Abstract 15325: New Potent Inhibitor of Necrotic Cell Death: Novel Therapeutic Potential of Necrosis Inhibitor, NecroX Against Myocardial Ischemia-Reperfusion Injury
Background: Although reperfusion is essential for salvage of the ischemic myocardium, paradoxically reperfusion itself may cause a wide variety of harmful injury to the myocardium. NecroX is known to inhibit caspase-independent cell death with necrotic morphology against mitochondrial oxidative stresses. We hypothesized that necroX prevents the myocardial ischemia-reperfusion (MI/R) injury by suppression of necrotic cell death.
Methods and Results: In vitro study, H9C2 cells were incubated under hypoxia and oxidative stress with pretreatment with 0.01% DMSO, necroX 20μ M, vitamin C 10μ M, and caspase inhibitor 20μ M. FDA/PI staining and FACS showed the lowest necrotic cell in the necroX(43.9±3.2, 14.1±1.8, 42.8±7.1, 41.4±4.1%). We evaluated mitochondrial membrane potential(MP) measurement with JC-1 in living cell, necroX group was markedly higher MP than other treated group (fig.A and B). In vivo study, rat underwent 45 minutes of ischemia followed by reperfusion(N=12,each group). 5% dextrose, 5mg/kg cyclosporine A(CsA), and necroX was intravenous administrated 5 minutes before reperfusion. Cardiac function and dimension were assessed at baseline, 3, 7, and 14days after infarction with echocardiography. Compared with other groups, necroX-treated rat exhibited less expansive remodeling and preserved systolic function. Also,extent of necrosis was assessed at 12h after MI/R by anti-myosin heavy chain antibody(anti-MHC) staining in identical group(N=6). The area of necrosis as assessed by anti-MHC staining was significantly decreased in the necroX group compared with others(Fig. C). TUNEL assay showed no difference between treatment arms.
Conclusion: In vivo and vitro study showed that NecroX was potent necrosis inhibitor that prevents MI/R injury. Hence,NecroX is a potential candidate as an adjunctive for reperfusion therapy with myocardial infarction through inhibition of necrosis, not apoptosis.
- © 2011 by American Heart Association, Inc.