This proposal represents collaboration between investigators in the Sections of Pulmonary Medicine & Critical Care and Emergency Medicine under the newly formed Emergency Resuscitation Research Center at the University of Chicago. Studies are proposed to examine the mechanisms and consequences of ischemia/reperfusion (I/R)-induced apoptosis in cardiomyocytes and to examine the protective effects of hypoxic preconditioning on this apoptosis. The central hypotheses of this proposal are that preconditioning decreases apoptotic cell death through a number of mechanisms that block the initiation and/or propagation of apoptosis. To test these hypotheses, we propose three specific aims: (1) Test which reactive oxygen species (ROS) act as intracellular activators of apoptosis. Experiments will (a) Determine the sequence of apoptotic events including disruption of mitochondria membrane potential, release of cytochrome c into the cytosol, and activation of caspase-9 as """"""""initiator"""""""" caspase as well as downstream casases-3 and others; (b) Using specific inhibitory treatments, assess the effects of altered superoxide and/or H202 during (I/R) on these apoptotic events. (2) Determine whether preconditioning blocks certain apoptotic events via Bcl-2 family regulation through PKC-mediated phosphorylation. Experiments will (a) Determine pre- and post-ischemic levels of expression of Bcl-2, Bcl-x, and Bax in cardiomyocytes during I/R in preconditioned (PC) or non-PC cells; and determine the effects of PC on serine phopshorylation of Bcl-2 proteins (b) Assess the effects of over and underexpression/blockade of PKC, Bcl-2, and expression of a nonphosphorylatable Bcl-2 protein on oxidant stress, nitric oxide synthesis, NF-kappaB activation and apoptotic events. (3) Determine the relationship between NF-kappaB and nitric oxide (NO) synthesis in preventing apoptosis. (a) Determine the effect of PC on phosphorylation Of IkappaB and subsequent activation and nuclear translocation of NF-kappaB; (b) Determine the expression of immediate-early genes, Al and chIAP, and examine their effects on mitochondria events, ROS generation, oxidant stress, NO generation, caspase activity and apoptotic cell death through correlative and direct over expression and antisense studies. (c) Determine the levels of NO generation during reperfusion with or without PC and the direct effects of generated NO or specific blockade of NO generation on caspase activity and subsequent cell death in each condition. Results from these studies have the potential to improve post-resuscitation care following cardiac arrest and other ischemic diseases such as myocardial infarction and stroke.
| Shao, Zuo-Hui; Wojcik, Kimberly R; Dossumbekova, Anar et al. (2009) Grape seed proanthocyanidins protect cardiomyocytes from ischemia and reperfusion injury via Akt-NOS signaling. J Cell Biochem 107:697-705 |
| Dossumbekova, Anar; Berdyshev, Evgeny V; Gorshkova, Irina et al. (2008) Akt activates NOS3 and separately restores barrier integrity in H2O2-stressed human cardiac microvascular endothelium. Am J Physiol Heart Circ Physiol 295:H2417-26 |
| Lavani, Romeen; Chang, Wei-Tien; Anderson, Travis et al. (2007) Altering CO2 during reperfusion of ischemic cardiomyocytes modifies mitochondrial oxidant injury. Crit Care Med 35:1709-16 |
| Shao, Zuo-Hui; Chang, Wei-Tien; Chan, Kim Chai et al. (2007) Hypothermia-induced cardioprotection using extended ischemia and early reperfusion cooling. Am J Physiol Heart Circ Physiol 292:H1995-2003 |
| Anderson, Travis C; Li, Chang-Qing; Shao, Zuo-Hui et al. (2006) Transient and partial mitochondrial inhibition for the treatment of postresuscitation injury: getting it just right. Crit Care Med 34:S474-82 |
| Qin, Yimin; Vanden Hoek, Terry L; Wojcik, Kim et al. (2004) Caspase-dependent cytochrome c release and cell death in chick cardiomyocytes after simulated ischemia-reperfusion. Am J Physiol Heart Circ Physiol 286:H2280-6 |
| Vanden Hoek, Terry L; Qin, Yimin; Wojcik, Kim et al. (2003) Reperfusion, not simulated ischemia, initiates intrinsic apoptosis injury in chick cardiomyocytes. Am J Physiol Heart Circ Physiol 284:H141-50 |
| Anderson, Travis; Vanden Hoek, Terry L (2003) Preconditioning and the oxidants of sudden death. Curr Opin Crit Care 9:194-8 |
| Shao, Zuo-Hui; Vanden Hoek, Terry L; Xie, Jingtian et al. (2003) Grape seed proanthocyanidins induce pro-oxidant toxicity in cardiomyocytes. Cardiovasc Toxicol 3:331-9 |
| Qin, Yimin; Camoretti-Mercado, Blanca; Blokh, Lyubov et al. (2002) Fas resistance of leukemic eosinophils is due to activation of NF-kappa B by Fas ligation. J Immunol 169:3536-44 |
