PARP in Cardiac Arrest

尽管关于心脏骤停/心肺复苏术（CPR）的研究已经进行了四十年，但临床效果仍然很差。这方面的许多研究都采取了开发新的CPR方法或药理学方法的形式。然而，现在需要新的基础科学和分子遗传学方法来提高我们对心脏骤停/心肺复苏过程中损伤的关键机制的理解，从而开发新的治疗干预措施。聚（adp -核糖）聚合酶（PARP）是一种丰富的核酶，有助于维持

Despite four decades of research concerning cardiac arrest/cardiopulmonary resuscitation (CPR), clinical outcome remains poor. Much of this research has taken the form of developing new methodologic or pharmacologic approaches to CPR. However, now, novel basic science and molecular genetic approaches to CPR are needed to improve our understanding of critical mechanisms of injury during cardiac arrest/CPR to develop new therapeutic interventions. Poly (ADP-ribose) polymerase (PARP) is an abundant nuclear enzyme which helps maintain genomic integrity in neurons and numerous other cell types. Inhibition of PARP with pharmacologic agents or PARP deficiency via PARP knockout animals reduces injury after focal cerebral ischemia, but there is little information concerning PARP and cardiac arrest/CPR. Our preliminary studies show that cell injury after cardiac arrest/CPR in PARP null mutants (PARP-/-) is markedly reduced relative to wild type mice. Aim 1 will investigate this apparent neuroprotection observed in PARP deficient mice, characterizing extent and longevity of protection in intact animals over days of the evolving injury. We will use a combination of functional behavioral evaluation over time and terminal histopathology. Aim 2 will establish the importance of nitric oxide generation to PARP activation in vivo and subsequent injury during cardiac arrest/CPR. The relative consequences of inhibiting PARP vs neuronal or inducible nitric oxide synthase will be examined in the cardiac arrest/CPR mouse model. Lastly, using a strategy of transfecting virus carrying PARP mutant at two distinct catalytic and cleavage sites, we will begin to examine the molecular mechanism of PARP's importance in cardiac arrest/CPR. The role of the C-terminal NAD binding domain in PARP-mediated neuroprotection will be determined by comparison of cardiac arrest/CPR outcome in PARP-/- with or without transfection of a mutant form of PARP with inactive catalytic domain. Also, we will examine cysteine aspartase (CASPASE)-PARP interactions by comparison of cardiac arrest/CPR outcome in PARP-/- with and without transfection of a mutant form of PARP lacking in CASPASE 3 cleavage site (D214G mutant). These experiments will further our understanding of PARP-mediated mechanisms of in vivo ischemic brain injury and may provide a rational basis for development of effective, new therapeutic strategies to preserve neurological function atter cardiac arrest/CPR.