Reactive oxygen species released from mitochondria during brief hypoxia induce preconditioning in cardiomyocytes
Reactive oxygen species released from mitochondria during brief hypoxia induce preconditioning in cardiomyocytes
复制标题
DOI：
10.1074/jbc.273.29.18092
复制
发表时间：
1998-07-17
影响因子：
4.8
通讯作者：
Schumacker, PT
中科院分区：
文献类型：
--
作者：
Vanden Hoek, TL;Becker, LB;Schumacker, PT
活性氧参与了心脏预适应的诱导过程。然而，其来源和诱导机制尚不清楚。我们测试了短暂缺氧是否通过增加鸡心肌细胞线粒体ROS的产生来诱导预适应。缺氧10 min，模拟缺血1 h，再灌注3 h。预处理将细胞死亡从47 +/- 3%降低到14 +/- 29。在3/3的预处理与0/6的非预处理实验中观察到收缩的恢复。在诱导期间，探针二氯荧光素（对H2 O2敏感）的ROS氧化增加了2.5倍。作为低氧的替代品，在常氧期间加入H2 O2（15 μ mol/L）也诱导了预处理样保护。相反，在缺氧期间的ROS信号可以用硫醇还原剂2-巯基丙酰甘氨酸、胞质Cu，Zn-超氧化物歧化酶抑制剂二乙基二硫代氨基甲酸和阴离子通道抑制剂4，4 '-二异硫氰酸根合-二苯乙烯-2，2'-二磺酸盐减弱，所有这些也废除了保护。低氧期间ROS的产生减弱myxothiazol，但不是由diphenyleneiodonium或一氧化氮合酶抑制剂L-硝基精氨酸。我们的结论是，缺氧增加线粒体超氧化物的产生，启动预处理保护。此外，线粒体阴离子通道和胞浆H2 O2歧化可能是氧化诱导低氧预适应的重要步骤。
Reactive oxygen species (ROS) have been proposed to participate in the induction of cardiac preconditioning. However, their source and mechanism of induction are unclear. We tested whether brief hypoxia induces preconditioning by augmenting mitochondrial generation of ROS in chick cardiomyocytes. Cells were preconditioned with 10 min of hypoxia, followed by 1 h of simulated ischemia and 3 h of reperfusion. Preconditioning decreased cell death from 47 +/- 3% to 14 +/- 29. Return of contraction was observed in 3/3 preconditioned versus 0/6 non-preconditioned experiments. During induction, ROS oxidation of the probe dichlorofluorescin (sensitive to H2O2) increased similar to 2.5-fold. As a substitute for hypoxia, the addition of H2O2 (15 mu mol/liter) during normoxia also induced preconditioning-like protection. Conversely, the ROS signal during hypoxia mas attenuated with the thiol reductant 2-mercaptopropionyl glycine, the cytosolic Cu,Zn-superoxide dismutase inhibitor diethyldithiocarbamic acid, and the anion channel inhibitor 4,4'-diisothiocyanato-stilbene-2,2'-disulfonate, all of which also abrogated protection. ROS generation during hypoxia was attenuated by myxothiazol, but not by diphenyleneiodonium or the nitric-oxide synthase inhibitor L-nitroarginine. We conclude that hypoxia increases mitochondrial superoxide generation which initiates preconditioning protection. Furthermore, mitochondrial anion channels and cytosolic dismutation to H2O2 may be important steps for oxidant induction of hypoxic preconditioning.