High Uric Acid Inhibits Cardiomyocyte Viability Through the ERK/P38 Pathway via Oxidative Stress.

BACKGROUND/AIMS: Clinical studies have shown that hyperuricaemia is strongly associated with cardiovascular disease. However, the molecular mechanisms of high uric acid (HUA) associated with cardiovascular disease remain poorly understood. In this study, we investigated the effect of HUA on cardiomyocytes.

METHODS: We exposed H9c2 cardiomyocytes to HUA, then cell viability was determined by MTT assay, and reactive oxygen species' (ROS) production was detected by a fluorescence assay. Western blot analysis was used to examine phosphorylation of extracellular signal-regulated kinase (ERK), p38, phosphatidylinositol 3-kinase (PI3K) and Akt. We monitored the impact of HUA on phospho-ERK and phospho-p38 levels in myocardial tissue from an acute hyperuricaemia mouse model established by potassium oxonate treatment.

RESULTS: HUA decreased cardiomyocyte viability and increased ROS production in cardiomyocytes; pre-treatment with N-acetyl-L-cysteine, a ROS scavenger, and PD98059, an ERK inhibitor, reversed HUA-inhibited viability of cardiomyocytes. Further examination of signal transduction pathways revealed HUA-induced ROS involved in activating ERK/P38 and inhibiting PI3K/Akt in cardiomyocytes. Furthermore, the acute hyperuricaemic mouse model showed an increased phospho-ERK/p38 level in myocardial tissues.

CONCLUSION: HUA induced oxidative damage and inhibited the viability of cardiomyocytes by activating ERK/p38 signalling, for a novel potential mechanism of hyperuricaemic-related cardiovascular disease.