The Mitochondrial Derived Peptide Humanin Protects The Heart From Age-Related Fibrosis

Introduction: Aging is associated with myocardial fibrosis and reduced performance. The mitochondrial derived peptide (MDP) humanin (HN) has been previously demonstrated to have myocardial protection properties. Endogenous HN levels, and consequently its protective effects, fall with age. HN analogs, such as HNG, have beneficial effects on the cardiovascular system, but their role in protecting the heart from age-induced fibrosis has not yet been demonstrated. The current study was designed to test the hypothesis that chronic replenishment of HN by administration of HNG can attenuate the development of age-induced cardiac fibrosis in mice. Methods: Thirteen C57Bl/6 female mice were divided into 3 groups. Young mice (n=5) were euthanized at 20 weeks old. Additional 18-months old mice were randomized to untreated (Old, n=3) or treated with HNG (Old + HNG, n=5, 4mg/kg/Bw IP) for 14 months. Old mice were euthanized at 32 months of age and hearts harvested to evaluate tissue collagen content with Picrosirius R...