Oxidative stress-dependent sphingosine kinase-1 inhibition mediates monoamine oxidase A-associated cardiac cell apoptosis

Pchejetski, Dmitry, Kunduzova, Oxana, Dayon, Audrey, Calise, Denis, Seguelas, Marie-Hélène, Leducq, Nathalie, Seif, Isabelle, Parini, Angelo and Cuvillier, Olivier (2007) Oxidative stress-dependent sphingosine kinase-1 inhibition mediates monoamine oxidase A-associated cardiac cell apoptosis. Circulation Research, 100 (1). pp. 41-9. ISSN 0009-7330

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Abstract

The mitochondrial enzyme monoamine oxidase (MAO), its isoform MAO-A, plays a major role in reactive oxygen species-dependent cardiomyocyte apoptosis and postischemic cardiac damage. In the current study, we investigated whether sphingolipid metabolism can account for mediating MAO-A- and reactive oxygen species-dependent cardiomyocyte apoptosis. In H9c2 cardiomyoblasts, MAO-A-dependent reactive oxygen species generation led to mitochondria-mediated apoptosis, along with sphingosine kinase-1 (SphK1) inhibition. These phenomena were associated with generation of proapoptotic ceramide and decrease in prosurvival sphingosine 1-phosphate. These events were mimicked by inhibition of SphK1 with either pharmacological inhibitor or small interfering RNA, as well as by extracellular addition of C(2)-ceramide or H(2)O(2). In contrast, enforced expression of SphK1 protected H9c2 cells from serotonin- or H(2)O(2)-induced apoptosis. Analysis of cardiac tissues from wild-type mice subjected to ischemia/reperfusion revealed significant upregulation of ceramide and inhibition of SphK1. It is noteworthy that SphK1 inhibition, ceramide accumulation, and concomitantly infarct size and cardiomyocyte apoptosis were significantly decreased in MAO-A-deficient animals. In conclusion, we show for the first time that the upregulation of ceramide/sphingosine 1-phosphate ratio is a critical event in MAO-A-mediated cardiac cell apoptosis. In addition, we provide the first evidence linking generation of reactive oxygen species with SphK1 inhibition. Finally, we propose sphingolipid metabolites as key mediators of postischemic/reperfusion cardiac injury.

Item Type:	Article
Uncontrolled Keywords:	animals,apoptosis,cells, cultured,ceramides,down-regulation,drug resistance,hydrogen peroxide,lysophospholipids,mice,mice, knockout,mitochondria, heart,monoamine oxidase,myocardial reperfusion injury,myocytes, cardiac,oxidants,oxidative stress,phosphotransferases (alcohol group acceptor),rats,rats, sprague-dawley,reactive oxygen species,serotonin,sphingolipids,sphingosine,up-regulation
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User:	Pure Connector
Date Deposited:	16 Dec 2014 10:06
Last Modified:	21 Oct 2022 00:23
URI:	https://ueaeprints.uea.ac.uk/id/eprint/51543
DOI:	10.1161/01.RES.0000253900.66640.34

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