Study Of 20-HETE Induces CardiacMyocytes Apoptosis Through Mitochondrial-dependent Pathways

20-Hydroxyeicosatetraenoic acid (20-HETE), aω-hydroxylation product of arachidonic acid catalyzed by cytochrome P450 4A (CYP4A), may play a role in cardiovascular system. However, the direct effect of 20-HETE on cardiomyocytes are still poorly investigated. Here, we studied the effect of 20-HETE on cardiacmyocyte apoptosis and the apoptosis-associated signaling pathways. The cardiomyocyte apoptosis was measured by FITC-annexin V/propidium iodide (PI) double staining cytometry, indicating that the percentage of apoptotic cells increased from 20.7±0.8% to 31.7%±2.0% in control and 20-HETE-treated cells respectively. The mitochondrial membrane potential (ΔΨm) was measured by detecting the ratio of JC-1 green/red emission intensity. A significant decrease in the ratio was observed after treatment with 20-HETE for 24 h in comparison with control group, confirming the disruptive effect of 20-HETE on mitochondrialΔΨm. In addition, 20-HETE stimulated caspase-3 activity, intracellular calcium, and Bax mRNA expression in cardiac cells. In contrast, the Bcl-2 mRNA levels were significantly decreased by 20-HETE treatment. These results demonstrate that 20-HETE induces cardiacmyocyte apoptosis by activation of several intrinsic apoptotic pathways. The 20-HETE-induced apoptosis could contribute to the CYP450ω-hydroxylase-dependent cardiac injure during cardiac ischemia-reperfusion.