Department of Anesthesiology, Support Center for Advanced Medical Sciences, The University of Tokushima Graduate School, Tokushima, Japan.
Anesthesiology. 2011 Nov;115(5):955-62. doi: 10.1097/ALN.0b013e31822fcede.
Cardiac protection by volatile anesthetic-induced preconditioning and ischemic preconditioning have similar signaling pathways. Recently, it was reported that augmentation of protein modified with O-linked β-N-acetylglucosamine (O-GlcNAc) contributes to cardiac protection. This study investigated the role of O-GlcNAc in cardiac protection induced by anesthetic-induced preconditioning.
O-GlcNAc-modified proteins were visualized by immunoblotting. Tolerance against ischemia or reperfusion was tested in vivo (n = 8) and in vitro (n = 6). The opening of the mitochondrial permeability transition pore (mPTP) upon oxidative stress was examined in myocytes treated with calcein AM (n = 5). Coimmunoprecipitation and enzymatic labeling were performed to detect the mitochondrial protein responsible for the mPTP opening.
Isoflurane treatment and the consequent augmentation of O-GlcNAc concentrations reduced the infarct size (26 ± 5% [mean ± SD], P < 0.001) compared with the control. The protective effect of O-GlcNAc was eliminated in the group pretreated with the O-GlcNAc transferase inhibitor alloxan (39 ± 5%, P < 0.001). Myocyte survival also showed the same result in vitro. Formation of the mPTP was abrogated in the isoflurane-treated cells (86 ± 4%, P < 0.001) compared with the control and alloxan-plus-isoflurane-treated cells (57 ± 7%, P < 0.001). Coimmunoprecipitation and enzymatic labeling studies revealed that the O-GlcNAc-modified, voltage-dependent anion channel restained the mPTP opening.
Isoflurane induced O-GlcNAc modification of mitochondrial voltage-dependent anion channel. This modification inhibited the opening of the mPTP and conferred resistance to ischemia-reperfusion stress.
挥发性麻醉剂诱导预处理和缺血预处理的心脏保护具有相似的信号通路。最近，有报道称，O-连接β-N-乙酰氨基葡萄糖（O-GlcNAc）修饰的蛋白质的增加有助于心脏保护。本研究探讨了 O-GlcNAc 在麻醉诱导预处理诱导的心脏保护中的作用。
通过免疫印迹法观察 O-GlcNAc 修饰蛋白。在体内（n = 8）和体外（n = 6）检测对缺血再灌注的耐受性。用钙黄绿素 AM 处理心肌细胞检测线粒体通透性转换孔（mPTP）在氧化应激下的开放情况（n = 5）。进行共免疫沉淀和酶标记以检测负责 mPTP 开放的线粒体蛋白。
异氟烷处理和随之而来的 O-GlcNAc 浓度增加可减少梗死面积（26 ± 5%[均值 ± 标准差]，P < 0.001）与对照组相比。在用 O-GlcNAc 转移酶抑制剂别嘌醇预处理的组中，O-GlcNAc 的保护作用被消除（39 ± 5%，P < 0.001）。体外肌细胞存活也有相同的结果。与对照组和别嘌醇加异氟烷处理的细胞（57 ± 7%，P < 0.001）相比，异氟烷处理的细胞中 mPTP 的形成被阻断（86 ± 4%，P < 0.001）。共免疫沉淀和酶标记研究表明，O-GlcNAc 修饰的电压依赖性阴离子通道重新开放 mPTP。
异氟烷诱导线粒体电压依赖性阴离子通道的 O-GlcNAc 修饰。这种修饰抑制 mPTP 的开放，并赋予对缺血再灌注应激的抵抗力。
