Sod2 KO anemic mice
Ontology highlight
ABSTRACT: Gene expression profiling was performed using Anemic Sod 2 Knockout mice and was compared to Gene expression profiles from Sod 2 WT mice. Background: Our laboratory is interested in the role of oxidative stress in aging and human disease. Currently, a major focus of our efforts is the characterization of a murine hemolytic anemia resulting from oxidative stress, a model for the human disorder Sideroblastic Anemia. This model is based upon transplantation of hematopoietic stem cells from mice that are deficient in the antioxidant protein SOD2 (Friedman J. Exp. Med. 2001 193:925). SOD2 protects against the cytotoxicity of mitochondrial superoxide produced as a byproduct of oxidative phosphorylation (Weisiger J. Biol. Chem. 1973 248:4793). In characterization of the model to date, we have focused upon RBC proteomic analysis to identify 41 proteins differentially expressed when comparing membrane and soluble RBC fractions from SOD2-/- vs. SOD2+/+ mice (Friedman et al. submitted). In addition, we have characterized the in vivo response of animals to a novel catalytic antioxidant (Euk-189) that has b! oth SOD and catalase activities. In addition to proteins involved in mitochondrial function and stress response we find a number of cell surface molecules with significant differential expression. Thrombospondin is found at higher levels in SOD2-/- red cell membrane fractions. This is an extracellular matrix glycoprotein involved in cell adhesion and migration that interacts with glycosaminoglycans (especially the heparan sulfate proteoglycan perlecan) expressed at the endothelial cell surface (Feitsma J. Biol. Chem. 2000 275:9396, Vischer Eur. J. Cell. Biol. 1997 73:332, Sun J. Biol. Chem. 1989 15:2885). Thrombospondin is likely an acquired surface molecule on our red cells, which is of interest as this molecule has been found on the surface of sickle red cells and appears to mediate abnormal adhesion of red cells to vessel wall (Hillery Blood 1996 87:4879, Sugihara Blood 1992 15:2634). CD44 is also found at higher levels in SOD2-/- membrane fractions. CD44 is an adhesion receptor for the high molecular weight polysaccharide hyaluronic acid and has been shown recently to be involved in the trafficking of stem cells to the bone marrow (Avigdor Blood January 2004). Higher expression of these molecules on the surface of SOD2-/- red cells may affect their adhesive interactions with vascular endothelium and may in part explain the early removal of these cells from the circulationóresulting in the observed hemolytic anemia. Some proteins that accumulate on the surface of SOD2 deficient red cells are likely molecular damage sensors, binding to surfaces altered by oxidative damage. The role of specific glycoproteins in such binding remains to be elucidated. Additional surface proteins from red cells show differential expression, many of which are also glycosylated. Planned Experiment: As the next step in characterization of the anemia model, we will compare the gene expression profile of red cell progenitors isolated from Sod2-/- and Sod2+/+ animals. We have defined cell-sorting conditions for isolation of erythroid progenitor cells from marrow of our mice.
ORGANISM(S): Mus musculus
SUBMITTER: Steven Head
PROVIDER: E-GEOD-27053 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
ACCESS DATA