impairment due to reduced unconventional motor protein myosin-5b expression
Authors' conclusion
Impairment in MYO5b expression and function promotes cardiac dysfunction, heart failure, and death.
Study context
- Population
- Mice and human cardiac tissues; isolated adult cardiomyocytes; young SCD/sudden infant death syndrome cohort
- Comparison
- Cardiac-specific MYO5b knockout (KO) vs wild-type (WT) mice
Main finding
As reported in the abstract
- MYO5b, but not MYO5a or c, expression increased during postnatal cardiomyocyte maturation
- Myosin-5b reduced in end-stage failing human hearts and infarcted murine hearts
- Heterozygous rare, likely pathogenic missense MYO5B variants (n = 6) in 3 patients of a young SCD/sudden infant death syndrome cohort (n = 95)
- MYO5b-KO mice: impaired electric conductance and metabolism, sarcomeric disarrangement, HF and death, with altered mRNA levels (sarcomere, fatty acid and glucose metabolism, ion channels, Ca2+-homeostasis) before HF
- In cardiomyocytes, myosin-5b associated with mitochondrial and ribosomal proteins
- Myosin-5b-associated ribonucleoprotein particles (RNPs) contained mRNAs of sarcomeric, metabolic, cytoskeletal and ion channel proteins
Original publication
Cardiac dysfunction related to cardiac mRNA and protein traffic impairment due to reduced unconventional motor protein myosin-5b expression. Eur Heart J. Published 19 February 2025. doi:10.
Summarised from the published abstract; every number is checked against it