Cardiomyocyte-specific PCSK9 deficiency compromises mitochondrial bioenergetics and heart function.

PCSK9 is mainly present in the circulation where it regulates plasma cholesterol levels. Here we show that PCSK9 mediates intracellular functions that differ from its extracellular functions. We further show that intracellular PCSK9 in cardiomyocytes, despite low expression levels, is important for maintaining physiological cardiac metabolism and function.