Bmi-1, a polycomb transcriptional repressor, is implicated in cell cycle regulation and cell senescence. Its absence results in generalized astrogliosis and epilepsy during the postnatal development, but the underlying mechanisms are poorly understood. Here, we demonstrate the occurrence of oxidative stress in the brain of four-week-old Bmi-1 null mice. The mice showed various hallmarks of neurodegeneration including synaptic loss, axonal demyelination, reactive gliosis and brain mitochondrial damage. Moreover, astroglial glutamate transporters and glutamine synthetase decreased in the Bmi-1 null hippocampus, which might contribute to the sporadic epileptic-like seizures in these mice. These results indicate that Bmi-1 is required for maintaining endogenous antioxidant defenses in the brain, and its absence subsequently causes premature brain degeneration.
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This work was supported by grants from the National Nature and Scientific Foundation of China Key Project (No. 30971020 to M. Xiao, No. 30830103 to D. Miao) and the Natural Science Foundation of Jiangsu Educational Department (09KJA310003 to M. Xiao).
Cao, Guangliang; Gu, Minxia; Zhu, Min; Gao, Junying; Yin, Ying; Marshall, Charles; Xiao, Ming; Ding, Jiong; and Miao, Dengshun, "Bmi-1 Absence Causes Premature Brain Degeneration" (2012). Rehabilitation Sciences Faculty Publications. 9.