Monoamine Oxidases, Oxidative Stress, and Altered Mitochondrial Dynamics in Cardiac Ageing

Abstract

The advances in healthcare over the past several decades have resulted in populations now living longer. With this increase in longevity, a wider prevalence of cardiovascular diseases is more common and known to be a major factor in rising healthcare costs. A wealth of scientific evidence has implicated cell senescence as an important component in the etiology of these age-dependent pathologies. A number of studies indicate that an excess of reactive oxygen species (ROS) contributes to trigger and accelerate the cardiac senescence processes, and a new role of monoamine oxidases, MAO-A and MAO-B, is emerging in this context. These mitochondrial enzymes regulate the level of catecholamines and serotonin by catalyzing their oxidative deamination in the heart. MAOs' expression substantially increases with ageing (6-fold MAO-A in the heart and 4-fold MAO-B in neuronal tissue), and their involvement in cardiac diseases is supposedly related to the formation of ROS, via the hydrogen peroxide produced during the substrate degradation. Here, we will review the most recent advances in this field and describe why MAOs could be effective targets in order to prevent age-associated cardiovascular disease.

Body fat reduction without cardiovascular changes in mice after oral treatment with the MAO inhibitor phenelzine

“…Accordingly, hypotension has been observed in MAO‐A/MAO‐B deficient mice (Holschneider et al ., ), reproducing the hypotensive effect of chronic MAOIs via altered baroreflex sensitivity (Coupland et al ., ; Yamada and Yasuhara, ). More recently, a spontaneous increase in cardiac MAO activity was shown to contribute to age‐associated cardiovascular diseases (Maggiorani et al ., ). All these data may explain why phenelzine treatment had little effect on the cardiovascular system in mice, although it inhibited cardiac MAO activity and subsequent ROS generation.…”

The draft nuclear genome sequence and predicted mitochondrial proteome of Andalucia godoyi, a protist with the most gene-rich and bacteria-like mitochondrial genome

“…MAOs are characterized by a globular water-soluble main body that is anchored to the mitochondrial membrane via a C-terminal α-helix [126]. Mammalian MAO comes in two forms, A and B, and their activity has been implicated in oxidative stress [127]. Andalucia also encodes two distinct MAO forms, but both are specifically related to the MAO A type.…”

What We Know and What We Need to Know about Aromatic and Cationic Biogenic Amines in the Gastrointestinal Tract

“…It is well known that 5-HT has also been involved in very complex physiological processes such as being an essential neurotransmitter and paracrine molecule for brain-intestine crosstalk, commonly known as gut-brain axis [ 97 ]. The amine is involved in modulation of body temperature and circadian rhythm [ 98 , 99 ], as well as in cardiovascular activity, morphogenesis and cell proliferation [ 100 , 101 ]. In the GIT context, it has been described as a gastric motility and secretion, a nutrient absorption regulator and an immunoregulatory compound.…”