Kim Mihwa, Ham Ahrom, Kim Katelyn Yu-Mi, Brown Kevin M, Lee H Thomas
Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York, United States of America.
PLoS One. 2014 Jun 19;9(6):e99950. doi: 10.1371/journal.pone.0099950. eCollection 2014.
Endothelial dysfunction is common in acute and chronic organ injury. Isoflurane is a widely used halogenated volatile anesthetic during the perioperative period and protects against endothelial cell death and inflammation. In this study, we tested whether isoflurane induces endothelial ecto-5'-nucleotidase (CD73) and cytoprotective adenosine generation to protect against endothelial cell injury. Clinically relevant concentrations of isoflurane induced CD73 activity and increased adenosine generation in cultured human umbilical vein or mouse glomerular endothelial cells. Surprisingly, isoflurane-mediated induction of endothelial CD73 activity occurred within 1 hr and without synthesizing new CD73. We determined that isoflurane rapidly increased CD73 containing endothelial microparticles into the cell culture media. Indeed, microparticles isolated from isoflurane-treated endothelial cells had significantly higher CD73 activity as well as increased CD73 protein. In vivo, plasma from mice anesthetized with isoflurane had significantly higher endothelial cell-derived CD144+ CD73+ microparticles and had increased microparticle CD73 activity compared to plasma from pentobarbital-anesthetized mice. Supporting a critical role of CD73 in isoflurane-mediated endothelial protection, a selective CD73 inhibitor (APCP) prevented isoflurane-induced protection against human endothelial cell inflammation and apoptosis. In addition, isoflurane activated endothelial cells Rho kinase evidenced by myosin phosphatase target subunit-1 and myosin light chain phosphorylation. Furthermore, isoflurane-induced release of CD73 containing microparticles was significantly attenuated by a selective Rho kinase inhibitor (Y27632). Taken together, we conclude that the volatile anesthetic isoflurane causes Rho kinase-mediated release of endothelial microparticles containing preformed CD73 and increase adenosine generation to protect against endothelial apoptosis and inflammation.
内皮功能障碍在急性和慢性器官损伤中很常见。异氟烷是围手术期广泛使用的卤化挥发性麻醉剂，可防止内皮细胞死亡和炎症。在本研究中，我们测试了异氟烷是否能诱导内皮ecto-5'-核苷酸酶（CD73）和细胞保护性腺苷生成，以防止内皮细胞损伤。临床相关浓度的异氟烷可诱导培养的人脐静脉或小鼠肾小球内皮细胞中的CD73活性并增加腺苷生成。令人惊讶的是，异氟烷介导的内皮CD73活性诱导在1小时内发生，且无需合成新的CD73。我们确定异氟烷迅速将含CD73的内皮微粒释放到细胞培养基中。事实上，从经异氟烷处理的内皮细胞中分离出的微粒具有显著更高的CD73活性以及增加的CD73蛋白。在体内，与戊巴比妥麻醉小鼠的血浆相比，异氟烷麻醉小鼠的血浆中内皮细胞衍生的CD144+CD73+微粒显著更高，且微粒CD73活性增加。选择性CD73抑制剂（APCP）可防止异氟烷诱导的对人内皮细胞炎症和凋亡的保护作用，这支持了CD73在异氟烷介导的内皮保护中的关键作用。此外，异氟烷激活了内皮细胞Rho激酶，这可通过肌球蛋白磷酸酶靶亚基-1和肌球蛋白轻链磷酸化来证明。此外，选择性Rho激酶抑制剂（Y27632）可显著减弱异氟烷诱导的含CD73微粒的释放。综上所述，我们得出结论，挥发性麻醉剂异氟烷通过Rho激酶介导释放含有预先形成的CD73的内皮微粒并增加腺苷生成，以防止内皮细胞凋亡和炎症。
