Project description:Aging is associated with an increased risk of cardiovascular disease and death. Here we show that oral supplementation of the natural polyamine spermidine extends lifespan, while it exerts cardioprotective effects through reduction of cardiac hypertrophy and preservation of diastolic function in old mice. Spermidine feeding enhanced cardiac autophagy, mitophagy, mitochondrial respiration and mechano-elastical properties of cardiomyocytes in vivo, coinciding with increased titin phosphorylation and suppressed subclinical inflammation. Spermidine failed to promote cardioprotection in mice lacking the autophagy-related gene Atg5 in cardiomyocytes. In Dahl salt-sensitive rats fed high-salt diet, a model for hypertension-induced congestive heart failure, spermidine reduced systemic blood pressure, increased titin phosphorylation and prevented cardiac hypertrophy and a decline in diastolic function, thus delaying the progression to heart failure. Finally, high dietary spermidine intake correlated with reduced blood pressure and a lower incidence of cardiovascular disease in humans. Our results suggest a novel and generic strategy against cardiovascular disease.
Project description:Caloric restriction and intermittent fasting prolong the lifespan and healthspan of model organisms and improve human health 1. The natural polyamine spermidine has been linked to autophagy regulation, geroprotection and reduced incidence of cardiovascular and neurodegenerative diseases across species borders 2. Here, we report that spermidine levels increase upon acute fasting in yeast, flies, mice and healthy humans. Genetic or pharmacological blockade of endogenous spermidine synthesis reduced fasting-induced autophagy in yeast, worms and human cells. Furthermore, perturbing the polyamine pathway in vivo abrogated the lifespan-extending, cardioprotective and antiarthritic effects of intermittent fasting. Mechanistically, spermidine mediated these effects via hypusination of the autophagy regulator eIF5A. In sum, the polyamine-hypusination axis thus emerges as a bona fide and phylogenetically conserved metabolic control hub for longevity and autophagy induction.
Project description:Administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extends the lifespan of various model organisms including yeast, flies and worms. In ageing yeast, spermidine treatment triggeres epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), leading to induction of autophagy and thereby suppressing oxidative stress and necrosis. In order to further characterize the effects by spermidine supplementation of aging yeast cultures and to understand how global histone deacetylation affects gene transcription during aging, Affymetrix-based microarray analyses of three day old as well as ten day old cultures with and without administration of spermidine was performed.
Project description:To compare the effects of spermidine, key polyamine, on the gene expression profile of organ cultured human hair follicles Vehicle treated Vs. 0.5 µM spermidine treatment. Two control samples, two spermidine treated samples
Project description:Polyamines are absolutely required for cell growth and proliferation. While polyamine depletion results in reversible cell cycle arrest, the actual mechanism of growth inhibition is still obscure. This experiment aimed at determining the cellular processes elicited by re-addition of polyamines to polyamine-depleted (growth arrested) cells. In order to reveal the general transcriptional responses to polyamine re-addition, NIH3T3 mouse fibroblasts were first treated with 1mM L-Difluoromethylornithine (DFMO) for 96 hours and then growth stimulated by spermidine. Cells were collected at 0, 30, 60, 120, 240, 360, 480 and 600 min upon addition of spermidine to polyamine-depleted (growth arrested) cells. Total RNA was isolated, reverse-transcribed, fragmented, labeled and hybridized to Affymetrix MoGene 1.0 ST DNA array.