Genetic redox preconditioning differentially modulates AP-1 and NFκB responses following cardiac ischemia/reperfusion injury and protects against necrosis and apoptosis

Abstract

Reactive oxygen species have been established as key mediators of cardiac injury following ischemia/reperfusion (I/R). We hypothesized that superoxide formation at different subcellular locations following cardiac I/R injury may differentially regulate cellular responses that determine pathophysiologic outcomes. Recombinant adenoviruses expressing Cu/ZnSOD or MnSOD were utilized to modulate superoxide levels in the cytoplasmic or mitochondrial compartments, respectively, prior to coronary artery I/R injury in the rat heart. Ectopic expression of both MnSOD and Cu/ZnSOD afforded protection from I/R injury, as evidenced by a significant reduction in serum creatine kinase levels, infarct size, malondialdehyde levels, and apoptotic cell death in comparison to controls. MnSOD and Cu/ZnSOD expression also significantly altered the kinetics of NF kappa B and AP-1 activation following I/R injury, characterized by a delayed induction of NF kappa B and abrogated AP-1 response. Western blot analysis of Bcl-2, Bcl-xL, Bad, Caspase 3, PDK1, and phospho-Akt also revealed SOD-mediated changes in gene expression consistent with protection and decreased apoptosis. These findings support the notion that both mitochondrial and cytoplasmic-derived SOD induce changes in AP-1 and NF kappa B activity, creating an antiapoptotic microenvironment within cardiomyocytes that affords protection following I/R injury.

Resveratrol-Mediated Activation of cAMP Response Element-Binding Protein through Adenosine A3 Receptor by Akt-Dependent and -Independent Pathways

“…Finally, Akt is detached from the membrane and goes to both cytosol and nucleus where it regulates gene expression by the stimulation of transcription factors, including nuclear factor-B and CREB (Brunet et al, 2001). Several downstream targets of Akt have been recognized to be apoptosis regulatory molecules, including bcl-2-family member BAD (Yang et al, 2003) and CREB (Shaywitz and Greenberg, 1999). We recently showed that resveratrol could induce the expression of Bcl-2, which was inhibited by A 1 and A 3 receptor antagonism.…”

Antioxidant Gene Therapy for Cardiovascular Disease

“…The role of MnSOD and CuZnSOD in the protection of cardiac I/R injury has been demonstrated by transgenic approaches 64 -66 ; these approaches have also been used in gene therapy for myocardial protection (Table). 36 derived from both cytosolic and mitochondrial compartments contributes to myocardial I/R injury. In contrast to EC-SOD, most reports show that gene transfer with either CuZnSOD or MnSOD has no impact on endothelial dysfunction.…”

Nox2-containing NADPH oxidase and Akt activation play a key role in angiotensin II-induced cardiomyocyte hypertrophy

“…Concentrations of virus that induce efficient gene transfer without cell death have been optimized previously (2,15,57,60,62). Appropriate subcellular compartment targeting of AdCu/ ZnSOD also has been established (57). N17Rac, human Cu/ZnSOD, and DNAkt levels were determined by Western blot analysis as described (15,57).…”

“…N17Rac, human Cu/ZnSOD, and DNAkt levels were determined by Western blot analysis as described (15,57). Appropriate cytoplasmic targeting of AdCu/ ZnSOD was verified by double immunostaining as described (57,60). All gene transfer occurred 24 h before experimentation.…”