Role of Monoamine Oxidase A (MAO-A) in Cardiac Aging

Abstract

Among different sources that contribute in the global oxidative stress, the vast majority of cellular reactive oxygen species (ROS) originate from mitochondrial compartments. Recently, monoamine oxidases (MAOs) are identified as a prominent source of ROS. Monoamine oxidases are localized in the outer membrane of mitochondria and exist as two different isoforms, MAO-A and MAO-B. MAOs are mitochondrial flavoenzymes responsible for oxidative deamination of biogenic amines and during this process, H 2 O 2 and aldehydes are generated as intermediate products. The role of monoamine oxidase in cardiovascular pathophysiology has only recently gained some attention as it is demonstrated that H 2 O 2 and aldehydes may target myocardial function and consequently cardiac function. Results obtained by different research groups showed that MAO-A plays a key role in the regulation of physiological cardiac function and in the development of acute and chronic heart diseases through two mechanisms: regulation of substrate concentration and intracellular production of ROS. In this review, we will focus on the role of MAO-A in the field of cardiac aging and related diseases.