Soluble epoxide hydrolase activation by S-nitrosation contributes to cardiac ischemia-reperfusion injury.

Cardiac ischemia-reperfusion (I/R) injury always accompanies recanalization treatment for myocardial infarction. Here we found soluble epoxide hydrolase (sEH), which metabolizes cardioprotective epoxyeicosatrienoic acids into less effective diols, was rapidly activated during myocardial reperfusion in both mouse and rat models in expression-independent manner. Similar activation was mimicked by nitric oxide (NO) donor dose-dependently in vitro, along with an obvious induction of sEH S-nitrosation, a short-term post-translational modification, which diminished in sEH Cys-141-Ala mutant. In vivo, I/R induced sEH S-nitrosation could be reversed by NO synthase inhibitor L-NAME, with protective effect on cardiac dysfunction, which however vanished in sEH-/- mice. Further, a protective effect against I/R injury in the initial phase of reperfusion was observed in eNOS-/- mice, indicating inhibition of NO as a sEH-based cardioprotective in early time of I/R injury. Besides, sEH inhibitor directly targeting on activated sEH during cardiac reperfusion significant reduced infarct size after I/R in vivo. In summary, our findings show the critical role of sEH S-nitrosation in cardiac I/R injury and inhibiting sEH S-nitrosation may be a new therapeutic strategy clinically.