Studies on the molecular mechanisms of carbon monoxide on the induction or protection of cell death.

外源性或内源性一氧化碳（CO）已被证明通过NF-kB或线粒体atp依赖的K^+通道保护心肌和血管细胞免受缺血或脂多糖引起的损伤。血红素加氧酶(HO)-1产生一氧化碳，从而保护细胞。我们已经证明，在缺氧条件下，Ca^<2+>依赖性蛋白酶calpain通过α-fodrin蛋白水解促进心源性H9c2细胞的坏死死亡(Aki， T., Yoshida， K., and Fujimiya， T. (2002) J.Biochem。132年,921 - 926)。在这里，我们展示了CO抑制Ca^<2+>-内流的第一个证据，正如fluo-3荧光检测到的那样，这种荧光被l型Ca^<2+>-通道激动剂BAYK8644增强。缺血死亡的特征是坏死或染料排斥，脱氢脱氢酶释放，或碘化丙啶渗透。western blotting检测Ca^<2+>-内流、α-fodrin蛋白水解和缺血死亡均受CO和l型Ca^<2+的抑制。-通道抑制剂维拉帕米。JC-1检测显示，缺血还会诱导线粒体去极化，而CO或维拉帕米可抑制线粒体去极化。此外，DCF、氢乙胺或Amplex Red过氧化氢检测的活性氧（ROS）生成在缺血时增强，但不受Co的影响。western blotting检测的Hemin处理增加了缺氧细胞中HO-1的表达。HO-1诱导减少缺血后Ca^<2+>-内流和细胞死亡。因此，外源性和内源性CO通过l型Ca^<2+>通道抑制Ca^<2+>-内流和钙蛋白酶激活来保护心肌细胞免受缺血。

Carbon monoxide (CO), either exogenous or endogenous, has been shown to protect the myocardial and vascular cells against injuries due to ischemia or lipopolysaccharide, through NF-kB or mitochondrial ATP-dependent K^+-channel. Heme-oxygenase (HO)-1, generates CO, thereby protecting the cells. We have shown that a Ca^<2+>-dependent protease calpain promotes necrotic death in the cardiogenic H9c2 cells under hypoxia through α-fodrin proteolysis (Aki, T., Yoshida, K., and Fujimiya, T. (2002) J.Biochem. 132, 921-926). Here, we show the first line of evidence that CO inhibits Ca^<2+>-influx, as detected by fluo-3 fluorescenece, which was enhanced by a L-type Ca^<2+>-channel agonist BAYK8644. The ischemic death was characterized as necrotic either by dye exclusion, LDH release, or propidium iodide permeabilization. The Ca^<2+>-influx, α-fodrin proteolysis, as detected by western blotting, and the ischemic death, were inhibited by CO ora L-type Ca^<2+.-channel inhibitor verapamil. Ischemia also induced mitochondrial depolarization, as detected by JC-1, which was inhibited by CO or verapamil. Additionally, reactive oxygen species (ROS) generation, as detected by DCF, hydroethidine, or Amplex Red Hydrogen Peroxide, was enhanced by ischemia, but unaffected by Co. Hemin treatment increased the HO-1 expression in the hypoxic cells, as detected by western blotting. The HO-1 induction reduced the Ca^<2+>-influx and cell death after ischemia. Thus, exogenous and endogenous CO protect the cardiomyogenic cells against ischemia by inhibiting Ca^<2+>-influx through L-type Ca^<2+> channel and calpain activation.