Abstract
Mn superoxide dismutase (MnSOD)-deficient mice (Sod2−/−) suffer from mitochondrial damage and have various survival times and phenotypic presentations that are dependent on the genetic background of the mutant mice. The mitochondrial NADPH transhydrogenase (NNT) was identified as a putative genetic modifier based on a genome-wide quantitative trait association study on the molecular defect of the protein in more severely affected Sod2−/− mice and on the biological function of NNT. Hence, Sod2−/− mice on the C57BL/6J (B6J) background have the shortest survival time, and the mice are homozygous for the truncated Nnt allele (Nnt T). On the other hand, genetic backgrounds that support longer survival of Sod2−/− mice all have at least one normal copy of Nnt (Nnt W). To confirm the role of NNT in the phenotypic modification of Sod2−/− mice, we introduced a normal copy of Nnt allele from a C57BL/6 substrain into B6J-Sod2−/− mice and analyzed survival time, cardiac functions, and histopathology of the heart. The study results show that the presence of a normal Nnt allele preserves cardiac function, delays the onset of heart failure, and extends the survival of B6J-Sod2−/− mice to the end of gestation. Postnatal survival, however, is not supported. Consequently, the majority of B6J-Sod2−/− mice died within a few hours after birth and only a few survived for 5–6 days. The study results suggest that NNT is important for normal development and function of fetal hearts and that there may be other genetic modifier(s) important for postnatal survival of Sod2−/− mice.
Similar content being viewed by others
References
Arkblad EL, Egorov M, Shakhparonov M, Romanova L, Polzikov M et al (2002) Expression of proton-pumping nicotinamide nucleotide transhydrogenase in mouse, human brain and C. elegans. Comp Biochem Physiol B Biochem Mol Biol 133:13–21
Arkblad EL, Tuck S, Pestov NB, Dmitriev RI, Kostina MB et al (2005) A Caenorhabditis elegans mutant lacking functional nicotinamide nucleotide transhydrogenase displays increased sensitivity to oxidative stress. Free Radic Biol Med 38:1518–1525
Conrad M, Jakupoglu C, Moreno SG, Lippl S, Banjac A et al (2004) Essential role for mitochondrial thioredoxin reductase in hematopoiesis, heart development, and heart function. Mol Cell Biol 24:9414–9423
Fjellstrom O, Bizouarn T, Zhang JW, Rydstrom J, Venning JD et al (1999) Catalytic properties of hybrid complexes of the NAD(H)-binding and NADP(H)-binding domains of the proton-translocating transhydrogenases from Escherichia coli and Rhodospirillum rubrum. Biochemistry 38:415–422
Huang TT, Carlson EJ, Kozy HM, Mantha S, Goodman SI et al (2001) Genetic modification of prenatal lethality and dilated cardiomyopathy in Mn superoxide dismutase mutant mice. Free Radic Biol Med 31:1101–1110
Huang TT, Naeemuddin M, Elchuri S, Yamaguchi M, Kozy HM et al (2006) Genetic modifiers of the phenotype of mice deficient in mitochondrial superoxide dismutase. Hum Mol Genet 15:1187–1194
Li Y, Huang TT, Carlson EJ, Melov S, Ursell PC et al (1995) Dilated cardiomyopathy and neonatal lethality in mutant mice lacking manganese superoxide dismutase. Nat Genet 11:376–381
Nonn L, Williams RR, Erickson RP, Powis G (2003) The absence of mitochondrial thioredoxin 2 causes massive apoptosis, exencephaly, and early embryonic lethality in homozygous mice. Mol Cell Biol 23:916–922
Sheeran FL, Rydstrom J, Shakhparonov MI, Pestov NB, Pepe S (2010) Diminished NADPH transhydrogenase activity and mitochondrial redox regulation in human failing myocardium. Biochim Biophys Acta 1797:1138–1148
Toye AA, Lippiat JD, Proks P, Shimomura K, Bentley L et al (2005) A genetic and physiological study of impaired glucose homeostasis control in C57BL/6J mice. Diabetologia 48:675–686
Yant LJ, Ran Q, Rao L, Van Remmen H, Shibatani T et al (2003) The selenoprotein GPX4 is essential for mouse development and protects from radiation and oxidative damage insults. Free Radic Biol Med 34:496–502
Yu Q, Leatherbury L, Tian X, Lo CW (2008) Cardiovascular assessment of fetal mice by in utero echocardiography. Ultrasound Med Biol 34:741–752
Acknowledgments
We thank Xinli Wang for excellent animal care and Tim Doyle at the Stanford Center for Innovation in In-Vivo Imaging for instructing us on the in vivo microimaging procedure. This work was supported by funding from the National Institutes of Health (AG24400) and from the Stanford Digestive Disease Center, and by the resources and facilities at the VA Palo Alto Health Care System.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kim, A., Chen, CH., Ursell, P. et al. Genetic modifier of mitochondrial superoxide dismutase-deficient mice delays heart failure and prolongs survival. Mamm Genome 21, 534–542 (2010). https://doi.org/10.1007/s00335-010-9299-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00335-010-9299-x