12Feb 2023
Slower Calcium Handling Balances Faster Crossbridge Cycling in Human MYBPC3 HCM

Slower Calcium Handling Balances Faster Crossbridge Cycling in Human MYBPC3 HCM

This study aimed to gain insights into the pathogenic mechanisms of MYBPC3-associated hypertrophic cardiomyopathy caused by the MYBPC3-c.772G>A mutation. A large patient population was used in combination with surgical myectomy samples, human-induced pluripotent stem cell (hiPSC)-cardiomyocytes and engineered heart tissues to provide a comprehensive investigation. The results showed that the MYBPC3-c.772G>A mutation leads to reduced expression of the cardiac myosin binding protein-C and sarcomere energetics dysfunction, which was intrinsic to the reduction in cMyBP-C. Compensatory electrophysiological changes were observed, such as slower excitation-contraction coupling and reduced potassium channel expression. These changes counterbalanced the faster sarcomere kinetics but also increased arrhythmic propensity and disease progression. The study concluded that correcting the primary sarcomeric defects may prevent secondary cardiomyocyte remodelling.

  • #cardiology

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