Knockouts of Se-glutathione peroxidase-1 and Cu,Zn superoxide dismutase exert different impacts on femoral mechanical performance of growing mice.
The objective of this study was to determine the impact of knockout of Cu,Zn-superoxide dismutase (SOD1) and Se-glutathione peroxidase-1 (GPX1) on murine bone biomechanical properties. Femora samples were collected from wild-type (WT), SOD1-knockout [SOD1(-/-)] and GPX1-knockout [GPX1(-/-)] female mice (9-wk old, n = 7-8 per genotype) to assay for bone enzyme activities and mechanical properties in three point bending. Prior to testing, all mice were fed a torula yeast diet supplemented with 0.4 mg Se/kg as sodium selenite. Compared with the WT mice, SOD1(-/-) mice displayed a series of reductions (p < 0.05): 24% in body mass, 8% in femoral length, 43% in femoral structural strength, and 32% in bending stiffness. When differences in body size were accounted for, femoral failure moment in SOD1(-/-) mice remained lower (p < 0.05) than that of WT. Femoral tartrate resistant acid phosphatase activity in SOD1(-/-) was 47% greater (p < 0.05) than the WT. In contrast, GPX1(-/-) mice showed no significant differences in femoral mechanical properties from those of WT mice. In conclusion, knockout of SOD1 exerted a greater impact on femoral mechanical characteristics than that of GPX1 in growing mice.
Wang
Xiaodan
X
Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
Gillen
Elizabeth A
EA
van der Meulen
Marjolein C H
MC
Lei
Xin Gen
XG
D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000235:genetics; D005260:Female; D005269:Femur / Q000201:enzymology / Q000254:growth & development / Q000502:physiology*; D005838:Genotype; D005979:Glutathione Peroxidase / Q000172:deficiency*; D051379:Mice; D018345:Mice, Knockout; D013314:Stress, Mechanical; D013482:Superoxide Dismutase / Q000172:deficiency*; D013718:Tensile Strength / Q000502:physiology; D000094765:Glutathione Peroxidase GPX1
D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000094765:Glutathione Peroxidase GPX1; C000722068:Gpx1 protein, mouse