ePrints

Monoamine oxidase-A is a novel driver of stress-induced premature senescence through inhibition of parkin-mediated mitophagy

Lookup NU author(s): Damien Maggiorani, Dr Joao Passos

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

© 2018 The Anatomical Society and John Wiley & Sons Ltd. Cellular senescence, the irreversible cell cycle arrest observed in somatic cells, is an important driver of age-associated diseases. Mitochondria have been implicated in the process of senescence, primarily because they are both sources and targets of reactive oxygen species (ROS). In the heart, oxidative stress contributes to pathological cardiac ageing, but the mechanisms underlying ROS production are still not completely understood. The mitochondrial enzyme monoamine oxidase-A (MAO-A) is a relevant source of ROS in the heart through the formation of H2O2 derived from the degradation of its main substrates, norepinephrine (NE) and serotonin. However, the potential link between MAO-A and senescence has not been previously investigated. Using cardiomyoblasts and primary cardiomyocytes, we demonstrate that chronic MAO-A activation mediated by synthetic (tyramine) and physiological (NE) substrates induces ROS-dependent DNA damage response, activation of cyclin-dependent kinase inhibitors p21cip, p16ink4a, and p15ink4b and typical features of senescence such as cell flattening and SA-β-gal activity. Moreover, we observe that ROS produced by MAO-A lead to the accumulation of p53 in the cytosol where it inhibits parkin, an important regulator of mitophagy, resulting in mitochondrial dysfunction. Additionally, we show that the mTOR kinase contributes to mitophagy dysfunction by enhancing p53 cytoplasmic accumulation. Importantly, restoration of mitophagy, either by overexpression of parkin or inhibition of mTOR, prevents mitochondrial dysfunction and induction of senescence. Altogether, our data demonstrate a novel link between MAO-A and senescence in cardiomyocytes and provides mechanistic insights into the potential role of MAO-dependent oxidative stress in age-related pathologies.

Publication metadata

Author(s): Manzella N, Santin Y, Maggiorani D, Martini H, Douin-Echinard V, Passos JF, Lezoualc'h F, Binda C, Parini A, Mialet-Perez J

Publication type: Article

Publication status: Published

Journal: Aging Cell

Year: 2018

Volume: 17

Issue: 5

Print publication date: 01/10/2018

Online publication date: 12/07/2018

Acceptance date: 28/05/2018

ISSN (print): 1474-9718

ISSN (electronic): 1474-9726

Publisher: Wiley-Blackwell

URL: https://doi.org/10.1111/acel.12811

DOI: 10.1111/acel.12811

Altmetrics

Share