Tomoyuki Honjo a , Nobutaka Inoue a , Rio Shiraki a , Seiichi Kobayashi a , Kazunori Otsui a , Motonori Takahashi a , Ken-ichi Hirata a , Seinosuke Kawashima a , Hiroshi Yokozaki b , Mitsuhiro Yokoyama a
16 February 2006
Background: Urocortin, a neuropeptide discovered in the midbrain, is a member of the corticotropin-releasing factor family and is expressed in heart tissues. Urocortin exerts potent cardioprotective effects under various pathological conditions including ischemia/reperfusion. However, the regulation and function of vascular urocortin are unknown. Methods and Results: Immunohistochemistry showed definitive expression of urocortin in endothelial cells of coronary large arteries and microvessels from autopsied hearts. RT-PCR confirmed the expression of urocortin in human umbilical vein endothelial cells (HUVECs). Urocortin (10<sup>–8</sup> M) potently suppressed the generation of angiotensin II-induced reactive oxygen species (ROS) in HUVECs. Tumor necrosis factor-α and interferon-γ increased the urocortin mRNA levels and its release from HUVECs. Incubation with pitavastatin (0.1–3.0 µ M) significantly increased the urocortin mRNA levels and its release from HUVECs. Furthermore, treatment with pitavastatin (2 mg/day) for 4 weeks increased the serum urocortin level from 11.0 ± 6.5 to 16.4 ± 7.3 ng/ml in healthy volunteers. Conclusion: Endothelial urocortin was upregulated by inflammatory cytokines and pitavastatin and suppressed ROS production in endothelial cells. Treatment with pitavastatin increased the serum urocortin level in human subjects. Thus, endothelial urocortin might protect cardiomyocytes in inflammatory lesions. Urocortin might partly explain the mechanisms of various pleiotropic effects of statins.