scholarly journals Radioprotection In Vitro and In Vivo by Minicircle Plasmid Carrying the Human Manganese Superoxide Dismutase Transgene

2008 ◽  
Vol 19 (8) ◽  
pp. 820-826 ◽  
Author(s):  
Xichen Zhang ◽  
Michael W. Epperly ◽  
Mark A. Kay ◽  
Zhi-Ying Chen ◽  
Tracy Dixon ◽  
...  
2008 ◽  
Vol 0 (ja) ◽  
pp. 081015093227032
Author(s):  
Xichen Zhang ◽  
Michael W Epperly ◽  
Mark A Kay ◽  
Tracy Smith ◽  
Darcy Franicola ◽  
...  

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1057
Author(s):  
Joel S. Greenberger ◽  
Amitava Mukherjee ◽  
Michael W. Epperly

Manganese superoxide dismutase (MnSOD) is a dominant component of the antioxidant defense system in mammalian cells. Since ionizing irradiation induces profound oxidative stress, it was logical to test the effect of overexpression of MnSOD on radioresistance. This task was accomplished by introduction of a transgene for MnSOD into cells in vitro and into organs in vivo, and both paradigms showed clear radioresistance following overexpression. During the course of development and clinical application of using MnSOD as a radioprotector, several prominent observations were made by Larry Oberley, Joel Greenberger, and Michael Epperly which include (1) mitochondrial localization of either manganese superoxide dismutase or copper/zinc SOD was required to provide optimal radiation protection; (2) the time required for optimal expression was 12–18 h, and while acceptable for radiation protection, the time delay was impractical for radiation mitigation; (3) significant increases in intracellular elevation of MnSOD activity were required for effective radioprotection. Lessons learned during the development of MnSOD gene therapy have provided a strategy for delivery of small molecule SOD mimics, which are faster acting and have shown the potential for both radiation protection and mitigation. The purpose of this review is to summarize the current status of using MnSOD-PL and SOD mimetics as radioprotectors and radiomitigators.


2005 ◽  
Vol 70 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Srdjan Stojanovic ◽  
Dragana Stanic ◽  
Milan Nikolic ◽  
Smiljana Raicevic ◽  
Mihajlo Spasic ◽  
...  

The peroxynitrite-induced nitration of manganese superoxide dismutase (MnSOD) tyrosine residue, which causes enzyme inactivation, is well established. This led to suggestions that MnSOD nitration and inactivation in vivo, detected in various diseases associated with oxidative stress and overproduction of nitric monoxide (NO), conditions which favor peroxynitrite formation, is also caused by peroxynitrite. However, our previous in vitro study demonstrated that exposure of MnSOD to NO led to NO conversion into nitrosonium (NO+) and nitroxyl (NO?) species, which caused enzyme modifications and inactivation. Here it is reported that MnSOD is tyrosine nitrated upon exposure to NO, as well as that MnSOD nitration contributes to inactivation of the enzyme. Collectively, these observations provide a compelling argument supporting the generation of nitrating species in MnSOD exposed to NO and shed a new light on MnSOD tyrosine nitration and inactivation in vivo. This may represent a novel mechanism by which MnSOD protects cell from deleterious effects associated with overproduction of NO. However, extensive MnSOD modification and inactivation associated with prolonged exposure to NO will amplify the toxic effects caused by increased cell superoxide and NO levels.


1994 ◽  
Vol 180 (5) ◽  
pp. 1995-1998 ◽  
Author(s):  
K Ritter ◽  
R J Kühl ◽  
F Semrau ◽  
H Eiffert ◽  
H D Kratzin ◽  
...  

Antibodies directed against the autoantigen p26 were detected in sera from 32 patients with acute Epstein-Barr virus (EBV) infection and clinical symptoms of infectious mononucleosis. P26 has now been identified as the enzyme manganese superoxide dismutase (MnSOD) by comparison of the NH2-terminal amino acid sequence. Antibodies against MnSOD belong to the immunoglobulin class M. They are not detectable in sera of patients with other herpesvirus infections. In the 32 patients investigated, the rise and fall of the autoantibodies coincides with the clinical symptoms. In vitro, the autoantibodies were shown to inhibit the dismutation of superoxide radicals by blocking MnSOD. As presented in the discussion this effect may contribute to the pathogenesis of acute EBV infection.


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