Cardioprotective Role of Paraoxonases in Heart Failure

Paraoxonases isoforms 1, 2, and 3 (PON-1, -2, -3) constitute a family of calcium-dependent esterases which exhibit arylesterase, paraoxonase, and lactonase activities. Decreased serum PON activity is associated with increased oxidant stress and adverse clinical outcomes in the setting of heart failure (HF), yet whether decreased PON is mechanistically linked to HF is unclear. We tested the hypothesis that PON is cardioprotective in the following studies. First we measured PON expression in explanted human hearts. Both PON2 and PON3 protein and mRNA levels were significantly higher (>2 fold, p