A novel inducible cholesterol efflux peptide, FAMP, protects against myocardial ischemia reperfusion injury through a nitric oxide pathway

ObjectiveWe evaluated whether a novel inducible cholesterol efflux (iCE) peptide [Fukuoka University Apolipoprotein A-I Mimetic Peptide (FAMP)] protects against myocardial ischemia reperfusion injury (IRI) through a nitric oxide (NO) pathway by an improvement of high-density lipoprotein (HDL) functionality.Methods and resultsMale C57BL6/J mice were intraperitoneally injected with phosphate buffer as a control, low-dose (10 mg/kg) or high-dose (50 mg/kg) of FAMP before 18 h of IRI (n = 6-12 in each group). After 30 min of ischemia followed by 6 h of reperfusion, blood pressure, and infarct size were measured and cardiac function was evaluated by a Millar catheter. FAMP significantly improved stroke volume, cardiac output, left ventricular ejection fraction, and infarct size. FAMP significantly preserved cytochrome C in the mitochondrial fraction and inhibited its release into the cytosolic fraction in the heart, but did not significantly reduce mRNA levels of monocyte chemoattractant protein-1 or interluekin-6. In a TdT-mediated dUTP nick end labeling (TUNEL) assay, FAMP significantly suppressed the appearance of TUNEL-positive nuclear. We also performed same experiments with endothelial nitric oxide synthase-knockout (eNOS-KO) mice and FAMP-induced improvements of cardiac function were not observed in eNOS-KO mice.ConclusionsFAMP activated HDL-functionality and improved cardiac function in a model of myocardial IRI. It may have anti-apoptotic effects by protecting mitochondria through a NO pathway as a pleiotropic effect.