SOD3 Variant, R213G, Altered SOD3 Function, Leading to ROS-Mediated Inflammation and Damage in Multiple Organs of Premature Aging Mice.
OBJECTIVE
Among the isoforms of superoxide dismutase, SOD3 is uniquely associated with the extracellular matrix (ECM) by virtue of its heparin-binding domain (HBD). Substitution of arginine by glycine at amino acid 213 (R213G) of its HBD was first identified in patients with heart failure, followed by many studies that focused on the role of this variant (SOD3(R213G)) in ischemic heart disease and cardiovascular disease. However, the biological significance of this mutation in a physiological context is largely unknown.


RESULTS
As a first step, we generated SOD3(R213G) transgenic mice, in which the variant gene was driven by the β-actin promoter allowing expression in all tissues. Unexpectedly, we found that SOD3(R213G) transgenic mice exhibited premature aging, including hair graying, abnormal gait, and a shortened life span. Specifically, the aged mice showed systemic inflammation and organ degeneration. In addition, aged SOD3(R213G) mice are susceptible to neutrophil-mediated inflammation. Among other functions, the neutrophils of SOD3(R213G) mice produce high amounts of reactive oxygen species, which would normally be controlled by SOD3 in ECM.


METHODS
These findings showed for the first time that arginine 213 in the HBD of SOD3 is critical for maintaining proper organ function through moderating the normal innate immune response, which would otherwise lead to chronic inflammation and degenerative diseases in aged mice.


CONCLUSIONS
Therefore, patients with this variant may be treated with SOD3 as a therapeutic strategy to prevent or cure these diseases.
1 Department of Dermatology, Catholic Research Institute of Medical Science , College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Myung-Ja
MJ
Kwon
2 Department of Hospital Pathology, College of Medicine, The Catholic University of Korea , Seoul, Republic of Korea.
Kyo-Young
KY
Lee
3 Department of Biochemistry, College of Life Science and Biotechnology , Yonsei University, Seoul, Republic of Korea.
Han-Woong
HW
Lee
1 Department of Dermatology, Catholic Research Institute of Medical Science , College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Jung-Ho
JH
Kim
1 Department of Dermatology, Catholic Research Institute of Medical Science , College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Tae-Yoon
TY
Kim
D019588:Aging, Premature / Q000378:metabolism* / Q000473:pathology; D000825:Animal Structures / Q000378:metabolism*; D000818:Animals; D001120:Arginine / Q000378:metabolism; D045744:Cell Line, Tumor; D005998:Glycine / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008544:Melanocytes / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009154:Mutation; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
D020033:Protein Isoforms; D017382:Reactive Oxygen Species; D001120:Arginine; C441642:SOD3 protein, human; C499090:Sod3 protein, mouse; D013482:Superoxide Dismutase; D005998:Glycine