Immunocytochemical study on the distribution of c-myb in the central nervous system of the transgenic mice expressing a human copper/zinc superoxide dismutase mutation

Although our previous study showed the constitutive expression of c-myb in neurons, suggesting that this gene might be involved in the normal function of these cells, there were no reports on the expression pattern of c-myb under pathological conditions. In the present study, we first investigated the changes in c-myb immunoreactivities (IRs) in the central nervous system of the transgenic mice expressing a human copper/zinc superoxide dismutase (Cu/Zn SOD) mutation. The distribution of c-myb was enhanced in the various brain regions of transgenic mice expressing a mutated human Cu/Zn SOD gene. Immunohistochemistry showed intensely stained c-myb IR glial cells with the appearance of astrocytes within the various brain regions of transgenic mice such as the gray matter of the midbrain, medulla oblongata and spinal cord. Even though the exact functions of c-myb in the normal and pathological states were not clearly revealed until now, we think that the increase in c-myb expression in the mutant mice could be due to the compensate mechanism of the astrocytes for the reduced defence against superoxide toxicity because the only known function of c-myb was its correlation with the prevention of programmed cell death, which could be deduced from the previous studies.