Abstract：
Poly (ADP-ribose) polymerase-1 (PARP-1) activity significantly increases during cerebral ischemia/reperfusion. PARP-1 is an NAD+-consumption enzyme. PARP-1 hyperactivity causes intracellular NAD+ deficiency and bioenergetic collapse, contributing to neuronal death. Besides, the powerful trigger of PARP-1 causes the catalyzation of poly (ADP-ribosyl)ation (PARylation), a posttranslational modification of proteins. Here, we found that PARP-1 was activated in the ischemic brain tissue during middle-cerebral-artery occlusion and reperfusion (MCAO/R) for 24 h, and PAR accumulated in the neurons in mice. Using immunoprecipitation, Western blotting, liquid chromatography-mass spectrometry, and 3D-modeling analysis, we revealed that the activation of PARP-1 caused PARylation of hexokinase-1 and lactate dehydrogenase-B, which, therefore, caused the inhibition of these enzyme activities and the resulting cell energy metabolism collapse. PARP-1 inhibition significantly reversed the activity of hexokinase and lactate dehydrogenase, decreased infarct volume, and improved neuronal deficiency. PARP-1 inhibitor combined with pyruvate further alleviated MCAO/R-induced ischemic brain injury in mice. As such, we conclude that PARP-1 inhibitor alleviates neuronal death partly by inhibiting the PARylation of metabolic-related enzymes and reversing metabolism reprogramming during cerebral ischemia/reperfusion injury in mice. PARP-1 inhibitor combined with pyruvate might be a promising therapeutic approach against brain ischemia/reperfusion injury.
摘要：
在脑缺血/再灌注期间，聚（ADP-核糖）聚合酶-1（PARP-1）活性显着增加。PARP-1是NAD+-消耗酶。PARP-1过度活跃导致细胞内NAD+缺乏和生物能量崩溃，导致神经元死亡。此外,PARP-1的强大触发器引起聚（ADP-核糖基）化（PARylation）的催化，蛋白质的翻译后修饰。这里,我们发现PARP-1在大脑中动脉闭塞和再灌注（MCAO/R）24小时的缺血脑组织中被激活，和PAR在小鼠的神经元中积累。使用免疫沉淀，西方印迹,液相色谱-质谱,和3D建模分析，我们发现PARP-1的激活导致己糖激酶-1和乳酸脱氢酶-B的PARA化，which,因此,这些酶的活性受到抑制，导致细胞能量代谢崩溃。PARP-1抑制显著逆转己糖激酶和乳酸脱氢酶的活性,梗死体积减少,和改善神经元缺陷。PARP-1抑制剂联合丙酮酸进一步减轻MCAO/R诱导的小鼠缺血性脑损伤。因此，我们得出结论,PARP-1抑制剂在小鼠脑缺血/再灌注损伤过程中通过抑制代谢相关酶的PARP化和逆转代谢重编程部分减轻神经元死亡.PARP-1抑制剂联合丙酮酸可能是一种有希望的治疗脑缺血/再灌注损伤的方法。
