Cytochrome P450-derived epoxyeicosatrienoic acids accelerate wound epithelialization and neovascularization in the hairless mouse ear wound model

Abstract

Epoxyeicosatrienoic acids (EETs) are known to modulate proliferation and angiogenesis in vitro. Tissue levels of EETs are regulated by the cytochrome P450 (CYP) epoxygenases that generate them as well as by the soluble epoxide hydrolase metabolizes them to their less active diols. The aim of this study was to determine the effect of locally administered EETs (11,12- and 14,15-EETs) and the selective sEH inhibitor (sEHI) trans-4-[4-(3-adamantan-1-ylureido)-cyclohexyloxy]-benzoic acid (t-AUCB) on wound healing in vivo. Standardized full thickness dermal wounds were created on the dorsum of hairless mouse ears. Wound epithelialization was directly viewed and measured using intravitalmicroscopy and computerized planimetry every second day until healing was complete. Wound sections were analyzed by immunostaining for endothelial lineage marker CD31, vascular endothelial growth factor (VEGF), and angiogenic cytokine stromal cell-derived factor (SDF) 1α on days2, 4, and 13. Treatment with EETs and t-AUCB, respectively, significantly accelerated wound epithelialization and neovascularization by synergistic upregulation of SDF1α and VEGF in vivo. These findings demonstrated that exogenous CYP-derived EETs and globally decreased EET hydrolysis by sEH inhibition significantly accelerated wound epithelialization and neovascularization in unimpaired healing wounds. Given that hypoxia induces CYP expression and subsequently EET-dependent angiogenesis, EETs and sEHIs provide a promising new class of therapeutics for ischemic non-healing wounds.